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BIGHORN SHEEP IN IDAHO
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BIGHORN SHEEP IN IDAHO
L.
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By
~~t R. Smdlt.
STATE OF IDAHO
Department of Fish and Game
Boise, Idaho ARLIS
Alaska Resources
Library & Information Services
Anchorage Alaska
STATE OF IDAHO
Department of Fish and Game
PARTI
The Bighorn Sheep m Idaho
Its Status, Life History and Management
PART II
A Survey of Win ter Ranges
along the Middle Fork of the Salmon River
and on Adjacent Areas
DWIGHT R. SMITH
Game Biologist
Illustratiol!s by Cecil Smith
Wildlife Bulletin No. 1
1954
Prepared and Published Under the Provisions
of the Federal Aid to Wildlife Restoration Act, Idaho Project 99-R
Foreword
It was only through the unfailing cooperation from many
outside agencies and individuals that the collection and evaluation
of a large part of the information presented in this bulletin were
possible. The study was initiated and, for the first year and a half,
directed by the Idaho Cooperative Wildlife Research Unit. Sub-
sequently, the work was carried on by the Idaho Fish and Game
Department as a Federal Aid project.
Acknowledgments are due the Federal Aid Division office in
Portland, Oregon, for approving necessary funds and providing
helpful advice concerning the conduct of the investigation. Other
major contributions were made by the U.S. Forest Service; the
Public Health Service Laboratory in Hamilton, Montana; and the
Fish and Wildlife Service Laboratory at Denver, Colorado. Severa!
departments at the University of Idaho, Montana State College
and Idaho State College furnished important services.
This bulletin is divided into two parts. Part I deals chiefly
with the history, habits and ecology of the bighom sheep. Part II
is concerned with evaluating the condition, trend and productive-
ness of the winter range, not only as related to mountain sheep
but to other big game animais as weil. The ultimate purpose of
the study was to learn more about the bighorn's status, life history
and relationship to the range in order to formulate a management
program which would not only give maximum assurance of the
species' perpetuation, but maintain a population capable of pro-
viding a surplus for sportsmen to harvest.
The assets provided by the estimated 2,500 bighorn existing
in Idaho today cannot be measured in dollars and cents. The
aesthetic and recreational benefits to hunters, photographers and
others who appreciate nature, far outweigh any material worth.
This bulletin is presented for the information and enjoyment
of those who hope, along with us, that the opportunity to view a
bounding lamb with its mother, or a majestic ram atop a rocky
crag, will not be denied future generations.
Ross LEONARD, Director
Idaho Department of Fish and Game
FIGURE 1. Twenty-four bighorn sheep string out along the hase
of a cliff in the Big Creek drainage, a tributary of the Middle Fork
of the Salmon River. Note how body co lor and white n .. mp patches
blend with rocks and snow.
January 22, 1953
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CONTENTS
FOREWORD.
A LOOK INTO THE FUTURE.
INTRODUCTION .
THEPROBLEM
·PART 1
HISTORY OF BIG HORN IN IDAHO.
Early numbers.
The initial decline .
Origin of present-day herds.
Recent status
APPROACH TO THE PROBLEM ..
Early studies in Idaho ....... .
Study methods ....... .
BIGHORN HABITAT.
Location
Topographical features ................. .
Geology ............. .
Climate .
Summer range.
Win ter range.
Intermediate range ................ .
DISTRIBUTION .
BIG HORN BEHA VIOR ....... .
Seasonal migration
Non-migration .
Local drifts .
Herding characteristics.
Daily routine .
Reaction to man . . . ..... .
Inter-relationships with other species.
REPRODUCTION
Sexual development ..................... .
Courtship and breeding ..
Physical effects of the rut ......... .
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Page
3
. .......... 11
. ...... 17
19
20
20
21
22
22
25
25
26
29
29
29
30
31
32
38
39
41
43
43
46
47
48
49
50
52
55
55
56
58
Lambing ranges .
Birth and early activities ............... .
FOOD HABITS.
Methods of study.
General account of food preferences .
Mineral requirements ....... .
DISEASE AND PARASITES
PREDATORS
Page
59
59
62
62
62
67
72
77
Cougar 77
Coyotes. 77
&~. ~
Other predators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
ACCIDENTAL DEATHS. . . . . . . . . . . . . . . . . . 83
ILLEGAL KILL.
THE PRODUCTION PROBLEM ..
Sex ratios and age classes .
85
86
86
Basic requirements of habitat. . . . . . . . . . . . . . . . . . . . 90
Significance of life habits. . . . . . . . . . . . . . . . 92
BIGHORN MANAGEMENT IN IDAHO.......... 95
Objectives
Cens us
Control of predators .
Salting
Hunting
Trapping and transplanting.
Preservation of wilderness habitat.
PART II
95
96
98
99
100
. .... 103
. .. 104
INTRODUCTION . . . . . . . . . . . . . . . . . . . . ... 107
RANGE CONDITION AND TREND STUDIES ............. 108
Trend in range conditions as determined by the
3 step method . . . . . . . . . . 108
An analysis of condition and trend through
study of ex clos ures. . . . . . . . . . . 115
BROWSE UTILIZATION STUDY ............ 123
Twig measurement method.
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~ .. . ..... 123
Availabi1ity-and its importance to utilization.
\
Use of browse by species other than big game.
COVER TYPE MAPPING.
Methods
Open timber type .
Browse type .
Cliff type.
Open grass type ..
Waste
Page
... 128
.130
. .132
133
. .. 136
...... 138
140
. .. 142
.. 144
Summary-cover type mapping. . ...................... 144
AN AN AL Y SIS OF CARRYING CAP A CITY. . .. 147
APPENDIX. . ...... 149
LITERA TURE CITED ........ . 152
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Figure ILLUSTRATIONS
1. Twenty-four bighorn sheep at the base of a cliff ..
2. Boa ting the Middle Fork of the Salmon River.
3. A granitic type summer range in the Bighorn Crags.
4. A sedimentary type range in the Twin Peaks area west
of Challis.
5. Harbor Lakes basin .
6. Aerial view of an area including both win ter and summer
bighorn habitat.
8. Stoddard Creek win ter range ..
11. Ewes migrating in Dwyer Creek drainage.
12. Sheep, watching approach of man, display curiosity but
notfear .....
13. Big horn ram with herd of domestic sheep.
14. Lambing range on a southern exposure overlooking the
Salmon River ..
16. Snow trenches where bighorn sheep have been pawing
through snow to feed.
17. Utilization of balsamroot.
18. Four ewes visit Sammy Gulch salt lick.
19. A "mineral cafeteria".
20. A bighorn ram killed "by hanging" after falling from a
15 foot cliff.
21. Lamb on a ledge .
Page
2
27
30
32
33
34
37
46
51
53
60
65
67
68
70
82
83
22. A young ram-about 11;§ years old. . ...... 87
24. Good bighorn sheep range along the Middle Fork of the
Salmon River. . . . . . . . . . . . . . . . . . 91
25. Big horn Ahead!. . 100
26. Employing 3 step method for measuring trend in range
condition . . . . . . . 109
27. Photographie record for Transect 1, Cluster9 111
29. Exclosures on Middle Fork of the Salmon River winter
ranges
33. "Hedged" chokecherry.
34. An avoided "island" of mountain mahogany ..
35. The effects of snow on availability of forage.
36. Topography and its relationship to availability.
37. "Highlined" bitterbrush.
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... 116
128
. ..... 128
129
.129
. .129
Figure Page
38. A complex intersrrersion of cover types common on Middle
Fork winter ranges . . . . . . . . . 132
40. Open timber cover type
41. Browse cover type.
... 137
..... 139
42. Cliff cover type .
43. Open grass cover type ..
MAPS
141
143
9. Distribution of bighorn sheep in Idaho. . 40
10. Estimated bighorn sheep population within the Intensive
Study Area. 42
39. Co ver type map of bighorn winter range along Middle Fork
of Salmon River. . . .134-135
GRAPHS
7. Comparison of the vegetation on two slopes within a sub-
alpine range . . . . . 36
15. Forage classes utilized by bighorn sheep on Salmon River
ranges . . . . . . . . . . 64
23. Ewe-lamb and ewe-yearling ratios as indicators of pro-
ductivity of bighorn sheep. 89
28. Correlation of vegetation condition with cover composi-
tion, desirability of plants and use. . .. 114
30. Scale drawings of Cabin Creek Study Plots. . .... 118
31. Scale drawings of Cow Creek Study Plots. . .. 119
32. Vegetation changes on Cabin Creek and Cow Creek ex-
closures and check plots during the past 21 years. . 120
44. Classification of 55,800 acres of usable bighorn winter
range . . . . . . . . . . . . . . . . . . . . . . . . . . ...... 145
TABLES
1. Bighorn sheep population estimates for the Salmon
National Forest. 24
2. Contents of five bighorn sheep stomachs . . . 63
3. Bighorn feeding habits as determined by direct observation 66
4. Use by bighorn sheep and deer on different minerais at
Short Creek and Sammy Gulch cafeterias. . . . . . . . 69
5. Parasites found in 229 fecal specimans. 75
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Figure Page
6. Classification of 937 occurrences of food items in 687 coyote
droppings collected on Salmon River ranges. 78
7. Summary of 19 bighorn occurrences in 687 coyote droJ}-
pings . . . . . . . . . . . 78
8. Bighorn sheep sex and age ratios. . 88
9. Composition of primary forage species as determined by 3
step method. . . . . . . . . . . . . . . . . . . . . . 110
10. Form and age classes of primary browse species. 112
11. Desirable browse species and invader plant compared as to
favorability of age classes. 113
12. Utilization of browse on Middle Fork of the Salmon River
win ter ranges . . . . . . . . 125
13. Comparison of annual growth utilization of browse on a
heavily and moderately used range. .126
14. Relationship of cover types to area and use as determined
by bighorn feeding observations. . .146
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L_
A LOOK INTO THE FUTURE
To interpret events of the pastis as important asto evaluate
conditions of the present if a wise course is to be charted for the
future. Therefore, we shall begin at the beginning ... as recorded
in early Idaho history.
Early explorers and settlers reported seeing bighorn sheep by
the thousands in the valleys and mountains of Idaho. Disease and
the restrictions of native habitat by an advancing civilization were
cardinal factors in reducing the statewide population to an esti-
mated 1,000 animais by the early 1920's. At about this point the
downward trend was halted. More rigid hunting restrictions and
a decrease, during that period, in the number of people and live-
stock in wilderness areas were key factors coming to the bighorn's
a id.
When this study of bighorn sheep in Idaho was initiated in
1949, it was generally accepted that sorne recovery had been made.
Forest Service estima tes indicated a statewide population of more
than 2,000 animais. Nevertheless, game administrators and sports-
men agreed that increases had been unsatisfactory, particularly in
view of the many years that mountain sheep had received protec-
tion from the sportsman's rifle. Evidence supporting these opinions
was obscure, however, and management procedures were not based
on adequate information. Interested persons were asking, "What
losses are suffered by big horn sheep? How important is each source
of loss? What is the current status of bighorn in Idaho and how
should they be managed in the future? Can sportsmen expect the
opportunity to harvest surplus animais?"
In searching for answers to these and other important ques-
tions, broad aspects of life history and ecology were investigated.
Extensive studies of mountain sheep habitat provided data for
describing ranges occupied during different seasons of the year.
Key winter ranges along the Middle Fork of the Salmon River
were selected for intensive studies, and permanent plots were
established to analyze range condition and trend. Utilization of
browse was determined by linear twig measurement. About 56,000
acres of important winter range land was mapped to show major
vegetation cover types. Productivity studies were made and most
of the major herd units were censused. Food habits were investi-
gated by severa! methods while searching for any deficiencies that
might exist in quality or quantity of forage. The bighorn's rela-
tionships to other species of wildlife were observed and analyzed.
In relating these life history and ecological data to management,
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emphasis must be placed on the practical question: "What factors
are currently depressing big horn productivity to a point where sat-
isfactory population gains are not being made?"
Disease and parasites, though important in early declines, are
believed to have caused few deaths in recent years. However,
diseased conditions may have escaped notice or contributed to
death in cases where the casual agent was not determined.
Predation is popularly accepted as an important mortality
factor. In reality the loss from this source appears to be small. The
cougar is limited in number but, as an individual, is probably the
most effective of all predators on sheep. Coyotes are the most num-
erous of the predators on Salmon River ranges; yet evidence of
this study indicates that they kill few bighorn. Eagles are widely
credited with killing the young of wild sheep and there are verified
records to support this contention. Close examination of their
predatory activities, however, indicates that lasses to eagles are
not large. Bobcats and black bears are present in small numbers
on the ranges studied, but their toll of mountain sheep is thought
to be negligible.
Accidents are high on the list of established causes of bighorn
deaths as determined by this investigation. Sorne animais died in
rock or snow slides, others by falling on precipitous terrain. It is
conceivable, too, that ftight from predators or weakness related to
disease contributed to sorne of these accidents. Severa! injured
rams were seen during and after each breeding season. Fatal
injuries may be sustained by rams and ewes alike during this hectic
period.
Illegal killing is a factor of unknown importance. Many local
persons having knowledge of the situation believe that poaching
is largely responsible for lack of increase in sorne herds.
A low birth rate is characteristic of mountain sheep. Ewe-lamb
ratios based on counts held shortly after lambing were found to
average about 1 : 0.75. By the second winter after birth the ratio
dropped to an average of about 1 : 0.30. This represents a loss of
60 percent of the juveniles in the first 1% years of life.
Other limiting factors, though less obvious than disease, pred-
ation, accidents or poaching, may be highly significant and should
be considered. One possibility is a nutritive deficiency in the food
supply at one or more seasons of the year. Or perhaps the scarcity
of one or more key plant species is more detrimental than has been
recognized-bitterbrush and mountain mahogany appear to be
likely candidates for this classification. Other limitations to pro-
duction are related to the basic habitat requirements of bighorn.
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Mountain sheep require areas with highly specifie topographical
and vegetational characteristics. And because of this limitation,
expanded human populations have drastically confined bighorn
distribution.
Severa! factors now have been discussed. Standing alone, none
are fully responsible for the lack of satisfactory increase among
mountain sheep herds. Combined, however, they exert considerable
pressure-particularly now, when the bighorn population is low.
Now t'hat the current status of bighorn sheep in Idaho has
been described, it is time to "look into the future." To improve the
view it is necessary to define the principal objectives toward which
management should aim.
There is little question t'hat the bighorn management pro gram
in Idaho still must be concerned with "restoration." Recent gains,
while encouraging, do not constitute an adequate safeguard against
dangerous population declines. Therefore, a primary goal is to
increase the numerical margin of safety by building up existing
herds and establishing new ones. Another objective is to furnish
sportsmen with the maximum amount of hunting, provided harvest
is on a sound basis and does not conflict with the goal of increasing
the population. A third objective-and a very important one-is
to integrate bighorn sheep management with multiple use objec-
tives of the habitat in a manner assuring the public the fullest
aesthetic values from both the bighorn and his environment. It
is highly improbable t'hat the economie and recreational values
enjoyed by sheep hunters will ever constitute more than a small
fraction of the total values rewarding those who have the oppor-
tunity to see and photograph the impressive bighorn in his natural
surroundings.
What are the tools t'hat can be used to attain the objectives
outlined? Census is the first logical step. T'his is not necessarily
true of ali game species, but bighorn are present in small numbers
and the need for accurate population data increases inversely to
abundance. While the population of many of the larger herds is
known with sufficient accuracy to require only annual trend counts
on key areas, little is known about many small, isolated herds.
Predator control is another management tool. But it should be
applied only after thoughtful determination of local needs. While
mountain sheep in Idaho are scarce enough to merit every reason-
able protection, management should carefully consider ali predator-
prey relationships before attempting to manipulate their balance.
Sai ting may be of sorne value in bighorn management but little
is known concerning physiological need-and effectiveness in con-
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trolling migration has yet to be demonstrated. Bighorn preference
for various mineral compounds has been tested and iodized salt
has been distributed experimentally. A need exists for additional
study along these lines. Sodium chloride as a factor controlling big
game migration is now under statewide scrutiny.
Hunting seasons and bag limits are among the most easily
manipulated and commonly used tools of game managers. With
sheep populations at present levels, only mature rams should be
harvested and these on a permit basis so that the number of ani-
mals from any area can be controlled. The opportunity to collect
management data from these hunts should not be overlooked.
Harvest regulations for elk and deer are at least as impor-
tant to bighorn management as harvesting of the sheep. Once the
desired priority of game animais has been determined, time and
length of hunting seasons can be employed, not only to bring game
populations into balance with range capacities, but to eliminate
adverse competition with preferred game species. It is the writer's
opinion that, on a few key wilderness ranges, the preferred species
should be bighorn sheep.
Trapping from weil established herds and releasing in new
areas is a potential means of extending the range and thereby in-
creasing production. However, this type of operation is expensive
and frequently only moderately successful. It is important, there-
fore, that such a program be approached with caution. The tech-
nique of managing Iimited areas for the maximum benefit of sheep
may often be the most practical and inexpensive means of increas-
ing total production.
Bighorn sheep, as indeed ali living things, ultimately depend
upon the fertility of the soil for their well-being. Care of the range,
then, is of utmost importance in a bighorn management program.
The term "wilderness" is filled with wonderful connotations. It
brings to mind a picture of natural splendor, of lush stands of
flowers and grass and nourishing shrubs, of sparkling clear water
and abundant game and fish living in this setting of primeval
beauty. "This pleasant state of affairs, unfortunately, is seldom
found. Game populations-uncontrolled by man or the predators
which remain after being poisoned, trapped or shot--have multi-
plied and left stark reminders of our failure to grasp the signifi-
cance of nature's checks and balances. Short-lived grasses, un-
healthy shrubs, unpalatable weeds and eroded hillsides are found
where once, old settlers tell us, bunchgrass bound the soil beneath
fine stands of bitterbrush or mountain mahogany.
Long-term range studies should be carried out along with
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other phases of management. It is important that the intensive
studies already begun on winter ranges along the Middle Fork of
the Salmon River be continued. Other key bighorn ranges should
be analyzed and long-term studies initiated.
Severa! known principles of game management have been pro-
posed in this discussion. They are ali important. However, it is
essential that management objectives for a species as scarce as
mountain sheep provide for the continuing collection and interpre-
tation of basic data against a possible time when ali our knowledge
and ingenuity may be required to main tain the species.
The present degree of understanding of the bighorn and his
habitat has been materialiy increased by this study. A manage-
ment plan, based upon the findings of research, is beginning to
opera te. N evertheless, it would be far from the tru th to assume
that there is nothing further to be learned. Management, which
must be conducted on a practicallevel, is still attempting to func-
tion without full understanding of many of the fundamentals in-
volved.
Ali too apparent is the lack of understanding concerning
mortality among young sheep. The importance of key forage plants
to the welfare of the animal is not fully comprehended. More infor-
mation is needed concerning seasonaliPigrations and interchange
among herds if harvest regulations are to be applied wisely and
trend counts interpreted realisticaliy. Social behavior patterns are
only partially understood. The. importance of artificially supplied
minerais, to both animais and range, needs further study. The
significance of such mortality factors as disease, predation and
illegal killing should be weighed more precisely. And these are but
a part of the problems still unsolved.
At the risk of over-simplifying these complex questions, the
author believes when fundamental ecological relationships are
more thoroughly understood, the clue to good bighorn manage-
ment may be found in good, basic conservation practices rather
than spectacular and artificial techniques available to modern game
managers. Present information strongly suggests that the grea test
challenge today is the task of maintaining adequate suitable habi-
tat in the face of growing commercialization and industrial de-
mands. A wilderness animal, the bighorn will surely be the loser
if there are additional exploitations of the wild lands in central
Idaho. An important hattie will be won if the Rocky Mountain Big-
horn Sheep, in addition to reasonable protection, can be assured
adequate food and cover and an undiminishing habitat in which
to live.
-15-
....__
PARTI
The Bighorn Sheep In Idaho
Its Status, Life Histo.ry and Management!
INTRODUCTION
Approximately 125 Rocky Mountain Bighorn Sheep2 have been
killed legally in Idaho during the past 25 years. Despite this small
hunting removal sheep populations have failed to show any marked
increase. Realizing that good conservation practices require more
than restriction of legal hunting, the Idaho Fish and Game Depart-
ment encouraged a big horn sheep investigation which was initiated
in May 1949, under the supervision of Dr. Paul D. Dalke of the
Idaho Cooperative Wildlife Research Unit. This study continued
through October 1950, culminating in a master's thesis entitled
"Life his tory and ecolo gy of the bighorn sheep ·in Idaho." Then, on
December 1, 1950, the Fish and Game Department, in cooperation
with the Federal Aid Division of the U.S. Fish and Wildlife Service,
initiated a project to continue the study. Field work on the Federal
Aid project was concluded in November 1952, although yearly
population trend counts, range studies and other phases of the
investigation are being continued by conservation officers and
biologists of the Idaho Fish and Game Department.
Major objectives of the investigation were to accumulate
information concerning the life habits and requirements of
mountain sheep, to study and analyze factors affecting produc-
tivity and to make accurate censuses as a basis for bighorn man-
agement. The tangible result most urgently desired was to formu-
late, from this collection of facts, a management pro gram designed
to increase the present number of bighorn within the Iimits of
range capacities, at the same time permitting maximum harvest
consistent with that goal.
As is common with an investigation of this sort, the key
problem was found to be too complex, too inter-woven with the
biology of other wildlife and too dependent upon the nature and
condition of the habitat to be isolated from the many facets of
wild lands and wild game management. For this reason, while
emphasis was placed on phases most directly related to practical
management, other relationships were explored as well. These
1This study was conducted in cooperation with the Idaho Cooperative Wildlife Research Unit,
and with Federal A id in Wildlife Restoration funds un der Idaho Projeet W -99-R.
!!For convenient reference, scientific names of plants and animais mentioned in this bulletin
are listed in the Appendix and do not appear in the text.
-17-
associated findings are presented whenever they contribute to the
major purpose of this bulletin-ta relate past and present status
and life history data of the bighorn sheep to an action program
that will be: (1) practical enough to provide contemporary, wise
management; (2) fundamental enough to recognize the complexity
of the ecological relationships that exist; and (3) flexible enough to
permit ready adjustments of the pro gram as new facts are brought
to light.
In addition to the agencies and institutions mentioned in the
"Foreword," many individuals cooperated in various phases of
the investigation. Special thanks are due Melvin Hyatt, John G.
Kooch and Glenn A. Thompson of the U. S. Forest Service for their
cooperation with the field work. Dr. William L. Jellison of the U.
S. Public Health Service contributed significantly to the study.
Food habits analyses of coyote scats were made by Charles C.
Sperry of the U.S. Fish and Wildlife Service. Fellow employees of
the Idaho Fish and Game Department whose assistance will be
especially remembered are Stewart M. Brandborg, Melvin R.
Francis and Wesley M. Shaw. Many other members of the depart-
ment have assisted with phases of the field work and preparation of
the manuscript.
Men who were hired for specialized and hazardous work were
A. P. Smothers, veteran riverman, and Smith Stoddard, back-
country pilot, who was later killed when his plane crashed in the
Salmon River mounta-ins. The willingness with which Wally Hutch-
ison, Clay McCulloch, Mike Mitchell and Ed Tewalt, all temporary
state employees, shared the hardships of extended pack trips,
long hikes and wet boat trips is gratefully acknowledged. I will
not attempt to mention ali of the ranchers and other old-timers
who helped, but they are not forgotten. To the A. A. Bennett, Jess
Taylor and Willard Rood families, I am especially indebted for
their western hospitality and fine cooperation.
I am grateful to the following men for their critical review of
the manuscript and their many constructive suggestions: Drs.
John C. Craighead, Paul D. Dalke, George H. Kelker, Jessop B. Low,
D. I. Rasmussen and Lee E. Yeager; and RobertE. La timore, Ken-
neth W. Parker and William P. Dasmann. Ànd to Bob Gilliam-
my appreciation for his fine editorial assistance.
Expressions of appreciation would not be complete without
mentioning the contribution of my wife, Carol. She and our two
youngsters, in a succession of isolated cabins and through long
weeks alone, never failed to accept the unfamiliar role of pioneer
with cheerful resourcefulness.
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-
.._
THE PROBLEM
There have been alarming declines in the number of wild
sheep in North America since the latter part of the nineteenth
century. And game administra tors, wildlife specialists and conser-
vation-minded sportsmen have combined their efforts in serious
analyses of possible counteractive measures to rescue the bighorn
from his apparent plight.
Ernest Thompson Seton (1929) estimated the number of
mounta'Ïn sheep in North America to be between 1,500,000 and
2,000,000 in primitive times. He estimated the population in the
United States to be about 28,000 in the 1920's. Big game inventory
figures released by the Fish and Wildlife Service for the year of
1952 place the population of native sheep in the United States at
17,500.
Early losses were rapid and widespread. Entire herds were
wiped out while others were reduced to a fraction of their primi-
tive number. Regulations restricting or eliminating the legal
harvest of mounta:in sheep were put into effect. Still many herds
remaining in remote and rugged wilderness outposts continued
to decline, becoming separated into small and isolated groups.
Fortunately, this unhappy status of mountain sheep has been
recognized and heeded-we shall hope in time. Several research
projects have been initiated, principally during the past 15 years,
to gather data from which a management program could be formu-
lated. Sorne of these surveys pursued only those phases where
potential findings could be applied directly to management. Other
projects employed pure research to obtain information concerning
life history and ecology, regardless of the immediate utility of
the facts discovered. Together, these two approaches have borne
fruit in the form of much valuable information. But despite the
combined efforts of pure and applied research, many problems of
productivity remain unanswered, and many basic ecological rela-
tionships are still a mystery.
-19-
HISTORY OF BIGHORN IN IDAHO
A problem soon becomes apparent when you begin reviewing
literature and interviewing old-time residents concerning popu-
lations of a wilderness species such as mountain sheep. In the first
place, these animais are difficult to count or study. Seemingly
insurmountable problems are encountered in piecing together a
historical sketch when this fact is combined with the faultiness
of normal memory and the frequent relating of impressions as
facts. Many other factors tend to dim and confuse unrecorded and
sometimes initially inaccurate observations. Nevertheless, the
written and verbal accounts relied upon for this historical review
were selected carefully and a reasonably accurate chronology of
population fluctuation is believed to have been assembled.
Early Numbers
Records from nineteenth century traders, explorers and
naturalists indicate that sheep were quite abundant throughout
the Rocky Mountain chain and the central portion of Idaho.
During the winter of 1832 Captain Bonneville, his men and a
large party of Indians, camped along the Salmon River a few miles
north of the present site of Salmon City. The Indians had reported
plenteous hunting in this region and Bonneville's party was not
-20-
....._
disappointed, as the following report attests (Irving, 1843, p.169):
"Besides numerous gangs of elk, large flocks of the ahsahta or
bighorn, the mountain sheep, were to be seen bounding among the
precipices. These simple animais were easily circumvented and
destroyed. A few hunters may surround a flock and kill as many
as they please. Numbers were daily brought into camp, and the
flesh of those which were young and fat, was extolled as superior
to the finest mutton." Now bighorn are reported only occasionally
in this same area.
The first white settlers appeared in the Salmon River drainage
in the 1850's. At this time bighorn were considered to be very
abundant, especially ·in Lemhi Valley, according to Mr. George E.
Shoup, a long-time resident of the Salmon River Valley. Much of
Mr. Shoup's historical information cornes from conversations with
early white settlers and old Indians whose memories reached back
to dates preceding the Civil War. Mountai'n sheep have not been
reported in the Lemhi Valley in recent years.
Seton (1929) remarks that his guide, Abe Leeds, had seen
thousands of sheep in the Lost River area of Idaho in the late
1800's. Ali but perhaps a few dozen animais have disappeared from
these ranges. In a letter from M. W. Miner, Mr. Seton was informed
of an estimated 2,000 to 2,500 sheep ranging in the mountains
near the upper end of the Middle Fork of the Salmon River in 1897.
Though the exact geographical Hmits involved in this estimate
are uncertain, there are certainly no more than a few hundred
sheep on the same ranges today.
The Initial Decline
It is generally agreed that a major decline in this area occurred
between 1870 and 1880, when scores of mountain sheep died from
what now appears to have been scabies. Epidemies of scabies and a
severe winter around 1890 are reputedly the cause of a second
decline ·in numbers. Another reduction occurred about 1910. Since
the first die-off in the 1870's, the bighorn population has never
returned to primitive levels.
Other conditions frequently mentioned by old-timers as caus-
ing heavy losses are hunting pressure, competition of domestic
livestock for forage and space, and the presence and activity of
man on the bighorn's native domain. A combination of ali these
factors undoubtedly contributed to the rapid elimination of this
species from many of i ts original ranges.
-21-
Origin of Present-Day Herds
The principal question regarding the origin of recent popula-
tions of bighorn sheep in Idaho is whether they were originally
confined to the valleys and foothills, as recorded by early explorers,
or also populated the cliffs and steep canyons which are inhabited
today. There is much supporting evidence that the bighorn sheep
of the Rocky Mountain region once roamed far from the rugged
terrain that is now considered an essential part of their habitat.
Reliable early-day accounts, such as those by Baillie-Grohman
(1882) and Roosevelt (1888), tell us of bighorn sheep being
observed on prairies and valleys, many miles from the nearest
mountains.
Old-timers interviewed during this study expressed the opin-
ion that white man's intrusion onto arable and grazing lands of
central Idaho precipitated a graduai migration to the remote and
relatively inaccessible ranges along the east, south and middle
forks of the Salmon River and the rocky, precipitous canyons of
the main Salmon below Shoup.
On the other hand, early written records about the Middle
Fork and Salmon River drainages reported an abundance of big-
horn sheep on ranges that are occupied today. Mr. George E.
Shoup, mentioned previously, has become skilled in deciphering the
many Indian paintings found in this area. From these drawings
he reached the conclusion that mountain sheep were abundant on
their present ranges as far back as 300 years ago. The evidence
provided in the literature and from interviews with men having
intimate knowledge of early-day conditions, indicates that there
may have been limited migration of sheep from the areas of
settlement, but that most of the ancestral stock of modern herds
were indigenous to present ranges. It appears that unrestricted
hunting, disease of epidemie proportions and competition from
domestic livestock may have destroyed valley and foothill herds
until few remained to escape westward into the mountains now
inhabited.
Recent Status
Probably the bighorn sheep population reached its lowest ebb
in the 1920's and early 1930's. The history of individual herds,
however, varies considerably. Sorne groups have remained rela-
tively stable throughout the past 30 years, while others have
declined and risen again during that period. Perhaps a few herds
are still diminishing in numbers.
-22-
..._
A. P. Smothers, who has observed mountain sheep along the
Salmon River during most of the last 25 years, states that he has
noted little change in their status from Little Squaw Creek to Big
Squaw Creek, a distance of about 10 miles. There has always been,
he reports, about 30 or 40 sheep ranging in that area. Upriver from
this herd, Mr. Smothers believes that the sheep declined in the la te
1930's and early 1940's but have slowly increased in recent years.
Frank Lantz, a long-time employee of the U. S. Forest Service,
has lived along the Salmon River since 1916. He reports that a
herd near the mouth of the Middle Fork apparently disappeared
just prior to 1920 and sheep were not seen in that location for the
next eight or 10 years. Detailed counts made during the current
study show that about 60 animais now inhabit the same area.
Gutzman and Buckingham (1935) estimated that there were
400 bighorn in 1934 on the 60 miles of Middle Fork winter range
from Marble Creek downstream to the mouth. The 1952 estimate
for the same area was 920 head.
During the period of 1929 to 1933, inclusive, the Forest Serv-
ice, in cooperation with the Biological Survey and State Game
Department, kept two men on winter game studies on the Middle
Fork of the Salmon River. On the basis of this 5 year study and
other observations, Godden and Gutzman (1938) concluded that
sheep numbers had remained fairly constant since 1917 except
for a possible decline during the last few years bef ore 1938.
Severa} pioneer residents were interviewed during the investi-
gation. Sorne of their impressions are pertinent to this discussion.
"Les" Gutzman, a forest ranger, first studied game on the Middle
Fork in 1928. He reports that bighorn numbers were small at that
time and further decreased until 1936 or 1937, when slight in-
creases were noted in certain bands. A. A. Bennett, long acquainted
with the Middle Fork country, stated that the Short Creek and
Rattlesnake Creek herds have decreased materially since about
1930. Lantz, mentioned earlier, reported observing 212 mountain
sheep in the Stoddard Creek drainage in 1916 or 1917. The writer
counted an even 100 sheep in the same general area in 1951.
Gaufin and Ellis (1941) report the mountain sheep population
was either static or decreasing slightly at the time of their study.
They listed a total of 125 sheep between Papoose Creek and Reese
Creek. The 1951 count for this same area was 133. It would appear
that the Gaufin and Ellis 1941 count should be the most complete as
it resulted from many repeated counts, while the 1951 count was
based on a 3 day census. These figures indicate sorne increase in
these herds over the past 10 years.
-23-
Various game reports and records, which have been reviewed,
indicate that past bighorn population trends on the Salmon
National Forest were quite typical of conditions on other ranges.
Consequently, the trends indicated in Table 1 are roughly com-
parable with those in other parts of the state. It is recognized
that the populations shown in Table 1 are derived from general
estimates made by forest rangers and
men assigned to game studies and are
not based on detailed counts. Still these
estimates were made by men who spent
much time in the field and usually con-
sulted local residents and other informed
persons before submitting their reports.
Therefore, the statistics should indicate
general trends.
The period from 1917 through 1927
shows relative stability. In 1928, despite
the fact that sorne additional territory
had been added to the Salmon Forest, a
downward trend is noted. Small popu-
lations are reported until 1934, when the
figures rise to about the same level re-
ported during the 1917-1927 period. A
decided increase appears in 1940. How-
ever, in February 1940, over 66,000 acres
along the west side of the lower Middle
Fork were added to the Indianola Ranger
District. This district reported 215 more
sheep in 1940 than in 1939, which nearly
accounts for the increase from 250 to
510 shown for the entire forest. Con-
sidering this enlargement in area, it
appears that the population remained
nearly static between 1934 and 1945. A
fairly constant increase is reflected by
the estimates from 1945 to the present.
The statewide population of moun-
tain sheep ranging on national forests in
1922 was estimated at 869. Today there
Table 1
Bighorn sheep
population estimates
for the Salmon
National Forest
Year
1917 .
1918 .
1919 .
1920 .
1921 .
1922 .
1923 .
1924 .
1925.
1926 .
1927
1928 .
1929
1930 .
1931 .
1932 ....... .
1933 .
1934
1935 .
1936 .
1937 .
1938 .
1939 .
1940 .
1941 .......... .
1942 .
1943 .
1944 .
1945
1946 .
1947
1948 .
1949 .
1950
1951 .
1952
No. of
Sheep
205
250
250
250
255
250
250
331
320
236
156
94
112
198
196
205
271
245
230
225
250
250
510
550
480
505
510
560
630
700
790
810
850
880
880
are about 2,500 bighorn in the national forests of Idaho.
-24-
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APPROACH TO THE PROBLEM
Early Studies in Idaho
This investigation is not the first study of bighorn sheep to
be conducted in Idaho. Foster Robertson, an employee of the U.S.
Forest Service, investigated mountain sheep for a two month
period during the summer of 1938. His headquarters were at Reese
Creek, a tributary nine miles up the Middle Fork of the Salmon
River. Mr. Robertson also spent a month studying the sheep on
their summer range in the Bighorn Crags.
On January 2, 1940, David M. Gaufin, leader, and F. Gordon
Ellis, assistant leader, initiated the Idaho Mountain Sheep Survey
under the Federal Aid Project No. 7-R-C. The project was sched-
uled for five years duration but was discontinued in June 1941,
when the project leader entered the armed forces. At this time
there had been 17 months of nearly constant study by one or both
men. The headquarters for this investigation was on Stoddard
Creek, about three miles south of Robertson's camp on Reese Creek.
Wesley M. Shaw carried out, under the auspices of the Idaho
Fish and Game Department, a survey of the bighorn sheep along
the East Fork of the Salmon River and near Challis during the
win ter and spring of 1942.
-25-
In addition to the reports resulting from these full-time
studies, considerable historical data have been assembled from
letters, newspaper articles and miscellaneous reports. Most of the
material was found in the files of the Salmon and Challis National
Forest headquarters and the Idaho Fish and Game Department
office. Many pioneer residents with intimate knowledge of early-
day game conditions have been interviewed. Their statements
were recorded and filed for future reference. These opportunities
to build a background of historical information were helpful in
many ways. Not only was duplication of investigative efforts
reduced but a basis was provided for comparison of findings over
a substantial period of time.
Study Methods
Transportation-first, last and always-is the matter of
greatest concern in a wilderness study. The problem, not only
of getting where you want to be, but keeping supplied with food,
camping paraphernalia and study equipment becomes almost
monumental at times.
Where roads lead into mountain sheep country, a pickup or
jeep can be used. Wh en trails are followed y ou walk or ride a
horse; and, if the trip is long, a packstring is led behind. Horseshoes
and hobbies are basic necessities; but, even so, horses may become
lame, or master the art of traveling while hobbled and you spend
hours-or days-catching them again. Where the trail ends you
walk, or maneuver a rubber boat down the river.
Food spoils in summer, freezes in winter and gets soaked in
the boat or wh en fording a river; but you soon learn to overcome
most of these difficulties. Porcupines, mules, packrats and bears
may raid the grub boxes or otherwise raise havoc with the outfit.
Anyone who has shared these experiences knows that he will
spend one-third of his working hours just "living" and "getting
ready to do something." But ali of this is a part of the job and,
when recalling it, one never feels that it has been a hardship.
In July and August 194'9, two pack trips, covering 450 miles
and requiring six weeks time, were made on summer and winter
ranges to count game and become familiar with sheep country.
A camp was established in the Bighorn Crags in 1950. One month
was spent here observing the summer activity of bighorn and
surveying their ranges.
Two boat trips were made through the lower 50 miles of the
Middle Fork of the Salmon River during the summer of 1951. One
-26-
FIGURE 2. Camp supplies and study equipment are moved down-
river in a rubber boat while conducting range survey. No pack trails
or roads traverse winter ranges along the lower 25 miles of the
Middle Fork of the Salmon River.
S e ptember 19, 195 1
trip, principally to census mountain sheep and other big game,
required 18 days to complete. Most of the count was made during
side trips on foot. Nearly six weeks were spent on the second boat
trip, when a survey of winter range was conducted.
From mid-December 1951, until early April1952, study head-
quarters were at the Flying B Ranch, 40 miles up the Middle Fork
of the Salmon River and over 20 miles by trail from the nearest
road. This area is accessible only by airplane in the winter, and
includes sorne of the finest bighorn range in the state. Close
surveillance was maintained over 20 miles of sheep range along
the Middle Fork throughout the winter.
Three pack trips, requiring a total of 33 days, were made on
summer ranges during the summer of 1952. An additional 18
days were spent on two trips into the Middle Fork winter range
area to investigate game use of browse. A 13 day boat trip through
65 miles of the main Salmon River canyon was made late in April
to count big game and inspect winter range. These are the major
trips. Many trips of shorter duration were made on foot or
horseback.
To summarize-more than 500 days were spent in the field
observing the animais, investigating range conditions or studying
-27 -
other factors related to mountain sheep. Over 3,200 bighorn were
tabulated during the study. This figure includes repetitions and
possibly represents an observed population of no more than half
that number. An additional 400 sheep were counted in aerial cen-
suses conducted in March 1951, and the same month in 1952.
In addition to the detailed notes taken regarding bighorn
sheep and their habitat, notice also was taken of predatory birds
and mammals and their relationship to sheep. To add to the
ecological picture the occurrence of ali big game, fur-bearers,
predators, rodents, upland game birds and song birds was recorded.
From May 1949, until April 1950, Stewart Brandborg, who
was conducting a study of mountain goats, operated from the same
base camp and cooperated on the many phases that were common
to both studies. After the first year a temporary employee was
hired from time to time for a specifie task or an extended trip
into the back country. Otherwise, the study was a one-man project.
-28-
-
i
1
1
1
L
BIGHORN HABITAT
Location
Mountain sheep in Idaho have been geographically restricted
by the encroachment of civilization upon much of their ancestral
range. At one time the domain of Idaho sheep herds abutted the
state boundary at many points. Now, with the exception of the
few small and scattered herds shown in Figure 9, mountain sheep
populations have been reduced until they are confined almost
entirely to the Salmon River watershed in the central part of
the state.
Present sheep herds of importance can be further circum-
scribed to three major tribu taries of the Salmon River: The East
Fork, Middle Fork and South Fork rivers; and ranges along the
main Salmon River from Shoup to Riggins. This area spreads over
four counties: Custer, Idaho, Lemhi and Valley. Six national
forests, the Bitterroot, Boise, Challis, Nez Perce, Payette and
Salmon, are represented in the same locality.
Topographical Features
On their historie expedition to the Pacifie, Lewis and Clark
turned back only once-when they heard the roar of the "white
water-rapids" and saw the forbidding walls closing in on the banks
of the Salmon River. It was here, a few miles below the mouth
of the North Fork of the Salmon, that Indians convinced the two
captains that the Salmon River canyon was impassable (DeVoto,
1953). Today the canyon has been traversed but is recognized as
one of the most rugged in North America. From rim to river its
depth in several places exceeds 6,000 feet.
From its source amid the rugged peaks of the Sawtooth Range,
through 390 miles of valleys and canyons to its confluence with
the Snake River, the Salmon falls more than a mile. Within the
area where basic studies were conducted, the river flows at an
elevation of about 3,000 feet and has an average gradient of 14
feet per mile. Large areas along the canyon are bordered by cliffs
and the talus originating from them. The high country is char-
acterized by subalpine valleys surrounded by ridges which are
studded with spires of jagged rock. Glaciated basins are rimmed
with talus and outcroppings of barren granite.
There is considerable difference in the elevations of summer
and winter ranges adjoining the lower Salmon River, as compared
with the heights at which sheep summer and winter near the
-29-
FIGURE 3. Mountain sheep habitat in the Bighorn Crags. This
area is typical of the granitic high altitude ranges common to the
Salmon River watershed.
Photo by M. Edson , Aug u s t 30, 1953
upper end of the drainage. The elevation at the mouth of the
South Fork is 2,000 feet above sea level. Few of the peaks in that
region rise above 8,000 feet. By way of contrast the East Fork
fl.ows at about 6,000 feet through the sheep range, and there are
peaks exceeding 11,000 feet in the White Cloud Mountains where
East Fork bighorn herds range in summer.
While there are definite variations between micro-habitats
found in the two extremes described, there is marked homogeneity
in their over-all physiographic character. Therefore, unless excep-
tions are noted, it may be assumed that subsequent discus s ions
of physiography are applicable to all major ranges in the state
which are now occupied by bighorn sheep.
Geology
The Salmon River canyon and the Middle Fork and South
Fork tributaries eut deep into the huge Idaho batholith, a vast
granitic mass measuring sorne 70 by 240 miles. This body of
granite is one of the largest of its kind in the world (Shenon and
Reed, 1'936).
It is interesting to note that, while much of the historie
population occupied areas underlain by sedimentary rocks, modern
-30-
herds are almost entirely confined to granitic regions. The Lemhi
and Lost River ranges and the Miocene lake beds around Salmon
are described by Rhodenbaugh (1953) as being largely sedimentary
in nature. These areas were inhabited by thousands of bighorn
a hundred years ago. Though it was the early settlers with their
agriculture and industry and guns who first eliminated wild sheep
from these fertile river valleys, there may be a direct relationship
between the healthy condition of those early herds and the
low productivity of our present-day herds. Since soils derived
from sedimentary rock are generally more fertile than granitic
soils, the historie herds were occupying inherently better ranges
than are mountain sheep today. This difference could be significant
in determining the productive potential of a herd.
Climate
The Salmon River drainage has a rather dry, hot climate.
In the city of Salmon, the mean annual precipitation has averaged
8.79 inches over a 42 year period. Weather records available from
areas in the mountains west of Salmon indicate average precipita-
tion to be about 12 inches annually. Most of this precipitation is
received from late autumn to early spring. Six to 18 inches
of snow can be expected on most of the winter ranges from Iate
December through February, and sometimes weil into March. High
winds are infrequent in most areas and drifted snow seldom
interferes with the winter movement of big game. Snow slides,
however, are common and the presence of big game carcasses
in slide debris attests to the hazard presented.
Temperatures of more than 100°F. are often recorded during
July and August. However, Iow humidity combined with the gentle
air currents that are usually present, greatly reduce effects of the
heat. Sub-zero temperature can be expected for short periods in
December, January and February. The Iowest reading for the study
period was in February 1951, when the mercury dropped to -30°F.
at Salmon. Temperatures this Iow are seldom recorded in this
region, however. The highest reading was in August 1949, when
the temperature soared to 111 °F. near the mouth of Colson Creek.
But most of the sheep are in high subalpine country during the
summer, and temperatures are much cooler there. At study head-
quarters, elevation 8,100 feet, the hottest day between July 20
and August 17, 1950, was 80°F. During the same period at the
mouth of Camas Creek, elevation 3,800 feet, the mercury rose
to a maximum of 99°F.
-31-
FIGURE 4. This summer range, near Twin Peaks and west of
Challis, is largely sedimentary in nature. Limestone and chalk forma-
tions are found to a limited extent on both summer and winter ranges
in the upper Salmon River watershed. Seven bighorn sheep and one
mountain goat were grazing on the open slope in the left foreground
when this photo was taken. Close inspection reveals a network of
trails gouged out of the hillside by game.
August 13, 1952
It is important to record snow depths, maximum and minimum
temperatures, total precipitation, barometric pressures and wind
velocities. However, unless there are marked extremes in any of
these factors, a most exhaustive review of such data tells little
about the direct effect of elima te upon the welfare of game animais.
The most satisfactory means for judging the consequence of
weather on game populations is by direct observation of conditions
in the field. The amount of snow present is not as important as
the condition of the snow. A heavy crust may render large areas
of range unavailable. The degree and duration of this crust, as
well as the temperature and depth of snow, determine the severity
of a winter. It is on winter ranges during winter and early spring
that weather becomes a particularly signi:ficant factor in the
bighorn's odds for survival.
There is, of course, a very important relationship between
precipitation and temperature and the development of forage.
The part that climate assumes in the production and availability
of food ; and the effects of varying snow conditions, are discussed
later in connection with range studies.
Summer Range
Most bighorn sheep summer ranges in Idaho are qui te similar
in topography, geology and vegetative characteristics. The Bighorn
Crags, a high altitude range lying immediately east of the Middle
-32-
FIGURE 5. Harbor Lakes Basin. These two lakes lie at an elevation
of 8,800 feet and are fed by melting snow and icy freshets from
subterranean springs emerging from the surrounding slopes. Visits
to this basin during the summer of 1950 were often rewarded by
the sight of severa} ewes and lambs feeding, sunning or frolicking
around the basin walls. Bighorn were not observed near the lake
shores which are surrounded by lush stands of sedge, grass and
rushes. Rather, the sheep preferred the upper slopes with their
sparse vegetation and abundance of talus slides and barren rock.
Photo by M. Edson, August 30, 1953
Fork of the Salmon River, was studied most intensively and the
following is based largely upon the finding of that survey.
AU of the mountain sheep observed in the Bighorn Crags
were found at elevations over 8,000 feet. Most of this summer
range occupies a subalpine position between the forest proper and
the treeless alpine tundra, assuming characteristics of the spruce-
fir zone at its lower border and abutting the alpine zone on sorne
of the highest peaks. (Classification of vegetation zones is in
accordance with the standards established by Daubenmire [1952]).
There are perpetuai snowbanks scattered throughout most of the
high country range. These may be remnants of wind-blown
cornices, drifted snow in deep crevices or the residual snow and
debris that inevitably collects at the base of narrow chutes and
steep basin walls. Bighorn frequently eat this snow rather than
descend to the creeks or lakes for water. It is not uncommon to
see entire bands of sheep s unning themselves on a large snowbank,
or kicking up sprays of icy snow as they run and slide over its
surface.
-33-
....._
The floor of each basin contains from one to a half-dozen lakes
surrounded by scattered stands of alpine tir, Engelmann spruce
and occasionally white-bark and lodgepole pine. Labrador tea,
mounta:in heath and beargrass often flourish under spruce, tir and
lodgepole, especially near the lakes and streams. Frequently small
mountain meadows dot the lake shores and border the creeks
which flow through glaciated valleys before pitching downward in
h:multuous descent to the river below. Spruce and lodgepole
dlsappear as the slopes are ascended; white-bark pine and alpine
tir become stunted and deformed. Small-leaved huckleberry is an
especially characteristic member of the impoverished ground
cover. A species of rush, little ricegrass and sedges are abundant
in sorne areas.
Dwarf juniper and wind-distorted white-bark pine can be
found in crevices nearly to the summits of the peaks, but the
density of ali vegetation is noticeably decreased above 9,500 feet.
It appears, however, that this dearth of vegetation is related more
to a lack of soil than to altitude. On one peak, at an elevation
exceeding 9,900 feet, small patches of soil were producing vigorous
stands of herbage.
In considering Figure 7, it must be borne in mind that there
are many micro-habitats within subalpine ranges; it would th us
be unsound to conclude that ali sites at the same elevation and
exposure would necessarily conform to the plant composition
shown. The major difference between the slopes examined is
that the drier, south west exposure is essentially a grass type while
moist conditions prevailing on the northeastern exposure have
encouraged the production of shrubs.
On a few of the major summer ranges visited, considerable
variation was noted in physiographic characteristics. A brief
discussion of these variations follows.
Twenty miles south of the Bighorn Crags an important
bighorn summer range is situated between Camas Creek and Loon
Creek. This range, while retaining the familiar deeply dissected
FIGURE 6. An aerial view of ranges occupied by the Tumble
Creek-Parrot Creek bighorn sheep herd. The topography is more
precipitons than usually found, but there are several bighorn herds
in Idaho that range in country equally rugged. Boundaries shown
must be considered with certain reservations. In reality, they can
be defined only generally because use varies from year to year in
response to weather conditions. The habitat shown cannot be con-
sidered as the entire range for this herd because it is known that
they roam beyond the pictured area, particularly on the sommer
range.
Photo by Geological Survey, September 24, 1947
-35-
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15 -
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0 Southwest exposure, 9,300 feet <'levation, Terrace Lakes Basin,
Bighorn Crags
~ ~orthwest exposure, 9,400 feet elevation, Harbor Lakes Basin, Big-
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Grasses and Grasslike Plants IForbs 1 Shrubs Trees
FIGURE 7. Comparison of the vegetation on two slopes within a
subalpine range as indicated by measurements of forty 10-meter line
intercepts on each slope.
relief and glaciated cirques, exhibits wider contrasts in soil and
vegetation than is found in the Crags. Huge extrusions of granite
alternate with areas of red and purple-hued shale and occasional
limestone ledges. Evidence of the complexity of micro-climate and
soil is mustrated by the islands of sagebrush-grass type that
appear on sorne of the southerly slopes overlooking subalpine
basins. Big sagebrush, arrowleaved balsamroot, bluebunch wheat-
grass and Idaho fescue are the more important plants inhabiting
these ecological oddities. Another departure from the associations
observed in the Bighorn Crags was the occurrence of curlleaf mo un-
tain mahogany at high elevations. North of Bear Creek, stands of
vigorous mountain mahogany are first associated with the upper
limits of Douglas fir, then extend up through scattered lodgepole
FIGURE 8. Stoddard Creek winter range. This is one of the better
mountain sheep habitats in centra:! Idaho. Open grass is the dominant
type; bluebunch wheatgrass and Idaho fescue are the principal forage
species. Mauntain mahogany and other desirable shrubs are rela-
tively abundant among the flanking cliffs. Approximately 125 big horn
win ter largely within the area pictured at right.
Photo by Geological Survey, September 24, 1947
-36-
..
' •t
pine and open cliffs until they intermingle with white-bark pine at
elevations over 9,000 feet.
The White Cloud range, which furnishes the East Fork herd
with summer pasture, differs from the Bighorn Crags principally
in elevation. Severa! peaks are in the neighborhood of 11,000
feet, with Castle Peak towering 11,820 feet above sea level. Big-
horn summering in these mountains are reported to spend most
of their time at the upper limits of the spruce-fir zone or above
timberline. This survey was too cursory to establish limits of
summer use in that area with accuracy.
During the summer more than 500 bighorn sheep range in
the mountains immediately west of the Middle Fork of the Salmon.
There are few peaks above timberline and the sheep pasture at
elevations between 6,500 and 8,500 feet, usually in the spruce-fir
or Douglas fir zones, but sometimes within the upper extensions
of the ponderosa pine zone.
Winter Range
Just as winter and early spring is the critical period in the
life of the bighorn, sois the abundance and condition of available
winter range a determining factor in his survival. In recognition
of this fact, intensive range studies were conducted on limited
key areas occupied by mountain sheep in win ter. The findings and
conclusions based on these studies are presented in Part II of this
bulletin, where winter ranges are described in detail. Therefore,
only sufficient description is given here to familiarize the reader
with general winter range characteristics. The following dis-
cussion is based largely upon the intensively studied lower 50
miles of the Middle Fork and adjacent Salmon River ranges,
which are repre.sentative of most bighorn habitat in the state.
Vegetation zones are vaguely defined in terms of elevation
on ali ranges in the Salmon River drainage. Sharp definition of
these zones is especially lacking on the lower ranges. Ponderosa
pine constitutes the principal zone and reaches its best develop-
ment within certain fairly definite limits of altitude. However,
it characteristically sends extensions down to considerably lower
elevations bordering the river on the north-facing slopes and
may be scattered intermittently on the south-facing slopes. Pon-
derosa pine also occurs along the summits of dry ridges and on
southern exposures at altitudes weil above those where well-
defined Douglas fir stands are found on northern exposures. Open
grassland parks typical of the wheatgrass-bluegrass zone are
-38-
i...._
associated with timber stands in many situations on the lower
ranges.
With the exception of lodgepole pine found at the uppermost
limits of winter ranges, the only noteworthy trees are Douglas
fir and ponderosa pine. The major shrubs are mountain ma-
hogany, spiny greasebush, rubber rabbitbrush, big sagebrush and
bitterbrush within its range. Bluebunch wheatgrass, Idaho
fescue and Sandberg's bluegrass, in that order of importance, are
the usual grasRes present. Numerous forbs, of which balsamroot
is the most common and most important in the bighorn's diet, are
found on all ranges.
Intermediate Range
On most sheep ranges there is an area between the upper
limits of winter range and the lower limits of summer range that
does not belong to either. This region is important in that it pro-
vides food and cover during spring and fall migrations and, on
sorne ranges. is used during the lambinf, and breeding periods.
It is difficult to define because its location and extent varies
greatly with each locality.
Sorne ranges have long migration routes that cross 15 or 20
miles of intermediate range. In other areas there may be prac-
tically no intervening territory between summer and winter
ranges. Upper extensions of ponderosa pine, the Douglas fir zone
and, sometimes, lower reaches of the spruce-fir forest compose
the usual intermediate range.
-39-
Il
0
ThreeCrt~O
Distribution determined by
intensive investigation
Distribution determined by
extensive investigation
Distribution based on other
sources
SCALE IN MILES
25 50 75 100
o Almo
FIGURE 9. Distribution of bighorn sheep in Idaho in 1952.
N
~
DISTRIBUTION
It was decided at the outset of this study to confine major
efforts to certain key areas of bighorn abundance rather than to
engage in a state-wide survey. In those areas inhabited by moun-
tain sheep but not visited by this writer, it was necessary to rely
upon the observations and knowledge of others to arrive at popu-
lation estimates.
Foremost contributors of information relating to the size
and distributions of sheep herds were U. S. Forest Service person-
nel. Game counts, reports from employees, packers and guides
and persona} observations were sorne of the means relied upon by
forest rangers in making yearly estimates. Game department
officiais furnished much reliable data, often secured in the same
manner as by the forest rangers.
Sources of information were considered carefully before
population data were accepted in this study. Figure 9 indicates
the basis for the population estimates for each bighorn area in
the state. Figure 10 shows estimated herd numbers within the
area selected for Lasic studies. Herd boundaries shown in Figure
10 roughly approximate the limits of winter range.
Highly specifie habitat requirements and the delimiting
effect of civilization have greatly restricted the distribution of
mountain sheep in Idaho. This is apparent in Figure 9, which
shows that about 95 percent of the bighorn population lives
within the Salmon River drainage. Approximately one-half of
these animais find suitable year-around habitat inside a rectan-
gular area about 20 by 60 miles in size, which is bisected by the
Middle Fork of the Salmon River. The expansion or restriction
of future distributions will depend largely upon industrial and
other developments by man. Even the most intensive type of
management will ultimately have little value if present ranges are
opened up by roads or exploited by industrial developments.
-41-
~....;::'-~~~-A~~;'~
~ Boundary of winter herd unit
15 Number represents population
in herd unit
0 1
SCALE lK MILES
5 10
FIGURE 10. Estimated bighorn sheep population within the Intensive Study Area
as determined by repeated counts during the winter of 1951-1952. Boundary lines
shown approximate the upper limits of bighorn winter range.
-42-
.....
j\
1 y''l,
:(f1._
BIGHORN BEHA VIOR
Seasonal Migration
Topographical characteristics, featuring steep slopes and
cliffs that rise abruptly from winter to summer ranges, reduce
the necessity of long seasonal migrations. This feature of the
terrain provides summer and winter pastures often separated
by only a few precipitous miles. Measurement showed sorne of
the canyon walls to average over 90 percent slope. In a few places
the distance between a grassy slope 3,000 feet above sea level
and a subalpine basin at 9,000 feet is not more than two miles.
The actual migration route taken by the sheep may not exceed
five miles. It is more common, however, for the animais to travel
10 to 20 miles.
Sheep that winter near Challis and on the East Fork of the
Salmon River are reported to travel as rouch as 40 miles between
their wintering and summering areas. These are believed to be the
longest bighorn migrations in Idaho. The Clear Creek herd mi-
grates about 25 miles and the Rush Creek herd travels at least
that far on fall and spring treks.
Fall migration of the herds observed seemed to be entirely a
response to weather conditions. In most cases bighorn do not
-43-
1
l'
1
! l
i
:'
have to cross a series of high passes enroute to winter range.
They already are "on top of the world," near the rim of the drain-
age in which they will winter. Their preference for high country
habitat apparently induces them to remain on subalpine pastures
until the first snowstorm. Since their diet on these ranges con-
sists almost exclusively of low-growing herbage, only a few
inches of snow buries this food supply, causing them to descend
to lower snow-free elevations. If the season's first snowstorm
occurs in September, as frequently is the case, the downward
movement may be checked by "Indian summer" weather and they
may return to higher ridges and basins throughout another
month of mild conditions.
Ewes, yearlings and lambs are usually the first to arrive on
the winter range. The date of arrivai varies with the weather
but generally is between October 15 and November 15. Perhaps
the reason for the rams appearing shortly afterward can be
attributed to the courtship and breeding activities which are near
at hand.
Fall snowstorms in the high country were observed to pre-
cipitate more rapid migrational activity among sheep than elk or
mule deer. Presumably this difference is related to food habits. Elk
and deer are able to forage successfully on the taller browse
species after the sedges, rushes, grasses and low forbs, so highly
favored by sheep, are covered with snow. However, it should
be explained that all big game moves out of the high regions qui te
rapidly; the principal difference being that bighorn sheep, once
started downward, continue at a fast rate until they are well
beneath the upper limits of the winter range. Frequently they
continue virtually to the banks of the drainage where they will
spend the winter. Elk and deer, in contrast, may descend only
part way, then tarry for several weeks in timbered and brushy
areas described previously as "intermediate" range.
It is interesting to note that Spencer (1943), in describing
the Tarryall herd of Colorado, states, "It was found that regard-
less of weather conditions, these migrations ... take place about
the same time each year ... " Contradictory to this, Honess and
Frost (1942) found in Wyoming that, "In short, the seasonal
movement of the bighorns are conditioned by the weather."
Observations in Idaho decidedly agree with the situation reported
in Wyoming.
The urgency, so apparent as the animais leave the snow-
covered mountains in the fall, is not to be found in their leisurely
departure from the lower altitudes in spring. When the snow has
-44-
melted from south-facing slopes and extensions of Lare ground
begin creeping upward, the sheep often stay near the snow line
where they feed on freshly uncovered mosses and lichens as weil
as cured grasses and forbs. This initial tendency to move to
higher slopes lasts only until forage along the stream banks
begins to "green-up." Then the bighorn will be found near the
streams, feeding on fresh blades of cheatgras.s, young balsamroot
leaves and other vernal vegetation.
Plant growth on the lowest ranges can be expected to start
about the middle of March, and low-growing plants often remain
succulent weil into June. Nevertheless, this does not keep the rams
from starting their drift back to summer pastures. Usually they
have disappeared entirely from the winter range by the middle of
May. Bands of young animais frequently begin moving toward the
high country a:t about the same time.
Considerable variation in behavior was detected among the
ewes. Where suitable terrain was available near the rivers, ewes
delayed spring migration until after lambing in late May or early
June. On those ranges where long, grassy slopes bordered the
river, the ewes would work their way up side drainages, seeking
seclusion among the cliffs to bear their young. This habitat was
located about midway between summer and winter range in sorne
of the areas studied. Sorne ewes remained in the lambing terri tory
for a few weeks after parturition. Other ewes resumed, or began,
their upward drift almost immediately; either in small groups or
as family pairs.
In localities where mountain sheep summer at moderate
elevations, the rams usually precede other groups by a few weeks.
Where slowly melting snow delays their arrivai until early July,
groups of rams, juvenile bands and ewe-lamb groups appear in
the high country almost simultaneously. Both sexes and ail ages
were seen at elevations over 9,000 feet in the Bighorn Crags on
July 3, 1950. At this time many north-facing slopes still lay
buried under deep snowdrifts, and protected sites on southerly
exposures were snow-covered also.
There were numerous instances when bighorn were seen
crossing the Salmon River and its tributaries in search of salt
or more desirable pastures. Picking their way across on the ice
in winter seemed to be as common as swimming across in summer.
In either case their cross-over appeared to be only temporary
and they would soon be back on their "home" side. It was generally
assumed that rivers were not crossed in the course of seasonal
migration. An occurrence on April 15, 1952, however, indicated
-45-
FIGURE 11. These ewes are near the upper limits of the winter
range in Dwyer Creek. They will continue moving upward to their
lambing grounds located on the intermediate range. In sorne areas
the ewes lamb within a few hundred yards of the river.
April 17, 1952
that the full extent of seasonal migrations may not be fully
appreciated. On this date three large rams were observed swim-
ming across the Middle Fork of the Salmon River from east to west.
The significance of this incident lies in the fact that mature
rams seem to be scarce on sorne ranges east of the Middle Fork
in summer, while a high percentage of rams are found in the
summer herds ranging west of the river. Winter counts show that
ram abundance is comparable between opposite sides of the river,
so the inference of this lone observation is that rams may migrate
to the west side of the river in the spring and not return to the
east bank until fall.
The import of such a situation on the establishment of hunting
unit boundaries for the harvest of mature rams in September is
obvious. One isolated observation is far from conclusive, of
course, but it does merit thought and points to the need for a
trapping and marking program to help piece together the puzzle
of migration.
Non-Migration
While definite shifts of population were apparent, many
exceptions to regular migration were observed. Probably more
than three-fourths of ali sheep adhere to the normal pattern, but
-46-
the remainder engage in short, erratic movements apparently not
extending above the intermediate range.
Mountain sheep were observed on low winter ranges through-
out each summer of the study. A barren ewe, or ewe with lamb,
were occasionally seen alone at low elevations in mid-summer, but
they were more often in small to medium-sized bands which usually
included a few yearlings. Rams were rarely seen on winter ranges
during summer months. Two year old males are apt to accompany
the rams to high-altitude ranges although sorne remained with
those ewes, lambs and yearlings occupying low ranges throughout
the summer.
Minerallicks are usually located on win ter ranges where sheep
are seen in summer. Frequently these sheep were utilizing the
licks when observed, which suggests that a desire for minerais may
contribute to non-migration.
Local Drifts
There is an entirely different type of movement, apart from
migration, which characterizes the habits of mountain sheep. In
the summertime a group of sheep may enter a subalpine basin and
remain there for a few days, feeding haphazardly around the basin
walls, but seldom traveling more than a mile in any direction. Then
one day, in response to what appears to be a synchronous compul-
sion, the flock moves out. They travel slowly but steadily along
the divides, grabbing a mouthful of forage here and there as they
move. They may travel a mile, or severa! miles, before settling
down to a few more days of feeding and resting in another basin.
In the winter a herd of sheep may occupy one section of the
range for severa! days, circulating within a radius of only a few
hundred yards each day. Then, as described for the summer range,
they will move as rouch as severa! miles to a new location suitable
to their tastes. A pattern of grazing rotation was observed on the
lower slopes of Clear Creek during the winter of 1949-50, and on
Short Creek, Soldier Creek and Waterfall Creek in the winter of
1951-52. One area would be occupied for severa! days, vacated
for about two weeks, then re-occupied. This procedure would be
repeated severa! times during the winter. In addition to the rota-
tion of use described, there is a temporary shifting of preferences
for exposure and cover type associated with changes in weather.
Sheep eventually move to the protection of cliffs or scattered
stands of timber during extended periods of inclement weather.
There is a very noticeable movement of bighorn onto open, grassy
-47-
slopes once the snow has melted in the spring. A decided shift in
preference for exposures at different seasons was noted on all
winter ranges studied. Over three-fourths of the sheep observed
during the earl y spring period were occupying southerly exposures.
The fact that south-facing slopes are the first to be open and fur-
nish new vegetation is probably the attracting feature. Conversely,
an equal preponderance of use was found on northerly exposures in
late summer and autumn. Shady north slopes are cooler and the
vegetation more succulent than on southerly exposures at this time
ofyear.
Besides weather and the unknown causes discussed, disturb-
ance by predators, the activity of man and the presence of domestic
livestock all are potential causes of local drifts.
Herding Characteristics
The number of bighorn sheep comprising each of the 496
observations made during this study varied from solitary animais
J.p to herds with as many as 46 sheep. Herd sizes are indicated in
the following tabulation:
Group size: Singles 2-9 10-19 20-29 30-39 45 46
No. of obs.: 73 331 68 15 7 1 1
Thirty-eight of the 73 lone individuals were rams, 23 were
ewes and the remaining 12 were either immature or unidentified
animais. Excluding those found singly, the herd size averaged 7.3
sheep per herd. Baillie-Grohman (1882) reported that the average
flock in the Rocky Mountains, over 70 years ago, numbered about
eight. This comparison is interesting as it indicates that, despite
the greatly reduced populations of today, the degree of gregari-
ousness among mountain sheep has remained about the same.
There are, in a sense, no definite herds in areas of relative
bighorn abundance. True, certain individuals winter on given
ranges and summer within certain general limits; but, even dur-
ing the rut when gregariousness is most prominently displayed,
there are frequent fluctuations in herd composition as rams roam
between groups of ewes, and immature animais periodically join
their eiders, then drift away. At other seasons there is an erratic
display of individualism as numerous combinations of sexes and
ages are formed, broken up and formed again.
Gaufin and Ellis (1941) point out that yearlings and lambs
along the Middle Fork of the Salmon River band together after the
la te fall breeding season and remain separated from the ewes until
late spring. The findings of the current study revealed that,
-48-
..
L
although there were exceptions, this type of segregation in the
winter and spring seasons was a common occurrence. This herding
characteristic, added to the fact that young animais were inclined
to inhabit the least "observable" sites, frequently resulted in
unrealistically low lamb and yearling spring count. For example, in
April1951, the census in the vicinity of Stoddard Creek was show-
ing a decided paucity of lambs. On the last of a 3 day census in
that area, a herd of 10 ewes and 20 lambs was discovered. This
evidence that family groups were broken up indicated the ease
with which erroneous sex and age ratios can result if groups of
animais are missed during spring counts.
The herding instinct of mountain sheep seems to be an ally
when facing the danger of predators. On severa! occasions coyotes
were watched as they stalked a scattered herd of sheep. Once
appraised of the danger the stragglers would hasten to join the
main band, from where they would ali maintain an alert attitude
un til the danger had passed, or would fiee as a group to the nearest
cliff s.
'Daily Routine
Significant in the daily life of bighorn sheep is the seeming
lack of "routine" connected with their daily habits. With high
disregard for the stereotyped activity patterns sometimes attrib-
uted to them, the bighorn often acts in an unpredictable manner.
Roosevelt (1888, p. 247) reported that he observed badland sheep
that were moving across open valleys, far from their natural hab-
itat, at mid-day in the summer. He points out that, " ... mountain
sheep act more erratically and less according to rule than do most
other kinds of game."
When large ftocks of sheep were observed feeding, there
usually would be one to severa! individuals bedded in their midst.
Conversely, at times when most of the herd was resting, a few
sheep would be up feeding. It was noticed, however, that consider-
able bedding occurred after both morning and midday feeding
periods. After arising from their mid-afternoon siestas, most ani-
mals feed untillate evening when they begin seeking a bedground
for the night. Beds used for daytime siestas are hastily selected
and may be in any location where the animal happens to be feed-
ing. On the other hand, night beds are carefully chosen, usually
on a steep, rocky site near the crest of a ridge. Frequently they
are situated in such a manner that the recumbent sheep will be
protected from the rear by a cliff or large rock.
-49-
After all field data had been compiled, several methods of
analysis were attempted to determine if weather or seasons
directly affected the daily activity of sheep. N othing of real signif-
icance was discovered. It appears that the typical alternation of
feeding and bedding periods occurs throughout the day, with only
slight regard for weather or time of year. The primary modifica-
tion of habits related to the season was that more time was spent
foraging in winter when deep snows forced the sheep to paw for
food. Consequently, less time was devoted to bedding during the
win ter months.
Couey (1950) found evidence of sheep escaping storms by
utilizing caves and protected places at the base of cliffs. Similar
behavior in the face of severe weather was occasionally observed
on the study area, but for the most part, the sheep seemed to be
indifferent to moderately severe conditions. Sunny weather fol-
lowing showers was found to be an ideal time for observing, as
the animais were most active at that time.
A character of sheep, differing markedly from elk and deer,
is the infrequency with which they "shade-up" during the heat
of the day. Rather thau seeking shade they usually can be found
sunning themselves on exposed areas. The principal exception to
this habit is found among the non-migrating individuals that
remain on winter ranges during the hot summer months. These
bighorn often congregate in groups under stands of timber.
Reaction to Man
Mountain sheep are one of the most easily approached of big
game species in Idaho. The author has frequently walked to with-
in less thau 50 feet of sheep herds on the winter range. Animais
on the summer range were somewhat more wary but would often
permit an observer to come within 100 feet or less.
Findings from this study agree with the following description
by Couey (1950, p. 33) concerning his experiences with the Sun
River herd in Montana.
A peculiarity of bighorns is their tendency to become alarmed when
one is a great distance away but their apparent disregard of a person
when he is quite near ... it was found that the best way to approach a
band was to appear in plain sight below them and, keeping in sight of
them, approach slowly in a quartering direction, never directly at them.
In this way, one can work up to within 20 to 50 feet of them without
alarm. If one approached from above, they would quickly stampede.
Contrary to sorne popular opinion the old rams and ewes do
not appear to be "sentinels of the flock" or the ones to sound the
-50--
r
FIGURE 12. Five ewes and two lambs, watching man approach,
display curiosity but not fear.
Photo by M. Francis, April 5, 1952
danger alarm. In mixed herds, mature rams were the least con-
cernced about the presence of an observer. If present, lambs most
frequently stampeded the herds. Yearlings., too, were more wary
than their eiders. An example of younger animais becoming frigh t-
ened without inciting fear in an adult was provided by the follow-
ing incident. A ewe, three yearlings and one lamb were bedded
when the writer's sudden appearance startled the young animais,
who promptly fied pell-mell down the slope. The ewe, lying across
the only escape route, remained bedded and nonchalantly continued
chewing her cud. Her only acquiescence to their behavior was to
duck sharply as each sheep hurtled overhead. Later the ewe arose
to begin feeding in a normal manner, indicating that her quietude
was not the result of injury or abnormality.
Curiosity or indifference are more frequent reactions to hu-
mans than fear. The following account of an adult ram's curiosity
is taken from the author's daily notes for November 18, 1949.
He (the ram) was about 50 yards away. As 1 ... remained completely
still, he began approaching ... rapidly up the slope ... When he had ap-
proached to within 10 feet, 1 jumped to my feet; whereupon he stopped,
then leaped in a stiff-legged fashion for about 35 yards down the slope
where he stopped to look back. 1 spoke in a low tone and he ran quickly
for another 100 yards down the slope bef ore stopping to look back again.
From the writer's daily notes of May 29, 1951, is the following
account of curiosity displayed by two rams.
-51-
(They) ... were within 25 yards before seeing us. My dog and I were
in a conspicuous spot ... to the windward of the rams. After detecting
us, they came straight in our direction until only 10 yards away, then
abruptly turned and walked over the ridge.
The persistent efforts of bighorn to attain higher ground often
results in an entire herd angling upward, following an adopted
course which may nearly converge with the observer's line of
travel.
In one instance the writer surprised a group of 37 ewes, year-
lings, lambs and young rams. A promontory of rock overlooking
the river was directly below them and they sped directly to this
temporary refuge. Their agitation increased as they were ap-
proached until finally, despite the fact that there were two easy
avenues of escape downhill, they suddenly fied upslope, passing
within 50 feet of the writer.
The following observation concerning two rams, two ewes and
a yearling is recorded in the field notes for March 16, 1952 .
. . . when I was about 200 yards directly above them, all five, led by a
ewe, started up the slope toward me. They were indecisive, seeming not
to know whether to go behind or in front of me. Finally they broke into
a run and passed within 30 feet ...
Inter-Relationships With Other Species
That mountain sheep prefer to travel in bands the year around
long has been a recognized characteristic, according to the records
of early explorers. Their sociability extends to several other big
game species as weil, the principal one being mule deer. On 16
occasions deer and sheep were observed grazing or utilizing min-
erallicks together. Small groups-two sheep with three deer; large
groups-31 sheep with five deer and nine sheep with 14 deer; and
such associations as one ewe with seven deer and nine sheep with
two deer were among the combinations observed.
All16 instances of fraternization between sheep and deer were
observed in the spring at times when they were grazing on young
vegetation. In most cases there was an attitude of complete indif-
ference between the two species. However, the following excerpt
from the author's field notes describes a more sociable relation-
ship.
Three sheep were grazing in company with two deer. At one time
the sheep began shaking their heads, then ran playfully toward the
deer; whereupon the deer jumped and frolicked about the sheep, sorne-
times acting as though they were going to bu tt them.
Oftentimes the presence of deer was a liability wh en the sheep
were being studied. The bighorn, usually undisturbed by human
intruders, were frequently stampeded by nearby deer which began
running while the observer was still at a considerable distance.
-52-
r
FIGURE 13. A young bighorn ram with a herd of domestic sheep.
On the open range, and in the corral, he was most content when near
the center of the band.
Photo by S. Brandborg, October 20, 1952
Elk were observed feeding with bighorn only twice. In each
instance there were deer in the same group. Eleven sheep were
observed feeding for more than an hour in the company of
six mountain goats. On another occasion four sheep and two moun-
tain goats fed and bedded together for nearly an hour. Neither
species gave evidence of being disturbed by the presence of the
other. A discussion of competition for food among big game species
is given in Part II of this bulletin.
The literature is replete with references to fraternization of
bighorn sheep with horses, cattle and domestic sheep. The follow-
ing incident which occurred near Shoup, Idaho, in October 1952,
deserves mention. The young bighorn ram shown in Figure 13
entered a rancher's corral one night with a band of 60 domestic
sheep. He remained with them for about 10 days, leaving the corral
in the morning to graze on the foothills and returning in the
evening when the rancher's dog fetched the band. It was reported
that on his last morning with the domestic herd, the wild ram ap-
peared very restless. When released from the corral he headed for
the mountains and was not seen again.
On a number of occasions during la te winter and early spring,
magpies were found perched on the backs of bighorn sheep where
they busily pecked along the spinal region. At other times they
would peck at the heels. Usually severa! birds visited a band simul-
taneously, and it was not uncommon to see two birds on one sheep
at the same time. One magpie was in constant attendance to a
flock of four ewes for 75 minutes. Each ewe was visited several
times. They usuall y appeared unconcerned about the presence of
-53-
the bird, but occasionally seemed to resent the pecking. It is known
that ticks and 'mites infest the pelage of the mountain sheep, so
perhaps a symbiotic relationship exists between magpie and big-
horn whereby the bird receives its dinner in return for a de-para-
sitization service. Murie (1940) suggests the possibility of magpies
th us performing valuable service. He cites an example of the stom-
ach of a magpie, collected near sorne deer, containing engorged
ticks. On the other hand, magpies have caused running sores by
irrita ting the wounds of domestic livestock; hence the relationship
may not always be beneficiai.
-54-
REPRODUCTION
Sexual Development
Biologically it is probable that both male and female bighorn
reach puberty by the second breeding season after birth. A wild
ram, which was approximately 1% years old, remained with a
herd of domestic sheep near Shoup, Idaho, for about 10 days.
During that time this ram was reported to have copulated severa!
times with the tame ewes. This was in mid-October. It is not
known whether or not his efforts met with success because the
ewes were sold later that fall and no record of their progeny has
been found.
It is known that deer and antelope, both males and females,
are sexually mature when 1% years of age. Domestic sheep fre-
quently breed when they are long-yearlings. From information
that he had collected, Seton (1929) concluded that bighorn ewes
conceive when 1% years old. Honess and Frost (1942) concluded
that bighorn ewes do not breed until they are 2% years of age.
This opinion is supported by Spencer (1943) and Allen (1939).
It is the opinion of the writer that a few ewes breed at 1% years
of age, and that all normal ewes are receptive to breeding in the
autumn when they are 2% years old.
-55-
Presumably the opinion that rams may not breed until they
are four years old, as suggested by Couey ( 1950), is founded upon
the supposition that service by younger rams is prevented by
combat. However, the indifference exhibited by older rams after
having copulated is an indication that physical superiority may
not be a cardinal factor in eliminating younger males from their
quest for a mate. Young rams are physically outclassed by the
old rams, it is true, but the ewe is sometimes secured by a 3 year
old ram after the victor has lost interest in her, or by stealth while
the old rams are engaged in hattie. Interested as they were, 2
year old rams were not observed taking advantage of opportunities
presented during the confusion of rutting activities. In this regard
it should be mentioned that, while the field observation method
employed in this study furnishes sorne information about the
sexual conduct of juveniles, it does not provide conclusive data
concerning the minimum age when insemination or conception
occurs.
Breeding activities are limited to a period of Jess than two
months but interest exists the year around, especially among young
males. Behavior, consisting chiefly of mild jostling, butting and
occasional mounting of females, was observed in J anuary, Feb-
ruary, April, May and July. This activity was indulged in mostly
by 2 and 3 year old rams, although yearling males joined in at
times. The ewes were never observed to be receptive and actual
copulation was not witnessed except during the breeding season.
Since nature is harsh in her treatment of the aged and infirm,
it is believed that the number of senile rams or anile ewes on a
range would be few. However, there is little positive information
about the maximum age attainable by mountain sheep. Cowan
(1940) reports that two rams shot in British Columbia were
determined to be between 15 and 17 years old. Se ton ( 1929)
mentions the dea th of a captive bighorn ram in Washington Zoo
at the age of 20 years. Dr. Cowan, basing his conclusions on a
study of 761 specimens gathered throughout North America,
reported that he found no evidence to indicate that bighorn in
the wild normally reach the advanced age mentioned by Seton.
Courtship and Breeding
An interesting characteristic of bighorn sheep is the extreme
fervor with which they engage in the perpetuation of their kind.
By la te October or early N ovember the rams have moved to the
lower ranges and are beginning to Jose the fraternal attitude with
-56-
r Î
L
which they regarded their fellows during the summer months.
Their necks become noticeably swollen and their coats are rich
and glossy. The playful bouts seen in the high country take on a
more serious aspect and frequently their conduct becomes decidedly
unsportsmanlike. Rams were observed using their horns to deliver
tierce blows to the rear or side of an adversary as weil as to
engage in the more common direct charges. Striking upward at the
sides or belly of an opponent with a stiffened foreleg may precede an
ail-out battle. Spencer (1943) mentions "battles royal" involving
as many as 14 rams, and chases with up to 11 rams following one
ewe. Mills (1937), in Yellowstone National Park, witnessed nine
rams in pursuit of one ewe. The number of rams observed jousting,
or chasing ewes, in the Salmon River country varied from two to
five.
The question of physical superiority may be decided at the
conclusion of a battle, but the victor does not attempt to evict the
vanquished from the berd. No instances were observed where one
warrior was battered until exhausted or unable to continue. On
the contrary, after severa! terrifie head-on collisions or a few weU-
placed blows from sorne other quarter, the weaker male would walk
away or merely ignore the stronger ram.
On severa! occasions rams were seen methodically visiting
each ewe in a ftock, apparently in search of one in oestrus. Often
they were unsuccessful and would either continue grazing or lie
down after having inspected the berd. Severa! times when groups
were quietly feeding or were bedded down, a ram would leap sud-
denly to his feet and start toward a ewe. He might pass severa!
other ewes in order to reach the one of his choice. If the ewe was
lying down when he reached ber, he would strike her with a front
hoof until she arose. It is evident that rams are quickly aware of
a ewe in oestrus. Usually only one ewe in a berd is in a receptive
mood at any one time.
The ram has a characteristic manner when approaching the
ewe. The head is cocked slightly to one side, nose outstretched
and upper lip curled back. He often stops severa! feet short of the
ewe, waiting for ber to make the first move. At this point one or
more rams may join the first. Sometimes the ewe voluntarily
begins the chase. Other times she is encouraged to do so by a
vicious butt from the ram. Once the chase has begun it may lead
back and forth across a slope for a quarter of a mile or more in
each direction. The rams frequently interrupt their pursuit with
battles between themselves. The ewe stops running until the fight
-57-
is over, then the chase is resumed. Sometimes the ewe stops sud-
denly, whereupon the rams pose, motionless, with heads back and
noses tilted upward. At other times the ewe will be covered almost
instantly when she stops. One ewe was observed to be covered by
two rams within the space of a few seconds.
When a ewe has been singled out for pursuit the remainder
of the berd usually displays no particular interest. At times the
younger animais will climb upon a van tage point from where they
appear to view the an tics of their eiders with interest.
The breeding season lasts for more than a mon th. The average
ram-ewe ratio calculated was approximately 1 to 1.3. Mature rams
were seen moving freely between bands of ewes and juveniles dur-
ing the rut. Therefore, it seems nearly impossible for a ewe to
remain unbred at the close of the ma ting season. In fact, it has been
suggested by Pulling (1945) that temporary sterility of the ewes
may have resulted in Nevada because of over-breeding by the rams.
Rush (1942) also proposed the theory that excessive service by
the rams may cause sterility.
The earliest actual breeding which was observed during this
study was on November 17. The intensity and frequency of rutting
activities reached the most fevered pitch around the first of Decem-
ber. Breeding activities tapered off during the latter part of
December, and copulation was not observed in January.
Physical Effects of the Rut
Mountain sheep are in excellent condition when they return
from summer pastures. But much of this physical well-being is
lost during the rut. The outburst of courtship and breeding activ-
ity, carried out over the most rugged terrain, is physically exhaust..,
ing. Less time is devoted to eating and numerous injuries are sus-
tained.
Rams, moving from one herd to another and constantly alert
for receptive females, undoubtedly expend more energy than the
ewes. Y et the exhaustion and abuse suffered by the females during
an unrelenting chase by several males, may result in as much
physical depletion as experienced by the rams. Excluding serious
injury, however, neither sex is truly in poor condition at the end of
the rut.
It is possible, however, that the frequent injuries and occa-
sional deaths directly related to rutting activities are of less im-
portance to productivity of the herd than the psychological dis-
turbances that may be incurred. Considering the relationship of
-58-
r i
a healthy psychological atmosphere to fertility among humans,
it would seem that the excessive fatigue and excitement visited
upon the ewes by their suitors might induce a temporary condition
of sterility. This is mere conjecture, but it "reasons well" and
deserves future attention.
Lamhing Ranges
Lambing ranges all embody similar characteristics. One corn-
mon requisite is that all areas be precipitons and liberally covered
with cliffs and rock outcroppings. The protection afforded the
lambs from predators would seem to be the motive behind selection
of these topographical features. The warmer and drier southerly
exposures were the only ones where very young lambs were ob-
served. The physiography of each particular range determined the
location and elevation of lambing areas. Where cliffy terrain is
available at low elevations, lambs may be born within a few hun-
dred feet of the river. On other ranges suitable lambing habitat
might be situated halfway between winter and summer range.
Lambing grounds were close to a good supply of forage in all
cases, but the distance from water did not appear to be significant.
Figure 14 was photographed from the head of a "chute" which
drops 1,500 feet to the Salmon River below. Average slope from
top to bottom is 70 percent. The area in the left foreground is well
covered with bluebunch wheatgrass and Idaho fescue. Smallledges
and crevices among the rocks support scattered mountain mahog-
any and fairly dense stands of wheatgrass. The grassy area in the
left foreground was observed to be a favorite playground for lambs.
Ewes with lambs were observed among these cliffs during four
consecutive seasons. The following counts show the maximum
number of lambs counted each spring:
May 20, 1949-6 ewes and 7lambs
June 6, 1950-8 ewes and 8lambs
May 29, 1951-7 ewes and 7lambs
May 27, 1952-9 ewes and 8lambs
Birth and Early Activities
A few workers believe the gestation period of mountain sheep
to be 150 days in length, but the majority agree that 180 days is
more nearly correct. In this study the earliest observation of actual
breeding was on November 17, 1'949. The earliest date that lambs
were recorded was on May 15, 1950, when two lambs estimated to
be two days old, were seen. Each season of the study the breeding
-59-
FIGURE 14. Lambing range on a southern exposure overlooking
the Salmon River.
June 1950
intensity was greatest around December 1 and the peak of lamb-
ing occurred between May 15 and June 1. These observations would
indicate that the gestation period is 180 days or slightly less.
Twin births are exceedingly rare among bighorn ewes in
Idaho. Several times it seemed that twins had been located
when suddenly another ewe would appear to claim the extra lamb.
There were only two instances out of 215 observations of ewe-lamb
groups in which there was one more lamb than ewes. In both cases
the observation had been prolonged for more than two hours. Twin-
ning may, and probably does occur, but not in sufficient instances
to materially affect productivity.
Lambs scamper after their mothers with astonishing speed
and stamina when only a few days old. Throughout the early part
of the summer their coats are noticeably lighter in color than
those of the adults. The rump patch is less distinct and there is
a dark stripe down the back. By the middle of September the rump
patch becomes clearly visible, the dark stripe ali but disappears
and the coat co lor becomes very similar to th at of ad ul ts.
Lambs were seen nibbling at vegetation a few days after they
w.ere born. The exact diet was difficult to ascertain, but their nib-
blings included ali classes of forage. Mother's milk probably re-
mains the staple dietary item un til the lamb is weil past two months
of age. A lamb nurses ravenously, sometimes butting the ewe's
-60-
1
l
udder vigorously. The discomfort th us inflicted must at times over-
come mother instinct, as the ewe frequently kicks at her offspring
-an effective means of termina ting the feeding period. The lambs
were never found to stop suckling voluntarily. Very young lambs
were observed to suckle at intervals of approximately 30 minutes.
Gradually the feedings became more and more infrequent. Lambs
observed late in July went more than four hours without nursing.
The age at which lambs are weaned seems to vary widely.
Gaufin and Ellis (1941) observed nursing on the Stoddard Creek
range as late as September 23. Coüey (1950) gives the latest nurs-
ing date observed in Montana as October 21. Honess and Frost
(1942) state that in Wyoming, ewes did not start weaning the
lambs until January or February. The latest suckling observed
during this study was on September 13. Many hours were spent
each year observing ewe-lamb groups during the N ovember-Decem-
ber rutting period. Not a single case of nursing was observed at
that time. It may be concluded from this that lambs in the Salmon
River country are weaned before they are six months old.
Gregariousness of lambs becomes evident after they are one
or two weeks old. Whenever two or more lambs were present in
a group, they appea'red to exhibit more affinity for one another than
for their mothers, usually bedding and playing together. Play
routines of these youngsters are zestful and amusing to watch.
Much of their gamboling takes the form of butting and pushing,
and group games are frequently engaged in wherever lambs
congregate. At one time eight lambs were observed playing "fol-
low-the-leader" for several minutes. They bounded recklessly over
rocks and down precipitous slopes at breath-taking speed. Once,
four of them broke away to chase each other around a large tree
for several revolutions. One ewe remained near the lambs all the
while they were playing. She grazed a little but spent more time
watching her charges. Seven other ewes grazing nearby did not
show the slightest interest in the lambs.
-61-
FOOD HABITS
Methods of Study
The food items and forage classes utilized by bighorn sheep
were determined by six methods: 1) direct observation of feeding
animais, 2) band trailing, particularly in winter, 3) careful inspec-
tion of restricted areas immediately after observed feeding, 4) for-
age utilization transect studies (summer range), 5) linear measure-
ments of twigs before and after use (winter range) and 6) analy-
sis of stomach samples taken from ali bighorn found dead.
A total of 488 feeding observations were made during the
study. Each feeding observation indicates only that sheep were
feeding upon a particular class of forage when observed. An obser-
vation might either consist of one animal or a group of several
animais. Species of plants being fed upon were recorded whenever
they could be recognized. Of 341 observations of feeding on grass
or forbs only 122, or 36 percent, could be identified as to species
being used. One hundred and twenty-two, or 92 percent of the 132
browsing observations, could be classified as to species taken.
Band trailing was an effective means of determining forage
preferences, particularly when there was snow to facilitate track-
ing. At times it was feasible to inspecta restricted area immedi-
ately after it had been vacated by a herd of feeding sheep. Compo-
sition of the vegetation was estimated and recorded. Plants eaten
were noted and the degree of utilization of each species was esti-
mated. Twenty 2 x 50 foot transects were studied in the same man-
ner. The twig measurement method, used to study browse utiliza-
tion on the win ter range, is described in Part II.
General Account of Food Preferences
That the bighorn's appetite is versatile has been shown in
several studies. Their diet is generally conceded to favor the more
succulent and tender forms of foliage, but in times of adversity an
amazing assortment of items may be eaten. Couey (1950) reports
that the stomach of a very old ewe that died in February contained
30 percent grass and 70 percent material which appeared to be
dry duff, composed of twigs, soil, dry fir needles, bearberry leaves,
sage and miscellaneous roots. Eight stomach samples collected
by Honess and Frost (1942) contained a wide assortment of
grasses, forbs and shrubs; and even traces of fir, pine, spruce and
juniper needles.
-62-
,.
On Idaho ranges bighorn diet is composed of considerably
more grasses and forbs than browse. In only about one-third of
the feeding observations was it possible to identify herbaceous
species being taken, but usually grasses could be distinguished
from forbs. Evidence of the study pointed out that substantially
more grasses and grasslike plants than forbs were being consumed
the year around.
Various methods for studying mountain sheep food habits
have been employed by other investigators with comparable
results. Over a dozen studies have been reviewed in which grass in
the diet varied from 60 to over 90 percent. Murie (1944), examined
75 Dall Sheep stomachs in Mount McKinley National Park, Alaska,
and found the contents to average 81.5 percent grass; these stom-
achs were collected in fall, win ter and early spring. Cowan (1947),
basing his information on 4,060 animal minutes of feeding, reports
the December diet of bighorn in Jasper National Park, Alberta, as
83 percent grasslike plants, 10 percent forbs and 7 percent shrubs.
In Montana, Couey (1950) found that the stomachs of 6 sheep
dying in late fall and winter contained an average of 63 percent
grass, 14 percent weeds, 17 percent browse and 6 percent miscel-
laneous.
During the course of this study, stomach samples were col-
lected from five bighorn sheep which were found dead. Contents
of these stomachs are shown in Table 2. Identification and quanti-
tative analysis of food items was made under the supervision of Dr.
Edson Fichter, Idaho State College at Pocatello, Idaho (Fichter,
1953).
Table 2. Contents of five big horn sheep stomachs collected on
Salmon River ranges in Idaho.
Principal food items (in percent)
=» "' ' Month of Description ·~ = = ·~ "' .,., 0"'
...,
dea th of sheep til "'"'bll ... ~ =._,
oS =o .!~ ~~ Remarks ... =-= ·~ ... 1;.!) o., ="'"' = :;;::= 0 ~ u
February ram 40 60 Trace Died a lingering death after
falling in rockslide.
April ram 95 5 Trace Also trace of barberry.
Died in fall from cliff.
August lamb 85 8 5 Also 2 percent willow. Believ-
ed killed by falling rocks.
September lamb 100 Died from unknown cause.
Unknown undetermined 80 Trace 7 13 No skull for determination of
sex. Identified by hair.
-63-
WIN TER
DEC. 16
to
MAR.I5
GRASS
GRASS·UKE
PLANTS
AND
FORBS
56%
BROWSE
39%
MOSS a LICHENS
~%
SPRING
MAR.I6
to
JUNE 30
GRASS
GRASS-l.IKE
PLANTS
AND
FORBS
77%
BROWSE
22%
r«'SS f\IJ.GHENS
SUMMER AUTUMN
JULY 1
to
SEPT. 30
GRASS
GRAS&-LIKE
PLANTS
AND
FORBS
86%
BROWSE
14%
OCT. 1
to
DEC 15
GRASS
GRASS-LIKE
PLANTS
AND
FORBS
66%
BROWSE
25%
MOSS. a LICHENS
9%
AVERAGE
YEAR· LONG
GRASS
GRASS·LIKE
PLANTS
AND
FORBS
70%
BAOWSE
27o/0
MOSS a LICHENS
3%
FIGURE 15. Forage classes utilized by bighorn sheep on Salmon
River ranges, May 1949 -September 1952, as determined by 488
feeding observations. A group feeding on one class of forage was
recorded as (1) observation.
Figure 15, showing a win ter diet of 56 percent grass and forbs,
reftects the increased dependence of bighorn upon shrubs at a
time when smaller plants are buried under the snow. Nevertheless,
the fact that more than one-half of the winter diet is herbaceous
-64-
FIGURE 16. Snow trenches where bighorn sheep have been pawing
through about 18 inches of snow to feed on grasses and forbs. The
trails above show the bighorn's characteristic of contouring across
the slope when feeding.
January 23, 1952
testifies to the desirability of such plants. Because the importance
of winter feeding habits requires more than brief treatment, Part
II of this bulletin contains a detailed discussion of the effects of
snow, weather, exposure, vegetation types and other factors.
Food habits undergo rapid changes early in the spring. The
consumption of grasses and forbs increases markedly, averaging
77 percent for the spring season as indicated by observation of
feeding animais. Cheatgrass is relished for three or four weeks,
then completely dis-regarded when it becomes mature. Idaho fescue
appears to receive more early use than bluebunch wheatgrass.
Balsamroot is one of the most favored species while in its early
stages of growth. On April27 the writer observed four rams feed-
ing for two hours on a hillside. The slope was visited immediately
after their departure and it was discovered that they were feed-
ing exclusively upon shoots of balsamroot. Fifty-two of these
plants were counted in a circle having a 20 foot radius. All had
been grazed nearly flush with the ground.
The summer diet of 86 percent herbs is made up largely of
grasslike plants and forbs. Transects studied on Bighorn Crags
summer ranges, where sheep had been observed feeding, revealed
the following plants to have been utilized: bluegrasses, rushes,
little ricegrass , sedges, woodrush, spike trisetum, tufted haïr-
grass, western ryegrass, and Penstemon. These forage plants
-65-
are listed in order of decreasing numbers taken. Band trailing
and direct observations of feeding substantiated the importance
of sorne of the plants listed above. As determined by these
methods, sedges, rushes and little ricegrass seemed to receive
the most summer grazing pressure. lt is of interest to note
that rushes are not generally mentioned as food items for bighorn
in other parts of North America where investigations have been
conducted. However, Godden and Gutzman (1938) also found that
rushes received considerable use on the same high country ranges
that were investigated in this study.
Table 3. Bighorn feeding habits as determined by direct
observation. As considered here, an observation may represent
either an individual or a group.
Food Item
Number of Observations
Win ter Spring Summer Fall Total
Grass-Grasslike Plants-Forbs
Bluebunch wheatgrass 20 28 6 15 69
Idaho fescue. 7 5 2 14
Arrowleaved balsamroot . 1 8 1 lU
Sedges .. 7 7
Rushes 4 4
Goat's beard. 1 1 1 3
Horsetail 2 2
Hawkweed 2 2
Eriogonum 2 2
Cheatgrass . 2 2
Little ricegrass 2 2
Woodrush. 1 1
Pen stem on 1 1
Junegrass 1 1
Vetch 1 1
Thistle 1 1
Browse
Curlleaf mountain mahogany .. 35 31 2 10 78
Big sagebrush. 11 1 12
Rubber rabbitbrush. 6 1 7
Spiny greasebush. 3 2 5
Syringa . 3 1 4
Golden currant. 4 4
Bitterbrush 1 2 3*
Western chokecherry. 1 1 2
Rose 1 1
Willow 1 1
Labrador tea 1 1
Haplopappus 1 1
Small-leaved huckleberry . 1 1
Snowbrush . 1 1
Aider . 1 1
Moss and Lichens
Moss and Lichens 8 5 2 15
* Bitterbrush was present on less than half of the winter ranges studied;
consequently, this number does not reflect the true importance of bitter-
brush wherever it was present.
-66-
FIGURE 17. Utilization of balsamroot by bighorn sheep. A herd
of 14 sheep was observed feeding at the site of this picture. More
than 100 plants, within an area of about one acre, had been dug out
and eaten in their entirety. A ewe was frightened away from the
· large roots shown above. The root on the left has been shredded
as the ewe attempted to jerk it from the ground with her teeth. The
amount of soil removed by pawing can be appreciated by looking
at the root on the right.
March 15, 1952
Consumption of grasses and forbs decreases again in the
fall when they become dry and apparently less palatable. A factor
which accounts, at least in part, for the increased use of browse
is that over three-fourths of the animais observed during the fall
period were occupying northerly exposures. North-facing slopes
characteristically produce more shrubs than are found on southerly
aspects, and this undoubtedly has sorne effect upon bighorn feeding
habits.
Mineral Requirements
Mineral licks are scattered over summer and winter ranges
throughout the Salmon River watershed. As far as has been deter-
mined, naturallicks are substantially outnumbered by those that
have been artificially salted. Often, licks thought to be natural
were discovered to have resulted from earlier salt placement by
stockmen, packers and Forest Service or Fish and Game Depart-
ment personnel.
Five natural licks on the Middle Fork river were analyzed
(Gaufin and Ellis, 1941) and found to contain an average of 900
-67-
FIGURE 18. Four ewes visit Sammy Gulch Salt Lick. They are part
of a herd of 31 bighorn. The entire herd came to the lick while the
author was sitting on a rock only 25 feet away. This lick was
artificially salted a few years ago. A soil sample collected in 1951
tested 574 p .p .m. total salts.
M arch 28, 195 1
parts per million of water soluble salts. Soil from each of four
artificial licks was analyzed during this study. Soluble salts in
these samples ranged from 575 to 800 p.p.m. Although still ac-
tively used, none of these licks had been replenished with salt
for several years. In 1949 a lick was started on Stoddard Peak by
a herd of bighorn. No s a lt had been placed on the site. Mineral
content of the s oil, as determined from several samples, averaged
250 p.p.m. On the Middle Fork winter range, samples of normal
soil taken from an open, southerly exposure contained only 70
p.p.m. of water soluble salt. None of these soil analyses indicate
high concentrations of minerais. Many good garden soils, as a
matter of fact, contain more than 1,000 p.p .m. of soluble salts.
Lack of minerais in the soils of these granitic ranges warrants the
speculation that plants growing in them may be low in mineral
content.
The avidity with which the bighorn seeks minerais appears to
exceed that of other big game animais on these ranges. Early
spring is the period when eagerness for minerais is most pro-
nounced, but a desire for saline materials is evident throughout
the year.
-68 -
Animais often were observed urinating in salt licks. The pres-
ence of urea is presumably a factor encouraging use of licks, years
after artificially supplied salt has been consumed. An interesting
sidelight in this regard was encountered during the summer of 1950
when the study headquartered in a high mountain meadow for a
month. The men in camp urinated each morning from the top of
a low cliff. In a short time a buck deer began coming in to eat the
urine saturated soil. By the end of a month a sizable hole had
been dug at the base of the cliff and the deer would be waiting
each morning as the supply of urine was replenished. Two years
later the writer returned to find this "lick" was no longer being
used.
An aerial salting program is employed in Idaho to place 50
pound blacks of sodium chloride on summer and intermediate
ranges. Mountain sheep locate and begin utilizing this salt with
surprising promptness. Sorne of the local drift in summer seems
to be infiuenced by the presence of salt. The actions of non-
migrating bighorn suggest that their habit of frequently visiting
licks at low elevations during the summer may be a factor in-
fluencing them not to migrate.
Limited experimentation was conducted to determine the pref-
erence, if any, of bighorn sheep for various compounds. Two
"mineral cafeterias" were established on the Middle Fork of the
Salmon River ranges in 1952. This technique for studying mineral
Table 4. Bighorn sheep and deer use of different minerais at
Short Creek and Sammy Gulch cafeterias. Ali samples weighed 96
ounces when cafeterias were established.
SHORT CREEK SAMMY GULCH
CAFETERIA CAFETERIA
(Established Feb. 11, 1952) (Established April 1, 1952)
Actual Weight Est. Weight Actual W eight Est. W eight
Compound May 23, 1952 Sept. 20, 1952 May 23, 1952 Sept. 20, 1952
Na! .......... 6*(t) 3* 37* 10*
NaHzPO •........ 35* 15* 74 60*
NaCI ........... 59* 40* 5.9* 50*
HzSO, .......... 79 destroyed 78 no use
Fe SO •. 7Hz0 ... 79 no use 76 "
KCL ............ 78 " 73
MgCh. 6Hz0 ... 79 " 73
CaClz . 6Hz0 .... 80 " 75
cuso •.......... 78 " 75
CoClz . 6Hz0 .... 55* 40* 75
Untreated soiL ... 81 no use 80
* Use evident as determined by examination of samples.
t A second 96 ounce sample of Na! was placed in the Short Creek cafeteria
on May 23, 1952.
-69-
FIGURE 19. This "mineral cafeteria" is constructed of poles. These
support the waxed cardboard containers into which the mineral
samples were placed. Each compound was dissolved in one pint of
water. Five pounds of soil were then saturated with this mineral
solution. Untreated soil served as the control.
Apr il 5, 1952
preference was adopted after consultation with E. L. Cheatum
and D. S. Stockstad of the Montana Cooperative Wildlife Research
Unit.
The first cafeteria was established in the Short Creek drainage
on February 11, 1952. The second one was set up near Sammy
Gulch on April 5 of the same year. At each cafeteria five grams
of sodium chloride and the equivalent ionie weights of nine other
chemically pure compounds were placed in a pint of water and
mixed with five pounds of soil taken from the cafeteria site. Each
sample of mineral-saturated soil weighed 96 ounces when it was
placed in the containers. The experiment tested preference for
the following elements:
Calcium Copper Iron Phosphorus Sodium
Cobalt Iodine Magnesium Potassium Sulfur
The samples were re-weighed on May 23, 1952. At this time
sodium iodide had been so heavily used in the Short Creek cafe-
teria that a new sample was supplied. The weights recorded in
Table 3 cannot be considered on a strictly quantitative basis since
the amount of moisture added by rain and snow, and the moisture
!ost through evaporation, were not the same for each container.
This was because differing amounts were consumed from the
various samples and sorne containers became tipped in such a
manner that they caught more precipitation than others. It is
not significant that ali of the samples fall below the original 96
ounces since they were much drier when re-weighed than when
-70-
the cafeterias were established. Samples were checked a second
time on September 20, 1952. At this time scales were not avail-
able, so estimated weights of the mineral-saturated soil remaining
in the containers had to be relied upon.
Populations of bighorn sheep and mule deer were about equal
at both cafeteria sites. Elk and mountain goats did not occupy
these ranges during the experimental period, and deer were absent
after the middle of May. Therefore, it is believed that the major
use was by sheep.
Table 4 shows that each compound containing the sodium ion
was taken to sorne extent and the sodium iodide sample received
the greatest amount of use. This preference for sodium appears
to support the findings of Stockstad and his colleagues on Montana
ranges (Stockstad, et. al., 1953). Only one non-sodium compound,
cobaltous-chloride, was utilized, and this in limited quantities at
one cafeteria. This compound also received light use in the Mon-
tana study. Whether or not these preferences indicate a physio-
logical need is an unanswered question, however.
-71-
DISEASE AND PARASITES
Many theories have been advanced in an attempt to explain
the causative agents responsible for bighorn mortality. Foremost
among these is the belief that parasites and disease are major
factors. Strong evidence of what now appears to have been Scabies
epidemies in the late 1800's and early 1900's, indicate that the
infecting Psoroptes mite may have been largely responsible for
the initial decline of mountain sheep herds. It should be stressed,
however, that so-called "epidemies" often have many con tribu tory
factors, including prolonged adverse weather, malnutrition and
over-crowded range conditions. N ormally healthy sheep are com-
monly infected with both internai and external parasites without
noticeable harm. The infestation may become debilitating, how-
ever, if there is simultaneous and prolonged exposure to one or
more of the conditions described above.
For the past several years, there has been little incidence
of disease reported. Few unthrifty bighorn sheep were observed
during the study, but disease and parasites may have contributed
to dea th in sorne cases where the cause or causes were not definitely
established. Vigorous scratching or rubbing of nearly all parts
of the body was commonly witnessed, particularly in late winter
and early spring. This, along with the frequent occurrence of
magpies pecking on sheep, suggests the presence of irritating
external parasites.
An old ewe from a subalpine range in the Bighorn Crags was
collected on August 15, 1950, for the purpose of autopsy. Dr.
Charles L. Davis of the Bureau of Animal Industry Pathological
Laboratory in Denver examined lung and li ver sections and reports
as follows (Davis, 1950) :
On section the areas of consolidation in the lung were found to be
due to extensive parasitic infestation in the bronchi and in the lung
parenchyma of a nematode, probably Muellarius capillaris. The liver
section shows chronic inflammation and proliferation of the bile ducts
resulting from the cestodes found in the liver.
The cestodes were tentatively identified by Mr. Mclntosh of the
Agricultural Research Center in Beltsville, Maryland, as the tape-
worm Wyominia tetoni.
Between July 1949 and August 1951, 229 fresh droppings
samples were collected from several bighorn sheep herds in Idaho.
Analysis of fecal specimens for endoparasites was made by Dr.
Stewart C. Schell of the University of Idaho (Schell, 1954).
A sedimentation method was used to examine the droppings,
which had been preserved in a 5 percent potassium dichromate
-72-
solution. In this method the feces are soaked in water, then mashed
and strained through cheesecloth into a 500 c.e. sedimentation
cone. Solid matter settles and the supernatant fluid is poured off.
After this decanting process bas been repeated a second time,
the sediment plus sorne water is poured into a 10 c.e. cone. One
hour later two to three drops of sediment are drawn from the
cone with a pipette and this sample is placed on a slide for exami-
nation under the 32 rn.rn. objective of a microscope.
Most of the infected specimens contained a few parasites, us-
ually less than a half dozen eggs, oocysts or larvae in the 2 or 3 drop
samples inspected. Only 15 specimens, or seven percent, were
regarded as being heavily parasitized. Eleven of these were
infected with lungworrn larvae, Protostrongylus sp., and four
contained the oocysts of a coccidial parasite, Eimeria arloingi. A
specimen was considered heavily infected if one to four larvae
or oocysts could be seen in each field of the microscope as the slide
was moved across the stage.
Packard (1946), reporting the results from bighorn pellets
analyzed by a sugar-flotation method, scaled parasite presence in
one drop of sugar solution as follows: 1 to 5, light; 5 to 25, mod-
erate; over 25, heavy. Many of the specimens which he collected
in Rocky Mountain National Park, Colorado, were judged as
moderately or heavily infested by these standards. Couey (1950)
commonly found severa! dozen lungworm larvae in each field of
the microscope when he examined bighorn droppings gathered
on the Sun River range in Montana. By comparison, then, it
would seem that the most heavily parasitized bighorn feces col-
lected during the current study actually represent only light
infestation. However, it is a difficult matter to translate abund-
ance of parasites in fecal material into terms of harmfulness to
the host animal. At best, the results from limited samples, such
as the one reported here, can furnish only enough information to
warrant generalization.
In 7 4 instances, samples were gathered from mountain sheep
that were observed defecating. The sex, age and apparent condition
of these individuals was recorded for future correlation with
results from examination of their feces. These data were analyzed
in a number of ways to compare the relationship of sex and age
to degree of infestation. No significant differences were detected
among rams, ewes and yearlings. But lambs were freer of endo-
parasites than older animais. This would be expected, however.
ûnly three out of 13, or 23 percent, of the lamb feces collected
in July and August harbored parasites. Ali three infected samples
-73-
contained Eimeria arloingi. Species of Eimeria are the causal
agent of hemorrhagic coccidiosis in cattle, swine and domestic
sheep. Udall ( 1943) reports that coccidiosis is typically a disease
of the young in domestic livestock, with most cases in cattle
occurring between the ages of four months and two years. The
disease may reach epidemie proportions where animais become
concentrated. Although moderate numbers of coccidian oocysts
may be harbored without apparent ill-effects, heavy infestations
have been known to kill large numbers of juvenile domestic
animais in a short time.
Lungworms in addition to coccidia, were found in only one
lamb fecal specimen. This was collected on August 2 when the
animal was probably about two months old.
Table 5 summarizes, by herd areas, the percent of samples
infested by each kind of endoparasite found in bighorn fecal
samples. The comparatively low incidence of parasites, and the
light infestation of those feces containing eggs, larvae or oocysts,
indicates that debility caused by parasite-induced pathologies is
unlikely. Only 50 percent of the 229 specimens collected held
lungworm larvae. Couey found from 75 to 100 percent infestation
among Montana bighorn herds. Average occurrence of lungworm
in 360 droppings samples which he collected on the Sun River
range was 85 percent. It is interesting to note that Gaufin and
Ellis (1941) found lungworms in only 52 percent of 68 fecal
specimens collected from the Stoddard Creek herd along the
Middle Fork of the Salmon River.
Lungworm infestations ranged from 35 percent in January
to 93 percent in February, but these percentages are based on
small samples, 11 and 15 respectively, and are not reliable indi-
cators of true conditions. Samples taken during the remaining
months of the year varied only slightly from the mean of 50
percent. To truly measure any seasonal fluctuations that may
exist, it would be necessary to collect greater numbers of samples
from the same herd during each month of the year.
Flies were frequently observed annoying the sheep on sum-
mer ranges. Twelve species of gnats and flies were collected in
the Bighorn Crags during the summer of 1950. Nine of these
species were identified by Dr. C. B. Philip of the Rocky Mountain
Laboratory in Hamilton, Montana (J ellison, 1950). The other
three were classified by Dr. Alan Stone of the National Museum,
Washington, D.C. (Stone, 1950). Eight of the flies were members
of the sub-family Tabaninae, commonly known as horseflies. One
deerfly, Chrysops pertinax, was identified. Two species of Simu-
-74-
r----~--~------~-
-.:]
01
1
Table 5. Parasites found in 229 bighorn sheep fecal specimens collected on Salmon River ranges between
July 1949 and August 1951.
PERCENT OF SAMPLES CONTAINING PARASITE
SUMMER RANGE:
Bighorn Crags ...........
WINTER RANGES:
Cramer Creek ............
Clear Creek ..............
Middle Fork, above Big
Creek .................
Number of
sam pies
87
64
37
18
Corn Creek to Dwyer Creek,
Salmon River ....... 12
East Fork ............... 11
Average percent infestation
in al! samples ............
Tapeworm Whipworm
(M oniezia ( Trichuris
Lungworms1 benedeni) ovis)
60 6 3
34 25 17
60 3 16
44 6
42 33 8
36 18
50 11 10
Stomach Worms Pinworm
(Ostertagia (Skrjabi-Ail
Coccidia2 marshallia) nema ovis) parasites
IH 1 2 63
6 :J 58
11 62
44
58
27 64
10 3 1 60
1 Three types of lungworm were identified, and were found in the following number of droppings: Protostrongylus sp. (possibly
P. rushi)-109; P. rufescens-2; Muellerius minutissimus-2.
2 Two coccidia were identified, and found in the following number of droppings: Eimeria arloingi-18; andE. granulosa-5.
liidae, snipe flies, and a buffalo gnat Symphoromyia atripes, com-
plete the collection. Simulium arcticum, one of the Simuliids
collected, is reported by Twinn (1947) as having caused the death
of 94 cattle and 39 other farm animais, and the brief but serious
illness of many more. A textbook on medical entomology states
that another species of Simulium was responsible for the death
of over 16,000 horses, mules and cattle in Rumania severa! years
ago. Scores of deer and other big game were killed at that time.
Actual loss of blood was reported as the probable cause of the
deaths.
In this study the oldest and the youngest animais were found
to be least able to resist adverse environmental influences. Old
rams and ewes, and yearlings and lambs were often thin, even
emaciated, by early spring. Severa! times animais in this condition
were followed by the author. The difficulty with which they
breathed after only slight exertion attested to their weakened
condition.
In attaching significance to physical condition in the spring,
it is weil to point out that wild game, as opposed to domestic stock,
are seldom sustained by wholly adequate winter diets under even
the most favorable range conditions. Moderate numbers of para-
sites may infest perfectly normal animais. Consequently, observ-
ers should be cautious about diagnosing thin or heavily parasitized
big game as "abnormal" when the condition is detected in late
winter or early spring. Healthy individuals will generally recover
with the improvement of forage supplies and weather conditions.
-76-
PREDATORS
Cougar
Considered as an individual, the cougar is an important
predator on bighorn sheep in Idaho. His agility and size, combined
with his habit of seeking prey in rough terrain, are characteristics
that cause him to be potentially dangerous to bighorn populations.
Mr. Willard Rood, Jr., a rancher and former state trapper, reports
an incident which occurred severa} years ago when he trailed a
cougar to the freshly uncovered carcasses of six bighorn sheep
that were previously cached. A few cougar-killed bighorn were
reported in Banff National Park by Green (1949). Mr. Green
reporting an 11 year study of the bighorn, cites three instances
of observations of a cougar stalking or pursuing a group of ewes
and lambs. The sheep successfully eluded the big cat on each
occasion.
Cougar have been hunted quite consistently for many years
in the Salmon River watershed and their numbers have not
reached alarming proportions. However, in recent years high
wages have enticed many part-time bounty hunters to more lucra-
tive means of earning a living. This may account, at least in part,
for recent reports of increased numbers of these huge cats.
Bounties formerly were paid in only part of the state. They were
made statewide in 1953, which may revive wider interest in cougar
hunting.
From the standpoint of abundance of large prey-particularly
deer-and the general difficulty in keeping total game numbers
within range capacities, a moderate cougar population appears
desirable. It must be considered too, that a number of people hunt
this animal primarily for sport. However, there should be no
hesitation to destroy individual cougars whenever there are
reliable reports of specifie predation upon bighorn herds.
Coyotes
Coyotes are by far the most numero us of the predators occupy-
ing bighorn ranges, and there are reliable reports of their predation
upon mountain sheep. Therefore, considerable effort was made to
collect data concerning the importance of the coyote as a sheep
killer. The collection and analysis of coyote droppings was one
of the techniques employed.
Inspection of Table 6 indicates that bighorn sheep are rela-
tively unimportant in the diet of the coyote, being found in 2.8
-77-
Table 6. Classification of 937 occurrences of food items in
687 coyote droppings collected on Salmon River ranges-May 1949
to September 1952.
Droppings Droppings
in which food in which food
item occurred item occurred
Food Items ... No. Percent Food Items No. Percent
Large Mammals Birds
Deer ......... 412 60.0 Grouse ...... ........ 46 6.7
Bighorn ...... 14 2.1 Non-game bird ....... 10 1.5
Bighorn lamb. 5 0.7 Eggshell .. .......... 6 0.9
Horse .... 1 0.1 Owl ........ 1 0.1
Magpie ... .......... 1 0.1
Small Mammals Others
Meadow mouse ....... 116 16.9 Grasshopper .... 31 4.5
Rab bit and Hare ..... 106 15.4 Snake ............ 16 2.3
Pocket gopher .. 37 5.4 Lizard ....... 4 0.6
Ground squirrel . 32 4.7 Grass ....... 2 0.3
Marmot .......... 27 3.9 Sedge ...... 2 0.3
Pine squirrel .... 24 3.5 Ribes. 2 0.3
Packrat ........ 17 2.5 Beetle ...... 2 0.3
Chipmunk ....... 9 1.3 Ponderosa pi ne ....... 1 0.1
Porcupine. 8 1.2 Ant ................. 1 0.1
Beaver .... 1 0.1 Corn ....... 1 0.1
Mole ..... 1 0.1 Leather strap. 1 0.1
percent of the droppings. Deer, providing the largest single food
supply, was. recorded in 60 percent of the scats. The remains of
small mammals were found in 55 percent of ali droppings collected.
By studying the dates and locations of the 19 sheep-containing
scats collected (Table 7), it can be seen that probably not more
than eight carcasses are represented. In three areas where scats
containing sheep remains were collected, a bighorn was known to
Table 7. Summary of 19 bighorn occurrences in 687 coyote
droppings.
No. of
Date droppings Location
7-31-49 3 Salt lick near Stoddard Lookout
3-23-50 1 Wilson Creek Ford, Middle Fork
River
4-18-50 6 Between mou th of Middle Fork and
5 -3-50
5 -5-50
6-13-50
4 -6-51
5-20-51
4 -6-52
1
3
1
2
1
1
Color Creek
Cramer Creek, Salmon River
Between mou th of Middle Fork and
Color Creek
Dry Gulch on Panther Creek, Sal-
mon River
Stoddard Creek, Middle Fork River
Horse Creek, Salmon River
Wilson Creek, Middle Fork River
-78-
Remarks
Lamb. Snake in one scat
One occurrence each of
marmot, meadow mouse
and rabbit
Also rabbit
Lamb
Also rabbit
have died from causes other than predation. How much of the
remaining ingested material was carrion and how much was from
kills is, of course, mere conjecture.
Significance may be attached to 230 droppings that were
gathered in May and June. Most of the lambs were born between
May 15 and June 15. These months, then, would seem to be the
time when the young would be most vulnerable to predator attack.
Y et lamb remains were absent entirely from droppings collected
during this period.
Coyotes were observed hunting in the vicinity of mountain
sheep on several occasions, and a few times were seen actually
stalking them. Ordinarily, groups of a half dozen or more sheep
would watch nearby coyotes with interest but without outward
manifestation of fear. If approached directly the sheep would
band together before fteeing to the nearest cliffs where they re-
mained alert until the danger had passed. On a few occasions one
or two coyotes were seen stalking young animais or ewes and lambs
detached from larger groups. In these cases the sheep sped to their
companions. Then, emboldened by safety in numbers, the entire
herd would present a common defiance that discouraged further
pursuit.
Many trappers and long-time residents of the Salmon River
back country were interviewed regarding their observations and
opinions relative to the extent of coyote predation upon bighorn.
Although there was not complete agreement, the general opinion
was that coyote predation is a relatively unimportant drain on
bighorn populations.
The over-abundance of deer inhabiting many bighorn ranges
constitutes a valuable buffer for the sheep. However, it is con-
ceivable that sharp reductions in deer numbers would increase
coyote pressure on the bighorn. Then, because of their limited
population, bighorn sheep might need protection in the form of
local coyote control. But, aside from this, the status of coyote
predation on the ranges studied is aptly described in the following
statement by Craighead (1951, p. 22), "On wildlife lands where
economie returns are slight, the natural regulatory control exer-
cised by predators on their prey constitutes a harmonious relation-
ship that cannot be improved on by man."
Eagles
The golden eagle is common throughout the central part of
Idaho. Bald eagles also are present but were observed only
-79-
occasionally on mountain sheep ranges. Because of the contro-
versial nature of their relationship to the young mountain sheep,
these raptors were closely observed.
Eagles frequently were seen soaring high above sheep ranges
in ali seasons. In 123 instances they were observed flying near
the ground in search of food. Eight were frightened away from the
carcasses of deer. It did not appear that the eagle had made the
kill in any of these cases. On six occasions eagles were observed
swooping over or diving at groups of bighorn. Their presence did
not elicit more than casual watchfulness on the part of the sheep,
unless they approached suddenly and without warning.
It is not desired to make light of the possibility of eagle
predation. There are verified cases where golden eagles attacked
and killed big game animais. Kennedy (1948), in New Mexico,
discovered a golden eagle feeding upon the carcass of a bighorn
lamb. The body was still warm and tracks nearby indicated an
attempt by the ewe to protect her young. Casebeer, et al. (1950)
reported observing a bald eagle in Montana out-feint a mountain
goat nanny in order to grasp her kid and soar away, with the
kid dangling helplessly in its talons. Other instances can be cited
of actual observations of eagle predation on big game.
Early investigations of the relationships of various big game
species to eagles often gave much credence to tales of extensive
killing of large mammals by these birds. Then, as a background
of creditable observations was accumulated, researchers became
more critical of "hearsay" evidence. Nests were located in many
states and Alaska. The birds were observed as they fed their
young and the contents of their nests were examined. Thousands
of man-hours were spent observing eagle activity. Little by little,
it became evident that the eagle's diet was composed largely of
rodents and small game, and that most of the large prey consumed
was in the form of carrion. The same holds true in Idaho where
the bulk of the evidence indicates that a program of eliminating
eagles would not be a panacea for our problems.
Other Predators
The importance of bobcats as predators on sheep was not
established during the course of this study. There is little question,
however, that bobcats are capable of capturing bighorn sheep.
But these cats are not numerous on the ranges studied and their
scarcity would seem to exclude them as serious predators. Never-
theless, it is of interest to note the importance of large prey in
-80-
their diet as shown by Latham (1950), who reports two Vermont
studies of bobcat food habits. One study lists deer as comprising
the largest single food source. The other, based on analysis of
244 stomachs, placed deer as second to hares and rabbits, with
deer making up 17.1 percent of the diet.
Black bears are common on central Idaho mountain sheep
ranges. Their diet is composed chiefly of small rodents, insects
and vegetable matter in season. They do eat the flesh of large
mammals, but mostly in the form of carrion. Bears are com-
paratively slow and clumsy and, except for the occasional "killer,"
it is doubtful that they catch healthy big game animais under
normal circumstances. Their habit of hibernating throughout the
winter lessens the probability of predation on big game species
which are most vulnerable during those months. The precocity of
bighorn lambs and their tendency to inhabit rough terrain should
give them more safety than is accorded the young of elk or deer
which are killed occasionally by bears.
Ravens are quite numerous on both summer and winter
ranges. Einarsen (1948) postulates that, since ravens are known
to indirectly kill domestic lambs by picking out their eyes, they
might also be predatory upon antelope kids in the same manner.
Jones (1950) states that F. R. Oberhansley, reporting on Yellow-
stone bighorn, found that ravens were apt to attack newborn
lamb s. No indication of su ch activity was observed during this
study, but it is a possibility that merits consideration.
-81-
FIGURE 20. A bighorn ram killed "by hanging" after falling from
a 15 foot cliff. He may have been chased by a predator, become blind
or dizzy because of pathological conditions or perhaps was simply
careless. When found, he had been dead too long for the post-mortem
autopsy to be diagnostic.
Photo by S. B rand borg, April 24, 195 1
-22 -
ACCIDENTAL DEATHS
Accidenta! deaths are a common source of loss among moun-
tain sheep, but most of these !osses must be considered as a normal
drain on the population. It is possible that sorne accidents, such
as falls from high places, may involve pathological conditions.
Heavy parasitization by lungworms, for exa mple, may r esult in
a pneumonie condition which could bring about weakness or
dizziness resulting in the so-called accidentai death of an affiicted
animal.
Travel over precipitous terrain is often the circumsta nce
responsible for accidentai fatalities. A dead ram was found April
24, 1951, at the base of a 15 foot cliff (Figure 20). His horns were
caught in the crotch of a largè aider. Tracks indicated that he
walked directly off the face of the cliff.
FIGURE 21. This lamb had been trapped on the ledge pictured
above for at least a day before it was so badly frightened by the
author and a companion that it made, and survived, a desperation
leap to the rocks more than 25 feet below.
· Photo b y M . F ran c is , N ovember 28, 195 1
On November 28, 1951, a lamb was observed bedded on a
smallledge in cliffy terrain. A day later the lamb was stiil there.
When approached to within 10 feet it leaped to the rocks more
than 25 feet below (Figure 21). The lamb appeared weak and was
limping a s it traveled to more level country. The presence of hair
on the rocks above the ledge indicated that the lamb had lost its
-83-
footing, but was stopped by this protrusion from the face of the
cliff. Considering the length of time the lamb was known to have
been stranded, it appeared that it was unable to climb and afraid
to leap from its entrapment until frightened by the approach of
the writer and a companion. It is believed that this animal would
have weakened and eventually perished had it remained undis-
turbed.
A ram was observed on February 9, 1952, with severe head
injuries and a front leg that would not support him. It appeared
to have been in a serious accident. Nine days later he was found
dead.
Injured rams were seen during the rutting season each year
of the study. Other studies have reported serious injuries being
sustained during battles. Murie (1944) knew of at least one ram
suffering a broken neck after falling in the course of a strenuous
hattie.
Several times during the study remains of sheep were found
where rock or snow slides were known to have occurred. In Feb-
ruary and March 1952, 74 slides varying from 10 to more than
600 feet across were encountered along 12 miles of trail bordering
the Middle Fork of the Salmon River. This evidence of high slide
hazard conditions indicates the potential danger to animais living
in the area.
-84-
ILLEGAL KILL
The greatest loss to illegal hunters was sustained in the early
1900's. This period witnessed the peak human population in back
country areas inhabited by bighorn sheep. Men, swarming into
the Salmon River mountains to search for gold, were closely
followed by those who served their needs. Families settled in
the rugged canyons and began raising cattle, sheep and horses.
Laws protecting the bighorn had just been enacted, but the
deeply imbedded philosophy of "living off the land" had not been
overcome.
The end of the mining "boom," followed by W orld W ar I and
better times, emptied the mountains of most of their human
occupants before 1920. After more than a decade, the depression
years of the '30's brought men and families back into the hills to
eke a living from their mining claims and gardens-and the wild
game. Again the curious sheep were easy targets for their guns.
The 1940's saw another war and more good times remove ali
except a few rugged individualists and guest ranch operators who
yet remain in wilderness places. Undoubtedly sorne bighorn sheep
still are being killed illegally each year, although the extent of
this Joss is difficult to measure. In the early stages of the study it
was believed that local inhabitants were accounting for few losses.
Severa! had, in fact, aided in the protection of sheep herds and the
apprehension of poachers. However, as information was collected
it became apparent that sorne of these folks were yielding to the
temptation provided by the fine flavored meat of wild sheep and
the ease with which they can be killed in winter-time. Unfor-
tunately, it is generally the most important animais, the females
and juveniles, that are hardest hit by illegal hunters.
Bighorn are sometimes killed for camp meat during other
big game hunts. A few may be lost to the over-anxious hunter
who mistakes them for a deer or elk. There are a few instances
where it has been reported that rifles have actually been "zeroed
in" on mountain sheep by men who have no compunction about
killing ali wild creatures which they encounter.
Severa! violators have been apprehended in recent years and
a maximum fine of $300 and costs has generally been assessed.
The evidence points out that a few accessible herds may have
decreased in recent years solely because of illegal killing. It is
to be hoped that continued vigilance by ali conservation-minded
persons and unceasing efforts to inform the public of the serious-
ness of illegal and indiscriminate killing will reduce this loss.
-85-
THE PRODUCTION PROBLEM
Knowledge of productivity is vital in the formulation of an
intensive game management program. The method selected for
determining the rate of production in this study involves analysis
of sex ratios and age classes which are based on incidence of occur-
rence. Taken from field observations during specifie seasons, cumu-
lative sex and age classifications. are believed to represent produc-
tivity with fair accuracy.
Sex Ratios and Age Classes
As the study progressed it became apparent that cumulative
sex and age ratios, taken over the entire study period, were not
always valid. First, in arder for year-around counts to constitute
reliable sex and age ratio information, one must assume that the
observer's opportunity to see a true cross section of the herd will
be equal throughout the year and, therefore, any errors will tend
to compensate. This assumption was made in the initial report
of the study (Smith, 1951). However, further investigation and
analysis of data revealed that certain errors in sex and age classi-
fication were cumulative rather than compensatory.
One such error stemmed from the nature of ram behavoir
during much of the year. With the exception of the fall rutting
season and early winter period, when rams are closely associated
-86-
with bands of ewes and young animais, it was found that mature
rams were consistently less "observable" than females and
juveniles. Among factors responsible for low ram counts was
their inclination to utilize inaccessible areas, early dispersal from
winter ranges and habit of breaking into small bands when not in
the company of ewes and lambs. For these reasons the only ram-
FIGURE 22. A young ram-
about 1 Y2 years old. At a dis-
tance even an experienced ob-
server might mistakenly class-
ify him as a ewe.
Photo by S . Brandborg, October 20, 1952
ewe ratios considered to be ac-
ceptable were those calculated
from the winter counts. Table 8
indicates wide variability in ram-
ewe ratios except during this
early winter period.
At long distances the most
easily recognized animais are
lambs and rams, two years and
older. Older ewes often can be
identified as can ewes accompan-
ied by lambs. Yearlings, particu-
larly males, frequently cannot be
distinguished from young adult
ewes unless they are near at
hand. The inclusion of identified
animais in partially classified
groups, then, would tend to er-
roneously lower the yearling
component of calculated age
ratios. This source of error was
overcome by the complete exclusion of partially classified groups
of animais in the computation of sex and age ratios given here-
after.
Yearlings were often inaccurately represented in pre-lambing
counts conducted in March and April and post-lambing counts
made in June, July and August. During these periods yearlings
are frequently separated from the ewes and lambs. When year-to-
year and season-to-season comparisons of the figures in Table 8
are made, it becomes apparent that sorne of the ewe-yearling ratios
do not representa true cross section of the herd. Yearlings mingle
most freely in heterogeneous groups during early winter. As for
mature rams, this is the optimum season to determine their true
status.
Figure 23 begins with each year's lamb crop and follows it
until accurate aging becomes impossible. The curves, showing
progressive decline in ewe-juvenile ratios, are located by inspection.
-87-
The unreliability of yearling numbers in ali except winter counts
prohibits serious consideration of ratios involving the yearling
age class. Vertical lines denoting time of counts are not equi-
distant because the period of time between counts was not equal.
Table 8. Bighorn sheep sex and age ratios as determined by
classifications of animais observed.
Total number of animais in
completely classified groups Ratios*
1949 1950 1951 1952 1949 1950 1951 1952
Post-lambing Counts
(June 15-Aug. 18)
Ram-ewe ........ 1Q1 114
Ewe-lamb ....... 101'1 191
Ewe-yearling. . . . . 88 121
Winter Counts
(Nov. 14-Jan. 18)
Ram-ewe .... .
Ewe-lamb .... .
Ewe-yearling .... .
Pre-Iambing Counts
(Mar. 15-Apr. 29)
113
93
76
81
85
69
18
21
13
119
96
82
35
47
35
2.26 15.29
0.54 0.78
2.00
0.75
0.08 0.26 0.13
1.35
0.41
0.24
1.61
0.70
0.38
3.37
0.74
0.30
1.13
0.52
0.30
Ram-ewe. . . . . 96 218 235 1.34 2.46 3.12
Ewe-lamb. . 75 230 241 0.36 0.48 0.35
Ewe-yearling.... 65 202 202 0.18 0.30 0.13
~ Heavy figures denote th ose ratios most representative of true herd status.
The post-lambing ewe-lamb ratios of 0.78, 0.75 and 0.74 for
1950, '51 and '52 respectively, do not indicate significant differences
in lambing success. Preceding the low 0.54 ratio calculated for
1949 was a winter of unusually low temperatures and deep snow.
The more successfullambing seasons following 1949 were preceded
by relatively mild winter weather. This suggests a correlation
between severity of winters and the successful bearing of young.
Only winter counts were used for calcula ting the average ram-
ewe ratio for the full study period. The weighted average for the
three winter counts conducted is 1 ram to 1.33 ewes. No optimum
ram-ewe ratio has been ascertained but, considering the polyga-
mous nature of bighorn sheep, this proportion of males should
be more thau adequate to insure breeding of ail receptive females
on the range. Because of the isolation and smallness of many of
the herds, it appears that a ratio wider than one ram to three
ewes would be undesirable.
Basic Requirements of Habitat
The ability of a game animal to survive, in the face of ever-
expanding agricultural and industrial development of its natural
habitat, depends largely upon its tolerance of wide variations in
-88-
r
t=i
~ s
~
:il
~ m .oo
:::!.. s·
~ .70
... c s "' .60 c = ~ ...... 50
[/l
00
"' c ...,
1 ~ .40
s·
:$! .30
:::"
~
= t.3 .20
:$!
~ ~ .10
1iï
< ~
2"* ~
~
~ ..... ,...., ....
'-'
~
tl94!l
lam
* Su -Summer
W -Winter
Sp -Spring
~
"'--
\1949
lam -i crop.
.. -' ,u w "P
(Post-lambing counts)
(Winter counts)
(Pre-lambing counts)
t'-.....
!'-.. ~~ --crop)
1
1
1
W Sp Su W Sp
49 49-50 50
Yearlings
Su
49 49-50 50
Lambs
51 50-51 51
Yearlings
1\
\
"' (1950
Su
50
lam crop)
W Sp
50-51 51
Lambs
"\
~
~
'
1
1
1
Su W Sp
51 51-52 52
Yearlings
\
\ 19E la
cr )
Su
51
\
U951 p~ lamt
cre
'\
'
1
1
1
W Sp 1 Su Su
51-52 52 1 52 52
Larnbs 1Yrs. Lambs
FIGURE 23. Ewe-lamb and ewe-yearling ratios as indicators of productivity of bighorn sheep.
the composition of its range. As the primitive state is altered to
suit the requirements of advancing civilization, native species often
must readjust to an entirely new pattern of living. Fortunately,
the history of wildlife has witnessed an amazing resiliency to dis-
ruption of their life habits.
At the outset of a discussion on basic requirements of bighorn
habitat, it should be understood that the standards are only con-
temporary. It should also be made clear that the requirements
described for Idaho ranges may not be applicable for herds of the
same sub-species elsewhere.
First, perhaps the relationship of the bighorn, a wilderness
animal, to its environment should be discussed. Leopold (1933,
p. 134 describes wilderness game as, ". . . species harmful to or
harmed by economie land uses, and therefore suitable for preser-
vation only in special public game reservations, or in public wilder-
ness areas." He then classifies mountain sheep, along with grizzly
bear, moose and caribou, as animais that usually fail to thrive in
contact with settlement. Bighorn in Idaho have undeniably been
"harmed by economie land uses." Unlike elk and deer, which often
migrate from their summer ranges in the mountains to agricul-
tural lowlands for winter, mountain sheep seldom trespass in an
agrarian community. Their range in the Salmon River watershed
is confined Iargely to areas receiving a minimum of disturbance
by man, and where settlement is in the form of an occasional iso-
lated ranch or cabin.
The first requirement of bighorn habitat, then, is that it be
located in a wilderness or other undeveloped area. A second re-
quirement involves competition for range. Although gregarious,
bighorn in Idaho have not exhibited an ability to thrive where
elk or deer are overly abundant. Where common game use
has not deteriorated the range, there is evidence that mountain
sheep can live harmoniously with the other inhabitants. It is from
abused areas that bighorn "disappear," leaving the elk and deer
to multiply and further deplete the vegetation. The requirement
for a thrifty range is not peculiar, of course, to bighorn sheep; but
they do appear to be more immediately and adversely affected by
mismanagement than either elk or deer.
Precise physiographical standards for ideal sheep range would
be difficult to define because of the variability among equally suc-
cessful ranges. N evertheless, certain characteristics were found to
be common to ali of the more productive sites. It was discovered,
for example, that the presence of open bunchgrass associations
increased the desirability of an area as winter habitat. Another
-90-
FIGURE 24 . Good bighorn sheep range along the Middle Fork of
the Salmon River. Browse covered cliffs intersperse numerous open
grassy slopes. Only a moderate population of deer compete for the
forage. On April 8, 1952, 78 sheep were grazing on the slope in the
foreground.
A p r il 8, 1952
common denominator of all sheep ranges is ruggedness of topog-
raphy. Even those open, grassy slopes utilized by sheep in winter
are bordered by steep rocky terrain. It is not clear whether this
requirement of proximity to cliffs is primarily in respon s e to a
need for protection from predators or becaus e there is less com-
petition for the mountain mahogany and bitterbrush that grow
on these cliffy sites. It is known that cliffs play an important role
as lambing grounds.
Paucity of suitable habitat is an important factor limiting
the total production of bighorn sheep. Restriction of their habi-
tat proceeded rapidly in the early stages of settlement of the
Lemhi, Lost River and S'almon drainages, but has slackened or
halted entirely in recent years. In fact, sorne lands have been with-
drawn from agricultural uses because of economie impracticability
or the restrictions imposed by controlling agencies. However, the
curtailment of livestock use may be offset by the enactment of
numerous proposais designed to open up many of the remaining
tracts of wilderness lands. These proposais include timber and
mining operations, hydroelectric and water storage projects, and
guest ranching-and the access roads and s ettlement tha t go
along with such economie uses.
If past bighorn behavior is a guidepost to the future, we can
-91-
be assured that the enactment of even part of these proposais
will result in significant losses of accepta:ble habitat. W e must,
however, remember that restriction of range is only partially
responsible for the present sparse population of sheep. On sorne
ranges it appears that mountain sheep numbers can be increased
materially without exceeding the carrying capacity. This is par-
ticularly so if a priority is established favoring sheep production
on inaccessible lands where it is difficult to encourage adequate
harvest of deer or, in sorne cases, elk. There are historie ranges
where bighorn can be reintroduced by transplanting or, perhaps,
through natural extension of their present range.
Can we expect to restore Idaho's sheep herds to their historie
status? The answer is, of course, "No." The reduction in available
range has been 'SO great that it cannat be compensated by improved
husbandry. However, it appears that our present estimated 2,500
head of mountain sheep can be increased materially, using only
the range resources now available. There is always the possibility,
too, that a wider tolerance for range composition may be slowly
acquired. This would open up areas not presently considered as
sheep habitat. It 'is true that the latitude of environmental toler-
ance exhibited by bighorn is much narrower than for deer and elk,
but we know that the pas't 100 years has witnessed significant
modifications in their requirements. Perhaps the next century will
bring about equally important adaptions.
Significance of Life Habits
The life habits of a species relate both directly and indirectly
to its productive potential. A problem deserving attention is the
interpretation of each behaviorism in terms of its plus or minus
value to the species concerned. Field observations indicate that a
particular behavior pattern may be detrimental under one circum-
stance while highly beneficiai under another. For example, the
high degree of polygamy among mountain sheep is advantageous
when populations are low and there are few rams among scattered
ftocks. This same characteristic, when populations are large and
rams congregate in numbers, may bring about injury, physical
exhaustion, and other undesirable results through excessive serv-
icing and harassment of the ewes.
The precocity of lambs can be extolled as a great asset in
evading predators. But can we truthfully say that ft<ight is a
superior technique? The elk calf or deer fawn, lying passively and
well concealed, may actually be safer in sorne instances· than the
energetic lamb for ali his strength and agility.
-92-
The strong herd instinct of the bighorn has been cited as a
protective measure against danger. But which is it, asset or
liability, when it contributes to decimation of herds through dis-
ease and other evils of localized over-concentration? Misfortune,
which might have spared a Jess gregarious species, has recently
struck the bighorn in Colorado. Excellent progress was being
made in building up mountain sheep herds. Then, even before
it was felt that a shootable population had been attained, verminous
pneumonia began killing numbers of sheep (Moser, 1953). Hair
lungworm (Protostrongylus stilesi) was determined to be directly
responsible for the pneumonia. Mr. Moser describes the relation-
ship of heavy parasite infestation to over-concentration of game
and states (p. 19), "the Game and Fish Commission has decided
that ... harvest ... can eliminate this over-concentration by
scattering herds into new areas." Could it be that the herd habit
works helpfully when populations are low but becomes a hindrance
at an abundance which man does not always recognize as the point
of saturation?
It has been suggested that the use of precipitons terrain by
mountain sheep is advantageous in escaping from predators. This
appears to be valid reasoning. Y et, is this protection from preda-
tors nullified by the high rate of accidentai deaths occurring
because of the rugged nature of that very same habitat?
It is not intended to attribute undue complexity to the cause
and effect of behavior. Many of the apparent contradictions in
the purpose of various life habits may, after ali, be entirely in
harmony with nature. But it is important to recognize our limita-
tions by maintaining adequate fiexibility in any management pro-
gram-and in our thinking-to permit adjustment to future
findings.
Eagerness to promote recovery of the bighorn is laudable.
But it may be that a very necessary process of natural selection
will be thwarted by over-protection or over-management. It fre-
quently develops that we cannot interfere too much with the
processes of nature without unfortunate results. Perhaps it will
prove wisest to heed the current trend in medical science and
return to a natural, "breast-feeding" approach.
-93-
ft/liAT /JOES TIIE FUll/RE Ht?L
Wildlife Livestock Logging Mining
Water lmpoundment Watershed Protection Recreation
BIGHORN MANAGEMENT IN IDAHO
Objectives
An important objective in managing a minority species, such
as bighorn sheep, must surely be to provide a numerical margin
of safety that minimizes the possibility of extinction or even
reduction of the species. While this means that the usual objective
of producing a huntable population may at times be subordinated
to other considerations, the prese"D.t status of Idaho herds indicates
that a few hunters also may be able to share the recreational values
provided by the bighorn. However, no matter how much success
rewards our efforts to increase the population, it does not appear
probable that economie and aesthetic values accruing to hunting
will ever contribute more than a fraction of the human values
that will reward those who cherish the spectacle of a magni:ficent
animal surrounded by na:tural primitive beauty, whether they are
hunters, :fishermen, photographers or casual visitors.
There are many interacting factors to consider in developing
any big game management plan. These include soil, vegetation,
weather and the inter-relationships among the species making up
the ecological community. So aside from perpetuating the species,
-95-
the over-all objective in bighorn management, as for all wildlife,
is to obtain proper balance of use; always, and sometimes unfor-
tunately, with a view to the current wants and needs of man. An
extremely important phase of management in Idaho is the preser-
vation of wilderness habitat in its natural state. Man's exploitation
of remaining wilderness tracts will diminish Idaho's capacity for
producing mountain sheep.
It is essential, too, that the objectives of a management plan
for a species as scarce as mountain sheep provide for the continuing
collection and interpretation of basic data against a possible time
when ali of our knowledge and ingenuity may be required to
maintain the species.
Cens us
Techniques for measuring trends in range condition, although
they are important indicators of the status of big game, do not
furnish adequate information about bighorn populations. Elk,
deer and mountain goats occur in sorne numbers on nearly ali
bighorn winter ranges. Knowledge of their feeding habits is of
sorne aid in determining the extent of forage utilization by each
species, but does not clearly define the position of the bighorn in
the common use picture. It then becomes necessary to find a more
precise method for determining current bighorn abundance and
direction of numerical trend.
Pellet group counts have been used successfully to estimate
game populations in other states. After sufficient testing, this ap-
proach may prove valuable in estimating mountain sheep popula-
tions in Idaho. However, it appears that the nature of the terrain
would be an obstacle to accurate sampling; and the fact that
pellets of deer, mountain goats and bighorn are often difficult to
distinguish would further complicate the technique.
Based on present knowledge, it appears that actual census
is required if bighorn populations are to be accurately evaluated.
But the sprinkling of small herds over a vast and extremely rugged
country makes total census an impractical, if not impossible, task.
Therefore, ground and aerial trend counts of key areas of bighorn
production appear to be the most practical methods for obtaining
the population data needed for management purposes.
Aerial census, while not always economically or operationally
feasible, can be of decided value in many situations. Aerial count-
ing over inaccessible areas is often the only means possible for
accomplishing the work at an optimum time. These counts should
-96-
be limited to areas where a maximum of open grassy slopes con-
stitutes the winter range, and at a time when the sheep are
concentrated on these slopes. This is usually about April 1. Data
obtained can be of considerable value in determining trend, pro-
vided the census areas are carefully selected and year-to-year
census techniques are weil standardized. Accordingly, annual trend
counts have been established and described in detail (Smith, 1952).
Aerial reconnaissance can also be extremely useful in determining
the proper time for ground counts.
The efficiency of two types of aircraft were compared on one
trend count. From a mode! 170, 145 hp. Cessna used in 1951, two
observers counted 155 bighorn sheep at the average rate of 0.57
animais per minute of flying time. A PA-11, 85 hp. Piper Cub
was used in 1952 when 236 bighorn were counted by one observer
at the rate of 1.1 animais per minute. Weather and range conditions
were similar each year and the same routes were followed. Ground
checks failed to reveal any significant change in population between
the two years. The difference in flight characteristics of the planes
is the most apparent explanation for the greater success of the
Cu b.
There are a number of light planes that perform satisfactorily
for game census over rough terrain. The following comparisons
are given to illustrate sorne of the problems found important in
aerial mountain sheep census rather than to recommend a certain
make or type of aircraft. The experience and ability of the pilot
undoubtedly transcends many other considerations.
The slower air speed of the Cub (60-70 mph) enabled the
observer to scan the slopes more thoroughly than when traveling
at an air speed of 90 to 100 mph in the Cessna 170. Furthermore,
it was easier to identify locations with respect to streams and
other landmarks from the slower plane. The Cub was more
maneuverable, making it possible to negotiate the twisting, turn-
ing canyons at a lower altitude while counting. Observations can
be made downward at a steeper angle from the Cub. This is
important when flying steep, narrow drainages where one must
stay midway between the cliffs, and tilting the plane to permit a
view of the terrain directly below is unsafe. The Cub's more rapid
rate of climb eliminated costly circling to regain altitude after
flying down a steep canyon.
On sorne ranges ground counts can add materially to the
understanding of population trends. Four ground trend count
areas have been established along Salmon River winter ranges.
These counts are scheduled during the spring months when it is
-97-
advisable to check range use, winter kills, predator losses and
general condition of big game. Therefore, the work can be carried
out by field personnel in conjunction with other phases of manage-
ment. Routes for counting are established along roads or trails
as a means of facilitating the work and obtaining uniformity of
coverage. Schedules and methods of coverage are described in
detail for each trend count established (Smith, 1953a).
Another source of cens us information is the observations made
by U.S. Forest Service employees on lookout stations located
within bighorn sheep summer range. The collection of these data
has been successful in past years and should be continued.
Control of Predators
The most apparent solution, when developing a program to
protect a scarce species such as bighorn sheep, is to recommend
the elimination of ali possible sources of loss. Closed seasons and
predator control are usually the first two measures that come to
mind. In our concern to protect a single species, however, we
should not lose sight of the importance of other members of the
biotic community nor overlook their significance to the whole
environment. To properly evaluate the relationship of predators
to bighorn sheep, we must consider not only predators and bighorn
but the status of the entire wildlife population as weil.
Predation is popularly accepted as an important mortality
factor among mountain sheep in Idaho. In reality the loss from
this source appears to be rather small, though it does exist
and most certainly must receive consideration in management
planning.
Field observations and food habits analyses of ail predatory
species, save perhaps the coyote, were insufficient in this study
to permit adequate appraisal of predator-prey relationships. It
can be said, however, that no evidence was uncovered to indicate
that it would be advisable to inaugurate a wholesale control pro-
gram for any predator on mountain sheep ranges. This is not to
say that local control of specifie predators may not become neces-
sary to protect the mountain sheep. Such necessity is always a
possibility and we must be alert to prevent serious predator !osses
from occuring without detection. On the other band, many of the
common use ranges occupied by bighorn are relatively inaccessible
to hunters. Frequently conditions on these ranges attest to total
over-population by big game. Under these circumstances it would
be short sighted, indeed, to initiate a predator control program
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based on the outmoded premise that, "lt might do sorne good and
surely couldn't do any harm."
Salting
Whether or not to include a salting program as a part of
bighorn sheep management is a difficult question to answer. It is
true that sheep eagerly lick blocks of stock salt and eat huge
quantities of soil found in natural and artificiallicks. But, insofar
as this writer is aware, it has not been demonstrated that the
absence of supplementary sodium chloride has ill effects upon
bighorn any more than it has been proven that its presence is
beneficiai. Certainly the data collected in this study are inadequate
for reaching definite conclusions regarding mineral requirements.
The entire salting program in Idaho is being reviewed criti-
cally and a concerted effort is being made to determine the value
of salt in controlling big game movement. At this writing there
are more conjectures than facts regarding the effectiveness of
the program. Jones and Moser (1953) report that, in Colorado,
they were able to lure the Pikes Peak bighorn herd a distance of
four miles with the aïd of salt. The most promising employment
of salt, then, seems not to be the fulfilment of physiological needs
but as a technique for securing proper distribution of range use.
Even in this respect the ultimate advantage gained by such a
procedure is open to question. Literature available indicates that
significant redistribution of big game through the use of salt
has been attained only in isolated situations, and then only by
very carefully executed programs. Leopold, et al. (1951) discusses
salting under the heading lmpractical Management Suggestions
where it is pointed out (p. 132), that "No evidence was obtained
that salt induced any general redistribution ofthe animais (deer) ."
In a letter to the writer, Arthur S. Einarsen (1954) advises that
after three years of experimental work in Oregon, salt has not
been proven to be necessary or particularly encouraging as a tool
in mule deer management. He further states that salt has been
ineffective as a means of influencing deer movements.
The introduction of salt, in the case of bighorn, may actually
concentrate range use rather than distribute it. Considering the
lack of knowledge concerning big game need for salt and the
general absence of evidence supporting its effectiveness in con-
trolling animal movement, it is weil to approach the subject with
caution. It seems ad visa ble that salt be supplied to mountain sheep
in Idaho only experimentally until proof, one way or the other,
can be furnished.
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Hunting
To kill a trophy ram is the cherished ambition of many big
game hunters. And an important objective of the Idaho Fish and
Game Department is to furnish the maximum hunting sport con-
FIGURE 25. Bighorn Ahead!
A sight to thrill the heart of
any sportsman.
Photo b y M . F ran c is, F e bruary 10, 1952
sistent with good management
practices. However, there are
many things to consider before
deciding whether or not to con-
duct a harvest of bighorn sheep.
Assuming that multiple use
objectives have been taken into
consideration, the next step is
to determine whether total game
numbers should be increased or
decreased. Following this, it is
necessary to establish a desired
management priority among the
s pecies present. Thus, establish-
ment of hunting regulations for
ali species of big game is an in-
tegral part of the bighorn man-
agement program. The order of
preference among species de-
pends, not only upon the inter-
relations between habitat and animais, but the relative attrac-
tiveness of each species to the hunter as weil.
A brief review of the status of ali resident big game species
is needed bef ore discussing bighorn sheep hunting. In recent years
elk have been increasing rapidly over much of the Salmon River
country. Bighorn are making slow gains, while deer have de-
creased in number. Mountain goats are competitive only in a
few localized spots. But the important consideration is that total
game use appears to have increased substantially on many Salmon
River wilderness ranges.
These ranges can support only so much use, and the most
desirable means for controlling this use is by hunting. But past
public apathy about the seriousness of range deterioration, coupled
with indignation concerning supposed "annihilation" hunts, has
lessened the effectiveness with which this important management
tool has been employed.
Hunting also has been impeded by the character of the Salmon
River back country. Much of the region is accessible only by trail
-100-
or air travel. Long pack trips are arduous, flying over rugged ter-
rain and landing on short, mountain airstrips is hazardous-and
both methods are expensive. Indeed, few people consider a deer
worthy of the inconvenience and expense involved to hunt in these
remote regions. More hurrters will enter the same territory for
either elk or bighorn. Both animais are highly desired for meat
or trophy.
The question then arises: "What priority should be estab-
lished where harmful competition exists, or may develop, on key
areas of bighorn production?" Before discussing this question
it should be stressed that such areas in Idaho are confined prin-
cipally to the S'almon River drainage between the Middle Fork and
South Fork, and along the lower half of the Middle Fork.
Based on hunter preference alone, it seems reasonable that
deer should be considered less desirable than elk or bighorn sheep.
It is of added importance that deer have the highest requirement
for the least abundant class of forage, which is browse. Also,
having a relatively wide tolerance for habitat, deer have prospered
in many sections of the state where there is easy access for hunters
and where elk or bighorn can never be established. Reductions of
deer in a few locations would be, therefore, of little consequence
to the sum total of deer hunting in Idaho.
The hunting trends witnessed in recent years make it quite
apparent that elk can be properly harvested in remote regions
if hunting regulations provide ample opportunity for the sports-
men to do so. Unfortunately, elk require more food, furnish less
hunting per unit area and usually are more destructive to the
range than deer. But, while elk might not be desirable on sorne
easily accessible ranges, they are of major importance as agame
animal on the wilderness lands under discussion here. In fact
they are, or may become, the foremost competitors of mountain
sheep on a large part of these ranges.
Top priority should be given bighorn in their key areas of pro-
duction. This thinking is based on consideration of their present
scarcity, the limited habitat in which they thrive and their desira-
bility, from both material and recreational standpoints. Such pri-
ority does not suggest elimination of ali other big game. It does
mean reducing deer numbers as low as possible through encour-
aged and directed hunting pressure. It also requires that elk popu-
lations should be kept low enough to bring about measurable
rèlief to depleted winter ranges. The resulting combination of
reduced competition and revitalized range should tilt the scales
sufficiently in favor of the bighorn to encourage healthy increases.
-101-
Bighorn have been protected more seasons thau hunted since
1910. Following eight years of closed seasons, special hunts for
mature rams were held in 1946 and 1947. Twenty-nine sheep were
known to be killed on the two hunts. After five more years of
closure, another special hunt was held in 1952. This followed nearly
three years of study which determined that sheep populations were
gradually increasing and there were approximately three rams to
every four ewes. Considering the upward population trend and
polygamous nature of the animais, it appeared that a carefully
controlled hunt of mature rams would not reduce productivity
of the herds.
Dates of the 1952 hunt were September 15-25, inclusive. A
total of 45 permits were issued for three hunt units, each of which
permitted 15 hunters. Location and size of units, and number of
permits, were determined on the basis of repeated censuses and
the completion of a spring trend count preceding the hunt. Thir-
teen rams were reported killed by 44 participating hunters. This
represents a hunter success of approximately 29 percent.
Another special hunt was held in 1953. Census of additional
areas, and data collected from the 1952 hunt, indicated that addi-
tional territory could be opened for hunting. The original three
hunt units were enlarged and two more units were added. Ten
permits were issued for each unit, making a total of 50 permits.
Dates for the hunt were September 1-10. Forty-seven participants
reported killing 18 rams for a hunter success of 38 percent. Severa!
fine trophy rams were killed. Four had horus measuring 39 inches
or more around outside of curl and had basal diameters up to 16
inches. Checking station records show that six additional rams
had curis Iarger thau 34 inches.
Lower jaws were collected at special checking stations to
aid in determining age classes harvested. Although most of the
rams were mature, a few 3 and 4 year olds were killed each year.
The minimum limit of "three-quarter or more curl" allows 4 year
old rams to be taken, while 3 year olds are in a "borderline" cate-
gory.
A program of conservative hunts held each year is more de-
sirable thau Iarger harvests held periodically and followed by long
clos ures. 1t is believed that in this way the game manager can best
meet his obligation to permit the hunter, not starvation, disease
or other causes to harvest the game resource. Naturally, any posi-
tive evidence of detriment to the productive potential of bighorn
herds would be grounds for termina ting the h unts.
-102-
With sheep populations at present leveis, only mature rams
can be harvested safely. The hunt should be continued on a permit
basis in order to control the number of animais removed from any
one area. It is important that the season be set early in the fall
when the rams are segregated from the ewes and juvenile animais.
Both sexes and ali age groups begin banding together late in
October. Hunting at this time would increase the likelihood of
ewes and young being killed, interfere with courtship and breed-
ing activities and be potentially dangerous to herd productivity-
and, furthermore, it cannot be overlooked that recreational value is
an important part of bighorn management. Such value would be
materially lessened by hunting when the animais are concentrated
on winter ranges where they can be shot from trails or roads
along the river. It should be.emphasized that it is not the aim of
game management to assure meat or trophies to every hunter but,
rather, to offer very fine sport along with reasonable opportunity
for success to as many sportsmen as possible.
Trapping and Transplanting
Reintroduction of animais on historie ranges or introducing
them into new areas has been accomplished successfully with most
big game species. Couey (1953) reports that 16 bighorn were
obtained from Colorado's tarryall herd in 1947 and planted on
Montana's Fort Peck Game Range. By 1952 the herd had multi-
plied to an estimated 75 head. Mr. Oouey suggests that transplants
should not be too small and that it may be advisable to construct
release pastures for holding the animais together as a unit until
they become acclimated to their new surroundings.
Although transplanting programs have been successful, as
pointed out in the Montana studies, this technique for increasing
total production should not be applied without careful preliminary
investigation. Trapping and transplanting of big game excites the
imagination and often gains widespread approval before its worth
has been given serious consideration. No record has been found of
a bighorn transplant in Idaho. No careful investigation of potential
transplant sites have been made. Wholly superficial observations
indicate, however, that favorable results might be obtained from
transplants on a few historie ranges. Most prominent of these
are the Lost River, Seven Devils and Sawtooth mountain ranges.
There are, however, many aspects that should be considered
before a transplant site can be adjudged "sui table." It is not enough
that the proposed range appears similar to ones currently occupied,
-103-
or even that it once harbored healthy bands of sheep. After it has
once been determined that general physiographical features are
satisfactory, the winter range should receive first consideration.
Is the range in good condition and what is its present trend? Is it
large enough to support an expanding population? Does it provide
the necessary interspersion of grass, cliffs and desirable shrubs?
What of the present competition by big game and domestic stock?
If important win ter ranges meet these requirements, a similar
analysis should be made of summer ranges. And, if they are satis-
factory, the survey can go on to more general questions. Are preda-
tors abundant and likely to be detrimental in the area? Is the
territory relatively undisturbed by man and what are the plans for
future industrial or agricultural development? What will be the
logical priority among big game animais if undesirable competi-
tion develops on the range proposed for transplants-and on
adjacent areas to which the sheep may migrate?
A survey should not be concluded without first determining
the reactions of local residents to the proposai for introducing
bighorn. Will they cooperate in protecting the sheep or is it quite
evident that they will con tribu te to their decline?
Trapping and transplanting should not be discouraged en-
tirely. W ell-planned operations may be advisable, but they should
be instituted only after adequate studies have been completed. Big-
horn trapping in other states has entailed mu ch vain effort and dis-
couragement before success has been attained. In nearly all cases
the operation has been costly.
Recent unexpected appearance of mountain sheep in locations
far from known herd concentrations indicate that key areas, if
developed into habitats capable of producing greater numbers of
sheep, might well result in sufficiently large herds to encourage
a natural extension of their range. The technique of managing
limi'ted areas for the maximum benefit of sheep may be a more
practical and inexpensive, if less spectacular, means of increasing
total production than by trapping and transplanting.
Preservation of Wilderness Habitat
It is difficult to choose one phase of management as being more
important than another. But we may be certain that, if civiliza-
tion continues its attrition of the remaining tracts of primitive
country, all of our scientific knowledge and its specialized tech-
niques may come to nothing. Not only the bighorn's existence, but
much of his intrinsic value to man as well, depends upon the pres-
-104-
ervation of his habitat. It is more than likely that a hunter's mem-
ory of his stately ram is at least equalled by remembrances of
mountain peaks, glittering lakes and green, untrampled meadows.
One of our greatest opportunities to aid the bighorn is to
work to prevent despoilment of his range. If we can be assur.ed
that the primitive areas in central Idaho will remain inviolate by
the advance of civilization, we can then turn to research and the
application of known principles of game and range management
with a feeling of lasting accomplishment.
An important battle will be won if we can assure the bighorn
of adequate food and cover and an undiminishing habitat in which
to live.
-105-
PART II
A Survey of Winter Ranges
along the Middle Fork of the Salmon River
and on Adjacent Areas
INTRODUCTION
Big game ranges in the Salmon River watershed of central
Idaho conform to the usual situation found in northern mountain-
ous regions where quantity, quality and availability of winter for-
age regula te the number of animais that a range will produce. The
condition of soil and vegetation, and trends exhibited by the range
as a who le, are measures for determining the total game population
which the range can properly support. Knowledge of interspecific
competition for food and space is essential to realistic evaluation
of the aggregate carrying capacity of the range.
With these thoughts in mind an intensive winter range sur-
vey was conducted in key areas of bighorn production along and
adjacent to the Middle Fork of the Salmon River. The stated ob-
jective, "To determine composition, availability, utilization and
abundance of forage on winter range, and to determine trends in
range condition," encompassed the habitat of deer, elk and
mountain goats as well as bighorn, but was intended to focus special
attention on the particular niche occupied by mountain sheep in
the common use picture.
Part of the range survey work, such as cover type mapping,
will not require further attention to satisfy the immediate purposes
of management. On the other hand, investigations initiated to
measure range condition, trend and use should be continued for
many years. Sorne of these studies will require yearly attention;
others may need only periodic checking through the years, but
none should be neglected if we are to know wha:t the range is doing
and what we should do for the range.
-107-
RANGE CONDITION AND TREND STUDIES
Wise management of the range resources requires more than
a precise method for appraising current status. A valid source for
drawing conclusions from past history is essential if we are to
predict future trends with accuracy. Consequently, the selection of
a range study method for use on bighorn winter ranges was in-
fluenced by the desire, not only to furnish a ba,sis for present man-
agement, but to establish a point of beginning upon which a cumu-
lative history of accurate data can be built.
Trend in Range Conditions as Determined by the 3 Step Method
The principal method employed in the bighorn sheep winter
range study was the 3 Step Method for Measuring Trend in Range
Condition. This method was developed by Kenneth W. Parker,
Division of Range Research, U. S. Forest Service. It has been ac-
cepted as the standard method for measuring condition and trend
on most national forest ranges in Idaho.
The 3 step method, as the name implies, consists of three
major steps. Briefly, they are:
1. Establishment of permanently marked transects and col-
lection of basic field data from these transects and the site
within which they are located.
2. Field analysis of these data, classification of condition
at time of record and estimation of current range trend.
3. Permanent photographie record of range conditions on
the site that is sampled.
Certain additions and omissions, with respect to the 3 step
method, were made to comply with the objectives and circum-
stances of this study. Furthermore, criteria for evaluating both
soil and vegetation condition and trend were developed for the
specifie ranges upon which the method was applied.
Provision was made for the collection of browse form and
age class information as suggested by Dasmann (1951). The
crown cover afforded by overstory species was measured and ali
big game pellet groups were recorded along each transect line.
Between July 20 and September 24, 1951, 18 clusteTs of three
100 foot transects each, and one elus ter of two transects were perm-
anently established on key range areas along the lower 50 miles of
the Middle Fork of the Salmon River. During the summer of 1952,
another cluster of three transects was established on the Middle
Fork. A similar cluster was measured on Marco Creek, a tributary
of the East Fork of the Salmon River.
-108-
FIGURE 26. Employing the 3 step method for measuring trend in
range condition.
August 2, 1952
A rock monument, witnessing the point of beginning for the
Marco Creek Cluster, can be seen at right in Figure 26. Leaned
against the monument is a 112 x %, inch angle iron stake used for
marking transect ends, and a 112 inch diameter steel rod which will
be driven at the 50.5 foot mark on the tape to further mark loca-
tion of the line. Both types of markers are 36 inches ih length.
Their tops were dipped in orange paint to increase visibility. The
stakes were driven until only nine inches remained above the
ground surface. A % inch section of %, inch waterpipe welded to
one end was used to take observations along the 100 foot steel
tape shown at the center of Figure 26.
Vegetation, litter, bare soil and rocks were recorded when-
ever they fell within the%, inch loop which is piumbed from each
foot mark along the transect. Plants were recorded by species and
classified as desirable, intermediate and undesirable. These classi-
fications were based largely on soil holding capa;bilities, succes-
sional S'tatus and value as big game forage. Criteria were estab-
lished and, along with each procedure, were outlined carefully in
a completion report submitted at the end of the range survey
(Smith, 1953).
-109-
AH browse plants occurring along the transect lines were
classified according to the form and age classes shown below:
Form Classes Age Classes
1. AU available ...... Little or no hedging S-Seedling
2. " " . Moderately hedged Y-Young plant
3. " " Severely hedged M-Mature plant
4. Largely available . Little or no hedging D-Decadent Plant
5. " " ... Moderately hedgerl
6. " " Severely hedge
7. Mostly unavailable
8. Unavailable
Parker (1951) employed keys to evaluate trends in forage
condition and soil stability. When the bighorn winter range sur-
vey was initiated, however, insufficient data pertaining to soil
characteristics and plant status had been collected from the ranges
investigated to warrant construction of keys. Therefore, range
trend was determined from general observations recorded at the
site of each study plot when the transects were measured. After the
field work was completed, information gathered was used to set
up tentative standards for determining soil and vegetation condi-
tion classes.
A photographie record of each study plot was made at the
time the transects were measured. Two photographs were taken
from each end of the cluster. The set of four photos taken at
each of the 21 cluster sites were filed as a permanent record of
Table 9. Summary of composition of primary forage species
as determined by measurement of 21 clusters (sixty-two 100 foot
transects) by the 3 step method.
No. of clusters Average composition
in which in clusters where Variation in
Species species occur apecies occur composition
(percent) (percent)
DESIRABLE SPECIES
Bluebunch wheatgrass. 20 30.7 5.2 to 57.8
Idaho fescue .......... 15 18.4 0.7 to 49.5
Balsamroot ........... 12 13.4 0.6 to 32.2
Bitterbrush ........... 4 8.1 4.5 to 11.9
lNTERMEDIATE SPECIES
Western yarrow ....... 7 3.5 1.6 to 7.3
Lupine ............... 3 2.5 1.3 to 3.9
UNDESIRABLE SPECIES
Cheatgrass ........... 15 24.5 2.9 to 72.4
Rabbitbrush .......... 8 6.8 1.2 to 25.9
Big S"!!'ebrvsh. 7 16.7 5.2 to 63.1
-110-
Oblique Close-up
General-type
FIGURE 27. Photographie records for Transect 1, Cluster 9. Big-
horn sheep and mule deer fall, winter and spring use has been exces-
sive on this range. The vegetation condition rating for this site, as
determined by the 3 step method, is VERY POOR. Soil stability is
POOR and the general range trend is "down."
August 11, 1951
-111-
,,,,
the study and will be used for comparison when the work is
repeated.
Only limited conclusions can be based upon present data. The
principal value of the study will be gained by its continuance over
a long period of years. Pertinent information which was collected
during the preliminary work is tabulated in Tables 9, 10 and 11 and
presented graphically in Figure 28.
The areas represented in the 3 step method studies are not
homogeneous with respect to composition, condition or trend. But
they are alllocated in areas that serve a common purpose as win ter
range for mountain sheep and deer and-to a limited extent-for
elk and mountain goa,ts. Cover composition varies widely among
clusters as can be seen in Table 9. Nevertheless, the relative im-
portance of important plants is apparent.
Table 10. Summary of form and age classes of primary
browse species encountered on sixty-two 100 foot transects.
Total
Species Shrubs Form Classes' Age Classes' De ad
(1) (2) (3) (4) (6) (7) (S) (Y) (M) (D)
Big sagebrush ...... 107 62 24 3 2 19 33 35 18
Rabbitbrush ....... 47 31 7 5 1 1 13 23 7 3
Forsellesia ......... 32 31 1 3 23 6
Bitterbrush ........ 20 8 3 1 3 1 1
Bitterbrush ........ 20 8 3 1 3 1 1
Bitterbrush ........ 20 8 3 . . .. 4 2 5 9
Mountain mahogany 6 2 1 1 1 1 3 1 1
1 See page llO for explanation of symbols.
A review of form classes in Table 10 reveals that most sage-
brush, rabbitbrush and spiny greasebush are not severely hedged,
but a glanee at the age classes of the same species shows that they
are not reproducing weil. Large numbers of sagebrush and bitter-
brush plants are dead. General observations indicated that over-
all use of bitterbrush and mountain mahogany was more severe
than it appeared from this small sample.
The two species shown in Table 11 were selected to point out
the plant succession that appears to be in progress on the ranges
studied. Bitterbrush was the most prevalent desirable browse
species. Rabbitbrush, a well-known invader species, was common.
Ali 21 clusters studied are analyzed in Figure 28. The fact
that cheatgrass was recorded as a "hit" caused sorne of the aver-
ages to be somewhat unrealistic, particularly within the poor
vegetation class. Cheatgrass was most abundant on the poor
ranges and exerted maximum influence upon results in that class.
-112-
Table 11. A desirable browse species and a common invader
plant compared as to favorability of age classes.
Age Classes
FAVORABLE UNFAVORABLE
Seed-Sub-Deca-Sub-
ling Young Mature total dent De ad total Total
(Per cent)
DESIRABLE
Bitterbrush. 0 20 10 (30 ) 25 45 (70 ) (1001
UNDESIRABLE
Rabbitbrush. 2.1 27.6 49 (78.7) 14.9 6.4 (21.3) (lOO)
Inclusion of this annual grass decreased the number of bare soil
readings and increased plant density. The average percent
undesirable species also was increased by measurements of cheat-
grass. On ranges classified as very poor, even cheatgrass was
much reduced. Although recording this undesirable annual as a
hit had little effect upon the final classification of condition, it does
tend to distort the picture and, when the work is repeated, should
be tallied but not considered as contributing to plant density.
"Classification of Plant Species" in Figure 28 lends graphie
emphasis to the relationships of desirable and undesirable forage
species on ranges of varying conditions.
Figure 28 shows that use, as determined by pellet group
counts, was lightest on good ranges and most intense on poor ones.
There was, however, a sharp curtailment of use noted on ranges
classed as very poor. This suggests that, once a range becomes
sufficiently depleted, herbivorous animais having free choice will
shun it in preference for areas of more abundant forage. This
natural reduction of animais on impoverished ranges is vividly
portrayed in Figure 28. When it is considered that eight out of
21, or nearly 40 percent, of the areas sampled were rated as very
poor, there is cause for concern. It is no more reassuring to note
that 10 cluster sites exhibited a downward trend, an equal number
were classed as static, and only one was judged to be improving.
Experience gained in the first year of the study, points to a
need for certain revisions and additions when the work is repeated.
Vigor measurements based on average growth of key perennial
grass species should be used as a factor for determining vegetative
condition. Damage by trampling should receive additional atten-
tion. Disturbance of litter, and soil displacement caused by game
movements on loose gr ani tic soils, deserve more consideration than
was given in the basic investigation. It would enhance the value
-113-
of the work to separate soil and vegetation for trend classification.
Range trend was considered as an entity and judged solely on the
basis of general observations in the initial survey.
'"' Q)
~
0
.-i
"' ..,
0 ..,
....
0 ..,
~
0
'"' Q)
A.
Vegetation Condition Ratings and
Number of Clusters in each Condition Glass
GOOD
(3)
FAIR
(7)
POOR
('3)
Composition of Ground Cover
VERY POOR
(8)
?lant density t!:t~tiiR Lit ter fe Eoss ~ Rock mm 'lare soil D
Classification of Plant Species
80
40
20
Relationship of Use to Range Condition
Horse
GOOD FAIR POOR VERY POOR
FIGURE 28. Correlation of vegetation condition rating with cover
composition. desirability of plants, and use; and presented as aver-
ages of the clusters within each condition rating ..
-114-
It should be stressed that continuance of this study is essen-
tial if its maximum value is to be realized. Only the initial phase
has been accomplished. Future repetitions of the work will
provide the basis for analysis of trends in range condition-trends
which may not become apparent for many years. However, there
is always the danger that if the study lies dormant for long
periods it may die from lack of interest and continuity of effort.
Therefore, it is suggested that re-examination of the study plots
be made at intervais of not more than five years.
An Analysis of Condition and Trend Through
Study of Exclosures
The U.S. Forest Service constructed a 16 foot x 16 foot ex-
closure on Cow Creek in 1929 and one on Cabin Creek in 1930.
See Figure 43 for locations. W oven-wire fen ces, about seven feet
in height, excluded both big game and livestock. An unfenced
check plot had been marked by rock monuments on similar sites
in the vicinity of each fenced plot.
In the spring of 1931, using a plane table, the crown cover of
each browse species was delineated in the exclosures and check
plots. Browse seedlings and balsamroot plants also were plotted.
General notes were taken regarding vigor and density of grasses,
forbs and shrubs.
The original data for these study plots were obtained with
the aid of Challis National Forest personnel. Techniques of the
initial work were duplicated as nearly as possible in 1952. Crown
cover of browse species was charted carefully, as shown in
Figures 30 and 31. Browse seedlings and balsamroot plants were
plotted and general notes pertaining to the vigor and density of
ali plants were recorded and compared with the original data.
The most recognizable changes in range condition and trend
are shown by Figures 30 and 31. Figure 32 summarizes trends
of the four principal species found in the study plots.
Before discussing trends it is necessary to describe two
assumptions made when analyzing the data. First, it was assumed
that related exclosures and check plots were established on sites
which were comparable in vegetative composition and condition.
Y et a glanee at Figure 32 reveals that the average ground cover
afforded by browse when it was first measured in 1931 was about
22 percent on the check plots as compared with 29 percent inside
the fenced plots. At this same time, balsamroot was most abundant
on the check plots. Check plots in each area have the same site
-115-
Cabin Creek Exclosure-established October 27, 1930
Cow Creek Exclosure-established March 23, 1929
FIGURE 29. U. S. Forest Service 16 foot x 16 foot exclosures lo-
cated within browse types on Middle Fork of the Salmon River winter
ranges . The current study is indebted to Arthur Buckingham and
Lester T. Gutzman who were the forest rangers in charge of the con-
struction and study of these plots over 20 years a go.
July 26, 1952
characteristics and are separated by only a few hundred feet from
their exclosure counterparts. Therefore, it is believed that part
of the difference shown between check plots and exclosures in
1931 was because one exclosure had received only one year's pro-
tection, while the other had been fenced for two years prior to the
1931 measurements.
The second assumption involves the ecological classification
of big sagebrush. It should be stressed that this shrub is not always
an invader species. The history and present ecology of the ranges
under consideration suggest that big sagebrush existed in pristine
associations and will persist in secondary climax plant com-
munities.
The two major changes related to the shrubs, both in and
out of the exclosures are: 1) increase or decrease in number and
2) growth or deterioration of those shrubs present in 1931 which
survived until 1952. Numbers of plants present on check plots
and exclosures are diagramed in Figure 32. Crown cover of living
shrubs was measured from the scale drawings, and percentage of
total ground cover was calculated for each shrub as it existed in
1931 and as it appeared in 1952. These percentages then were
plotted to indicate trend.
It should be pointed out that the classification partially dead,
as used in the exclosure study, does not imply that the shrub was
necessarily decadent. As a matter of fact, young and vigorous
plants frequently have dead portions caused by such factors as
browsing injury, rodent girdling and insect damage.
The history of use on the two study sites should be discussed
before analyzing vegetation changes. Field notes written in 1929
and 1930 by Forest Rangers Buckingham and Gutzman refer to
both areas as having been overgrazed badly by domestic stock
prior to that time. Deer use was reported as being very heavy
and, since then, has ranged from moderate to heavy. Elk were
mentioned as occasional summer visitors but did not winter on
Middle Fork ranges until the late 1930s. They are now abundant
on both Cabin Creek and Cow Creek. There was light use then,
as now, by mountain sheep.
Records of Iivestock allotments involving both study sites were
supplied by the Challis National Forest. The allotment which
included the Cow Creek area was cancelled after 1942. At that
time grazing was allowed for 23 horses from April 16 toN ovember
15, and seven head of cattle from July 1 to September 30. Cattle
and horse use had been quite heavy until 1936. The Cabin Creek
allotment was continuing in 1952, with 17 horses being permitted
-117-
EX CLOS URES
Exclosure fence
Check plot boundary
Rock monument
-corner marker for check
plots
Bitterbrush
Ptr (Purshia tridentata)
* Partially dead shrub
(Cow Creek plots only)
4 Plane table hub
~ Dead portion of shrub ~ (Cabin Creek plots only)
/\... Crown pattern of shrubs 0 Sagebrush seedling
Atr
Cna
Perimeter of shrubs
overstoried by larger plants
x Rabbitbrush seedling
Big sagebrush e Bitterbrush seedling
( Artemisia tridentata)
Rubber rabbitbrush Balsamroot plant
(Chrysothamnus nauseosus) ® (Balsamorhiza sagitatta)
Scale for ali plots (in feet)
0 1 4 8 12 16
FIGURE 30. Cabin Creek study plots. The scale drawings above
show crown area of shrubs and location of balsamroot plants and
browse seedlings.
-118-
'•
EX CLOS URES
1
1
1 0
~~----!~·-___ L __
1 : 1
1 1
1
1
1
-----+------1----~-----
1 1 1:/. ,'l-1 1
18
1
--Exclosure fence
- -Check plot boundary
~ Rock monument
--corner marker for check
plots
.._ Plane table hub
./"\._ Crown pattern of shrubs
.,.' '-..
Atr
Cnd
Perimeter of shrubs
overstoried by larger plants
Big sagebrush
( Artemisia tridentata)
Rubber rabbitbrush
(Chrysothamnus nauseosus)
<19---~--~--~-~
~ç;J 1 1 1 1
'"' 1 1 1 1
1 1 1 11"--~+---~---j . CCL? 1 1~ hg _JZ), 1 1 "'--' '"-' -v----,0----;-
,,. 1 1 1
1 :@ K 1
1 1 ~. c~.~ ~
rB __ _j_ -~-4---j
1 1 1, • 1
1 :"t•
1 1 "' 1 1
1 1 ~-___j_'_----@
CHECK PLOTS
~--i----1 ----~---'ji
1 1 1 1 1 n 1 1 1 rv"(Y 1 1 1 ' ~--c&---; ---r--i
R -:----t-----:--61
1 1 ~ 1 1
1
1 ~ 1 J ~e---~----:----8--i
l-1 1 1 ~
-__L_ -__l__ -____l_
,q !;l
Ptr
*
Bitterbrush
( Purshia tridentata)
Partially dead shrub
(Cow Creek plots only)
~ Dead portion of shrub
· (Cabin Creek plots only)
0 Sagebrush seedling
X Rabbitbrush seedling
e Bitterbrush seedling
® Balsamroot plant
(Balsamorhiza sagitatta)
Scale for ali plots (in feet)
0 1 4 8 12 16
FIGURE 31. Scale drawings of Cow Creek study plots.
-119-
six months grazing beginning on May 16. Use had been heavy
until1926 when the first sharp curtailments were made.
Undoubtedly, as Buckingham and Gutzman pointed out in
their early reports, a good part of the initial deterioration of the
Cabin Creek and Cow Creek ranges can be attributed to domestic
stock use.
45
= ii: e 40 ..,
;...,
,.Q 3 5 .._,
~
130
Il:
: 25
~
~ 8 20 .._,
= = 15 Q ...
~ .... = 10
~ .., ... 5 ~
Q.,
~~fi Number of dead plants
Number of partially dead plants
Number of live plants
__ Grou nd cover trend-ali browse species
__ Ground cover trend-each browse species
~-
-
;;; N
"' 22 !!!
~ = ..
.0 .. ::
i:iS
EXCLOSURES
1952 --z.-.
.c ~ "' = = .. ..
.0 -;: .. .. :E " .0 rn .. ~
...,
0
0 .. e ..
.!!l
" ~
Plant species
CHECK PLOTS
.c
"' = ..
"il ..
" rn
1 Rabbitbrush occurred on Cow Creek study plots only
2 Balsamroot occurred on Cabin Creek study plots only
rn -30 = co
'ii
25 .....
Q ...
20j e = 15 z
FIGURE 32. Vegetation changes that have taken place on the
Cabin Creek and Cow Creek exclosures and check plots during the
past 21 years.
Inspection of Figure 32 shows that total crown area of living
bitterbrush in the exclosures more than doubled from 1931 to 1952,
while the number of plants only increased from eight to nine.
By way of comparison, bitterbrush in the plots where use was
-120-
unrestricted decreased from eight to seven plants and total crown
area diminished considerably.
Big sagebrush inside the exclosures declined in numbers of
plants. The drop from 23 to 18 shrubs, however, did not prevent
the total crown area from increasing by almost a hundred-fold.
On unprotected plots the number of live plants remained constant.
Crown cover was reduced to less than one-half, a-reversai of the
trend inside the fenced plots.
It is important that rabbitbrush on both protected and un-
protected sites has decreased in numbers and volume; although
it is not unusual that this subclimax invader should be crowded out
where more than 20 years of protection has fostered a secondary
succession of better plants. The condition to which attention is
directed is : Where stock and game use was unrestricted, the
normally invading rabbitbrush is also diminishing in numbers and
size. Balsamroot, found only on the Cow Creek study plots, was
eliminated completely from the exclosure while its numbers nearly
doubled on the check plot. The trend for ali browse cover indicates
significant increases in the exclosure and equally important de-
creases on the check plots.
Seedlings of ali browse species present were reported in the
exclosures and check plots in 1931. When the plots were re-ex-
amined in 1952, the only seedlings were a clump of 13' rabbitbrush
plants in the Cow Creek exclosure. However, there were severa}
young bitterbrush plants in both exclosures. Seed production of
bitterbrush inside the fenced plots was noticeably superior to that
on the less vigorous shrubs occupying adjacent unprotected areas.
Comparison of initial estimates with those made in 1952
points out that there have been marked increases of grasses and
forbs within the exclosures but little change on the unprotected
sites. Number and volume of shrubs on the ranges studied have
decreased gradually during the past 20 years. Volume of browse
cover within the exclosures has increased ; and this would be
encouraging except that numbers of plants have not increased and
no desirable seedlings are being established.
The evidence points to a plant succession from browse to
grass type under present conditions of use. However, it appears
questionable that complete protection will result in a primary
restoration of browse cover. The implication of this limited study
is that the first manifestation of range recovery will be a vigorous
stand of bluebunch wheatgrass, other grasses and forbs.
With most of the winter ranges along the Middle Fork either
static or exhibiting a downward trend, there is little opportunity
-121-
to observe the characters of an improving range. It would be a
valuable contribution to the management of these ranges to go
further into the investigation of plant succession and other char-
acteristics on areas receiving total protection from big game. If
future management programs enable expansion of such range
studies, the exclosures should be at least one acre in size. The
"edge e:ffect" and other inadequacies of small exclosures were
obvious in the current study.
Results from the observation of additional exclosures might
not become apparent for 10 or 20 years, but it is from long-range
studies that sound management practices are formulated. Other-
wise, management continues to flounder amid the confusion and
contradictions that inevitably accompany short-lived, inadequate
surveys.
The results of the current study are presented with the reali-
zation that the sample was too limited to permit many factual
conclusions. If, however, the study succeeds in pointing out the
importance of adequate sampling and continuity of effort in long-
term investigations it will have served a good purpose.
-122-
BROWSE UTILIZATION STUDY
Twig Measurement Method
The principal method employed to determine browse utiliza-
tion by bighorn sheep and other big game species was the linear
measurement of twigs before and after game use. A total of 400
browse plants was tagged and measured on eight sites along the
Middle Fork of the Salmon River. See Figure 43 for locations.
Measurements were taken in November 1951, before fall use had
begun. Re-measurement of the shrubs in the spring of 1952 pro-
vided an accurate estimate of the degree of use during the winter.
Twenty-two shrubs were lost to the study during the winter
through various causes.
Locations for measuring utilization were selected primarily on
the basis of the presence of bighorn sheep on the winter range.
Each cluster of 50 tagged shrubs was situated where it appeared
t'hat past use had been normal for t'hat particular area. An attempt
was made to base selection of individual shrubs upon average con-
ditions of availability.
Both current and older growth was measured from attached
identification tag to terminal end of branch and recorded to the
nearest one-half inch. Growth in addition to the current year's
increment was measured because cropping of twigs frequently
removes more t'han annual growth under conditions of heavy use.
Failure to recognize this condition would be to predicate faulty
conclusions regarding the actual extent of use on the plant in
question.
It would have been desirable to confine measurement to the
young and mature classes, and the all available and largely avail-
able form classes. However, this was frequently impossible because
of the prevalence of undesirable form and age class shrubs on the
study areas. To check accuracy of twig measurements, 104 shrubs
showing no use were re-measured in the spring. Plus and minus
deviations from the fall measurements indicated t'hat the errors
from this source were small and largely compensatory. T'he cumu-
lative error, about one percent, indicated a slight tendency to get
larger measurements in the spring.
Ninety-six percent of all measured bitterbrus'h plants were
browsed. A vera ge use of annual growth was well over 60 percent.
Over one-fourth of the measured old growth also was consumed
on those plants receiving use.
-123-
Mountain mahogany is generally abundant in the vicinity of
rock outcroppings and cliffs, and is highly palatable to big game.
However, past over-use has resulted in such a large number of
hedged, high-lined and decadent plants that the selection of a rep-
resentative number of suitable shrubs was impossible in most clus-
ters. The extent of use shown in Table 12 implies that mountain
mahogany stands, as compared with other important shrubs, have
received sorne respite from severe over-use. This, unfortunately, is
not true. Because of the undesirable form and age classes present,
many shrubs of doubtful availa:bility were measured in order to
obtain a representation of this species. Observations in the spring
indicated that mahogany was browsed as heavily as physically
possible in most cases. Average utilization of annual growth on
browsed plants would undoubtedly have been much higher than
59 percent if the foliage had been available. Even so, over one-half
of these plants received more than 60 percent removal of the an-
nuai growth and over one-third of the measured old growth was
utilized.
Rabbitbrush received the highest average use on browsed
plants-72 percent on annual growth and 36 percent on old growth.
Over three-fourths of ail plants receiving use had more than 60 per-
cent of the current year's growth removed.
Removal of the current growth of sagebrush averaged 66
percent on browsed plants, but only about half of the measured
branches were browsed. The tendency to feed upon older growth
was not as pronounced as on rabbitbrush.
Spiny greasebush is quite localized, being found largely on the
more steep and rocky portions of the range. The fact that six of
the nine plants measured received an average use of 71 percent
suggests that, where present, this small shrub furnishes signifi-
cant amounts of food.
Ninebark and syringa received scattered light use. Their gen-
eral confinement to browse and timber types on the more northerly
slopes further reduces their usefulness to mountain sheep, who
make only limited use of these slopes in winter. An average of 50
percent of the annual growth was utilized on four of the six choke-
cherry branches that were measured. This shrub occurs sparsely
on most ranges. Otherwise it would be an important source of
forage.
Breaking of branches by feeding animais is an important con-
sideration. The more over-populated the range and less available
the forage, the more serious becomes this destruction of browse
-124-
.....
"" Ol
1
Table 12: Utilization of browse on Middle Fork of the Salmon River win ter ranges during the win ter of
1951-52, as shown by linear measurement of twigs.
Species
Bitterbrush .......................
Mountain mahogany ...............
Rabbitbrush ......................
Big sagebrush .....................
Golden currant ....................
Syringa ................ .........
Western chokecherry ...............
Ninebark .........................
Spiny greasebush ................. .
No.
of
shrubs
**
176
84
33
21
19
16
6
6
9
No. of
browsed
plants
A 0
168 94
66 38
26 ..
11 4
4 2
4 . .
4 . .
1 . .
6
Total
length
measured
A 0
(inc hes)
11,652 4,320
2,898 3,878
3,687 698
1,481 521
'823 791
828 667
324 206
296 319
617
Average
utilization,
ali plants
A 0
(per cent)
62 15
46 19
57 14
35 4
5 1
7 . .
33 . .
3 . .
47
Average
utilization,
browsed plants
A 0
(per cent)
64 27
59 34
72 36
66 22
23 13
28 . .
50 ..
19 ..
71
Browsed plants
with over 60
percent use
A
(percent)
64
54
77
73
..
. .
17
83
**In this table A=Annual growth; O=Old growth-that portion between annual growth and identifyin&" tag.
and its capacity to produce. Continued severe cropping increases
the brittleness of shrubs and their susceptibility to breakage.
One-half of the 400 browse plants measured for utilization
were located in Short Creek drainage, an area of heavy deer and
moderate mountain sheep use. The remaining 200 shrubs studied
were on ranges in Soldier Creek, Survey Creek and Rattlesnake
Creek. Deer and bighorn use is moderate to light on the last three
sites named.
Table 13. Comparison of annual growth utilization of princi-
pal browse species between a heavily and moderately used range.
Species
Bitterbrush ...
Mountain mahogany ..
Rabbitbrush .......... .
Big sagebrush ..
Short Creek
(a heavily used area)
(Av. percent use)
62
46
77
33
Soldier-Survey-Rattlesnake
(moderately used areas)
(Av. percent use)
62
46
37
35
Table 13 considers ali plants measured, whether receiving use
or not, in the calculation of percentages. Bitterbrush and mountain
mahogany received the same average use, and sagebrush use was
essentialiy the sameon both areas. However, on heavily populated
Short Creek the animais readily shifted their browsing to rabbit-
brush which received more than double the use on moderately
browsed ranges. Results of the utilization study and field observa-
tions suggest that rabbitbrush, as a member of browse associations
found on Middle Fork ranges, deserves more credit as big game
forage than has generaliy been recognized. It is unfortunate that
it is often an indicator of unfavorable range trends.
lt should be emphasized at this point that the suppressed
condition of browse, particularly bitterbrush and mountain
mahogany, often makes it impossible for an animal to browse ali
of the current growth. A figure of 70 percent utilization, for ex-
ample, may mean that practicaliy 100 percent of the available
browse has been taken. Because of this condition it appears that,
while the measured utilization of a stand of desirable shrubs may
not appear excessive, the physical difficulty of browsing severely
hedged plants may cause the animais to turn to inferior species
where current growth is readily available.
If we accept the criteria suggested by many range specialists
-that utilization of most browse species should not exceed 60
percent of annual growth if plants are to remain healthy-it is
-126-
manifest that winter ranges studied on the Middle Fork of the
Salmon River are receiving excessive use. Form and age classes
of important browse species are over-balanced in favor of deca-
dent and unavailable individuals. Reproduction of the more valu-
able plants is almost nil and large segments of valuable bitterbrush
stands are dying out. A high percentage of desirable browse plants
are receiving use in excess of 60 percent of annual growth. Obser-
vations of this investigation and range study records kept by
Challis and Salmon National Forest offices add concurrence that
continued utilization at this level is decidedly detrimental to bitter-
brush and mountain mahogany stands.
Visual evidence from exclosures, reports by range techni-
cians and good commun sense tell us that protection from use is
an important aid to browse recovery.
But, we ask, how much is it necessary to curtail use? Murie
(1951, pp. 301-302) says, "When a class of forage has been reduced
virtually to the point of extermination, even any elk at ali, so to
speak, will tend to keep it at that point and prevent recovery." This
maxim applies to use by any browsing animal and merits thought-
ful consideration by those responsible for the management of
over-used ranges.
Present information does not provide us with a yardstick for
measuring the degree of utilization that will permit browse regen-
eration. Again the words of Dr. Murie accurately describe the situ-
ation here when he states (p. 301), "So far there is no answer. It
must be sought on a trial basis."
It is to be hoped that informed public opinion and thoughtful
administrative decisions will permit the setting aside of appropri-
ate game management units where use can be gradually restricted
un til: 1) the browse recovers or 2) it is proven that a plant suc-
cession is underway which cannot be halted by simply manipulat-
ing game populations. Perhaps the answer to deteriorated browse
stands will be found in the area of artificial plant propagation. In
any event, it will be deplorable if a policy of producing "the most
game for the most hunters" is followed without careful considera-
tion of how long a high yield can be maintained.
The degree and effect of big game utilization of key forage
species should continue to be analyzed through the use of the twig
measurement method. It is suggested that a growth index be
employed to evaluate relationships between volume produced and
amount consumed. The average twig length for each species should
be computed yearly as an index of the quantity of forage produced.
Differences in precipitation and other climatic conditions influence
-127--
the annual production of forage and this must be taken into consid-
eration if utilization measurements are to be applied realistically
as a factor for determining carrying capacity.
Availability-and Its Importance to Utilization
Although snow is commonly thought of as the principal deter-
rent to utilization, there are severa} other reasons why palatable
plants may escape use. The more important factors influencing
availability are portrayed in Figures 33 to 37.
FIGURE 33. This western
chokecherry has been severely
cropped or "hedged" by deer.
Ali of the current growth has
been removed as weil as many
of the older stems up to one-
half inch in diameter. Another
type of heaging, perhaps most
common to mountain mahog-
any, usually does not represent
total consumption of annual
growth as above. Nevertheless,
the mechanical obstruction pre-
sented by the stubby, cropped
twigs effectively shields re-
maining annual growth from
fp.rther use.
M a r ch 25, 1951
-128-
FIGURE 34. It is difficult to
visualize this healthy, vigorous
mountain mahogany stand as
being "unavailable"; yet it is
essentially that. Only 200 yards
away, this species is receiving
moderate use by deer and big-
horn sheep. None of the shrubs
above received use during the
last winter and their appear-
ance indicates that they may
never have been browsed by
big game. This aversion to ac-
cessible areas wh.ich, to man
appear wholly desirable, is an
often unaccountable character-
istic of animais in the wild.
S eptember 17 , 1951
Jo
.....
4
,,.. ~
fi.. b.
'•
FIGURE 35. This picture was taken from the same position as
Figure 27, only now the ground is covered with 15 inches of snow
and much of the shrubbery, along with grasses and forbs, is rela-
tively unavailable. Snow was 12 to 18 inches deep on this range for
more than two months during the winter of 1951-52.
FIGURE 36. This ledge and
cliff, 1,000 feet above the river,
is sprinkled with healthy moun-
tain mahogany; yet no use is
being made of these shrubs.
Thousands of acres of good for-
age are denied big game be-
caus e of this type of unavail-
ability. Septe mber 19, 1951
-129-
February 27, 1952
FIGURE 37. This bitterbrush
is an example of "highlining."
Vigorous twigs in the crown
are totally unavailable to the
deer and bighorn sheep that oc-
cupy the range. February 3, 1952
Use of Browse by Species Other Than Big Game
There are numerous ranges within the Salmon River drain-
age that have been seriously depleted because of past over-use by
cattle, horses and domestic sheep. Ranges included within the
boundaries of the cover type map, Figure 43, have been subjected
to a lesser amount of abuse; although early records are so frag-
mentary that accurate analysis of cause and effect is impossible.
In 1952, only three habitations were located within the 56,510
acres of cover mapped during this survey. Two horses were owned
by these three families. Five ranches are located adjacent to this
intensively studied area and, in 1952, they were not running more
than 75 head of horses. The greatest stock use is by transient rid-
ing and pack stock associated with fishing and hunting parties.
This use is limited primarily to the vicinity of camp sites and
headquarters for pack outfits. For the most part, little can be
done to alleviate unsatisfactory range conditions occasioned by
such use. It must be recognized that lack of access roads neoessi-
tates the extensive use of pack and riding stock if the wildlife
is to be properly harvested.
The importance of rodent damage is based only upon field
observations during this study and not upon detailed investigative
procedures. From the standpoint of ill effects to the revegetation
of primary browse species, it appears that small rodents are most
harmful. White-footed mice, meadow mice and pocket gophers are
among the small rodents present. They consume aerial portions
of herbaceous plants, but their primary destructiveness is the
girdling of roots. In addition, quantities of viable seeds falling to
the ground are either eaten or cached by mice.
Ground squirrels are scattered throughout the range and
occasionally reach sufficient proportions to seriously disturb the
ground cover by their burrowing activities. Marmots are common
on rocky sites. Snowshoe rabbits are scarce, while cottontail
rabbits may be locally abundant. Wood rats inhabit cliffs and rock
outcroppings. The importance of the rodents mentioned above is
confined principally to their consumption of the aerial portions of
shrubs, forbs and grasses. Browse utilization studies along the
Middle Fork indicate that rodent use of key forage shrubs is slight.
The relationship of insects to health and vigor of vegetation is
important and complex; and would require detailed investigation
to thoroughly interpret. Therefore, only apparent evidence of
insect damage is included here. The following discussion refers
-130-
'
l
1
l
specifically to the summer of 1951 when insect damage was partic-
ularly severe on Middle Forlqanges.
Scattered communities of tent caterpillars were noted on bit-
terbrush stands, but the most spectacular evidence was on choke-
cherry. Entire slopes were dotted with shrubs that were virtually
covered with caterpillars. Leaves would be stripped, leaving the
fruits to wither and fall to the ground.
Grasshopper damage was severe in 1951. Especially damaging
attacks were noted on elderberry and balsamroot. Cicada exoskele-
tons were found in a few places and their utilization of the foliage
of Haplopappus and bitterbrush was recorded. The insect damages
reported here refer only to seasonalloss of foliage and not to sorne
permanent damages which appear to have taken place.
-131-
COYER TYPE MAPPING
It is basic to intensive management to know the area and type
of habitat that supports the game population. In order to give
perspective to otherwise disassembled phases of the range sur-
vey, a cover type map was prepared for ranges along the lower 30
miles of the Middle Fork of the Salmon River and on areas adja-
cent to its mouth. Most of the field work was accomplished during
the summer of 1951.
Vegetation cover types were divided into five major classes.
They are: Op en timber, browse, cliff, open grass and waste. In
sorne cases, as with open g rass , these arbitrarily chosen type class-
ifications appear to correspond with Daubenmire's (1952) defini-
tion of a "plant association." But this does not apply in ali in-
stances. For example, many areas typed as cliffs may consist of sev-
FIGURE 38. An example of the complex interspersion of cover
types found on Middle Fork winter ranges. The foreground is oc-
cupied by an open grass type with a scattering of sagebrush and rab-
bitbrush. The upper and center background typifies the browse class.
An alluvial fan, lower left, supports a stand of open timber, while the
area at the extreme upper left assumes characteristics of the cliff
type. To avoid a refinement more detailed than warranted by the
· objectives and methods of this investigation, 20 acres was established
as the minimum unit to be considered for mapping purposes. No one
cover type represented above exceeds 20 acres so, despite the obvious
Jack of homogeneity, the dominant association of browse was the
class recognized .
August 19, 1951
-132 -
J
eral associations. Such inconsistencies with Daubenmire's widely
accepted system of classification are j ustified on the basis of the
initial purpose of this mapping project; namely, to evaluate big
game use in different types of habitat.
In most instances the cover types mapped were seral, or tem-
porary, rather than climax in condition. Sorne open timber stands
are occupied primarily by mature and over-age timber species, with
younger age classes absent or scarce. The history of plant succes-
sion, as reconstructed by plant ecologists, indicates that such
areas may, in time, assume the characteristics of browse or open
grass types. Many browse stands not only are failing to reproduce
but are further deteriorating from the combined effects of over-
use, insect and rodent damage and other factors. It is qui te possible
that these types will eventually appear as open grass. On the other
hand, there are grassy areas where abuse of the range is fostering
encroachment by such browse plants as sagebrush and rabbitbrush.
Methods
The bulk of the ranges involved in this study are in isolated
territory far from roads, or in sorne cases, trails. Transportation
was often difficult. This resulted in equipment and supplies being
limited to bare essentials, a requirement that fostered sorne tech-
niques more crude than normally used in range survey work.
A rubber boat proved to the most satisfactory mode of trans-
portation through the study area. Supplies, equipment and 200
pound boat were transported by pack string from Meyer's Cove to
the mouth of Camas Creek, a distance of 16 miles. Here the boat
was launched for the trip to the mou th of the Middle Fork. Most of
the range inspection was made on foot, though it was possible to
make Iimited use of horses.
The principal steps required to develop the cover type maps
were as follows:
1. Delineation of vegetation cover types on aerial photo-
graphs. This was accomplished in the office prior to entering
the field.
2. Field collection of qualitative range and ecological data
and correction of those type lines found, by on-the-ground
observations, to be inaccurate. Areas not sampled by the 3
step method were meandered through on foot or horseback.
3. Transfer of cover type boundaries from aerial photos to
a base map. The photos were taken to the U. S. Forest Service
Regional Office at Ogden, Utah, where the Maps and Surveys
-133-
*
ERm~S~ UTILIZATION STUOY CLl!STEn ESTABLJ3HED IN 1949
(1. total · of )2) shrut-s -numh~r varies b each cluster}
HR.Di'!SE t:TJLIZA.TIOf.! STUDY CLIJSTER ESTABLISHED Hl 1951
( Fifty shrubs measu:-t'd i n each -:lu!!terl
CLUSTER OF' )·.J'!'EP r/~THOD TRA!jSECTS
(Three 100-foot trdnsects in each clus~er)
• t'CREST SERVJC:t; 16 X If:' F:XC LOSl'RE
1-:.UHlU!-l 'f.'IIITER RANGE BOUNDARY
!J:lN IMm.: WINTER RANGE BOUNOARY
~ Ol :::u TI: .SER
c:::J BRO .. S!:
mrrn CL!FF
E3 o;-·:r;~ Gtu.S3
D ::.sr;:
SCALE IN MI LES
? oi s l f f
DATA
CC'V7:::1 TT~ : . .AXI!lll.' ~!!l'ï'::Jl: RJ..!'GE
·---·e sJ
c;•::::1 TJ!13ER
BiHr .• -s E
Cl.IFF
o· ::: c?_;,sc;
' .. 'A!; TE
TOT!\LS
21,380
20,190
1 0 ,260
3,970
710
56,5 1 0
.r-
é {
i'!~
-~--1.... '1 ! ' ' -' -L~_I , .. _:'r-.. _\,_/tl;,~~~--
/ '1·\ 1
• 1 ''1 ' ~~~-~"'--11·,-.;·:·,:.:--
\~· ·.. 1/ 1
"
~; ,..:, .. Y<
'"/'
1
1
1 1
1_ ~--l ()\ .. >
1 -' ---~---~--
1
1
-~
FIGURE 39. Cover type map of bighorn winter range along the lower Middle Fork of the Salmon River and on areas
adjacent toits mouth.
Section of the Engineering Division furnished specialized
equipment and technical assistance.
4. Determination of minimum and maximum win ter range.
After considering known elevations, measured snow depths
and observations of winter feeding by bighorn; and after ana-
lyzing browse utilization studies and such factors as slope,
exposure and cover type, a boundary was drawn along what
was considered available habitat during severe winters (mhii-
mum range). Since the intensive survey was conducted dur-
inga relatively severe winter, sorne of the above criteria were
lacking for establishing amount of usable habitat on a mild
win ter (maximum range). However, distribution of pellete:
and indications of past browse use gave a fairly accurate idea
of the areas used.
5. Calculations of total area for each cover type. After the
map was completed, a grid-type "acreage calculator" was
employed to measure each cover type unit to the nearest 10
acres.
The descriptions that follow are based upon data collected from
3 step method transects, line interception measurements and ocular
reconnaissance observations. The forage plants discussed are
species that have been recorded on the ranges visited during the
current study. Although a complete inventory of the flora is not
given, the major forage species have been included.
Open Timber Type
Bighorn sheep use during the period when the ground is snow-
covered is lighter in open timber than any other cover type. How-
ever, sheep that occupy low ranges during the summer tend to for-
age under open stands of timber. A short period in early autumn
also finds them using the timber type freely, particularly on shady
north-facing slopes.
The only noteworthy trees found in the open timber type are
Douglas fir and ponderosa pine. Composition of understory species
alters with variations in elevation, exposure, slope and other fac-
tors. However, analysis of the results from ali methods used for
measurement and estimation show that the average understory
composition is roughly: 45 percent grass, 25 percent forbs and 30
percent shrubs.
Bluebunch wheatgrass is the dominant grass on most south-
erly exposures, and on ali aspects at the lower elevations. Idaho
fescue is usually second in abundance, assuming its greatest im-
-136-
FIGURE 40. OPEN TIMBER cover type. Habitats shown are about
equally favorable to the requirements of mountain sheep. (UPPER)
An even-aged stand of ponderosa pine. Undercover species are
principally grasses, a few forbs and occasional shrubs.
September 18, 1951
(LOWER) An uneven-age stand dominated by Douglas fir. Under-
cover species present under ponderosa pine may be included here, but
shrubs are usually of more importance. Dominance of ali vegetation
fa vors species adaptable to moister sites.
August 18, 1951
-137 -
'U t
portance within the shade pattern of trees, on northerly slopes
and at higher elevations. At times it may predominate over
wheatgrass. Pinegrass is a common, sometimes dominant, grass
near the upper limits of the winter range. It may also be found at
elevations of 4,000 feet or lesson northerly slopes which are abun-
dantly covered with timber. Sandberg's bluegrass is scattered
throughout the winter range, usually occuring where wheatgrass
is dominant. Junegrass and elk sedge are extremely spotty in oc-
currence and are most abundant on north-facing sites. Cheatgrass
is present on sites which have been mistreated. It occurs in bed-
grounds, along trails, and on areas of general over-use as a rem-
nant of abuse so historical that other indicators are scarcely
recognizable.
A list of all forbs identified in the open timber type would be
lengthy, but important plants are not overly numerous. Balsamroot
is the most valuable and abundant. It is distributed widely but is
most common on south-facing slopes. The following forbs are pre-
sented in approximate order of abundance and by the aspect most
commonly supporting them.
Southerly exposures: Western yarrow, lupine, Eriogonum,
hawkweed and goat's beard.
Northerly exposures: Pea vine, Erigeron, gromwell, long-
plumed avens and western wood strawberry.
Though total density may be less, a greater variety of shrubs
flourish under stands of open timber than in any other cover type.
Most shrubs exhibit sorne preference for certain soil and micro-
climatic conditions. On southerly exposures sagebrush, rabbit-
brush, bitterbrush* and mountain mahogany are present, usually
in that order. Shrubs are more abundant on north-facing slopes
where the stand is closer and Douglas fir is the dominant tree. Com-
position varies greatly but the following shrubs are typical of
northerly aspects: Ninebark, snowberry, serviceberry, white spi-
rea and bar berry.
Spiny greasebush, syringa, golden currant, western choke-
cherry, Gooding's gooseberry, elderberry and snowbrush are ubi-
quitous with respect to exposure. The following species are fre-
quently scattered on moist sites and along streambeds: Willow,
aider, Red Osier dogwood and quaking aspen.
Browse Type
Mountain sheep use per acre was found to be lighter in browse
*Bitterbrush occurs along the Middle Fork of the Salmon River above Big Creek. Below Big
Creek it is virtually absent from the native flora.
-138-
FIGURE 41. BROWSE cover type. Quantitative data are lacking for
a valid comparison of the habitats shown. However, qualitative anal-
yses indicate that ranges similar to the one in the lower photo furn-
ish the most forage to bighorn. (UPPER) This stand of browse re-
ceives light use by bighorn but is heavily browsed by deer. Low den-
sity of grass and forb s and depleted condition of browse are factors
reducing its value for sheep.
July 27, 1952
(LOWER) Excellent interspersion of grass, shrubs and rocks creates
a favorable habitat for mountain sheep. Use on browse is heavy but
generally not severe.
September 21, 195 1
-139-
associations than on other types. This is due largely to the big-
horn's preference for grasses and forbs, and the limited period that
they occupy this cover type. Unless browse habitat is adjacent to
open grass or cliffs, or is liberally dotted with rock outcroppings,
its value is restricted. Nevertheless, the browse type is important.
lt constitutes 40 percent of the minimum winter range and furn-
ished 30 percent of the foraging observed during the study. Sorne
use has been noted during late fall rutting and on south slopes
in early spring when the bighorn are eager to abandon snow-
covered areas for any spot of bare ground. Peak importance
accrues to this type, however, during the critical winter months
when snow covers grasses and forbs, forcing the sheep to increase
their consumption of browse. Based on percentages, the three
major forage classes can be divided approximately as follows:
Grass, 30; forbs, 30; and shrubs, 40.
Species requiring conditions provided by an overstory of trees
are confined largely to northern exposures or are absent entirely.
Pinegrass and elk sedge, for example, either occur rarely or not
at ali in th ose areas typed as browse.
Shrubs favoring semi-desert conditions achieve general dom-
inance, with spiny greasebush, sagebrush and rabbitbrush being
the most abundant. Mountain mahogany, and bitterbrush within
its habitat, follow closely. Those plants described as ubiquitous on
open timber ranges have equally wide distribution in browse asso-
ciations. Shrubs listed under open timber as being especially adapt-
ed to northerly exposures or moist sites are often lacking in the
browse type.
Cliff Type
Perhaps the greatest importance of cliffs to bighorn sheep
is the provision of suitable habitat for lambing. Shortly after the
snow has melted, the sheep begin moving into cliffy terrain. The
rams remain only a few weeks, then move to higher summer pas-
tures. But the ewes stay on and begin lambing about mid-May. It
is frequently past July 1 before they leave the protection of the
cliffs. Again in the fall, cliffs come in for a share of use as the
animais move restlessly about after returning from summer pas-
ture. Use of the more precipitous escarpments is negligible dur-
ing mid-win ter; although the writer has witnessed the rather
alarming spectacle of sheep making their precarious way along
narrow, snow-covered ledges to nibble at vegetation clinging there.
About one-half of the plant caver is composed of shrubs while
the approximate percentages of grass and forbs are 30 and 20,
-140-
FIGURE 42. CLIFF cover type. Fortunately, low-value ranges like
the one pictured at the top of this page form a minority of this type.
(UPPER) These rocky escarpments rise sharply on either side of the
river. Small crevices and narrow ledges furnish a small amount of
forage but a large part of the shrubs, grasses and forbs clinging to
these steep walls are inaccessible even to sheep.
September 19, 1951
(LOWER) This range slopes obliquely from the river. Small benches
and soil-covered extrusions and gulleys are contiguous to cliffs and
barren rock and are inhabited by a variety of plants. This type of
country is favored as a lambing ground.
July 27, 1951
-141-
respectively. Sparse vegetation and inaccessibility are important
deterrents to big game use. Plant densities of less than 10 percent
are not uncommon.
Sorne differences are noticeable in plant occurrence and distri-
bution, as compared with browse or open timber. Cheatgrass and
balsamroot usually are less abundant, perhaps because of less
trampling and reduced seed dissemination between widely sepa-
rated ledges. Bitterbrush, sagebrush and rabbitbrush also find con-
ditions unfavorable for development, though they often are pres-
ent in limited numbers. Mountain mahogany, spiny greasebush
and Gooding's gooseberry, in that order, are important shrubs.
The steepness of sorne northerly aspects simulates the effect of a
shading overstory and results in the frequent occurrence of those
shrubs listed as being associated with moist sites and north-facing
slopes under open timber. Mosses and lichens reach their best
development in the cliff type.
Open Grass Type
The smallest yet most important cover type is open grass.
lt occupies only seven percent of the total area mapped but fur-
nished 24 percent of observed feeding by bighorn.
Most grass ranges are situated on southerly exposures where
slopes tend to be relatively gentle. The estimated composition of
major forage classes is: Grass-60 percent; forbs-30 percent;
and shrubs-10 percent.
Many factors combine to accentuate the importance of this
type. Being largely southerly in exposure and lying at such an
angle of repose as to receive maximum benefit of the sun, many
of these slopes are the first to "bare-up" in the spring. La te March
and early April of an average season finds mountain sheep con-
gregated almost exclusively upon open south-facing slopes. After
lambing among the cliffs, ewes often lead their offspring onto
grassy slopes for brief feeding periods. Considerable feeding has
been observed at times when up to 18 inches of snow covered the
ground. During the infrequent instances when snow accumulates
to that depth, open grass may be less important than adjacent
browse areas.
After the cover type map was completed, and compared with
known herd locations, it became apparent that open grass ranges
were focal points in the winter habitat of major bighorn herds.
Two of the largest wintering populations are at Soldier Creek and
Stoddard Creek. Lesser herds winter near the mouth of Rattle-
-142-
FIGURE 43. OPEN GRASS cover type. The specifie habitat require-
ments exhibited by bighorn fa vors the range pictured at top of page.
(UPPER) This wide hench is flecked with sagebrush and rabbitbrush
but grasses and forbs dominate. The exposure is southerly.
September 24, 1951
(LOWER) Except for bals amroot and a few minor forbs, this is a
nearly pure stand of grass. Volume of forage produced is high
but use is unexpectedly moderate. Absence of browse limits deer
use, and the northerly aspect may be a deterrent to sheep who prefer
south-facing s lopes during the winter.
September 10, 1951
-143-
snake, Waterfall and Cliff Creeks, and in Cramer Basin. A glanee
at the cover type map shows the correlation between open grass
and winter concentrations.
Composition of grass and forb species conform quite weil to
the description presented under open timber. Shrubs are sorne-
times present, but only in limited numbers.
Waste
The two principal conditions resulting in a classification of
waste are: 1) complete inaccessibility under win ter conditions
and 2) heavy stands of timber at ali elevations.
Only 710 acres were classified as waste within the maximum
and minimum winter range boundaries. Waste regions outside
these boundaries were not mapped.
Summary-Cover Type Mapping
In the course of mapping Middle Fork winter ranges, total
acreage of each cover type was calculated and the boundaries of
minimum and maximum winter range determined as accurately
as the techniques of this survey permitted. See Figure 44 for
total area of each cover type. Descriptions of each type included
a listing of the major plants and a general account of use by
bighorn sheep. But interpretation of this information in terms
of importance to big game requires a more specifie evaluation of
cover types.
The carrying capacity of a range is limited ultimately to
those wintering grounds providing forage during severe winters.
Therefore, only minimum win ter range is analyzed in the following
discussion. First, let us consider only mountain sheep. The big-
horn population wintering on the ranges mapped in Figure 43
was carefully estimated to be 680 head in 1952. The number of
acres available for each mountain sheep can be determined by
dividing acreage of each type by 680. It is quite apparent, how-
ever, that an acre in the browse type does not furnish the same
amount of desired and available forage as an acre of open grass.
In order to calculate the importance of each cover type, a
compilation was made of the vegetation type being used each
time sheep were observed feeding. A total of 304 observations
were recorded of bighorn feeding within the confines of the mini-
mum winter ranges. For this purpose one observation might
consist of one animal or a group. Numbers of observations and
their conversion to percentage use, by cover types, are shown
in Table 14.
-144-
22
20
18
16 -(/)
0 14 z
<1 (/) 12
::>
0
::t: JO
t-
z 8 --
(/) 6
"" a:
0
4
<1 2
0
OPEN
TIMBER
MAXIMUM
WINTER RANGE
BROWSE CLIFF OPEN
GRASS
MINIMUM WINTER RANGE
FIGURE 44. Classification of 55,800 acres of usable bighorn winter
range.
Based on data presented in Table 14, there are 43.4 acres of
minimum winter range available for each sheep. During open
winters an additional 26,280 acres, or 38.7 acres per bighorn, is
estimated to be available.
A means of comparing importance, on minimum winter
range, of the arbitrarily selected cover types recognized in this
study is to calculate the number of days bighorn use per acre
for each cover type. The approximate period that bighorn spend
on minimum winter range is from November 15 to May 15. This
is a total of 180 days.
Calculated on the basis of percent of observed use and
number of acres of each co ver type, big horn days per acre are:
Open timber, 3.8; browse, 3.1; cliff, 3.8 and open grass 10.6.
-145-
Table 14. Relationship of cover types to area and use as
determined by the number of times bighorn sheep were observed
feeding on each type. (Minimum winte'r range only)
Percent Percent Actual acres
of No. of of available
No. of Total observa. observed per bighorn
Cover Type acres are a ti ons use (Col. 1-;-680)
Open Timber .... 5,800 20 55 18 8.5
Browse ..... ........ 11,850 40 92 30 17.4
Cliff ....... 9,100 31 85 28 13.4
Open Grass. ........ 2,770 9 72 24 4.1
TOTALS .... _. .... 29,520 100 304 100 43.4
This indicates that an acre of open grass receives roughly
three times more use than an acre in any of the other cover
classifications. lt is important, however, to note that even during
severe winters the concentration of bighorn on these ranges
would be considered light by almost any standards.
lt is apparent also that this method for analyzing use is
subject to errors. However, the fact that the cover types con-
sidered are quite large, never less than 20 acres and usually
more than 100 acres, eliminates sorne of the variability that would
be caused by such factors as time of day, weather, season and
disturbance by an observer.
Although preference of mountain sheep for grass and forbs
reduces competition with other big game, there is common use
on many species of forage. This must be considered wh en analyzing
carrying capacity of the range for sheep. 1t is estimated that
approximately 1,000 elk, 3,000 deer and 200 mountain goats spend
at least part of the winter within the boundaries of the 55,800
acres mapped as maximum winter range.
Elk, for the most part, winter in basins and along open,
timbered ridges above the habitat classed as minimum range. In
early spring sorne elk, along with deer, join the sheep in grazing
young herbaceous plants on the lower slopes. The bulk of elk
winter diet, however, is composed of browse. Locally, elk may be
highly destructive to shrubs that also are utilized by bighorn.
Deer are more widely distributed and are present in greater num-
bers than ali other big game combined. But the fact that browse
is-the staple item in the winter diet of deer, and that they prefer
browse and open timber types, lessens the extent of their direct
competition with sheep. Mountain goat populations are low and
they compete little with bighorn sheep on these ranges.
-146-
AN ANALYSIS OF CARRYING CAPACITY
This study has developed no special formula, no magic num-
ber to be termed an absolute maximum of bighorn sheep that can
be carried safely on the ranges being discussed.
Conservation of soil and vegetation, as weil as consideration
for the fauna present, demands that minimum winter range be
given priority in management planning. This means that stocking
of the entire range should not exceed the carryîng capacity of
the area usable on a moderately severe winter. Management that
ignores this fact invites disaster to key wintering areas and
virtually assures periodic big game losses through starvation,
disease and other mortality factors operating on overpopulated
ranges. Moderately severe winters can be expected about every
four years. Is it prudent or humane to impose periodic death
sentences upon game animais? Certainly we cannot afford to
deplete our ranges seriously every four or five years by gearing
management to mild winter conditions.
A few of the difficulties encountered in fixing a desired
stocking figure should be pointed out. In many areas it appears
that deterioration of browse stands cannot be stopped short of
drastic herd reductions. Must this decline in shrub abundance
be halted at any cost to game numbers? Can we afford to sacrifice
sorne browse for the sake of maintaining huntable populations if
the condition of the soil and its cover of litter, grasses and forbs
is not impaired? Should the range be managed for the benefit
of elk, mountain sheep, deer, mountain goats? What other land
uses must be considered? Unless we can answer these and other
questions, any figure purported to represent proper stocking is
apt to be more hypothetical than realistic.
General appreciation is accorded the importance of perpetua-
tion of soil and watershed values. Y et management that insures
full recovery of deteriorated Middle Fork ranges might weil
necessitate reductions in game numbers far more severe than
anything now contemplated by game administrators. In the words
of Murie (1951, p. 301), " ... the normal carrying capacity of an
overpopulated range is less than that of one that has not been
injured, and to promote a recovery an abnormally low population
must be maintained." What could, in the light of future experience,
emerge as proper stocking may be considered entirely unaccept-
able for many years to come. No one would expect wholehearted
support for gross reductions of game, at least until after a long
period of presenting factual information to the public.
-147-
It is obvious that there must be sorne stated program-some
objective. The writer is convinced that this objective should not
be a number of animais to work toward but a certain range condi-
tion, or at least a favorable trend leading to that condition. Both
range condition and trend and game population trends must be
considered in units of several years to a void the chaotic fluctuations
of hunting regulations that would result from year-to-year com-
parisons of trend figures.
Creating goals in terms of numbers of animais has an air
of finality. Once the goal is believed to have been reached-present
census techniques seldom tell us precisely when-we frequently
find that conditions have changed and a new number is needed.
And once more the sport:"'llan, game administrator and public
must be convinced of the reasons they should favor revision of
the original objective.
Acceptance of the relationship of range condition and trend
to game population trend provides a dynamic policy for developing
management regulations. But this policy will be appropriate only
in proportion to the ability of land and wildlife managers to
recognize and interpret the trends exhibited by both game and
range.
-148-
APPENDIX
Common and Scientific Names of Species Mentioned
TREES
Fir, alpine
Fir, Douglas
J uniper, dwarf.
Pine, lodgepole ..
Pine, ponderosa ...... .
Pine, white-bark.
Spruce, Englemann's.
Alder, mountain
Aspen, quaking
Barberry
Abies lasiocarpa (Hook.) Nutt .
. Psuedotsuga taxifolia (Poir.) Britt.
Juniperus communis L. var. montana Ait.
. Pin us contorta Dougl. var. murrayana Engel.
. . Pi nus ponderosa Dougl.
. Pinus albicaulis Engelm.
Picea englemannii (Parry) Engelm.
SHRUBS
Alnus sinuate (Regel) Rydb.
Populus tremuloides Michx.
Berberis aquifolium Pursh.
Purshia tridentata (Pursh.) D. C. Bitterbrush .
Chokecherry, western
Currant, golden.
Elderberry
Prunus virginiana L. var. demissa (Nutt.) Torr.
Gooseberry, Gooding's.
Greasebush, spiny.
Happlopappus
Heath, mountain
Huckleberry, small-leaved
Mahogany, curlleaf mountain
Ninebark
Rabbitbrush, rubber.
Red Osier dogwood ..
Roses
Sagebrush, big.
Serviceberry ..
Snowberrys
Snowbrush
Spirea, white
Syringa.
Tea, labrador.
Willows
. . . . . . Ribes aureum Pursh.
Sambucus coerulea Raf.
. Ribes gooddingii Peck
. Forsellesia spinescens (Gray) Greene.
Happlopappus sp.
Phyllodoce empetriformis (Sm.) D. Don.
Vaccinium scoparium Leiberg.
Cercocarpus ledifolius (Pall.) Britt.
.. Physocarpus malvaceus (Greene) Kuntze.
Chrysothamnus nauseosus Nutt.
Cornus sericea f. stolonifera (Michx.) Fosberg .
. Rosa spp.
FORES
Artemisia tridentata Nutt.
Amelanchier alnifolia Nutt.
Symphoricarpos spp.
Ceanothus velutinus Dougl.
Spirea betulifolia Pall.
. Philadelphus lewisii Pursh.
.Ledum glandulosum Nutt .
. . Salix spp.
Avens, long-plumed Geum triflorum Pursh.
Balsamroot, arrow-leaved Balsamorhiza sagittata (Pursh.) Nutt.
Erigerons . . . . . . . . Erigeron spp.
Eriogonums . Eriogonum spp.
Goat's beard Tragopogon pratensis L.
Gromwell . Lithospermum ruderale Lehm.
Hawkweeds . . . . . . . . Hieracium spp.
Lupines . . . . . . . Lupinus spp.
Pea vines . . . . . . . . Lathyrus spp.
Penstemons. . ... Penstemon spp.
Strawberry, western wood .. Fragaria vesca L. var. bracteata (Heller) Davis.
Thistles . . . . . . . . . . Cirsium spp.
Vetches . . . . . . . . . . . . . . . . . . . . . . . . . Vicia spp.
Yarrow, western. . . Achillea lanulosa Nu tt.
GRASS AND GRASSLIKE PLANTS
Beargrass
Bluegrasses ....
Bluegrass, Sandberg's
Cheatgrass
.Xerophyllum tenax (Pursh.) Nutt.
-149-
. ....... Poa spp.
Poa secunda Presl.
. Bromus tectorum L.
Fescue, Idaho
Hairgrass, tufted .
Horsetails
Junegrass
Pinegrass.
Ricegrass, little
Rushes
Ryegrass, western
Sedges
Sedge, elk.
Trisetum, spike
Wheatgrass, bluebunch
Woodrush.
Antelope, pronghorn
Festuca idahoensis Elmer .
. . . . . . Deschampsia caespitosa (L.) Beauv.
Equisetum spp.
Koeleria cristata (L.) Pers.
Calamagrostis rubescens Buckl.
Oryzopsis exigua Thurb.
..... Juncus spp.
Elymus glaucus Buckl.
...... Carex spp.
.. Carex geyeri Boott.
Trisetum spicatum (L.) Richt.
. Agropyron spicatum (Pursh.) Scribn. and Smith .
. . Luzula parviflora (Ehrh.) Desv.
LARGE MAMMALS
Bear, Rocky Mountain black
Antilocapra americana americana (Ord)
Ursus americanus cinnamonum
Audubon Bachman
Castor canadensis taylori (New subspecies)
Lynx rufus pallescens Merriam
Felis concolor hippolestes Merriam
Canis latrans lestes Merriam
.. Odocoileus hemionus hemionus (Rafinesque)
Cervus canadensis nelsoni Bailey
Beaver, Snake River
Bobcat, pallid.
Cougar, Rocky Mountain
Coyote, Great Basin
Deer, mule
Elk, Rocky Mountain
Goat, Rocky Mountain
Sheep, Rocky Mountain bighorn
Oreamnos americanus missoulae Allen
Ovis canadensis canadensis Shaw
SMALL MAMMALS
Chipmunk
Gopher, pocket
Marmot, chestnut-bellied
Mo use, meadow.
Mouse, white-footed
Porcupine yellow-haired ...
Rabbit, Biack Hills cottontail
Rabbit, Rocky Mountain snowshoe
Rat, wood
Squirrel, ground
Squirrel, pine
Vole, mountain
Eagle, bald
Eagle, golden
Magpie, American
Ra ven
Eutamius sp .
. . . Thomomys sp.
Marmota flaviventer nosophora Howell
Microtus sp.
BIRDS
Peromyscus sp.
. . Erethizon epixanthum Brandt.
Sylvilagus nutalli grangeri Allen
Lepus bairdii bairdii Hayden
. N eotoma sp.
.. Citellus sp .
. Tamiasciurus sp.
.Phenacomys sp.
Haliaeetus leucocephalus
Aquila ch1·ysaetos canadensis
Pica pica hudsonia
Corvus corax
PARASITES
Cocci dia
Cocci dia
Lungworm
Lungworm
Lungworm.
Lungworm.
Lungworm, hair
Mite.
Pinworm
Stomach worm
Tapeworm.
Tapeworm
Ticks
Whipworm
Eimeria arloingi Marotel
. Eimeria granula sa Christenson
Muelleria capillaris Mueller
Muelleria minutissimus Megnin
. Protostrongylus rufescens Leuckart
.Protostrongylus rushi Dikmans
Protostrongylus stilesi Kamenski
Psoroptes sp.
-150-
Skrjabinema avis Skrjabin
. Ostertagia marshalli Ransom
M oniezia bene di ni Moniez
. ..... Wyominia tetoni Scott
... Dermacentor spp.
.. T1·ichuris avis Abildgaard
Deerflies .
Gnat, buffalo.
Horseflies
Horsefly.
Snipefly
INSECTS
-151-
. ..... Tabanus spp.
Symphoromyia atripes Bigot
........... Chrysops spp.
. . Chrysops perti'fiJUx Williston
... Simulium arcticum Malloch
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-152-
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-153-
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