HomeMy WebLinkAboutAPA1048r~r~·
~~e~
-~.~
~~R~~ ~~Ill
WILDLIFE
MANAGEMENT
TECHNIQUES
MANUAL
FOURTH EDITION: REVISED
Edited by: SANFORD D. SCHEMNITZ
Professor, Department Head
New Mexico State University
Illustrated by: LARRY TOSCHIK
Phoenix, Arizona
THE WILDLIFE SOCIETY
WASHINGTON, D.C.
1980
This document is copyrighted material.
Permission for online posting was granted to Alaska Resources Library and Information Services
(ARLIS) by the copyright holder.
Permission to post was received via e-mail by Celia Rozen, Collection Development Coordinator,
on April 15, 2013 from Lisa Moore, Director of Publishing and Communications, The Wildlife
Society.
This chapter is identified as APA 1048 in the Susitna Hydroelectric Project Document Index
(1988), compiled by the Alaska Power Authority.
Chapter Twenty
._...._.. • @I - -.... • • Habitat Improvement ·l·echniques
Introduction ....................................... 330
Food and Cover Production ........................ 330
Propagation .................. ; .................. 331
Transplanting .................................. 331
Direct Seeding ................................. 332
Ten Basic Principles for Successful
Plantings ...................................... 338
Regeneration .................................... 339
Mechanical and Manual Methods ............... 340
Chemical Application .......................... 341
Controlled Burning ............................ 341
Rejuvenation .................................... 342
Rejuvenating Bitterbrush ............... ~ ....... 342
Crushed Browse-Ways ............... :· ......... 343
Release ......................................... 343
Browse ........................................ 343
Mechanical Methods ........................... 343
Special Considerations ........................... 344
Cover Practices .................................... 344
Hedgerows ...................................... 344
Brush Piles ...................................... 345
Natural and Artificial Roosts ...................... 345
Nesting Cover ................................... 346
Snags ........................................... 346
Specialized Nest Structures ........................ 348
Nest Boxes and Tires ............................ 351
Platforms ........................................ 355
Baskets and Cones ............... : .............. 361
Burrows and Ledges ............................. 366
JIM YOAKUM
Wildlife Management Branch
U.S. Bureau of Land Management
Reno, Nevada
WILLIAM P. DASMANN (Retired)
Wildlife Management Branch
U.S. Forest Service
San Francisco, California
H. REED SANDERSON
Range and Wildlife Habitat Laboratory
U.S. Forest Service
La Grande, Oregon
CHARLES M. NIXON
Section of Wildlife Research
Illinois Natural History Survey
Urbana, Illinois
HE~TTES.CRAWFORD
Northeastern Forest Experiment Station
U.S. Forest Service
Orono, Maine
Water Developments ............................... 366
Water Holes ..................................... 366
Springs and Seeps ............................... 366
Reservoirs and Small Ponds .............•........ 368
Water Catchments ............................... 369
Modified Water Developments and
Safety Devices ...............................•... 372
Wetland Improvements .......................•....• 375
Development of Water Areas ...............•..... 375
Shallow Marshes .................. 1 •••••••••••• 3n
Potholes, Sumps, Ponds ........ : .....•...... 379
Greentree Reservoirs ........................... 381
Habitat Manipulation Practices ................... 382
Water Level Control ......................•..... 382
Plantings for Food and Cover ...........•...... 383
Resting Sites .................................• 384
Nest Structures ................................ 385
Man-made Islands ............................. 385
Constructing Water Control Devices ................ 385
Dikes and Embankments ....................... 385
Spillways ...................................... 387
Level Ditching ................................. 388
Plugs ......................................... 389
Structural Improvements and Facilities .............. 389
Fences .................... : ..................... 389
Interstate Highways .............................. 399
Power Lines and Raptors ......................... 399
Study Exclosures (Big Game) ..................... 400
Summary .......................................... 402
329
330
INTRODUCTION
W ildlife management is the science and art of the
interrelationships between wild animals, habitats,
and man (Giles 1969b:l). Therefore, the maintenance or
manipulation of habitats is a major component of the
wildlife biologists' responsibilities. This responsibility
cannot be slighted because wildlife habitats in North
America are undergoing tremendous changes. These
changes are primarily accomplished by man for man's
needs: grazing rangelands for red meat; logging forests
for building materials; or constructing towns, cities, and
highways for concentrated human activities. Man's ma-
nipulation of the environment for his needs is the most
prevalent factor affecting wildlife habitat and, conse-
quently, wildlife populations. Often it is not the act of
using natural resources, but the way man uses these
resources that determines the total impact on wildlife.
There are many examples of how the manipulated en-
vironment can be beneficial or detrimental to wildlife.
For example, logging dense old-growth forests may be
disastrous to the spotted owl's nesting and feeding re-
quirements, but could greatly increase preferred forage
for elk. Wildlife biologists must recognize the factors
that affect wildlife habitat, specifically those not de-
signed or implemented for wildlife, and understand the
habitat and animal interrelationships. The wildlife
biologist has the responsibility to show how such prac-
tices can be modified to increase habitat diversity for the
benefit of wildlife and man. These interrelationships are
well documented by Thomas et al. (1976) for habitats in
the Northwest and Holbrook (1974) for habitats in the
South.
Wildlife habitat management is basically concerned
with 2 major objectives: (I) to maintain quality habitat as
it exists in a natural ecosystem; and (2) to provide qual-
ity habitat where it has deteriorated, or where a specific
habitat component is lacking such as water, food, or
shelter. The following basic principles should be in-
cluded in planning and implementing habitat manipula-
tion practices:
1. Projects must be justified according to biological
needs based on intensive investigation.
2. Proposed practices must be evaluated for their ef-
fect on other natural resources and land uses.
3. Projects must be economically practical and should
specify if the objective is to maintain, improve, or com-
pletely alter the existing habitat character.
4. Improvements must simulate natural conditions.
Generally native flora and fauna should be perpetuated.
5. Manipulation projects must be designed to follow
natural topographical features as opposed to geometrical
squares or strips.
6. Projects must be evaluated at intervals to deter-
mine if the objectives have been accomplished.
Aldo Leopold's (1933) list of "axe, plow, cow, and
fire" as major habitat management tools has expanded
with new...J.!nderstandings and technological advances.
All of the land-use tools available to the farmer, forester,
and construction engineer have· been used to manipu-
late wildlife habitat. However, all the habitat manipula-
tion techniques cannot be described in 1 chapter; con-
sequently, a guide for selection of projects and ways to
"accomplish management goals" is presented. Each
method must be judged critically for each site and for
the goal to be accomplished.
Many of i.he methods discussed are from the following
major periodicals: (a) Western Browse Research pub-
lished annually by various western state wildlife agen-
cies from 1955 to 1963; (b) Game Range Restoration
Studies published annually by the Utah State Depart-
ment ofFish and Game from 1956 to date; and (c) Range
Improvement Notes published by the USDA Inter-
mountain Forest and Range Experiment Station, Logan,
Utah. By far the most important (!Ompendium on habitat
manipulation is the_ Wildlife Habitat Improvement
Handbook (U.S. Forest Service 1969). This handbook is
the best available compilation of State, Federal, and pri-
vate findings regarding foQd, cover' and water practices
for the benefit of wildlife in North America. Conse-
quently, we have incorporated much of the information
in this chapter. ·· .
The Wildlife Habitat Management Handbook (U.S.
Forest Service 1971), which has a "field reference" for
popular game species (Byrd and Holbrook 1974), is ~.lso
an excellent forest management guide for modifying sil-
viculture practices to maintain or improve wildlife
habitat. Although this handbook was developed for the
southeastern United States, much of the information is
applicable over a much wider area. Wildlife habitat
managers in western North America would also do well
to consult Vallentine' s (1971) book Range Development
and· Improvement, because there is considerable infor-
mation that can be used to develop habitat.
Other important sources of information are mono-
graphs and symposia on specific wildlife species, in-
cluding those concerned with nongame species (U.S.
Forest Service 1970, D. R. Smith 1975, U.S. Dept. Agric.
1976, U.S. Fish and Wildlife Service 1977b, DeGraff
1978).
This chapter concentrates on methods and techniques
of habitat manipulation specifically designed to increase
food, water, or cover for wildlife. The primary objectives
are to provide the basic principles for the variety of
techniques available. By being aware of these various
procedures, the wildlife or resource manager has the
basic tools to pwvide food, water, or shelter for wildlife.
FOOD AND COVER PRODUCTION
Here, the goal is to improve habitat by providing food
and/or cover for a particular species, or group of species.
In general, there are 3 major methods: Propagate "new"
plants, release existing plants by destroying "undesir-
able" competing species, and protect existing habitat
from such factors as nonprescribed livestock grazing,
fire, or draining.
"Propagation" is the direct planting of desirable seeds
or transplants; but it may also include the manipulation
of residual cover to produce mixtures of species impor-
tant to wildlife, such as even-aged forest management.
"Release" encompasses such practices as mechanical
crushing, controlled burning, and creating openings by
mechanical or chemical means to favor increased pro-
duction of desirable understory species. "Protection"
. i
l
I
includes preserving those species producing food or
cover important for wildlife.
Propagation
Although the art and science of plant propagation is
very old, information on propagating wild plants is lim-
ited to relatively few species. However, there is consid-
erable information on ornamental plant propagation that
can be readily applied. The same scientific rules apply;
the challenge is to apply these rules and the art of plant
propagation to establish "new" plant species success-
fully for improved wildlife habitat.
Land reclamation efforts in the 1930's to revegetate
wind-and water-eroded land and find suitable plants for
windbreaks, waterways, and wildlife cover provide an
information source which may require a diligent litera-
ture search for information on some plant species. More
recent efforts to revegetate drastically disturbed areas as
a result of surface mining provide valuable information
on both plant propagation and site preparation.
The interested habitat manager would do well to con-
sult further with the following major publications per-
taining to the propagation of plants by Koller and N egbi
(1961), Plummer et al. (1968), Gill and Healy (1974),
U.S. Forest Service (1974), Hartmann and Kester (1975),
Czapowskyj (1976), and U.S. Soil Conservation Service
(1976). .
Sources for n~rsery stock and seed are listed in such
publications as Source of Planting Stock and Seed of
Conservation Plants Used in the Northeast (Northeast
Regional Technical Center 1971), The Oregon Intera-
gency Guide for Conservation and Forage Plantings
(Oregon Interagency n.d.), and Pr.ovisional Tree and
Shrub Seed Zones for the Great Plains (Cunningham
1975).
The U.S. Soil Conservation Service maintains offices
in most counties and is a good source of information for
plant species best s~ited for a particular area. Such pub-
lications as Grasses and Legumes for Soil Conservation
in the Pacific Northwest and Great Basin States (Hafen-
richter et al. 1968), Shrub Plantings for Soil Conserva-
tion and Wildlife Cover in the Northeast (Edminster
and May 1951), or Plants Useful in Upland Wildlife
Management (McAtee 1941) also provide such informa-
tion. The general rule is to use native trees, shrubs, and
vines because they are adapted to the site and offer a
better opportunity of surviving. Exotic species generally
have poorer initial survival, frequently require more
cultural treatment, often grow slowly, and may produce
less seed.
The planting of food and cover species for wildlife is
often expensive and results are not always predictable.
Planting is no easy cure-all. From the standpoint of cost,
there is no good substitute for natural regeneration of
native species. Where possible, management should
aim at maintenance or improvement of existing native
species. Where it becomes necessary to introduce or re-
store species, this may be done by direct seeding or use
of transplants (Plummer et al. 1955, Brown and Martin-
sen 1959, Holmgren and Basile 1959, Hubbard 1964,
Plummer et al. 1966).
331
The most important considerations leading to a suc-
cessful plantation are: site selection, site preparation,
planting depth, and soil moisture. The best results may
be expected on sites which are known to have supported
the species concerned in the past. A knowledge of plant
requirements is essential, including answers to the fol-
lowing questions: Should the soil be coarse or fine tex-
tured; should it be well-drained or poorly drained, acid
or alkaline? At what depth should seed be planted?
An important cause of plantation failure is the compe-
tition for soil moisture given the transplants or seedlings
by established vegetation. Whether planting is done on
selected spots or over a broad acreage, care must be
taken to eliminate or reduce competition by existing
herbaceous and woody vegetation. With spot plantings,
reduction of competition can be secured through either
hand or mechanical scalping. For broad plantations, the
best results follow the preparation of the site by regular
farming methods. The objective is to plant in a clean,
firm seedbed. This may involve plowing or disking as
well as the drilling of seed.
TRANSPLANTING
Some native and exotic woody species suitable for
habitat improvement can be obtained from commercial
nurseries. Some will have to be found growing wild or
propagated. Regardless of source, transplants must be
kept moist until planted. Planting procedures should.
follow accepted nursery practices.
Elaborate facilities, although convenient, are not
needed to propagate transplants. If a greenhouse is not
available, cold frames or a plastic-covered greenhouse
can be readily constructed. Milk cartons and coffee cans
make convenient containers. However, one should be-
come thoroughly familiar with propagation facilities and
techniques before deciding on the course of action:
When a seed source is limited or not available, cut-
tings, layering, and suckers are appropriate methods for
propagating transplants. Grafting also may be a useful
means to establish a particularly desirable plant trait for
a seed orchard or nursery.
The following discussion provides some general in-
formation on plant propagation techniques that could
improve existing wildlife cover and/or food. Detailed
instructions for these techniques are available from most
state agricultural experiment stations and horticultural
textbooks such as Hartmann and Kester (1975).
Cuttings are a portion of a leaf, stem, or root that has
been removed from the parent plant and placed in a
suitable rooting medium to form roots and shoots. Al-
though some species are difficult to propagate by cut-
tings, other species root readily and only simple
facilities are needed to achieve success. Tree species,
which generally do not root from cuttings, may be stimu-
lated to form root primordia by girdling the shoot 4 to 8
weeks before cutting (Hare 1977). For those species that
root readily, cuttings are an inexpensive, rapid, and
simple method of propagating many new plants in a lim-
ited space.
The following general factors must be considered
when selecting cutting material:
332
1. Rooting ability varies greatly, even among indi-
vidual plants. Botanical relationships give a general in-
dication, and the rooting ability of some wild plants may
be predetermined by reviewing the literature on related
cultural species.
2. Stems with low-nitrogen and high-carbohydrate
content are firm and stiff, and break with a snap, which
can be confused with firmness due to tissue maturity.
Succulent, rapidly growing plants should be avoided.
Starch content, an indicator of nitrogen-carbohydrate
ratio, can be determined by the iodine test: Immerse the
ends of freshly cut stems in 0.2% iodine solution (potas-
sium iodide) for 1 minute. The darkest stained cuttings
have the highest starch content and are best suited for
propagating. It may be desirable to fertilize selected
wild stock plants to improve the rooting success of cut-
tings.
3. Usually cuttings taken from young plants root more
readily than cuttings taken from older plants. In some
cases, juvenile growth can be induced in mature plants
(Hartmann and Kester 1975).
There are also some specific factors that should be
considered, such as lateral versus terminal shoots: lat-
eral shoots may produce horizontal spreading plants;
terminal shoots may produce erect plants. Other factors
are flowering versus vegetative shoots, cuttings from dif-
ferent parts of the shoot, or cuttings that retain part of the
old wood, as well as the best time of the year to take
cuttings from specific plant species. Because plant
species respond differently to·these specific factors, no
generalized statements can be made to guide rooting
success. Specific data on individual species must be ob-
tained from the literature or through experience.
Layering stimulates root development on a stem
while it is still attached to the parent plant. Basically,
layering cpnsists of covering a portion of a plant stem
with a suitable rooting medium until it develops suffi-
cient root mass. The disadvantages of layering are that it
requires considerable hand labor, and the layered plants
need individual attention. The advantages to the layer-
ing technique are that it can be used by an individual
with little plant propagation experience and that larger
plants ~an sometimes be produced in a shorter time than
starting with cuttings.
Suckers are shoots produced from adventitious root
buds and should not be confused with watersprouts that
are produced from latent buds on the trunk or main
branches of established plants. Suckers are usually re-
moved in the dormant season by digging down and cut-
ting the shoots from the parent plant. In cases where no
roots are formed, suckers can be treated the same as
cuttings.
Grafting is a specialized propagation technique of
joining parts of plants together so they unite and con-
tinue to grow as 1 plant. Although grafting has only lim-
ited application for habitat improvement, it may be the
best method to obtain transplants of species that do not
readily reproduce by other means. Grafting may also be
used t~tablish a more convenient parent stock with
desirable fruiting or growth characteristics for later veg-
etative or seed production. Grafting can also be used to
obtain desirable fruiting qualities on root stocks that are
more tolerant of unfavorable soil conditions.
Regardless of the grafting method used, the following
requirements must be met:
1. Scion (upper portion of the graft that develops
stems or bra.Y!ches) 2.&"1d stock (lo\11.ler portion of L~e graft
that develops the root system) must be compatible.
Generally only closely related plants are capable of unit-
ing.
2. Cambial region of the 2 plant parts must be in inti-
mate contact.
3. Stock and scion must be in the proper physiologi-
cal stage. Depending on the grafting method, stock may
be either active or dormant, but the scion must be dor-
mant.
4. All cut surfaces must be covered with grafting wax
to prevent drying.
5. Grafted plants must be given proper care. Shoots
from below the graft must be removed to stimulate the
scion growth. Also, shoots from the scion may need extra
support to prevent breakage.
Smith (1973) recommended that clones of crab apples
that produce large annual seed crops be located and pro-
tected as a source of scion wood for grafting on young,
vigorous trees 7.6-10.2-cm dbh.
DIRECT SEEDING
The establishment and improvement of interspersed
forage and cover species is a wildlife habitat improve-
ment measure of broad application (Sampson et al. 1951,
Plummer et al. 1955, Edmundson and Cornelius 1961).
Frequently there are opportunities for forage or cover
improvement by coordinating wildlife needs with other
resource activities. It is important that such opportuni-
ties be recognized and used when available.
Some land management activities which offer oppor-
tunities to establish forage or cover at low costs are for-
estry (such as thinning, harvest, 'and postharvest treat-
ments), utility transmission corridors, soil stabilization
projects (such as after fires, road and ski-slope construc-
tion, and surface mining), range improvements (such as
reseeding and brush control), and any other project that
modifies the vegetative cover. It is often possible to
choose species best suited for wildlife habitat require-
ments.
Coordination of this kind is an economical way to im-
prove wildlife food and cover.
Sharecropping agreements with local farmers offer an
opportunity to maintain unharvested grains for wildlife
food and cover on lands in public ownership. In Illinois,
sharecrop farmers use a crop rotation of com or com and
soybeans, which may or may not be followed by small
grain (wheat or oats); then 1-2 years of legumes and
volunteer forbs. Farmers are not allowed to use her-
bicides or insecticides or to fall plow under these
sharecropping agreements. Sharecropping is also a more
economical and efficient method of maintaining unhar-
vested croplands than developing food patches for
wildlife. In most cases, it has been amply demonstrated
that small plots (less than 2 ha) of unharvested grain are
not effective in increasing the production of game
species. Further, development costs for a grain planting
program have risen to such high levels that their use
cannot be justified on the basis of the amount of game
harvested (Ellis et al. 1969).
Food patches are certainly no substitute for manage-
ment prognuns based on a u'lorough knowledge of
wildlife ecology and the culture of native vegetation.
Wildlife management is, after all, applied ecology. To
be cost effective it must be based on manipulation of
natural successions. Cropping and fallowing lands, pre-
scribed burning, and timber sales are all techniques de-
signed to manipulate natural succession. While food
plots have been used for many years in the East ( Sho-
mon et al. 1966), their effects on wildlife have not been
well documented. Food plots should be only used in
areas where sharecropping or burning is not feasible.
Seed Collection and Treatment
If seeds of native plants are not available commer-
cially, it will be necessary to collect them, which re-
quires specific information on time of seed ripeness and
the proper method of handling, storing, and treating
seed before planting. Such information is available in
the following publications: Collecting and Handling of
Seeds of Wild Plants (Mirov and Kraebel 1939) and
Seeds ofWoody Plants in the United States (U.S. Forest
Service 1974). Specific information is occasionally
available from regional botanical gardens such as Santa
Barbara Botanical Gardens which specializes in native
California plants (Emery 1964). .
Many plant characteristics are genetic, such as growth
form, seed production, and palatability. Therefore seed
collections should be confined to plants that display
characteristics desirable for propagation.
Seedbed Preparation
The first step ordinarily will be to get rid of woody
vegetation by crushing and burning or other disposal.
For some species, it is necessary to have a seedbed of
exposed mineral soil for the seed to germinate and grow.
Others do best on duff or litter. The type of equipment
needed for seedbed preparation will vary with species
to be planted, site and cover conditions. If domestic
livestock are in the area, they will need to be fenced
from the reseeded area until it is well established.
Fertilization
It is advisable to secure a soil test as a basis for decid-
ing about the need for fertilizer. The County Agent can
assist in getting the soil test, interpreting the results, and
recommending the time of application.
Williams (1972) attempted to show how commercial
fertilizers may be used to increase wildlife production
by improving forage production and the nutritional
quality of forage available to wild animals. The response
to fertilizers varies greatly among plant species; how-
ever, nitrogen fertilizers have been used successfully to
increase shrub and forb dry-matter production. Nitrogen
fertilizers also have increased crude protein in plants.
Sulphur and phosphorus applications have produced
the best results for increasing legumes and other plants
possessing nitrogen-fixing nodules on their roots. One of
333
Williams' major summary points is that plants growing
on soils of low fertility or soils having an improper nu-
trient balance have responded more to fertilizer applica-
tions than plants growing on fertile soils or soils having
proper nutrient baiance.
Barrett (1979), working on pronghorn winter range in
Alberta, concluded that nitrogen and phosphorus fertili-
zation on sagebrush-grassland steppes: (1) increased
total forage production and hence protein production,
and (2) that antelope use showed a definite preference
for treated areas.
Equipment
There are several kinds of equipment commonly used
for direct seeding. This equipment is described in the
Range Seeding Equipment Handbook (U.S. Forest Serv-
ice 1965) and information on new developments is gen-
erally available from the U.S. Forest Service Missoula
Equipment Development Center (Fort Missoula, Mis-
soula, Montana 59801). The commonly used equipment
is briefly discussed below.
• Deep-furrow Drill
The deep-furrow drill provides a furrow 5.1-7.6 em
deep, spaced at 35.6-cm intervals. Wider spacing is
achieved by removing drops. The 71-cm spacing is re-
garded the most practical for planting browse. Spacers
in the seedbox can be quickly provided to permit seed-
ing of different species in alternate rows. The drill is
mounted on rubber tires and can be pulled by a light
tractor or jeep. It was not designed for seeding rough
rangelands. On more level lands, the drill does an excel-
lent job of seeding as well as leaving a good seedbed for
emergence. The machine can be hauled on a 1364-kg
truck. Maneuvering ability of the drill limits its use. It is
not a practical tool for seeding small openings.
• Hansen Browse Seeder
The Hansen browse seeder can be equipped with
either 40.6-or 81-cm scalping wings. Whether equipped
with 1 or 2 scalpers, the seeder can be pulled by a jeep
or small tractor (either with wheels or tracks). The
equipment is small enough to operate in small spaces as
well as larger areas. Arrangements;can be made to pull2
drills at a time for large-scale seeding operations (Fig.
20.1). Successful plantings have been effectively made
with a variety of shrubs, broadleaf herbs, and grasses
(Plummer et al. 1968).
• Cutout Disk
The horse-drawn cutout disk used a decade ago has
been satisfactorily used in rocky and partially brushy
areas. This small disk pits the ground with many small
impressions or gouges. The seed is broadcast either
ahead of the disk or behind it. The gouges or im-
pressions aid in retaining moisture in the soil. The disk
is light in weight, compact, and rugged. It can be pulled
by a single horse or by a team.
• Seed Dribbler
Observations have indicated that soils disturbed by
crawler tractors are excellent seedbeds for browse, forb,
and grass species. Some of the best stands are often ob-
tained in these tracks. Because of the availability and
334
Fig. 20.1. Two Hansen browse seed drills hooked on a tandematic bar behind a t racto r. The purpose o f th is arrange me nt
was to drill over 1020 ha burned by w ildfire on critical deer ranges. (U .S. Bureau of Land Manage m e nt photo by Jim
Yoa kum.)
high cost of na tive browse, forb , and grass s eed, it is
important tha t a cos t-e ffici e nt m e tho d b e used in seed-
ings . Con sequently, th e seed dribbler was con s truc t ed .
This attachment dribbles seed onto the track-pad just as
it brea k s over the front idl er. The seed drops off the pad
and is imbe dded in a compact e d seedbed.
Seed dribblers are mo unted o n the d eck of a D-8 o r
similar size trac tor. The seed-drop m ech an ism h as a di-
rect drive from a rubbe r-tire d wheel riding o n the track s
of the tractor. The seed e rs m ay be mounted as a pa ir,
one on each side of the tractor, a nd a re adaptab le to
various t ypes of seed. The hoppe r h old s e n o ugh seed for
approximate l y 1.5 h o urs of opera ti on . With some mod-
ifications, it could b e u sed to broadcast in fr o nt of plows
or pipe h a rrows .
• Rotaseeder
The rotaseed e r, a 1.78-m rototill e r eq uipped with
special s lot c utting blades a nd a seed drill , h as b ee n
used t o seed ditch banks in the Midwest (Fig . 20.2). The
blades c ut narrow grooves in existin g sods and whe n
use d with a ch e mical d efoli ant , can b e u sed to seed
areas s ubject to e ro si o n .
--.;...
• Broad cast Seeding
Seed can be broa d cast b y aerial , ground, o r h and
equipment. Aerial broa d casting is particularly u sefu l on
ex te n sive ar eas foll o win g wi ldfires, on terrain too ir-
Fig. 20.2. The rotas eed e r features a 1.76-m seri es of blades
that c ut grooves and a ll ow seed placem e nt in establi sh e d sods.
(I lli nois D epartm en t of Con servation p hoto by Larry M.
David.)
reg ul a r , rocky, or s teep for drill s, o r on areas covered
with slash from tree or brus h r e moval programs (i nclud-
in g loggi n g). Cyclone seed ers can a lso b e attac h ed to
about any type of ground equipment: pickup trucks,
jeeps, all-terrain-vehicles, or crawler tractors. Hand
broadcasting is also an effective method of dispersing
seed on small areas or selected sites. Excellent results
have been obtained by seeding up to 32.4-ha areas w·ith
a 5-man crew using hand operated cyclone seeders. Two
days were required to seed such areas with 10.7-13.4 kg
of seed per ha. Many species of seed require covering
after broadcasting by mechanical procedures such as
harrowing, cabling, or chaining. However other species
do not require covering and need only be seeded into
the ashes after prescribed burning (Crawford and
Bjugstad 1967).
• Seed Spots
Shrub seeds, such as bitterbrush, can be planted
either by hand, by a modified com planter, or by a
"Schussler"1 planter in areas 0.6-0.9 m in diameter that
have been cleared and 1.27-2.5 em of topsoil has been
scraped away. Bitterbrush seed spots are particularly
applicable following fire on terrain where large equip-
ment cannot be used (Sanderson and Hubbard 1961).
• Seed Mixtures
On most lands, the use of "mixtures" of 2 or more
adapted species is advisable. Crawford and Bjugstad
(1967) successfully used grass and legume mixtures on
mesic sites. In Utah, Plummer et al. (1968) recom-
mended seed "mixtures" to include a minimum of 6
species each of grasses, forbs, and shrubs. Such mixtures
are consistent with natural vegetative communities
which most often have an endemic mixture of a variety
of grasses, forbs, and shrubs. Soil and moisture conditions
often change so markedly within short distances that
there may be great variation in the success and produc-
tivity of a single species within a seeded area. If a
species does poorly because of an unfavorable site con-
dition, or is killed by rodents, insects, disease, or frost,
one or more of the others may take its place. Another
advantage of "mixtures" is that some species develop
stands quickly and supply forage while slower develop-
ing species become established. "Mixtures" also pro-
duce vegetation with a more varied and often higher
food value. The adaptation and relative values of 56
most promising species for seeding western rangelands
with precipitation above 20.4 em are shown in Table
20.1.
If adapted legumes are available, their use with gras-
ses usually increases total production and improves the
nutritive value of the forage for many species of wildlife.
They also help increase soil nitrogen through the action
of associated nodule bacteria which converts free nitro-
gen from the air into available soil nitrogen.
The introduction of dry land Nomad variety alfalfa was
one of the most successful techniques accomplished on
antelope ranges in southeastern Oregon (Kindschy
1974). In excess of22,700 ha involving 36 separate seed-
ings have been planted to date. The alfalfa was gener-
ally aerially seeded onto plowed sagebrush ranges fol-
lowing drilling to adapted grasses and shrubs. Recent
analysis of the seedings disclosed that the majority have
1 Bitte rbrush seed planter designed by Mr. Howard Schussler
and sold by Crookham Seed Company, Caldwell, Idaho.
335
maintained alfalfa composition at a level of 10% of the
vegetation present over a 6-year or longer period. The
seedings have increased the forb composition from 2%
in untreated areas to 7% in seeded areas. During August
1976 antelope census, more antelope does \~..-ith fawns
were observed in grass and forb seedings than on adja-
cent, shrub-dominated rangelands (Yoakum 1978).
Browse species can b e mixed with grass and forb
seeds and drilled or broadcasted concurrently. Over
30,375 ha of rangelands in Utah alone have been planted
by s uch methods. On one 1,620 ha project in central
Utah, there was a 7-fold increase in forage production 3
years after treatment. Forage increased from about 89 kg
per ha to an average of nearly 623.5 kg per ha. Deer use
averaged 1.6 deer-days per ha on the adjacent untreated
lands and 34 deer-days of use per ha on the seeded areas
3 years after treatment-about a 20-fold increase . It was
noted that deer were attracted to the seeded areas from
adjacent untreated ranges. While the degree of deer u se
apparently had not damaged the forage plants at the
time of inspection, such heavy use might prove del-
eterious if continued over many years. Average deer
use of seeded range over the state of Utah is much less
than reported here, but it appears possible to increase
the carrying capacity on many thousand hectares of crit-
ical deer winter range b y seeding and planting (Plum-
mer et a!. 1966).
Forage on seeded areas is generally available earlier·
in the growing season and is more palatable than on
untreated ranges. An adequate supply of green forage on
seeded areas during the critical early spring period,
when fetuses are developing rapidly in pregnant does, is
of special value. The improved forage reduces winter
and early spring mortality and increases fawn s urvival.
Seeded ranges have been especially helpful in keeping
deer out of cultivated fields . Experience and knowledge
gained from seeding projects to date indicate that the
wildlife range manager obtains greatly i,ncreased live-
stock grazing capacities and watershed values-both of
which greatly add to multiple-use values.
On reclaimed surface mining or strip mining a reas ,
Riley (1963) successfully established 57 species of trees,
grasses, legumes, and shrubs that enhance wildlife
habitat. He tested these species on different soil types
having critical site factors such as' extreme acidity, high
total salts, and compacted surface soil. Successful seed-
ings grew on soils having a range of pH values from 3.4
to 7.2; most of the sites exhibited acid to extremely acid
soil reaction. Many species of shrubs, grasses, and
legumes displayed a tole rance to very acid soil s, high
concentrations of trace elements, sulfates, and soluble
salts.
For reclaimed areas on which fore st plantations pres-
ently grow, the technique of seeding strips of grass and
legume through the plantations has proven highly bene-
ficial t o wildlife. Older deciduous forests o ft en consist of
hardwoods with a high percentage ofblack locust, often
in a decadent condition. For such areas, a bulldozer can
create seeding strips. Recommended minimum widths
are no less than 15.2 m and a maximum of 30.5 m. On
strips less than 15.2 m wide, black locust usually in-
vades and closes the area within 5 years, often making
treatment of such areas uneconomical. Seeded strips
336
Table 20.1. Adaptation and recommended use1 of species for seeding in various precipitation and vegetation zones
on lowland and mountain areas in the Intermountain region (Plummer et al. 1955).
GRASSES
Lowlands
Species
Sand dropseed .................................... . c c
Bottlebrush squirreltail ............................ . c c
Indian ricegrass ................................... . c c c
Russian wildrye ................................... . c B B
Crested wheatgrass (Standard) ..................... . B A A
Crested wheatgrass (Fairway) ...................... . B A A
Bulbous bluegrass ................................ . X X
Bluebunch wheatgrass .............. · ............ -. .. B B
Beardless wheatgrass .............................. . B B
Pubescent wheatgrass ............................. . C4 A
Intermediate wheatgrass ........................... . C4 A
Western wheatgrass ............................... . C4 B
Beardless wildrye ................................. . C4 B
Big bluegrass ..................................... . C4 c
Mountain rye ..................................... . X
Great Basin wildrye ............................... . B
Tall wheatgrass . . . . . . . . . . . . . . . . . . ................ . B
Tall fescue ....................................... .
Bulbous barley ................................... .
Blue wildrye ..................................... .
Bearded wheatgrass ............................... .
Smooth brome (southern strain) .................... .
Smooth brome (northern strain) .................... .
Slender wheatgrass ............................... .
Mountain brome .................................. .
Meadow brome ................................... .
Kentucky bluegrass ............................... .
Tall Oatgrass ..................................... .
Orchardgrass ..................................... .
Reed canarygrass ................................. .
Timothy ................................... · · · · · · · ·
Meadow foxtail ................................... .
Sheep fescue (Sulcata) ............................ .
Red fescue (sod-forming) .......................... .
Subalpine brome .................................. .
Winter rye ........................................ . X X
Mountain lands
c
B c
B
A c
X
B c
B c
A B
A B
c c
c c c
c
X
B c
B c
c
B c
B B
B B
A A
c A
B B
B B
B B
X X
A A
B A
B4 B
B4 A
B4 A
c
c
X
B
A
c.
c
B
X
A
c
B4
B
B
c
c
B
Table 20.1. Continued.
LEGUMES
Lowlands
Species
Alfalfa ............................................ .
Sicklepod milkvetch .............................. .
Chickpea milkvetch ............................... .
Yellow sweetclover ............................... .
Strawberry clover ................................. .
Birdsfoot trefoil ................................... .
Mountain lupine .................. , ............... .
Alsike clover ...................................... .
OTHER BROADLEAF HERBS
Summercypress ................................... .
Fivehook bassia ................................... .
Palmer penstemon ................................ .
Wasatch penstemon ........... , .............. , .... .
Showy goldeneye ................................. .
Common cowparsnip .............................. .
Sweetanise ....................................... .
SHRUBS
Winterfat ......................................... .
Fourwing saltbush ................................ .
Antelope bitterbrush .............................. .
Oldman wormwood ............................... .
Blueberry elder .......................... / ........ .
X
c
c
c
B
B
B
X4
X
c
c
c
X
X
1A-Proved to be productive and widely adapted for seeding throughout the zone or type.
X
X
Mountain lands
B
B
B
X
c
X
X
X
c,
C4
c
c
c
X
c
c
c
B
c
c
c
C4
X
X
c
c
c
X
c
337
c
B
C4
X
c
c
B-Valuable over much of the zone or type, but value or adaptation either more restricted or not as well determined as species
designated A. . .. . '
C-Value or adaptation more restricted than those species designated B, but useful in some situations.
X-Recommended for special uses or conditions, usually as pure stands.
2 Applicable also for seeding openings in the ponderosa pine zone.
3Applicable also for seeding openings in Douglas-fir and spruce timber.
4 Adapted only to better than average sites in the zone or type.
through hardwood plantations, without black locust,
have remained open for 6 years with practically no inva-
sion by tree species. Large, nonforested areas support-
ing grasses and legumes can be improved for wildlife by
planting strips not over 6.1 m wide with shrub species.
Such woody plants, along with selected tree species,
may be used around the perimeter of croplands, on
slopes of strip-mine lands, or in abandoned fields.
The use of native grasses should also be considered in
those areas where they will grow and where controlled
burning or haying (in late summer) c::n be used to re-
juvenate old sods annually or at 3-to ~year intervals
(burning). Use of such species as little bluestem OP d.f
sites, Indian and switchgrass on sites with intermediate
moisture, and big bluestem on moist sites offers a means
of creatiug forage and nest cover at a reduced cost of
338
maintenance. These grasses should be sown in early
summer on ground dis ked just before seeding to remove
weed competition. Seeding rates of 2. 7 to 3.6 kg!ha have
proven successful. For the first few years, mowing may
be necessary to control competition until the grasses
achieve dominance on the site.
TEN BASIC PRINCIPLES FOR SUCCESSFUL
PIANTINGS2
There are 10 fundamental principles for making
ranges more productive by planting of browse, forbs,
and grass. They are based on over 25 years of research
and field-tested procedures developed at the Inter-
mountain Forest and Range Experiment Station (Plum-
mer et al. 1968). Recommendations usually cover broad
areas and need to be modified to fit local conditions,
availability of seeds, and facilities for doing the work.
Such modifications will usually be satisfactory if they
conform to the following principles:
1. Reduce competition.-Seedlings and suppressed
plants must have moisture to develop. Established
plants that use all or most of the available moisture must
be greatly reduced before seedlings or transplants can
develop into satisfactory wildlife cover or food.
2. Determine when and where planting will improve
the range.-Where good forage plants are present, re-
duction of competition may be all that is necessary for
the desired restoration. On western ranges, usually 1
shrub, on the average, to each 9.3 sq. m and 1 herb to
each 0.93 sq. m is an approximate minimum. Sometimes,
there is need to round out an existing forage resource by
introduction of a scarce element. For example, there
may be ample browse on a big game winter range, but a
lack of grasses and broadleaf herbs. Departure of deer
and elk from their native ranges to cultivated fields in
late winter and early springtime in search of succulent
plants is a particular problem in some states. A good
balance of browse and herbaceous plants on the winter
range may help to reduce such depredation. The estab-
lishment of early spring-growing herbaceous species,
such as crested wheatgrass, Russian wildrye, inter-
mediate wheatgrass, a range-type alfalfa, small burnet,
and balsamroot can provide desirable succulent herbs
on intermountain big game winter ranges.
3. Annual precipitation should be adequate.-
Ordinarily, artificial seeding should not be undertaken
on sites where precipitation is less than 25.4 em. The
amount of precipitation along with occurrence of indica-
tor species are the important guides in selection of
species to be used. Where precipitation is near the
lower limits, species which may be successfully seeded
are limited in the West to such plants as crested wheat-
grass, Russian wildrye, and range alfalfa. As precipita-
2Editor's Note: Although this section deals primarily with
semiarid range, it has been included because the principles
. have wide-1itility, because more millions of hectares ofland for
which these principles apply are manipulated for wildlife than
any other land type, and because of the need for making this
information available to wildlifers and land managers in the
U.S. and abroad where semiarid land management is critical.
tion increases, the number of species that may be suc-
cessfully established also increase.
4. Terrain and soil should be suitable to support the
desired forage species and to permit restoration
treatments.-Shallow, infertile soils naturally produce
little forage and may not justify restoration. On such
sites, using native species will usually result in better
success at less cost than attempts to use exotic species.
While some improvement is usually possible on unfa-
vorable sites, similar effort on favorable tracts will usu-
ally be more effective and more productive. With im-
provement of forage on good sites, game animals may
shift use to the better forage, and as a result, more severe
sites will improve naturally. There will be instances, of
course, where poor sites may require restoration treat-
ment solely to fill a critical need such as control of soil
erosion.
5. Plant adapted species and strains.-Returns on
the investment for restoration and seeding depend on a
lasting improvement. It is essential that the planted
species be able to maintain themselves and, preferably,
to spread by natural means. Sometimes it may be wise to
include rapidly developing short-lived species to meet a
planned objective, such as a nurse crop or a quick forage
supply. Such species as mountain rye, small burnet,
short-lived perennials, and yellow sweetclover, a bien-
nial, are useful for this purpose. A low seeding rate of
annual winter rye may achieve the same goal. Planting
rates of transient species in the mix should not be so
great as to offer serious competition to more desirable
and persistent species. Usually 2.7-4.4 kg per ha is
adequate for the short-lived perennials and sweetclover,
and 13.4 kg of winter rye per ha is adequate. Slower
developing but more persistent plants such as antelope
bitterbrush, fourwing saltbush, balsamroot, crested
wheatgrass, and bluebunch wheatgrass, will gradually
replace the short-lived plants. Where there is no need
for the rapid developing species, then only long-lived
perennials should be used.
It is particularly important that adapted sources or
strains be used. Ordinarily seed from plants growing on
greatly different soils, or in different climatic zones, are
much less preferable than seed from sites similar to that
planned for treatment. For example, it has been ob-
served that antelope bitterbrush seed collected from
acid granitic soils may develop chlorotic plants on basic
soils originating from limestone. Fourwing saltbush col-
lected in the blackbrush type in southwestern Utah has
failed to survive well in the higher elevation mountain
brush type. Similarly, Indian ricegrass from salt desert
shrub types has failed to survive on mountain brush and
higher elevation juniper-pinyon range. It appears that
sources from colder areas with greater precipitation can
survive better in warmer and drier areas than the re-
verse. There may be exceptions, but these are rare.
6. Plant mixtures, especially on variable sites.-A
major reason for using mixtures is to put different
species in the site conditions where they are best suited.
Site characteristics can change often and dramatically
within a limited area. Another advantage of mixtures is
that they provide a variety of forage. The total produc-
tion of a well-chosen mixture is considerably greater
than of single species stands. Where possible, seeds of
slower growing shrubs al)d herbs should make up the
initial seeding and fast growing, aggressive species in-
troduced later. Thus, grasses drilled in alternate rows
with shrubs permits better establishment of the slower
estabiishing shrubs than when both seeds are planted in
the same rows. Also, broadleafherbs generally establish
better if they can be similarly separated from the grass.
Some species are better suited to specific sites, such as
north versus south slopes or shady versus open areas.
Therefore, it may be best to confine them to such sites.
Of course, the practicability of separating species for
localized conditions depends on the size of the area.
Often it is not practical to segregate sites, so mixtures are
used.
7. Use sufficient seed to insure a stand.-One reason
to avoid heavy seeding is the unnecessary cost entailed.
Stands are usually not materially improved by excessive
s~eding. Usually; 7.1-17.8 kg per ha of total mixture is
adequate, depending on the sites involved and the
method being used. Ordinarily, when drilling, 7.1-8.9
kg per ha are advised; in broadcasting 13.4-17.8 kg are
recommended. With proper planting, 2. 7-7.1 kg of
shrub seed per ha is usually sufficient. Proper planting
depths and spacing of seed by drilling is often far more
effective than heavy broadcast seeding. However, there
are many sites where, because of terrain and obstacles,
broadcasting must be used in spite of its being more
wasteful.
8. Proper planting and coverage of seed is
essential.-Provision for some seed coverage must be
made. Seeds placed under 0.64-1.9 em of soil are usu-
ally satisfactorily covered. A few species with large
seeds may emerge from depths deeper than 2.54 em, but
most are suppressed by excessive planting depths.
Seeds which are very small should be sown no more
than 0.64 em deep. Establishment of seedlings from un-
covered seed, as from broadcasting, requires unusual
moisture conditions for successful establishment.
9. Seed in late fall and early winter but transplant in
early spring.-Seeding in October, November, De-
cember, and even January is essential for those that
need to lie over winter to break dormancy. With a few
species, notably alfalfa, fourwing saltbush, and win-
terfat, spring planting is superior to fall. This results
from their tendency to germinate during a warm period
in winter or early spring only to succumb later as a result
of freezing temperatures. The !llajor advantages of late
fall or winter seeding are: (1) inherent dormancy is
overcome; (2) some stimulation is provided by the cold
temperatures and seedlings are induced to more rapid
growth; (3) a longer period of adequate moisture is
available so that seedlings are larger and better able to
withstand the drought and heat of summer; (4) many
seed-collecting rodents tend to be inactive after late fall
so seed loss from this factor is reduced.
There are exceptions to this rule. Native grasses, such
as big and little bluestem, Indian and switch grasses, are
warm weather grasses and should be sown in early
summer.
Where rodent predation on seeds is a problem, as it is
on fall-sown black walnut seed in eastern forests, spring
sowing of seed may increase the chances of seedling
establishment (Engle and Clark 1959). This problem of
339
depredation is well documented in reports for birds
(Goebel and Berry 1976) and small mammals (Everett et
al. 1978). Sowing seed in the spring reduces the time
that rodents have to find the seed before it germinates.
10. Eliminate or reduce iivestock and wiidlife
use.-Young plants and seedlings do not develop well
when cropped off or severely trampled by large or small
animals. Livestock use of planted areas should be elimi-
nated until the seeded stand is established. Control of
game animals can be achieved by increasing the harvest
during the hunting season. Mice, chipmunks, rabbits,
kangaroo rats, and ground squirrels can also devastate
plantings if control measures are not employed. Person-
nel in the Division of Animal Damage Control of the
U.S. Fish and Wildlife Service, as well as county ag-
ricultural agents, can give up-to-date information on
animal control methods (see Chapter 22).
Regeneration
The acceptance of clear-cutting as a means of re-
generating most of the forests of the United States, both
soft and hardwood types, has created the opportunity for
increasing forage yields at little direct costs to wildlife.
The key to coordination of timber and wildlife lies in the
long-term scheduling of timber harvests using small
units of land (Roach 1974). Clear-cuts should be large
enough so deer and other wildlife will not eat much of
the tree reproduction, yet small enough so wildlife
adapted to the old-growth forest, such as squirrels and
wild turkeys, will not be seriously damaged by the prac-
tice. Narrow clear-cuts (<152.4 m wide) totaling about
8.1 ha in size seem to be a suitable compromise.
It should be remembered that non yarding deer do not
eat large quantities of woody browse but subsist mainly
on mast, fungi, forbs, and grasses (Cushwa et al. 1970,
Nixon et al. 1970). There are presently little data avail-
able on methods for increasing many of the forbs native
to the eastern hardwoods. Crawford (1976) summarized
the response of understory vegetation to overstory cut-
ting in eastern hardwood stands.
For browse cutting, clear-cuts 1 and 112 times as wide
as the uncut trees have been recommended. Rinaldi
(1970) found that strip clear-cuttipg spruce-fir stands in
patches 40.2 m wide yielded m~>re forage for deer and
hares than did strips cut 20.1 m or 60.4 m wide.
In the northeastern states, regular periodic winter-
harvested strip clear-cuttings are encouraged in and ad-
jacent to winter deer yards. Within the yards, strips of
conifers 40.2 m wide are left along streams and lake
shores for winter shelter for deer (Schemnitz 1974). In
eastern Canada, Boer (1978) recommended cuts in strips
or patches no wider than 60 min deer wintering areas.
Many of the procedures used to release desirable
browse plants from the competition of less desirable
species are the same as those used for complete removal
of existing vegetation. The results of such treatments
depend upon the intensity of application. For example,
chemical sprays may be used only to dessicate the
crowns of woody species, or to kill the plants com-
pletely, depending on strength of the mix and the
number of applications (Pechanec et al. 1954, Plummer
et al. 1955).
340
There are 4 general methods of eliminating
competition-mechanical and manual treatment, chem-
ical spmys, and prescribed burning. Often these
methods are used in combination to meet specific
needs. Mechanicai methods and hand methods are more
expensive than either chemicals or burning, but have
much wider application.
MECHANICAL AND MANUAL METHODS
The Range Seeding Equipment Handbook (U.S.
Forest Service 1965) contains descriptions of equipment
that may be used to treat areas for release from competi-
tion, together with the advantages and limitations of
each method. Only a few of the more common proce-
dures will be described briefly. Other important refer-
ences on these pmctices include Plummer et al. (1955),
Sampson and Jesperson (1963), Box and Powell (1965),
Pechanec et a~. (1965), Roby and Green (1976), and
Green (1977).
Chaining
Chaining consists of dragging a heavy chain through
vegetation to break off or uproot plants. The general
procedure is for 2 tmctors, 1 attached to each end of the
chain, to travel on parallel courses 18.3-30.5 m apart.
Additional disturbance can be gained with 1 tractor
ahead of the other so the chain rides in a "J" configura-
tion (Roby and Green 1976). The spacing is dependent
upon density of vegetation, weight, and length of the
anchor chain, size of tmctor, bite of tracks, and slope.
Ordinarily, tractors with a minimum of llO horsepower
on the draw bar are used. The chain size is dependent
upon the degree of kill desired. For dense stands of
target species with little desirable understory, a heavy
anchor chain weighing about 45.4 kg per link achieves
the best results. Dense young stands of trees or brush
require a heavier chain than older stands because of the
need to have the chain ride close to the ground. Links of
12.2-18.1 kg are used on areas where it is desired to
leave a fairly dense residual stand of browse plants.
A better kill can be ensured by chaining when the soil
moisture is at a minimum or when the first several em of
the soil are frozen. Chaining efficiently removes young,
flexible trees. Chaining also can create a good seedbed
for aerial broadcast seeding. In areas planned for twice-
over chaining along with aerial seeding, the second pass
should be timed so it will cover the seed. Properly
planned chaining projects will leave fingers or islands of
unchained trees to sirimlate natural openings in the
landscape (Cain 1971).
Vegetative type manipulation projects such as chain-
ing can change the aesthetic and biological values of an
area. Consequently the manager should be well in-
structed in the principles and procedures for pretreat-
ment, treatment, and posttreatment as described by
Cain (1971). The habitat manager should likewise be
concerne.d_ with and plan aesthetical values and designs
into vegetative conversion projects.
Chaining projects in Nevada increased fomge quality,
quantity, and diversity for deer (Tueller and Monroe
1976). Deer utilization was 139% higher in treated area·
and a 7-fold increase in deer-days use per hectare was
attributed to increase forage availability.
A "ball and chain" technique was developed to crush
brush on steep sideslopes. The equipment consists of
45.7 m of chain and a 1.5-m-diameter steel buoy filled
with water. Chain weight varies from 13.6 to 108.9 kg
per m depending on the length of chain used and steep-
ness of slope. Long chains should be of low weight per
meter so the ball will drop down the slope far enough to
work effectively (Roby and Green 1976).
Scalping
Scalping consists of scraping off the plants and part of
the top layer of soil from planting sites. It is a simple and
highly effective method of removing vegetation as well
as most of the seed in the soil beneath it (Brown and
Martinsen 1959, Holmgren and Basile 1959, Box and
Powell1965). The scalping ofbroad areas often leads to
soil losses from erosion.
There are a number of methods for scalping. The
simplest is with a hand hoe. The fastest and least exl)en-
sive is with mechanical equipment. However, me~hani
cal scalping is limited to terrain that can be negotiated
by a tractor or jeep. A pmctical method for scalping and
planting gentle slopes fairly free of rocks involves the
use of a Hansen seeder equipped with a wide
moldboard plow. Hand scalping is effective on steep
slopes and rocky areas. Scalps 0.19 sq. m and at least 5.1
em deep or deeper than the effective depth of the annual
roots are cleared with a hoe. Heavier, narrower hoes are
required for rocky, compact soils with perennial vegeta-
tion. In scalping, the matenal scraped off is piled on the
lower side of the plot to form a catch basin. Care should
be taken to avoid dirt spilling over the top of the blade
back into the plot, since this may contaminate the
seedbed with annual weed seeds. Sloughing of the soil
into the scalp from its upper edge is common on slopes
steeper than 50%. This sloughing can be minimized by
gmdually increasing the scalp in depth as the hoe is
pulled downhill rather than by vertically chopping.
Conventional Tillage
Where soil and vegetative conditions permit, plowing
is a desirable method to eliminate competitive vegeta-
tion (Pechanec et al. 1954, Plummer et al. 1955). Disk-
type plows, such as a heavy offset disk or wheatland
plow, are good for controlling nonsprouting species on
soils with relatively few rocks. The brushland plow is
best for rough, moderately rocky areas.
Plowing to a depth of 7.6 to 10.2 em is recommended
for most nonsprouting plants such as sagebrush. Depths
of 10.2-15.2 em are required to control plants which
spread by underground root stocks or from the crown. A
heavy-duty root plow is required to eliminate root-
sprouting species.
The Holt plow is effective in reducing competition on
slopes up to 40% where watershed measures are also
needed. It will create a continuous furrow in either di-
rection. This double disk furrower is attached to a
cmwler-type tractor by means of a specially built 3-point
hitch. The depth and angle is controlled by a hydraulic
ram. The tractor must have more than 100 horsepower
on the drawbar to handle the Holt plow effectively.
Chipping
Wood chipping machines are replacing some of the
traditional cutting and hauling equipment for timber
harvesting. Whole tree chippers used for clear-cutting
will leave a postcutting site almost devoid of tree limbs.
Because this technique is new, it deserves close obser-
vation to determine its appropriate value.
CHEMICAL APPLICATION
Herbicides offer possibilities for improving wildlife
habitat (Crawford 1960, Krenz 1962, Sampson and Jes-
person 1963, Halls and Crawford 1965, Kearl1965, Ore-
gon State University 1967). Selective spraying may be
used to reduce stands of undesirable browse plants.
Basal sprouting of browse species that have grown too
high or dense for deer and elk can be stimulated by
killing the aerial crowns with chemicals (Wilbert 1963,
Mueggler 1966). The variable sensitivity of different
species to the formulation, concentration, and time of
application of herbicides should enable discriminating
manipulation of the habitat, once these sensitivities are
known. Unfortunately, not a great deal is currently
known about this subject. Most big game ranges, for in-
stance, support a mixture of shrub species that differ in
sensitivity to chemicals. This often makes the effects of
sprays unpredictable. It is known, for instance, that
mixed stands of big sagebrush and bitterbrush may be
sprayed with 2,4-D butyl or isopropyl ester at the stand-
ard sagebrush control rate without serious loss ofbitter-
brush, provided spraying is done while bitterbrush is
still in bloom. On a California project, a 0.9-kg acid
equivalent 2,4-D spray with diesel oil as a carrier, at a
volume of 4.6 1 per ha, resulted in 95% removal of sage-
brush and 18% kill of the most severely hedged and dec-
adent bitterbrush plants. The remaining bitterbrush
plants, however, rapidly developed good form and
vigor. Leader growth of treated plants was 1.1 times
greater than that on controls 2 seasons after treatment
even though crested wheatgrass was planted in the
treated area. However, until more is known about selec-
tive sensitivities, caution is needed in application of
chemical sprays on mixed browse stands. Opportunities
to observe effects of forest or range management spray-
ing on plants of various species should not be over-
looked. The advantages of hand-or power-operated
ground sprayers for control of individual undesirable
species should be considered.
Pelletized picloram (4-amino-3,5,6-trichloropicolinic
acid), a 10% acid formulation in an extruded clay pellet
with low dermal toxicity, was effective in maintaining
forest openings in northern Wisconsin (McCaffery et al.
1974a). Picloram pellets (30-50) applied by hand at the
base of stems or suckers during the growing season,
achieved adequate control of aspen, willows, fir, and
alders at a cost of $23.47 to $46.93 per ha depending on
labor costs and distance travelled to the work site. Be-
cause picloram also kills broadleafed forbs, broadcast
applications are not recommended.
341
CONTROLLED BURNING
Controlled burning is one of the more economical
procedures for removing a stand of vegetation for a pre-
scribed purpose (Pechanec et al. 1954, Biswell and Gil-
man 1961, Riehle 1961, Sampson and Jesperson
1963:27, Cushwa 1968) and is a valid habitat improve-
ment technique (Beardahl and Sylvester 1974, Page
1975, Lovaas 1976). It can be used as a first step in
seedbed preparation to reduce competing plant species,
to create openings in dense stands of brush, or to create
essential habitat for wildlife species that have adapted
to fire climax vegetation such as the Kirtland's warbler
(Radtke and Byelich 1963).
Investigators have reported direct, immediate stimu-
lation of plant growth due to fire which results in greater
forage yield. Soils are warmer on burned areas and
spring growth starts earlier. On burned areas, soil fertil-
ity is usually increased. Plant vigor is promoted by re-
moval of old shoots and foliage, and in many situations,
burning of the mulch favors plant growth. Longer term
increases in growth have been achieved-by timing the
fire to favor the species with highest yields, by removing
undesirable, competing plants and by preparing seed-
beds for successful reproduction. In addition to measur-
able increase in forage yield, greater forage availability
was reported where unpalatable plants became palata-
ble after burning, where physical barriers to utilization
were burned, or where large plants were reduced in size
by burning. Most prescribed fires lead to an increase in
protein content and palatability of resprouting plants.
Fire has been a natural action changing vegetation
through all biomes of North America for centuries. Fire
is therefore a natural force in plant succession and has
always been a factor in wildlife habitat manipulation.
Uncontrolled, man-caused fires, which often have been
devastating, are one of the biggest problems to wildlife.
Such fires often have been started during the wrong sea-
sons of the year and sometimes repetitively set, which in
tum have created plant successional stages not always
beneficial to endemic wildlife. Consequently, fire as a
tool for habitat manipulation has been received with
hostility at times during the twentieth century.
The Tall Timbers Research Station was organized in
1958 near Tallahassee, Florida, to explore the role of fire
in land management. One of the station's primary inter-
ests is basic research regarding the influence of fire on
the environment and the application of fire in land man-
agement. It further recognized the right of the public to
be adequately and honestly informed as to the useful-
ness of fire in land management as well as to its destruc-
tiveness (Komarek 1962).
The Tall Timbers Station has held annual conferences
on fire ecology since 1962. Most of these meetings have
been held in Florida; however, some have been con-
ducted in California, Montana, Canada, etc. Each con-
ference has been summarized in a proceedings volume
containing papers presented. An example would be
Number 14, 1974, which was published in cooperation
with the Inter-mountain Fire Research Council and to-
taled 675 pages in 3 parts: Fire Management Section;
Fire Ecology Section; and Fire Use Section. Included
are some of the most current papers on the values, pro-
cedures, and techniques of planning and implementing
342
prescribed burning. Each annual proceeding contains
papers on the role of fire practices in relation to wildlife
habitat management. The proceedings are concerned
with fire ecology throughout the world as exemplified in
the 1971 edition devoted to "Fire in Africa."
The following is a suggested outline for planning,
execution, and evaluation for prescription burning (A.
Becker, pers. comm.):
1. Analyze Project
a. Ascertain present successional patterns fur the
area in question. Utilize historical references,
photographs, fire history (long term), environ-
mental influences and present vegetation pat-
terns.
b. Project where you wish to be. What vegetation
composition do you wish to manage for (short
term and long term)?
c. Assess site potential. Soil, moisture, residual
plants and/or seeds, etc.
d. Evaluate projected fire effects on resources
(vegetation, watershed, etc.). Utilize literature.
e. Determine: Can fire meet management objec-
tives?
2. Prepare Prescription
a. Gather field data such as:
Fuel loading (by size class)
Depth and structure of fuels
Fuel continuity
Type of fuels (volatility)
Slope
Aspect
Litter Depth
Existing firebreaks
Access
Adjacent fuels
Weather patterns
b. Determine the projected fire intensity needed
to meet objectives.
c. Utilizing the above, fuel models3 (if applicable)
and/or expertise, formulate prescription and
document. Acknowledge risk areas and mitigat-
ing measures. Prescription should include:
Temperature
Relative humidity
Ignition points
Wind speed and direction
Fuel moisture
Soil moisture
3. Execute Burn
a. Follow prescription and bum plan. If changes
are needed, document.
b. Document fire behavior (flame length, rate of
spread, etc.).
4. Evaluate
a. Immediate followup: Map intensity of bum.
Record amount of biomass left (by species such
as sagebrush skeletons, etc.), amount of litter
left, scorch height, etc. ----
3 Most fuel models are averaged over a large area; and do
provide good information. However, additional data gathered
for each site will assist in more closely predicting fire effects for
similar sites and altering prescriptions.
b. Doc':lment vegetation recovery, percent kill by
species, sprouting, production changes.
c. Insure proper management after bum. Docu-
ment wildlife use, location, etc.
The wildlife habitat manager planning a controlled
bum should review the reports by the Tall Timbers Re-
search Station (Komarek 1962). We urge the manager to
contact local authorities as to liability and seek expertise
during the initial planning stages for a controlled bum.
Rejuvenation
Many species of shrubs and trees can regenerate by
sprouting from adventitious buds on the stem or from
the root crown. The seed of chaparral species and other
species are heat resistant and germinate in abundance
after fire. When such species have grown too tall, dense,
or decadent to produce available browse, it is possible to
rejuvenate the stand by burning (Biswell et al. 1952,
Riehle 1961). With many species, it has been found that
the sprouts and young plants are considerably higher in
protein and other food values for several years after
burning than in older growth stages. However, some
species of shrubs and trees are killed by fire and may not
reestablish on an area naturally for decades after a hot
bum. These plants will, however, often respond by high
production of adventitious growth to a rejuvenation
treatment: crushing, cutting, or mowing. Chemical
spraying that bums back the tops but does not kill the
shrubs, has a similar effect on many kinds of woody
plants. The root systems remain largely undamaged; the
plants respond to the reduction of aerial growth by rapid
and expansive root and leaf development. However,
there is evidence that deer are reluctant to browse heav-
ily on plants where a multitude of dead stems are .inter-
mingled with new growth. Dead stems may be a disad-
vantage if moderate to heavy browsing is needed to hold
the growth at heights available for browsing. Crushing
of brush either before or after burning results in better
utilization of rejuvenated forage.
REjUVENATING BIITERBRUSH
Bitterbrush is an important browse species on mule
deer winter ranges in several western regions. Many
procedures have been used to rejuvenate tall, decadent
stands of bitterbrush (Driscoll 1963, Ferguson and
Basile 1966, Ferguson 1972). Results from railing or by
crushing with a bulldozer, with blade 30.5 to 61 em
above the ground, indicate a great increase in growth
the first year after treatment. This increase has been
followed by a decline in growth the second and third
year and by an actual loss of forage production. The
evidence at hand indicates that dozing and railing cause
severe mortality and diminishment of the total area of
crown.
Rolling bitterbrush with a heavy log covered with
rubber tires and pulled by a rubber-tired tractor shows
promise for plant rejuvenation. Although there was little
response the first year after rolling on a project in
California, bitterbrush leader growth averaged 54%
greater than that on the control area the second year, and
most of the treated plants showed excellent vigor. Only
2% of the rolled plants failed to resprout.
Roto-cutting bitterbrush in early spring with blade set
45.7 em above the ground level resulted in a 4 7% in-
crease in ieader growth the same year on 1 project.
Long-term results have not yet been evaluated. Pruning
of stems from an average height of over 1.5 m to heights
under 1.2 m coupled with removal of all shrub competi-
tion resulted, after 2 growing seasons, in an increase in
leader growth 2.1 times greater than on an adjacent con-
trol area. Again, long-term evaluation has yet to be made
(Schneegas and Zufelt 1965).
CRUSHED BROWSE-WAYS
Many chaparral-type brushfields are practically im-
penetrable to deer and offer little habitat to other
wildlife. Such brush ranges can be improved for wildlife
by creating interspersion of brush sprouts and herbace-
ous vegetation through development of small openings
connected by lanes (Biswell et al. 1952, Hiehle 1961).
The primary objectives of such work are the develop-
ment of both food and access.
Release
On many sites, seed-growth and production can be
improved for some species by removing the surrounding
competition. For example, Halls and Alcaniz (1968)
found that seed yields for some understory plants were
up to 32 times greater in openings compared to yields
beneath a moderately stocked pine stand.
Small group selection cuts or row thinnings c~n be
designed to admit more light, moisture, and nutrients to
potential seed-or browse-producing understory species.
In stands too young for commercial timber sales, indi-
vidual stems of important seed and browse species can
be released from surrounding competition using fire
(such species as sassafras and flowering dogwood re-
sprout vigorously after burning), herbicides, or cutting.
Release cutting of trees in older forest stands is best
accomplished in conjunction with some type of com-
mercial timber harvest. In the oak types, trees needing
release should be selected in the fall during a good
seeding year to insure that released trees will bear seed
crops. Due to genetic factors, some oaks never bear
much seed. In oak types, about 6.4 to 6.9 m 2 of basal area
of seed producers should be reserved per ha (Shaw
1971). .
In clear-cuts made in hardwood types, 0.5-0.9 m2 per
ha of basal area for seed-producing understory species,
5.1-12.7-cm dbh, should be reserved from cutting to
insure that some seed is available for wildlife during the
early years of regrowth after clear-cutting.
In addition, certain species important to wildlife, such
as the hickories and American beech, are slow growers
and are frequently overtopped by the vigorous growth of
intolerant tree species that generally follow clear-
cutting. If these slow-growing species are to reach
seed-bearing size in these clear-cut stands, they must be
released from competition. Nixon et al. (1975) recom-
mended that 20-25 suppressed hickory poles greater
than 15.2-cm dbh be left per ha after clear-cutting. Some
of these stems may die after complete release but the
343
remainder would have a good chance of reaching seed-
bearing size. Similar recommendations have been made
for beech and sugar maple in northern hardwood stands
(B. A. Roach, pers. comm.).
Another method of increasing fruit production is to
select trees, such as apple (wild or in abandoned or-
chards), wild cherry, hackberry, oak, or hickory, and
apply one of the orchardist's methods for producing
more fruit. This method involves measuring the diame-
ter of the tree in em at 1.3 7 m above ground. The diame-
ter is divided by 2. 78, and mare then substituted for em.
The resulting figure is the length of each side of a square
from which all trees are to be removed except the fruit
tree to be favored. Not only will this give the tree an
opportunity to produce more fruit, but the interspaces
are open for increased production of grasses, forbs, and
shrubs (Shomon et al. 1966).
With many fruit-producing chaparral species in the
West, such as manzanita, California redberry, and toyon,
decadent stands can be renewed by mechanical crush-
ing, chemical spraying, and especially by controlled
burning.
BROWSE
Browse is defined as leaves, shoots, and twigs of
shrubs and trees used as food. In some situations, such
as a range recently burned by wildfire; there may be a
need to plant desirable browse to introduce or restore a
supply of forage. Elsewhere, increased food production
may be a goal.
Twig growth has been found to be up to 7 times
greater for browse plants growing in the open compared
with those beneath trees (Halls and Alcaniz 1968). Cre-
ation of openings for browse production, like release
cuttings, are best made in conjunction with a timber
harvest. Browse manipulation practices can be grouped
into the following categories:
I. Release through thinning to remove competition
with less desirable species.
2. Rejuvenation through breaking, crushing, her-
bicide spraying, pruning, or burning rapidly regenerat-
ing species.
3. Planting to introduce seed ~1tock.
MECHANICAL METHODS
Cabling
Cabling is suited to areas where it is planned to save
residual stands of desirable shrubs and herbaceous
cover and where the target species are not young and
resilient (Plummer et al. 1955). Cabling is conducted
essentially the same as the procedure described in
chaining except a 45.7-to 61-m-long 3.8-cm cable is
used in place of a chain.
Hula Dozer
This mechanical device is a 100 to 125 drawbar-
horsepower crawler-type tractor with a "hula dozer"
blade. The blade consists of hinged pusher bars and
hydraulic tilting attachments. The pusher bar is used to
i i
I
I
I
1 I
!':''
illil ~.~I~~~~ p
:I:', ,,ol
i
!'II
II
'II
11,1
I.' II I!
344
tip trees, while the comer of the blade is used to lift
them from the ground. Hula dozing is economically ad-
vantageous in areas where target trees are clustered, and
clusters are widely spaced, or where trees do not exceed
240 per ha. This method is used primarily where stands
of browse plants are present, and it is desired to leave
them undamaged.
Mechanical Thinning
Equipment used to precommercially thin coniferous
forest species such as the Tomahawk and Hydroax may
be used to release browse or seed-producing species.
Other equipment that rolls, chops, or flails the vegeta-
tion also might prove useful depending on the objective
of a particular project and the availability of equipment.
Special Considerations
Vegetative manipulation projects, such as chaining,
burning, and spraying, are designed to alter the habitat
structure-both plant species and shape. Therefore,
depending on the individual involved, vegetative ma-
nipulation projects can be unsightly areas to observe.
Consequently, project planners must be concerned with
aesthetic values and plan projects to simulate natural
openings in the landscape. Project planners should also
be well instructed in the principles and procedures for
pretreatment, treatment, and posttreatment as described
by Cain (1971).
The size and pattern of food and cover treatments
should be geared to the requirements of the target
wildlife species involved and aesthetical values for
ecological conditions. With nonmigratory deer, for in-
stance, many small, treated sgots or strips scattered over
a large area will benefit more deer than a large, single
project. There are several reasons for this. In the first
place, the home ranges of bucks or doe-yearling-fawn
family groups can be quite small. Only the deer whose
home ranges impinge on or are immediately adjacent to
the treated area will move into and use the new forage.
In addition, deer often are reluctant to travel more than
61-91 m from cover and may use only the circumfer-
ence of a large opening. Of prime importance, also, is
the need to gear the amount of forage produced to the
number of animals that will use it. If use is too light, the
new sprouts and young plants may grow rapidly out of
reach or become as dense as the original untreated
stand. If, however, the treated areas are small enough so
that moderately heavy browsing of forage holds plants in
desirable forms, value will be prolonged over much
longer periods. If deer respond to better forage condi-
tions by in~rease in numbers, the frequency and size of
treated areas can be increased. Treatments can be ro-
tated so that no one area will be manipulated more often
than once in 10-20 years. In any case, no more than 30%
of the area should be treated to create better forage areas
and the other 70% left in cover, with size of cover
patches at least 16.2 ha or more (Taber and Dasmann
1958):""-
The prescribed treatments for key portions of migra-
tory deer winter range will necessarily differ from those
described above. Because heavy snows and other condi-
tions f~rce deer to·concentrate during mid-winter, deer
.i
densities and hence food demands tend to be high in
these areas. For this reason, it is essential that treat-
ments be large enough to prevent decimation of new
forage. Even here, the most productive patterns will be
in extensive broad strips or openings interspersed with
patches or strips of cover rather than in single large proj-
ects. Retention of cover should not be neglected in such
projects and should be given special emphasis where
winters are severe. In northern Maine, for instance,
dense conifer winter cover for deer should be inter-
mixed with open feeding areas not exceeding 91 m. in
width.
This brief description of requirements for deer will
show the need for analysis of the requirements of the
wildlife species to be favored and the importance o£
tailoring the program to fit these requirements.
Finally, it should be pointed out that managing
habitat for a single species of wildlife has essentially
ended, at least on public lands in the United States.
Today, the wildlife manager must strive to produce a
mosiac pattern of different habitats providing niches for
an array of wildlife species. A variety of techniques will
be needed to do the job. We reiterate again that wildlife
habitat management, to be successful, must be based on
the manipulation of natural plant successions. Tech-
niques that duplicate natural forces (such as fires that
create openings) offer the cheapest and most effective
means of providing wildlife with habitats they have
adapted to through time. There will be situations where
more artificial techniques such as planting will be re-
quired; but whenever practical, native species should
have priority in any planting program.
COVER PRACTICES
Cover fulfills varied habitat requirements for wildlife.
A hedgerow may provide escape cover for quail from
predators, or the same shrubs may provide nesting cover
for song birds. Cover can be provided by a variety of
items; rock piles, ground burrows, brush piles, or trees
(including cavities). The absence of cover, its sparce-
ness, or its poor distribution can be the factor limiting
the use of an area by wildlife. The habitat manager can
improve wildlife numbers or area of use by improving
cover quality or quantity. When manipulating food or
water, wildlifers should be careful to assure enough
cover of various kinds is left to meet wildlife needs.
Cover includes escape, nesting areas, and refuge from
inclement or adverse weather. It most often consists of a
form of vegetation-herbaceous, shrubs, or trees-that
provides protection from hunters or predators, mechani-
cal or thermal protection from winter storms or summer
sun, or a combination of these factors which provide a
secure nest site.
Hedgerows
In some areas, cover plantings are not necessary due
to rapid natural revegetation. However, other regions
may require the planting of cover such as hedgerows.
Hedgerows provide desirable escape, refuge, and nest-
ing cover, as well as travel lanes for many species of
wildlife. Low, woody vegetation can be planted along
fence rows, in gullies, and along streams or around
ponds, springs, food patches, and breeding grounds.
Such plantings generally are established by transplant-
ing seedlings or wildlings. Planting can be done by
hand or with a mechanical pianter depending upon the
size of the project. Three to 4 rows of different size
plants should be planted in a stairstep pattern so varied
degrees of cover exist. For instance, rows of Russian
olive, squawbush, and Siberian pea spaced appropri-
ately will provide travel lanes, cover, and food for many
wildlife species. Spacing of plants varies with species.
The smaller plants are planted every 45.7 to 61 em in
rows 0.9 to 1.2 m apart. Larger plants are planted every
2.4 to 3. 7 m in rows ~about 2.4 to 3.0 m apart. For most
wildlife species, hedgerows 4.6 to 6.1 m wide are
adequate. Row lengths vary, depending on the needs
and available space. One strip to each 49.4 to 61.8 ha in
open country appears adequate.
Hedgerows can also be established by plowing a strip
where a hedgerow is desired, then lining or staggering
fence posts about every 6.1 m down the strip. Wire or
twine is strung between the posts for a bird perch.
Droppings of birds that perch are laden with viable seed
and will "plant" the prepared seedbed. These "plow-
perch" plantings grow almost as fast as those produced
from root stock.
Brush Piles
When cover is limited in wildlife habitat, brush piles
may be provided. If possible, brush piles should be a
by-product of other land treatments, rather than a spe-
cific practice. Timber harvest, timber stand improve-
ment, pasture or cropland clearing, release cutting for
trees or shrubs all provide woody limbs suitable for
brush piles. Brush piles when correctly constructed and
located provide nesting and protection cover as would a
good stand of natural vegetation. Their values include
(Warrick 1976):
1. Concealment cover from predators-an overhead
canopy and surrounding brush hide nests from the view
of predators.
2. Protection from predators-the tight network of
strong twigs and small openings eliminate entry of many
predators.
3. Protection from the elements-nests are sheltered
from the cooling rains, wind, and excessive sunlight.
4. Harbor for various seeds to sprout in-the network
of twigs and grass provide a medium for seed germina-
tion and young plant growth.
Spacing of brush piles will depend on the mobility of
the species that are to use them. Brush piles for quail, for
example, should be within 61 m of other escape cover
and (for western quail) no more than 0.4 km from water.
The carrying capacity oflarge clearings for many upland
game birds can be increased by providing brush pile
cover.
Top pruning of trees on scaled quail range not only
provides slash that can be piled for cover but promotes a
bushy tree growth that makes preferred loafing cover.
Such piles should be about 1.5-1.8 m in diameter and
about 0.9 m high. It is best to elevate the pile about 15.2
345
em above the ground by using rocks or heavier limbs for
support. Where large clearings (40.5 ha or more) are
made on quail range, brush should be piled at an op-
timum rate of about 1 pile per hectare.
Long brush piles piaced in the upper portion of broad
arroyos or low profile ravines may be used to increase
cottontail rabbit populations. For rabbits, the pile may
be 7.6-15.2 m long, 1.5 m wide, and 1.2 m high (Shomon
et al. 1966). Brush piles should be at least 3.7-4.6 min
diameter and 1.5 m high to provide ra:bbit cover for sev-
eral years.
Both white-crowned and Harris' sparrows often are
found in association with brush piles. In Kansas, Harris'
sparrows often are found in winter wherever there are
brush piles (R. Graber, pers. comm.).
Turkey nests have been found in slash piles, thickets,
fallen tree tops or at the base of bushes and trees. There
are indications that carefully located brush piles may
provide nesting cover, and there may be advantages to
simulate turkey nesting cover preferences by piling
brush or slash at the bases of trees or around logs. Such
brush piles should be within 0.8 km of water.
Use of slash remaining after a timber harvest offers a
means of creating turkey nesting habitat adjacent to
openings created by the logging operation. Openings
are sought as feeding sites by hens with poults.
Brush or trees piled loosely in field comers or along
fence rows may extend pheasant habitat. Grass, forbs,
and vines will grow up through the brush and add den-
sity and permanence to the pile.
Javelina range may be extended by brush piles. A
wooden platform about 0.9 m high supported by rocks or
creosoted posts, with brush piled on top and on 2 sides,
may be used for this species. The structure may be
placed against a bank or overhanging cliff. Such javelina
brush piles should be at least 1.8 X 1.8 m and located in
an area protected from wind and near food.
Natural and Artificial Roosts
Some species of wildlife, such as quail and turkeys,
require adequate perching or roosting sites. Where
roosts are lacking, such cover can be provided through
natural vegetation plantings Oli by artificial roosting
structures.
Since 1958, the Rio Grande turkey has extended its
range into the scrub mesquite prairie of west Texas, in
part because of the installation of electric transmission
poles that are used as roost sites (Kothmann and Litton
1975). Use by these turkeys suggests the installation of
similar towers in other areas that lack roost sites but
offer food supplies and adequate rainfall.
The California quail is an example of a species that
needs at least a good roosting site per 12 ha for desirable
habitat. The lack of adequate sites may be corrected by
planting thick foliaged trees such as live oaks, olives,
citrus, and juniper. Where it is not practical or feasible to
plant trees, artificial quail roosts, e.g., brush piled on a
wire-covered frame held off the ground by 4 posts, can
be made with little cost and used as temporary roosts
while waiting for permanent natural vegetation to grow
(McMillan 1959). These roosts are constructed of pipe or
wood and should be approximately 2.4 x 5 m in diame-
It
" I
346
ter and installed 1.8 m above the ground when com~
pleted (MacGregor 1950, Fig. 20.3).
Another method to improve protective roosting sites
for quail is to cut the limbs of large trees above the
primary forks and pile these same limbs in the forks.
This also causes the tree to bush out, which creates good
dove nesting cover as well as quail roosting cover (Bauer
1963).
Eagles near Klamath Falls, Oregon, benefited from
the construction of a huge artificial tree. The traditional
roost was near a favored fishing lake. However, the few
trees used for perching were blown down by a heavy
wind. Recognizing their plight, an artificial tree was in-
stalled which has 3, 18.3-m poles placed in a tepee for-
mation with 3, 6.1-to 9.1-m cross perch poles. Fast-
growing poplars and elms were planted around the base
of the artificial tree to provide eventually a more natural
and permanent roosting site. Within less than a month,
bald eagles used this new structure and have been using
it each year since (Oregon State Game Commission
1972).
The extensive open grassland prairies of the West
provide good food sources for raptors but frequently lack
roost and nest sites. Olendorff and Stoddart (1974) noted
that raptors readily used trees and buildings made by
man, and, consequently, recommended planting trees to
improve raptor habitat. They observed that trees planted
near water are most frequently used. Until the natural
trees are large enough for nest sites, it may be necessary
to place an artificial nest structure (see "Specialized
Nest Structures: Platforms" for further specifications).
Nesting Cover
Mixtures of brome grass and alfalfa, each applied at
the rate of8.9-10.7 kg/ha, have been found to produce
suitable nesting cover for ring-necked pheasants and
other grassland nesting avifauna along roadsides in
otherwise intensively cultivated landscapes (Joselyn
and Tate 1972). Such seedings, once established, have
provided pheasants with 15 years of quality nest cover at
an amortized cost of less than $24.70/ha (R. E . Warner,
pers. comm.). Seedings are mowed once each growing
season after August 1.
On Wisconsin upland sites, canary g rass, Blackwell
switchgrass, and brome grass produced the best nesting
cover for grassland nesting species. On muck or peat
soils, canary grass and timothy gave the best results
(Frank and Woehler 1969). Plantings on upland soils
were most successful when seeded in April or May with
a nurse crop of oats; the oats were then harvested in late
July or early August. They used 3 .6-5.3 kg/ha of fine
seeded grasses such as canary grass, and 5.3-7.1 kg/ha of
the large seeded varieties such as brome ~rass. Oats
were-seeded at 42.8 1 per ha. August seedings were most
successful on muck soils because heavy weed competi-
tion occurred following spring planting. Forage sor-
ghums and sorghum-sudan grass hybrids, established
annually, provided good winter cover on Wisconsin up-
land sites. Such cover was useful on diverted acres or as
interim winter cover until woody plantings furnished
protective cover. For pure sorghum stands best results
were obtained using 7.1-13.4 kg/ha. In seeding com
and sorghum-sudan mixtures, 0.1 I of Hi-Dan 35 seed
were added to 17.6 I of seed com. Com planter boxes
~ere kept about 112 full and 55-80 g of Hi-Dan were
added to the plant boxes at regular intervals. As few as 4
rows received use by pheasants, but 0.4-1.2 ha were
usually seeded (Frank and Woehler 1969). Cost of estab-
lishing nest cover ranged from $37 to $91/ha, including
seed, fertilizer, site preparation, and planting. Winter
cover costs averaged $59 to $89/ha, if such planting were
renewed annually.
For prairie grouse, a successful seeding per ha of
1.8-2. 7 kg of redtop, 0.45 kg of timothy and 0.45 kg of
red clover, Korean lespedeza, and alsike clover, plus
0.45 kg of alfalfa when the pH of the soil is suitable, has
provided attractive nest cover in Illinois (Sanderson et
al. 1973).
Redtop seedings have been most attractive to nesting
prairie chickens the second nest season after seeding
and the second nest season after controlled burning of
redtop sods 4 or more years old (Westemeier 1973). Nest
cover for prairie chickens should be managed in 2.0-
8 .1-ha blocks, because most prairie chicken nests have
been located near breaks in cover types.
If native grasses (bluestems, switchgrass, Indian
grass, sideoats grama) are used for nest cover, they must
be mowed, burned, or grazed frequently to break up the
dense cover that will d e velop. The warm season grasses
mature late and can be mowed for hay in late July or
August after eggs are hatched and young are flying.
These grasses should be rotation burned in early spring
at 3-to 5-year intervals. This burning rotation benefited
prairie chickens, sharp-tailed grouse, pheasants, upland
plovers, and Hungarian partridge in North Dakota
(Kirsch and Kruse 1973).
Additional suggestions for maintaining or improving
nesting cover by Shomon et al. (1966) are as follows:
1. Maintain permanent, undisturbed cover along
fences, ditch-banks, roadsides, railroad rights-of-way,
and in waste areas (such as cattail sloughs) and odd cor-
ners, where possible.
2. Encourage farmers and ranchers to enter into 1 or
more of the several government programs which pro-
vide financial aid for planting vegetation which is suita-
ble for wildlife cover.
3. Work with state and local highway departments to
discourage burning of cover along roadsides during the
winter and spring; encourage the delay of mowing until
after July 1; and encourage the planting of grasses and
legumes for use by nesting pheasants.
4. Refrain from dry land fallowing operations between
the period of April 15 and June 20 to enable ground-
nesting birds to hatch in important stubble field nesting
areas.
5 . Use flushing devices on mowers to save nesting
females during the first cutting of alfalfa.
6. Fence nesting cover to prevent grazing by live-
stock.
7 . Plant shrubby thickets along gulleys and draws for
use as cover.
Snags
Over 85 species of North American birds use cavities
in dead or deteriorating trees (Scott et al. 1977). Thomas
Fig. 20.3. Install ation of an artificial quail roost in southern
California (photos by I. McMillan).
et al. (1976) observed that 24 mammal and 38 bird
species used tree cavities for a mountain range in Ore-
gon and Washington. Such trees ar e often called
"snags." The removal of snags can reduce wildlife popu-
lations. For example, in Arizona the removal of snags
re duced cavity-n esting bird populations by 50o/o. Much
of thi s d ecline was in populations of violet-green swal-
347
lows, pygmy nuthatc hes , and northern three-toed
woodpeckers. Swallows alone dropped 90%, whereas a
low woodpecker population was eliminated (Scott et al.
1977).
Foresters and recreation managers are now more
aware of th e econ o mi c and esthetic values of cavity-
nesting birds. The majority of snag-dependent wildlife
348
species are insectivorous and fill a major role in the con-
trol of forest insect pests (Thomas et al. 1976). Recogniz-
ing these wildlife values, the U.S. Forest Service (1977)
issued a new policy to "provide habitat needed to main-
tain viable, self-sustaining populations of cavity-nesting
and snag-dependent wildlife species." An example of
placing this policy into effect was the Arizona-New
Mexico Forest Service Regional Office recommendation
that 7 good quality snags per ha be retained within 152
m of forest openings and water, with 5 per ha over the
remaining forest. Some agencies are now placing signs
on snags and other valuable wildlife used trees identify-
ing them as "Wildlife Trees" not to be harvested or cut
down for firewood.
SPECIALIZED NEST STRUCTURES
Many species of wildlife that use tree cavities have
declined due to the loss of primeval forests. Examples
are the ivory-billed and red-cockaded woodpeckers
which are presently on the endangered species list due
mainly to the loss of habitat (Scott et al. 1977). There are
many mammals that also rely heavily on tree cavities for
part of their life cycle. For example, the best nest den
sites for the eastern gray or fox squirrel are tree cavities
with specific dimensions-. For fox squirrels, cavity di-
mensions averaged 16 x 17.5 em in diameter and
38.1-40.6 em deep, measured from the top of the den
entrance, with an entrance opening 6.1 em x 9.4 em in
diameter (Baumgartner 1938). Blackgum, beech,
maples, gums, basswood, and elms decay readily and
form dens within a few years; oaks decay slowly and
form dens in their later years. Sanderson (1975) recom-
mended a mixture of trees that decay and form cavities
at different rates.
Man should husband existing den or nest trees and
should look to artificial structures only as a secondary
technique after full evaluation of the need. It is more
realistic and justifiable, in view of the many human and
ecological values at stake, to make ample den or nest
trees continuously available as a natural and vital com-
ponent of the living forest.
At times, however, man-made structures must be used
or a species will not survive. As an example, nest trees
for double-crested cormorants have become scarce
along the upper Mississippi River in Illinois and Wis-
consin. In Illinois, an artificial nest tree was provided. A
single 14.6-m utility pole was anchored adjacent to 2
existing natural nest trees about 1.6 km from shore and
in water about 5.5 m deep. Twelve nesting platforms
were attached to the pole using 6 cross arms spaced 0.9
m apart (Fig. 20.4). The nest platforms consisted of
boxes 5.1 em x 40.6 em x 1.8 em deep with 3,
7.6 X 40.6-cm slats on the bottom. The boxes were lined
with 2.5-cm-mesh chicken wire (Kleen 1975). Another
type of platform with 2 cormorant nests was built on the
Agassiz National Wildlife Refuge in Minnesota (Fig.
20.12).
ThelJ.s: Forest Service system of managing nesting
trees for rare and endangered native wildlife such as the
bald eagle, ivory-billed woodpecker, red-cockaded
woodpecker, and osprey provides an example of how
the important, but seldom understood, technique of nest
tree protection is currently being practiced:
l. Maintain an iFlVentory of all nest sites and identify
in detail the location of each.
2. Check nests periodically and record a cumulative
history of nest use.
3. Within 100 m of any nest tree, development ac-
tivities will be limited to management measures benefi-
cial to maintaining the nesting site.
4. A special buffer zone, 201m in radius, will bees-
tablished and marked on the ground around each nest
site.
5. Timber cutting, timber stand improvement, pre-
scribed burning, road construction, recreation construc-
tion, and other disturbing activities will not be allowed
within the buffer zone during the period from
November 1 to June 15.
6. All practices such as insecticide spraying, aquatic
plant control, and the use of fish toxicants, will be criti-
cally evaluated regarding their effects on nesting sites
within the forest and areas outside of th~ forest, but
within 0.8 km of the forest's boundary.
7. Three to 5 old growth trees will be reserved as
roosting and potential nest trees within the buffer zone
surrounding the nest. For red-cockaded woodpeckers,
an aggregate of cavity containing live pines, 25.4-63.5-
cm dbh, 70-100 years old, are needed for each colony.
8. The location of all nests and their buffer zones will
be shown in the forest's "Multiple Use Atlas." These
special management considerations will stay in effect
until it has been conclusively determined that the nest-
ing site has been abandoned.
Artificial nest structures can substitute for a defi-
ciency of natural sites in otherwise suitable habitat.
Where primeval forests are primarily gone in the eastern
United States, purple martins now depend almost en-
tirely on man-made nesting structures (Allen and Nice
1952). Bird houses have been readily accepted by many
natural cavity nesters, and increases in breeding density
have resulted from providing such structures (Grenquist
1966, Strange et al. 1971, Hamerstrom et al. 1973). Nest
boxes are useful for wood ducks and squirrels, as well as
various nongame species, such as bluebirds, screech
owls, kestrels, and barn owls. Nest baskets and plat-
forms are readily used by waterfowl.
Bird houses have been built by man all over the world
for eons. Sometimes this was merely the placing of a
large gourd with a small hole in a nearby tree. At other
times it would be the elaborate construction of a 18-
compartment complex for the gregarious purple martin.
The practice continues today as attested by the variety
of different bird house designs and styles (Fig. 20.5).
Detailed plans for these structures are often available
from the National Audubon Society, local bird clubs,
Cooperative Extension Service (McDowell 1972), and
other sources (Shomon et al. 1966).
The very popular and helpful pamphlet Homes for
Birds published by the U.S. Fish and Wildlife Service
(Kalmbach et al. 1969) provides many excellent exam-
ples for constructing bird houses. The authors stress that
the bird house should be designed and constructed ac-
cording to the needs of the target species. These specifi-
349
D.C.CORMORANT NEST STRUCTURE
~11 X 2" WASTE SLABS
OR OTHER MATERIAL,
IDENTICALLY CONSTRUCTED
AT BOTH ENDS,
DRAWING "A"
(SEE DRAWING "B")
2" X 2"
DRAWING "B"
NOTE:
Upright angle
braces have been omitted
on Drawing 11 B11 to allow
for a less cluttered view
of the main structure.
See Drawing 11 A11 for detail
on these angle braces.
6
~II X 2"
WASTE SLABS
OPEN ClRCLES REPRESENT
WIRE BASKETS
1
Fig. 20.4. Nest tree for double-crested cormorants. The crossanns and nest baskets are attached to a 14.6 m telephone pole as shown in
Drawing "A." Crossanns spiral up the pole 60 degrees apart as shown in Drawing "B." The numbers in Drawing "B" refer to crossanns.
(Illinois Natural History Survey drawing by Lloyd Lemere.)
350
~--p: .. -.
l ' c. ' - t
1\
i 1\
lor ·~ p
f.\ ~ ~\
" '·
~ 'B I
(;IIV~D ~~ .Air13,_.?.1.~
n> -..rl. #AAM'I~ lllii'V~.PI
A-'TAHtlr AMIII'r/-ANP
-A?-" INVII/If!I!.S
7W£Y -.LIP 71 .-z,e.,..y
A6'At'AI'IIil 7%1 PI?S'r$.
$,../FC/1$
aU/!11/~P
CNKKADEE
T/TJ>fOUS'E
NUTHATCH
M/1V$EWKEN
CAIItD~/NA -EN
IVEITIII ,l>"CAn'N6Jit
"'ICKE/It
~-HEAPED 11111t1PPi!t:1rllf
DDWfVY W()()DPECKER
Pr/J/IJI',LE -lrT/N
,_E ·""MLOW
-J/IN Olt'.L
IPAJillf-NIIWK
,...
IN
8-10 ..
8·/0N
1·10 ..
~-~-,._,-
I·!D"'
/4•/F"
I..Z•IS'"
I·ID-
~-
(;"
/J"•/1-
/JI•IS"""
"B c 'P
S)r,s-· ti" ~-
of.k,.-,.,. ~Nr ,. .. .,.-#. ~.,. ,. . .,.. t:j• t;-1· .,..,.,.. ~o· /-~· ., . .,.. /I' 1-~-
~ ... ~-.e· ~-r
71<7" .zf• 14·1'"
~-~· a· '1·1/l..
.,. . .,.. 14 .. ,_,.
~-~· :u· ,.
.s-·.s-· , .. /-s-·
ID•/8" 6" .,... , .. ,. a· 'l-.12.-
Fig. 20.5. There are many styles or varieties of bird houses. The 1 main criteria for design is to build the nest facility to the
size and needs of the target species (Shomon et aL 1966).
I
cations vary greatly and can make the difference in the
success or failure of a newly constructed bird house
producing nestlings. Table 20.2 provides the various
specifications for 26 different birds.
In the U.S.S.R. and some eastern European countries,
increasing emphasis is being placed on the role of forest
birds in preventing irruptions of harmful forest insects.
While the role of birds is generally considered
prophylactic and contributive as a component in inte-
grated pest control (Khramtsov and Timchenko 1976),
certain species are believed to depress insect numbers
during high insect populations (Blagosklonov 1977).
Research efforts in attracting birds for insect utiliza-
tion have significantly increased (Kuteev 1977).
Blagosklonov (1977) discussed the results of an evalua-
tion of artificial nesting structures, differing in construc-
tion material, dimensions, construction form and color.
Evaluation criteria were based on the habitat require-
ments of 5 bird species important as insect predators.
Where intensive forest management has eliminated
dead and dying trees, the placing of artificial bird nest
351
boxes can be a beneficial wildlife management tech-
nique (Bruns 1960, Franz 1961, Williamson 1970, Beebe
1974). The installation of bird nest boxes can increase
bird abundance which in tum can be an important factor
on the control of insects injurious to forests.
Nest Boxes and Tires
Nest boxes must be properly designed, located,
erected, and maintained for beneficial results. They
must also be durable, predator proof, weather tight,
lightweight and economical to build. The boxes also
must meet the biological needs of the target species.
WOOD DUCK
No one type of nest box or placement meets all the
requirements imposed by the diversity of habitat and
predators. Consequently, each nest box program needs
to be designed for local conditions. However, certain
generalizations are warranted (Bellrose 1976):
Table 20.2. Dimensions of nesting boxes for various species of birds that regularly use them, and the height at which
they should be placed above the ground (Kalmbach et al. 1969).
I'
' "
352
1. Initially, wooden boxes are more acceptable to
wood ducks than metal boxes. But metal boxes have a
higher nest success rate and in a few years may have a
higher occupancy rate than wooden boxes. However,
wood ducks need to be conditioned to using metal boxes
by prior use of wooden boxes. For wooden boxes,
rough-cut lumber is best. Smooth lumber can be used if
a "ladder" of 0.64-cm mesh hardware cloth is attached
inside so the day-old ducklings can climb out. Vertical
metal boxes should be provided with either a hardware
cloth "ladder" inside or with a car undercoat material
sprayed or troweled inside to permit ducklings to exit.
2. Nest boxes should be made as predator-proof as
possible or mounted in such a way to prevent predators
from entering. Both wooden and metal boxes should
have elliptical, raccoon-proof entrances, or be protected
with inverted metal cones, or be attached to a steel pipe.
3. All nest boxes must be provided with 7.6-10.2 em
of sawdust, wood chips, or shavipgs to form a nest base
and cover the first few eggs.
4. Groups of 4 to 8 nest boxes per ha ultimately have
the highest use because of successful nesters and the
associated young birds' homing behavior. However,
grouped boxes have higher predator exposure and must
have adequate protection.
5. Wood ducks use nest boxes on poles in water at a
higher rate than those in woods. In woods, the nearer
the water the better; up to 0.4 km is good, 0.8 km satis-
factory, and 1.6 km a possibility for nesting. The more
open and parklike the woods, the better for wood ducks
and, unfortunately, for starlings. Dense woodland deters
starlings more than wood ducks. Houses in trees should
be placed 3. 7 to 6.1 m above the ground where the
canopy is open and does not overhang the entrance.
A design for both wooden and metal nest boxes for
wood ducks is shown in Figs. 20.6 and 20. 7.
Where starlings are a problem, a horizontal nest box
can be substituted for the vertical box (McGilvrey and
Uhler 1971). This nest box is constructed of galvanized
duct pipe 30.5 em in diameter and 61 em long with 2.5-
cm-thick wooden ends. The back is solid and the front
has a 10.2 x 27.9-cm semicircular opening. Cylinders
are mounted on steel fence posts over water and
equipped with 61-91 em lengths of aluminum down-
spout sleeves (7.6-cm diameter) to act as predator
guards. A shallow partition may be placed in the center
of the cylinder to prevent eggs or ducklings from moving
forward and becoming chilled.
Cylinder structures should be used in combination
with the metal or wooden vertical boxes to allow wood
ducks gradually to accept the horizontal cylinders. It
should be possible to switch the nesting population of
an area from vertical boxes to cylinders over a 5-6 year
period. Kestrels, tree swallows, grackles, purple mar-
tins, and great crested flycatchers have also nested in
these cylinders (Heusmann et al. 1977).
The British Columbia Fish and Game Branch erected
30 wood nest boxes for buffieheads. Most were used by
starli~and tree swallows from the ,start. However, 6
were used by buffieheads on 3 consecutive years. Re-
ports indicate that buffieheads also used nest boxes in
Alberta and California (Erskine 1971). Norman and
Riggert (1977) reported 36% of nest boxes examined
were used by ducks in Australia.
SQUIRRELS
The nest box designed by Barkalow and Soots (1965)
has been slightly modified to provide a more durable
and maintenance-free ·structure. See Fig. 20.8 for design
specifications. The use of rot resistant or treated wood
enhances durability of nest boxes; however, creosote
treated wood should be avoided. The wooden nest
boxes should be fastened to the tree with nonferrous
nails.
The dimensions of this box also meet the specifica-
tions of nest boxes for kestrels and screech owls. Other
species of wildlife known to use squirrel nest boxes for
shelter or nurseries include flickers, nuthatches, red-
bellied woodpeckers, starlings, flying squirrels, and tree
frogs.
Tire nests have also been utilized for nesting by east-
em gray squirrels (Burger 1969). The construction de-
tails are shown in Fig. 20.9. Tire nests should be hung
over a branch at least 4.6 m from the ground with the
open throat towards the tree trunk.
Nesting structures for squirrels should be erected at
densities of 5-7.4 per ha in areas producing 45.4 kg or
more mast per ha (Sanderson 1975). They are most effec-
tive in hardwood stands between 30 and 60 years when
mast crops are abundant, but tree cavities suitable for
sheltering squirrels are scarce. Nesting structures
should not be placed in trees already containing tree
cavities; squirrels will not readily accept artificial nest-
ing structures if natural cavities are available in the
same tree.
BLUEBIRDS, SWALLOWS
During the past 40 years, eastern bluebird popula-
tions appear to have plummeted as much as 90%
(Zeleny 1977). The western bluebird and the mountain
bluebird of the Rocky Mountain region have suffered
less, but gradually they are experiencing similar de-
clines. The loss is due in part to decreased old, decadent
cavity trees needed for nesting and competition with
starlings and house sparrows for limited nest sites.
Today' s bluebirds are taking more readily to artificial
nest boxes due to the scarcity of natural nest sites. Dur-
ing the past 5 years, nearly 1,000 bluebirds were raised
in 85 nest boxes along a "bluebird trail" 11.3 km from
Washington, D.C. (Zeleny 1977). Canada boasts a
3,218-km "bluebird trail" through the prairie regions of
Manitoba and Saskatchewan. Some 8,000 nest boxes
were installed which produced more than 8,000 young
bluebirds and 15,000 young tree swallows in 1976.
Bluebirds prefer open areas with scattered trees. Nest
boxes may be constructed of almost any type of wood.
They should be placed 0.9-1.5 m off the ground. Fence
posts make good sites. Boxes should be spaced at least
100 m apart to eliminate fighting among highly territo-
rial males. Figure 20.10 provides detailed plans for con-
structing a top-opening bluebird nest box.
Tree swallows also readily use nest boxes of the same
specifications. Ponds and marshy areas are ideal loca-
tions to place nesting boxes. Backyards are another good
place as swallows readily adapt to human activity and
are welcomed for their habit of consuming numerous
·mosquitos. Nest boxes should be spaced 22.9-30.5 m
apart on poles about 1.2 to 2. 7 m above the ground. Fig-
353
9 ~ I If_ \.., ~ _1!_ jl lr . .....
I
I I .
I
~' oLLff-'' ~ d :L _lJ ______ --!J-JI ~ .T
o - •
1 !1') I 0 0 I 1o It)
' .f.---1-I I __!_
OJ ,o • 1 I lo 1 lo til
-1-------+-T I l~ I 4" I I ., 0~ I
I I I r /2 HOi.£ lo 01 10 o, I I I I I I I I I • I I • I ~ I
I I 't-~10~ l I C\1 I I
:o I :o Ol 01
I I I I ,--------· oi , jO I ~ I I 10 f-T--------r-I I T I , I I I
I !Is #OLES I I I •
01 ~ ,o 01 10 't-
~.,;. 1o--~--ol,-~.. 1-~ ~,'o-,,-o "!!'.;. i,.. _....._
FRONT VIEW REAR VIEW SIDE VIEW
Fig. 20.6. Plans for a wooden nest box for wood ducks (Bellrose and Crompton 1972).
354
./""""-7\ u \t
METAL BASE
12" OIAM. HOUSE BODY SHEET METAL CONE
12M DIAM .•
FIT BOTTOM EDGE OF
CONE AROUND BODY
AND SECURE WITH
METAL SCREWS
24. ll:ONG
CRIMP THIS EDGE
TO FIT OVER BODY
12" DIAM. )( 15" HIGH
TOP EDGE OF BODY CRIMPED
3/8"
HOLE
PLAN
I,; X 3" X 22" WOOD BOLTED TO BODY.
USE TO FASTEN HOUSE TO
SUPPORTING OBJECT.
LAYOUT FOR CONE
/'.
2. MAKE A 7~• LOOP3\
OF STRING AND \
\,/ PLACE AS SHOWN
I. PLACE TWO -PINS 2 S/8" AF't4RT
3. INSERT PENCIL INSIDE LOOP AND,
KEEPING STRING TIGHT, ROTATE
PENCIL AROUND PINS. THIS
CURVE WILL RESULT.
INSERT METAL BASE INTO BODY
AND SECURE WITH SCREWS
OR SOLDER.
SECTION LAYOUT FOR ENTRANCE
Fig. 20.7. Plans for metal nest facility for wood ducks (Bellrose and Crompton 1972).
ures 20.5 and 20.10 list specifications to follow. Be sure
the box opening is small enough to prevent cowbirds
and starlings from entering (Ebert and Francis 1978).
KESTRELS
The commensal value of nest structures for wildlife is
well illustrated with nest boxes for kestrels.
Hamerstrom et al. (1973) noted that only 3 pairs of nest-
ing kestrels were located over a 20-year period on a
20,243=fia study area in central Wisconsin. Fifty nest
boxes were put up from 1968 through 1972. These boxes
successfully produced 8 to 12 broods per year, totaling
204 birds, or 1,600% increase in kestrels compared to
natural production in the same study area. This study
documents well that for some areas, the limiting factor
controlling cavity-nesting birds is the paucity of nest
sites, and that man-made structures can fulfill this
habitat requirement, thereby increasing wildlife popu-
lations.
Figure 20.11 provides a good diagram for construction
detail of a kestrel nest box. It is recommended that the
box not be painted or sprayed. Also, no entrance perch is
required, as kestrels do not need them and a perch at-
tracts starlings.
Kestrel nest boxes can be placed in towns and urban
communities, but they are most successful in rural areas.
Place the nest box on a lone tree or post in or on the edge
of a field. Kestrels generally nest 6.1-7.6 m from the
355
~-----Width of roof is 11"
20 go. galv.
board length is 20 112" ------'
Width of bogrd is 7" __ _,
Fig. 20.8. Plan for wood nest box for tree squirrels (modified from Barkalow and Soots 1965).
ground and the nest usually faces south or east. They
apparently prefer a clear flyway, so the space in front
should be free of shrubs, limbs, or obstructions. Another
favored site is old barns or buildings. Place 7.6 em of
coarse sawdust or wood chips in the bottom. This should
be cleaned out and new material replaced annually fol-
lowing the nesting season.
Kestrel nest boxes have proven so successful and easy
to install during the past decade, they are now located
across the country in both Canada and the Unite.d States.
This is another wildlife habitat improvement technique
popular as a conservation project for youth and educa-
tion groups.
MICE
Natural control of harmful insects is rece1vmg in-
creased emphasis to help offset massive chemical spray
projects. H. R. Smith (1975) recommended the use of
nest boxes to increase populations of deermice to prey
upon larvae and pupae of the gypsy moth in young,
even-aged hardwood stands. These nest boxes followed
the design of Nicholson (1941) and were 12.7-cm cubes
of 9.5-mm (3/8-inch) exterior plywood with a hinged lid
and a 2.5-cm hole for an opening. Cotton bedding was
supplied and replaced as it became fouled.
Platforms
WATERFOWL
Structures, such as illustrated in Figs. 20.12 and 20.13,
have been constructed for the benefit of geese in the
West (Saake 1968, Grieb 1970). Their value is especially
great in areas where predation by feral dogs is a prob-
lem. Many construction variations may be employed;
such as, 4 bales of hay instead of the tire, 1 stout pole
instead of 4, and a large metal washtub instead of the
wooden platform. The single pole specification is better
than 4 steel po~ts in regions where ice movement is a
problem.
Canada geese also will nest on floating nest structures
constructed of a 20.3-X 55.9-cm canoe-like platform
which supports a 48.3-X 66-cm nest box, an anchor, and
an equalizer (Will and Crawford 1970). To give extra
buoyancy to the platform, a sheet ofDyfoam 5.1 em thick
is encased with lumber. Splash shields are a necessity
during high winds to keep the nest and eggs dry: 1
shield to the side of the nest box and an additional
V-shaped shield to the bow of the platform. A dark-
colored preservative should be applied to the nest box
and box splash shield, not only to preserve the wood,
but to camouflage the newly cut lumber. Prairie hay or
coarse wood shavings should be packed tightly into the
356
B
(
D
E
Fig. 20.9. Tire nest for squirrels. Ins!Tuctions for con structio n i nclude:
(A) Remove steel bead from inner rim ; (B) Cut ttre in half, and c ut ears o ff
both sides at o ne end. Cut 7.6 em s li t s in the middle on each si d e; (C) F o ld
ti re and attach a t# l h o le inserting ro ofing n ail from ins ide o n b oth s id es.
I n sert roo fing nails in h o le# 2 on each s:cle ; (D ) Squeeze th e to p 2 edges of
the t ire together and a tt ach nails in# 3 holes w ith roofing nails . Cut 7.6 e m
s lits on outs ide edges of ti r e. Ma k e s ure uppe r s ide overl aps to keep o u t
ra in ; (E ) U se s t eel rod or heavy wire and inse rt 6.4 e m fr om e nd of tire.
H an g tire n est with throat towards tree truak a t least 4.6 m fro n• g round
(Maryland G ame and Fis h Commiss ion 1966). (Photos by Larry Farlow,
Illinois Nat u ral Hi s to ry Survey).
Pivot_
Nail
~ ."'
357
~EVIEW
~ __ nt 114
l
1
FRONT
~
:::. MOUNTING (2 )
.l WIRE
l--41rl'----tol
Dimensions shown are for
boards ~" thick.
Use 1~" galvanized siding nails
or aluminum nails.
TOP
I
g" BACK
r
I
Pivot nails must be located ex-
actly opposite each other as
shown for proper opening of
side board.
Cut top edges of front and back
boards at slight angle to fit
flush with top board. =·~· l l-2"-ol
0 0 0
Ita• Holes
Cut~~~ off each corner of bot-
tom board as shown.
Insert bottom board so that the
grain of the wood runs from
front to rear of box.
0 0 0
I--6 112" ---eo!
Fig. 20.10. Plans for a side-opening bluebird nest box (Zeleny 1976).
nest box to provide nesting material. The structures are
easily stored by removing the nest box and splash
shield.
In early experiments with floating -~tructures, high
winds dragged the anchor if it was attached directly to
the floating structure. To prevent this, an equalizer was
placed between the anchor and the structure, where it
rode broadside against the wind. Structures anchored in
this manner were not moved by winds exceeding 128
kph.
Forty-five kg of large rocks placed in a basket made
from a 76.2-x 91.4-cm section ofV-mesh wire laced to-
gether with galvanized wire has proved to be a satisfac-
tory anchor. A new anchor was recently developed using
heavy plastic bags obtained from the Ralston Purina
Company, St. Louis, Missouri. Two bags, one inside the
other, are large and durable enough to hold 49.9 kg of
fine sand. Just before the anchor is dropped into the
water, a number of small holes are punched into the bag
to allow trapped air to escape.
For best acceptability, floating structures should be
made available to Canada geese as soon as water areas
are completely free from ice.
I
I•
I·'
I'
i~
358
RAPTORS
Artificial nest structures for birds of prey is another
example of habitat improvement practices which h ave
greatl y accelerated during the past decades. References
~· 3"
• ~ ti"'L-'·
l6''
pi~· .3-
Fig. 20.11. Plans for a kestrel nest box.
documenting s uccesses for various raptors include:
eagles (Dunstan and Borth 1970, O lendorff and Stoddart
1974, Ne lson and Nelson 1976, Postupalsky 1978); os-
p reys (Kah l 1972, Rhodes 1972, 1977, Postupalsky and
Stackpoie 1974, Postupaisky 1978 ): great gray owi (Nero
e t a!. 1974); great homed owl (Scott 1970, Doty and Frit-
zell 1974); kestrel s (Hamerstrom et a!. 1973); ferrugin-
ous h awks (Oiendorff and Kochert 1977 ); and prairie fa l-
con (Brown 1976, F yfe and Armbrust er 1977, Olendorff
and Ko chert 1977, Postovit and Crawford 1978 ).
Working in Colorado on the open grasslands, Olen-
dorff and Stoddart (1974) found raptors using windmill
structures as n est sites. They also n o ted tha t the absence
of quality nest sites was a limiting factor to raptor den-
sity. Consequently they recommended the construction
of artificial nest p latforms (Fig. 20.14). A major objective
is to build the artificial nes t structure first a nd then im-
mediately plant trees. Later w h en the trees mature,
transfer the nest platfor m to the trees which results in a
more natural nest location. Alterations of this basic de-
sign might include eliminating the s hading device, plac-
ing the nest p latform atop the pole, and con stru c ting the
fence only where cattle are grazed or w hen necessary to
protect newl y planted t rees. Nest structures such as
these can serve a number of birds of prey including
eagles, osprey, ferruginous hawks, a nd great homed
owls. They can also serve as perc hing or roosting sites.
Nelson and Nelson (1976) proposed a habitat im-
provement technique deve loped to accommodate eagle
and other raptor nests on power lines. During 1973, 32
raptor nests were observed on a power line between
Twin Falls, Idaho, and Hells Canyon, O regon . These
nests can be a prob lem to t h e power company when nest
materials contact the wires and cause power outage. To
remedy this problem, the platform was placed on the
power pole chosen by the raptor {see Fig. 20.15 ). These
nest platforms were designed to {I ) provide shade for
the young birds, (2) provide a large p latform for nest
construction, and (3) p rovide a base for the nes t to re-
duce dangling sticks from contacting the wire. These
power line platforms have been used successfully by
golde n eagles, ospreys, ferrugi nous hawks, re d-tailed
hawks, and ravens.
Ospreys near Eagle L ake in northeastern Cal ifornia
have experienced major problems including the loss or
deteri o ration of nest sites. State and federal agePcy per-
sonnel joined efforts and developed 2 t echniques to im-
prove nest s ites, esp ecially for these raptors {Kahl 1972).
One p ractice required the topping of 15large trees along
the lake sh ores (Fig. 20.16). These trees ranged from
22.8 t o 38.1 m in height and from 1.2-to 1.8-m dbh. To
provide a good foundation for potential nests and reduce
windstorm losses, 30.5-cm spi kes were d riven into the
outer edges of th e topped trees and a 61-cm-diameter
platform was nailed on the topped tree. Osprey ac-
ceptance was especially good, and w ithin a month a pair
bu ilt their nest.
The second technique was to erect poles 7 .6 m high
and from 0.9-m to 1.5-m dbh near deteriorated snags
used for nest s ites . A 61-cm diameter nest box was
nailed on top of each pole to ancho r and protect it from
windstorm damage. These stmctures were also readily
accepted by th e ospreys (Fig. 20.16).
A
c
359
Fig. 20.12. Various artificial nest structures used by
wildlife: "A" placing wood chips in a wood duck box; "B"
fl oating raft nest stru cture for Canada geese; "C" newly
hatch ed Canada geese in a p lastic tub; a n d "D" 2 double-
crested cormorant nests on a platform. (Photos "A" and "B"
courtesy of Minnesota Department of Natural Re sou rces .
Photos "C" and "D" courtesy U.S. Fish and Wildlife Se rvice,
Agassiz National Wildli fe Refuge.)
360
TOP VIEW
BOLT 2" X 4"
BOARD TO
STEEL POSTS
1" X 8"
~~lJl~~:i;: -...t+--J.-+--TRUCK OR TRACTOR TIRE
TOP VIEW WITH TIRE PLACEMENT
END VIEW
APPRO X.
7'
HIGH
WIRED SECURELY TO
TOP OF PLATFORM
LOOSE HAY OR STRAW
Fig. 20.13. Diagrammatic plans for constructing a goose nest-
ing platform. (Nevada State Office, U.S . Bureau of Land Man-
agement.)
,----. r .. ' -( -,_
l
<..___
r'~·\ . 1\,.~ }V ,t .
·",I J~: (' '~{ .~. '/_,
' ' (
'" \1(1 I
I •
.;._J1t._·
361
Baskets and Cones
WATERFOWL
The following specifications have been used in the
construction of durable and economic nest baskets for
use of waterfowl. Materials needed include:
4 black metal rods, 53.3 em x 0.6 em (114 inch)
1 black metal rod, 2.1 m x 0.6 em
1 sheet of 0.&-cm (%-inch) hardware cloth, 91.4
em X 91.4 em
1 I. D. (inside diameter) galvanized pipe, 45.7
em x 3.2 em (I 1f4 inch)
1 machine bolt and nut, 9.5 mm (% inch) X 2.54 em
12 medium pig rings
1 I.D. galvanized pipe, 3.1 m x 2.54 em
Recommended procedures for construction of nest
baskets are:
a. Cut cone from hardware cloth according to pattern
"A" in Fig. 20.17, bend to shape, and fasten with 4 pig
rings.
Fig. 20.14. Plans for an artificial nest structure for raptors
(modified from Olendorff and Stoddart 1974).
b. Bend 2.1-m rod to form a hoop and weld.
c. Bend the 4 braces (53 .3 em) according to pattern
"B" in Fig. 20.17.
----~·.q•
W"ST!;
;;> SIDE
CUTTING PATTERN
..JOINT DETAIL
trr.li
1----
f'T20):U VIE.W
r
J~~ .. ·.o·~~
LE.f'T SIDE VI EW
NOT~
I='IREitGL"S.SeD Fott
MINIMUM SOVEARLIFI!-
PERSPECTIVE. -t&A9E tsuH&MIIiU>
CORNeR VIEW
Fig. 20.15. Plans for a raptor nest platform for placement on power lines (Nelson and Nelson 1976).
,,
,,
•'
"
362
A . Topping a pine tre e . B. T o pped tree ready fo r pl a tform .
C. E r ecting a cedar pole. D. P latform p laced on topped tree or ceda r pole.
E. Cedai:..pole without nest p laced by a deteriorating s nag. F . Adult os prey w ith c hick .
Fig. 20.16. Constructing artificial p latforms for osprey (after Kah l 1972).
363
"D" -DIAGRAM OF BASKET
"A "-CONE
1~"
"B"-BRACE
"C-TOP VI EW 1 W' PIPE
SHOWING BRACE LOCATIONS
Fig. 20.17. Patterns for construction of waterfowl nest haskets.
1 ) Be nd s h o rt h ook in 1 e nd to fa ste n ove r h oop.
2) Bend o the r end o f rod and place fl at aga in st pipe
fo r we lding .
d . Drill 1 hole, 11 mm (7/16 inch ), in 3.2-cm
(l lf4-i n c h ) I.D . pip e, 5 .1 em from end. This w ill b e re-
fe rred t o a s th e bottom of the p i pe.
e . W e ld nut t o pi pe over hole and in sert 9.5-mm (%-
inch ) mac hine holt as set screw.
f. Weld braces t o top e nd of 3 .2-cm I. D. pipe accord-
in g to p a tt ern "C" in Fig. 20.17 (l brace is welded ins ide
to se rve as a s toppe r in case the set screw loose ns, a ll ow-
ing th e b as ke t t o s li p on the pipe s tand ).
J I
I'
I II
364
g. Hook braces to h oop and we ld in place.
h. Place hardware cloth cone inside of hoop accord-
ing to the dia gram o f the b as ke t. Attach to braces and
hoop with pig rings.
i. Spray the h ardware cloth wi th light brow n or olive
color paint to reduce reflection.
j. The constructed basket is attached to the 2.54-cm
I.D. galvanized pipe at the time nesting structure is
erected.
Proce dures for placing nesting material in basket in-
clude the followin g :
a. Fill the baskets with a desira ble nes ting mate rial
prior to being erected. Suitable material may be fl ax
straw, sedge, grass, or upland "wild" hay.
b. Place a large handful of nes ting mate ri a l in the b o t-
tom of the basket.
c. Line the in side of the basket with nesting material
and secure it in place with s tovepipe wire woven
loosely through the straw and hardware cloth.
d. Completely fill the bas ket with loose nesting mate-
rial, leaving a slight depression in the middle of the
basket to simulate a nest.
e. Reple ni sh the s upply of nesting mate ri a l as
needed.
Care should be exercised to ins ure proper procedures
for erecting the nest baskets. General guidelines to con-
sider are:
a. Baske ts sh ould be erected in a minimum of30.5 em
of water on a 2.54-cm I.D. galvanized pipe. Length of
pipe will vary with type of soil. In many types of lake
bottoms, it may b e necessary to le ngthen the stand-pipe
by attaching it to a poie and push the poie further into
the muck.
b. The rim of the bas ket s hould be 76.2 em above the
normal water level.
c . Baskets should be erected in sh eltered areas t o re -
duce damage from ice.
d. Ba sket s should be located as close as possible to
emergent vegetation.
e, Baskets should be e rected in diamond-s h aped clus-
t e rs of 4 with 1 clus t e r per 1.6 km of shoreline. Spacing
of the nest baskets is shown in Fig. 20.18.
f. Baskets should be c h ecked for ice damage im-
mediately afte r spring breakup.
RAPTORS
Sykes and Chandler (1974 ) reported on use o f artificial
nest structures by Everglade kites . The structure co n-
s i sts of a shallow basket attached to a 1.5-m-l o ng shaft of
thin-walled metal tubing, 7.8 em in diameter and open
at the bottom end. The ·basket is similar in sh ape and
construction as the structure used for waterfowl (above
and Fig. 20.17) except this structure h as a tubular outer
ring, 1.27 em in diamete r, with 6 concen t ri c and 15 ra-
dial strips, each 1.27 em wide a nd ri vet ed together ,
SHORELINE
-
----------=-----= ill!~ --=-~=-=-=~""7.7--------ll'~\'~v:.-.. _---j..,_.k..___ o ~ -
~ ~ 'f--~ 300'
0 .. ----= :,,,
--"'"' ~
BASKET LOCATION PLAN
~\1/ ->-• 0... NEST BASKET
----.r--
SIDE VIEW OF BAS KET
Fig. 20.18. Diagram of cluster placement of waterfowl nest baskets.
365
DOVES forming the nest. The basket measures 55.~cm inside
diameter and 7.6 em in depth. It is supported on the
bottom by 3 braces, which are woven into the bas ke t and
are attached by rivets to the main support tubing. Stain-
less steel, aluminum, or galvanized sheet metal all pro-
duce a reusable structure. Care should b e taken to place
the structure close to and at the same height above water
as the existing n ests. Young fledged in th·e a rtificial
structur es after eggs were transferred from natural nest s
to the artificial structures (Sykes and Chandler 1974).
Perhaps egg transfer will not be necessary once a popu-
lation adapts to artificial structures.
Mourning doves generally build a loose, flimsy plat-
form of twigs for a nest. Many are destroyed by heavy
winds and rains. Artificiai wire cone nest structures im-
prove nestling survival (Cowan 1959). These wire cones
are made of 6.4-mm ('(.:~-in ch ) or 9.5-mm (%-inch) mesh
hardware cloth. They are easy to construct and install
(Fig. 20.19).
1. CUT OUT 12" SQUARE
PIECES OF HARDWARE
CLOTH
4 . CLOSE PIE CUT BY
OVERLAPPING EDGES
ABOUT 3"
I
The best location usually is a long limbs where
branches are forked and where there is moderate s hade.
Most doves seem to prefe r a height of 1.8 to 4.4 m above
2. TRIM THE 12" SQUARE
TO FORM A CIRCLE
5 . SIDE VIEW OF
CONE NEST READY
FOR NAILING IN
TREE
INSTALLATON
SELECT SITE FOR NEST IN MODERATE
SHADE FROM 6 TO 16 FEET ABOVE THE GROUND.
NEST SITES MUST HAVE LIMB CLEARANCE FOR
EASY ESCAPE FOR DOVES. USE 2 NAILS ON
EACH SIDE TO HOLD NEST IN PLACE. BEND
EDGES OF NEST DOWN SLIGHTLY AFTER IT IS
NAILED TO TREE OR BRANCH.
3. CUT OUT PIECE
OF PIE AS
SHOWN
Fig. 20.19. Construction and installation of wire nest cones for mourning doves (Cowan 1959).
1'1
I
I I
~I
366
the ground for their nests . Sites must command good
visibility and have enough clearance of brushy limb
growth so the birds can escape danger easily. After the
nest cone is properly secured, bend the outer rough
edges down slightly to form a smooth place for the birds
to alight. Best res ults in the Central Valley of California
were obtained by insta lling the wire cones in late Feb-
ruary, March, and April b efor e most doves selected their
nesting territories.
Periodic checks should be made to see that the wire
cones remain securely fastened and that they are n o t
obstructed by new branches. C lean out old nest material
from the cones each year.
Burrows and Ledges
BURROWING OWLS
Burrowing owls appear to be declining throughout
much of their historical range . Apparently there are 2
principle factors for this decline: (I ) loss of burrow sites
as a result of widespread burrowing mammal control,
and (2) direct loss of habitat to urban, indus trial and
agriculture development (Zam I974). To counteract this
problem, Collins and Landry (I977) deve loped artificial
burrows. The owls occupied 20 of 30 sites the firs t year
of installation. The artificial nest c hambers were
30.5 x 30.5 x 20.3 em deep with a I0.2 x I0.2-cm tun-
nel connecting the chamber to the burrow entrance. The
tunnel was approximately 1.8 m long with I right-angle
tum about 1.2 m from the entrance. The s ides and top of
the nest chamber and tunnel were con structed o f warp-
resistant, exterior plywood with natural dirt base. Ap-
parently the dime nsions are not critical. One tum in the
tunnel seems n ecessary to maintain the nest c hamber in
darkness. The artificial burrow should be buried I5.2
em to provide thermal stability in the nest chamber (Col-
lins and Landry I977).
FALCONS
Working in the grassland prairies of Colorado, Fyfe
and Armbruster (I977) found good populations of prey
species but a lack of nes t sites for prairie falcons. To
create more nest locations, artificial sites were made b y
digging holes in cliffs and constructing le dges. Care was
taken to select sites based on the following criteria: (a)
site location nea r suitable habitat for prey species, (b )
freedom from excessive human activity, (c) a minimum
cliff face height of 7 m, (d) a relatively permanent or
solid substrate of clay, conglomerate, or sandstone, and
(e) freedom from excessive erosion, such as seriou s un-
d e rcutting and slumping along river channels. Artificial
nest holes or ledges had the minimum dimensions of30
em deep x 60 em long X 30 em high. Several methods
of digging holes were used, including dynamite, but
h a nd digging was the most efficient.
Prairie falcons readily accepted these new artificial
s ites. I n_I970, 5 sites were completed and 4 were u sed
that year. Since then, the Canadian Wildlife Service and
the Saskatchewan Falconry Association have made over
200 similar artificial s ites and one-fourth have been oc-
cupied.
WATER DEVELOPMENTS
The amount, availability, and presence o f water
througho ut the year can be improved for purposes o f
increasing '.vild!ife numbers o r expanding the use of
habitat. Water can be "removed" to reduce an imal num-
bers and feeding in areas where they are undes ired.
Frequently water is developed for various other uses
than specifically for w ildlife. For one II-year rangeland
rehabilitation p rogram in a 96-by 282-km a rea of south-
eastern Oregon, I,600 water deve lopments were com-
pleted primarily for the needs of domes ti c livestock
(Heady and Bartolom e I977). Whe n th ese uses are
properly planned, water also can provide b e nefits to
wildlife. Consequently, the h abitat manager should be
famili a r with the va rious techniques for development of
water including natural sprin gs, seeps, a nd water holes;
and man-made structures such as re servoirs, "guzzlers,"
and wells.
Water Holes
Water holes are open water storage basins, either nat-
ural or artificial. Water is such a basic requirement to
wildlife in some areas that water holes a re often the hub
of wildlife activities; therefore, they should be designed
and maintained to be usable for a ll species of wild ani-
mals.
Natural water holes are often found in playas and
rocky areas where runoff waters are accumulated in a
depression. At times such holes can be improved by
deepening the catchment o r by trenching runoff waters
directly t o the basin. In the Southwest, cement em-
bankments have been added to large, flat rock surfaces,
thereby channeling water t o a nearby hole. Storage has
been increased by raising the lowest leve l of the basin's
edge .
Man-made structures can b e adapted to provide water
holes for w ildlife. Examples are the side basins on
pipelines as illustrated in Fig. 20.20. One s u ch pipelin e
development in Nevada provided 3 new water ~ole s
along a 24-km stretch w hic h formerly had no natural
waters for chukar partridge (U.S. Bureau of Land Man-
agement I964). Similar structures have been used in
New Mexico (Bird I977).
Springs and Seeps
No 2 springs are a like as to developmental needs;
however, there a re several different planning tech -
niques that can be applied. Before a spring or seep is
developed, the reliability and quantity of its flow should
be checked. Generally, it i s necessary to in st a ll a protec-
ti ve box to catch a nd s tore the water. Some times it is
advisable to provide large capacity storage a t s ites
w here waterflow is intermittent so that stored water will
be available after the spring or seep quits fl owing.
These waters should be dug out of firm ground,
hardpan, or rock to obtain maximum flow. The source,
whether one or several, s hould b e conduct e d to a collec-
tion basin and thence piped t o a trough. It is usually
necessary and des irable t o fence the water source and
collection basin from huma n or livestock use.
,_,__ ... ~0~::::::;:::=====:~,
1 I
I I
~
! ~ i
PROJECT SIGN
IC
"--->L ---)'(.. --->C._--,.-"
RUN WATER FOR WILDliFE USE
INTO NATURAL DEPRESSION
(SEE DETAil #1 FOR AITACHMENT)
TOP VIEW
SIDE VIEW
\._ PET COCK IN ESTABliSHED
PIPEliNE
DETAIL #l
PLANTED TREES OR SHRUBS
FOR WILDLIFE COVER.
AS NEEDED, TROUGHS MAY BE
PlACED INTERMIITENTL Y IN A
CONTINUOUS LINE AND AS LONG
AS THERE IS AN AMPL E WATER
SUPPLY.
367
Fig. 20.20. Water developments for many uses can be modified for the benefit of wildlife. This draw ing of a spring improvement for
li vestock in Nevada included a s ide basin in stallatio n for chukars. (Nevada State Office, U.S. Burea u of Land Management.)
In th e central and western U.S., many springs a re
fo und in canyon botto m s and when developed often b e -
come a maintenance proble m d u e to s torm fl ood dam-
age. Flood damage can be reduced for canyon b o tto m
projects by burying a s hmt length of perforat ed asphalt
soil pipe in packe d g ravel at the water source from
wh ic h the water is piped to a b asin o ut of th e canyon
b o tto m. Thi s technique allows storm water to flow over
the burie d source of spring water with out damage to the
deve lo pment work (Weaver et a l. 19 5 9).
F o r w il dl ife water developments, p lastic pi p e is usu-
ally preferre d to galvanized iron p ipe since it is li g h ter
a nd e a s ie r to transpmt and lay. The pipe shou l d be
buried deep e nough to escape damage by freezing,
••
e ,.
.. e:
368
trampling by livestoc k, or washing out during floods.
The pipe s hould also be laid to grade, in order to avoid
air blocks.
The development of a spring is not just a simple mat-
ter of coll ecti ng a maximum flow of water and making it
available. Th e development should be planned to
achieve a purpose with a minimum of detrimental ef-
fe c ts. Spring developments planned primarily for
wildlife u se, as well as those planned for other purposes,
should do the following:
l. Provide at least 1 escape route to and from the
water. Take advantage of the natural te rrain and vegeta-
tion where possible.
2. Provide an alternate escape route where feasible.
3. Fence water developments from livestock. Fences
can serve the purposes of preserving the water so urce
and protecting food and cover needed for small species
of wildlife. Protective fences should be negotiable by
wildlife except where trampling or wallowing by big
game w ill damage the spring source. Fence posts should
be pointed to discourage perching by avian predators.
4. Prov ide safety from wildlife drowning by con struc-
tion of gentle basin slopes or ramps in tanks (see Figs.
20.27, 28, 29.)
5. Maintain or provide adequate cover around the
watering area, either by saving the natural cove r or hy
plantings and brush piles.
6. Provide, where applicable, an information sign to
inform the public as to the purpose of the development.
7. Provide w ater developments of suffi c ient capacity
to supply water at all season s of the year during which it
i s n eeded for wild animals.
8. Provide public access to water by piping it outside
of fe n ced water developments. Where shy animals are
invo lved, pipe water for human con sumption some dis-
tance from wildlife water. For exampl e, it is r ecom-
m e nded that sustained camping be discouraged within
0.8-km rad iu s of water used b y desert bighorn sheep.
Many habitats in the Southwest have no form of per-
manent water. Such areas provide minimal use for
bighorn sh eep (McQuivey 1978 ) and other wildlife.
Recogni zing this limiting habitat compone nt, th e
California and Nevada Wildlife Agenci es h ave been
working for years to improve intermittent sp rings and
seeps. Sometimes these waters provide s u c h low quan-
tities that they are m easure d as "teaspoons" per hour
compared to the mo re common meas urement of "gal-
lons" per hour. Often, seeps can be detected only by
moist soil. Even with such little n atura l water, some of
these seeps have b een developed t o fill a 18.9-1 (5-
gallon) or 37.8-1 (10-gallon) container. Bighorns have
been seen to wait the ir tum for s uch available drinking
water (C. Hansen pers. comm.). Figure 20.21 illus trates
desert bighorn sheep using a spring development.
Reservoirs and Small Ponds
The term "reservoir" as used here refers to water im-
pounded b e hind a dam. It may be forme d by building a
dam directly across a drainage or b y enclosing a depres-
sion to one side of a drainage and constructing a diver-
sio n ditch into the resulting b asi n. Reservoirs should be
Fig. 20.21. Desert bighorn sheep at a developed spring on the
Dese rt National Game Range in Nevada. (U.S. Fish and
Wildlife Service photo by 0. Deming.)
designed to provide maximum storage with a minimum
of surface area to reduce evaporation loss. The following
are major points to consider in the selection of reservoir
sites:
l. The most suitable soils for dams are clays with a
fair propo rtion of sand and gravel (1 part clay to 2 or 3
parts grit). Soils with a high proportion of clay crack
badly upon drying and are apt to slip when wet.
2. The watershed above the dam s hould be large
enough to prov ide sufficient water to fill the reservoir,
but not so large that excessive flow s will damage the
spillway or wash out the dam.
3. The most economical site is one along a natural
drainage where the channel is narrow, relatively deep,
a nd the bottom is easily made watertight. The channel
grade immediately above the dam should be as flat as
possible.
4. Wildlife should have easy access to the water.
5. The dam should b e located, if possible, to take ad-
vantage of natural spillway sites. Otherwise, an
ad equate spillway must be incorporated into the devel-
opment.
The dam s ite should be surveyed and staked prior to
con s truction. If there is any question as to the suitability
of material for dam construction, an examination should
b e made by a soil scientist. Trees and shrubs should be
cleared from the dam site and flooded basin. The foun-
dation area of the dam s hould b e plowed or scarified in
the direction of the main axis of the dam so the r e will be
a good bond between the foundation and the fill mate-
rial. On sites where stability and permeability of the
foundation material is questionable, a narrow core
trench should be dug lengthwise to the dam, then re-
filled and packed with damp ciay soil. wbere suitable
material is available above the dam, it should be ob-
tained there so the borrow pit w i ll become part of the
reservoir and add depth to the impoundment. General
specifications for the construction of dams should in-
clude these items :
1. The base thickness of the dam must be equal to or
greater than 4lf2 times the height plus the crest thick-
ness. The slopes of the dam should be 2lf2: 1 on the up-
stream face and 2:1 on the downstream face.
2. Minimum width of the top of all dams should be
3.1 m.
3. The fill of the dam should be carried at least 10o/o
higher than the required height to allow for settling.
4. Freeboard (depth from the top of the dam to the
high-water mark when the spillway is carrying the esti-
mated peak runoff) should not be less than 61 em. The
spillway should be designed to handle double the
largest known volume of runoff and should be con-
structed at a level which will prevent the water from
ever rising higher than within 61 em of the top of the
dam. A natural spillway is preferred. It should have a
broad, relatively flat cross section, take the water out
well above the fill; and re-enter the main channel some
distance downstream from the fill. When a spillway is
built, it should be wide, flat-bottomed, and protected
from washing by riprapping (facing with rocks). The en-
trance should be wide and smooth and the grade of the
spillway channel mild so the water will flow through
without cutting (Hamilton and Jepson 1940).
New reservoirs usually do not hold water satisfactorily
for several months. It may be necessary to spread bento-
nite over the bottom and sides of the basin and face of
the dam to "seal" the impoundment so it will hold
water. Samples of soil from the reservoir, the dam mate-
rial, and the bentonite can be laboratory tested to de-
termine how much bentonite should be applied.
Another method of sealing reservoirs to prevent exces-
sive loss of water is to line the basin with polyethylene
(U.S. Bureau of Land Management 1966). After the
basin has been made, it is covered with plastic sheets,
then 15.2 to 20.3 em of dirt rolled evenly over the plas-
tic. Where there is the possibility of damage to the plas-
tic by animals, 30.5 em of soil must be placed over the
liner.
While working in the Southwest, biologists for the
U.S. Fish and Wildlife Service found that water-cut
canyons offer suitable sites for small concrete dams and
reservoirs to provide water for desert bighorn sheep
(Halleran and Deming 1956). These small reservoirs
were most effective where canyons narrowed down with
steep, vertical sides of bedrock. Such arroyos make good
construction sites, particularly on east or north facing
drainages which provide protection from the sun and
reduce evaporation. Dams should be firmly keyed into
the bedrock on both sides and bottom. A pipe outlet
should be incorporated into the dam. Water loss will be
prevented if rock formations are checked from cracks
369
and fissures. Rock sealing is, at times, an important
phase of sound construction. Commercial sealers can be
quickly applied to the dam after completion. Usually,
such canyon dams should be under 12.2 m long and not
over 3 or 3. 7 m high. During the first several years after
construction, the small ponds formed behind the dams
will provide water for wildlife. After the reservoir be-
comes filled with gravel and sand washed in by rain
floods, the water soaking into the gravel and sand is
stored and protected from excessive evaporation. The
stored water is piped through the dam to natural rock
basins below or to cement troughs constructed away
from the main water course (U.S. Bureau of Land Man-
agement 1964).
Small ponds can often be constructed quickly and ef-
ficiently for wildlife needs. Their small size and
strategic distribution provide not only an animal's water
requirements but add new diversity to habitats. One
example is an area that was devoid of natural surface
waters. Then an unsuccessful agricultural experiment
left an uncapped artesian well. Wildlife managers chan-
neled water from the well to a small excavated pond
which now services over 155 different species of wild
mammals, birds, fishes, and amphibians. It can be said
that in this case, man created a new environmental
niche which in turn provided a richer habitat for en-
demic wildlife.
Water Catchments
During the past 2 decades, there have been several
types of self-filling watering devices designed for the
use of wildlife. Probably the greatest numbers have
been constructed for primary use by quail. However,
many of these structures have been built specifically to
benefit other wild animals, including antelope, bighorn
sheep, deer, sage grouse, and turkeys. The California
Department of Fish and Game (Glading 1947, Leopold
1977) constructed over 2,000 catchments for quail be-
tween 1943 and 1974. Since so many of these devices
were installed for upland game birds (Galliformes) they
have been referred to as "Gallinaceous Guzzlers" or re-
cently, just "Guzzlers."
GUZZLERS
The guzzler is a permanent, self-filling water catch-
ment similar to a cistern. The whole structure is so sim-
ple there is very little that can get out of order, and so a
minimum of maintenance is required. Essentially, the
guzzler installation consists of a watertight tank set in
the ground which is filled by a rain-collecting apron.
This apron collects rainwater and drains it into a tank
where it is stored for use by wildlife. Where the device
is intended for watering birds or small animals, they
may enter the covered tank through an open end and
walk down a sloping ramp to the water level. If the birds
and other animals drink directly from the storage tank,
all floating valves or other mechanical devices that are
subject to failure are eliminated (see Fig. 20.22).
The most important step in the installation of a guz-
zler is locating an adequate site for its placement. A
guzzler should not be placed in a wash or gully where it
may collect silt or sand, or be damaged by flood waters.
.. a
•• •
370
Fig. 20.22. Water catchments for small wildlife species have been constructed in the western states . They have been an important
factor in increasing suitable habitat (U.S. Bureau of Land Management photo by Ed Smith).
The size of the water-collecting apron should be propor-
tioned so that the cistern will need no water source
other than rainfall to fill it. Since the cost of digging the
hole for the cistern is one of the largest expenditures, a
site should be chosen where digging is comparati vely
easy. The tank should be placed with its open end away
from the prevailing wind and, if possible, facing in a
northerly direction in order that a minimum of sunlight
will enter the tank. Such placement will cut down the
growth of algae, temperature of water, and evaporation.
The cisterns used for guzzlers usually are made of
either concrete or plastic. Occasionally steel tanks are
used. The plastic guzzler is a prefabricated tank con-
structed of fiber glass impregnated with a plastic resin .
If the construction site is a long distance from a source of
washed aggregate, or if labor costs are high, the p lastic
guzzlers offer savings in transportation and labor costs.
With concrete guzzlers, only washed gravel aggre-
gates should be used for construction; otherwise the
concrete may start to disintegrate after 5 or 10 years.
Tanks made of steel are used for guzzlers in some areas
and are reported as giving satisfactory service.
Collecting aprons have been made of many materials.
Concrete sealed with bitumul, galvanized metal sheet
roofing.,._glass mat and bitumul, rubber or plastic sheets,
asphalt, and plywood have all been used successfully.
From the standpoint of maintenance costs, however,
durable materials such as concrete or metal have proven
most satisfactory.
The size of the water collecting apron or surface
needed to fill a guzzler will depend on the size of guz-
z ler and the minimum annual rainfall that can be ex-
pected at the construction site. Actually, the size of the
needed interception area will prove surprisingly small
because nearly 100o/o of the rainfall is collected. Calcula-
tion of the potential yield of the rainfall collection s ur-
face can be determined by the following formula:
Surface area in square meters of apron x 9.9 = liters
per em of rainfall. It is important that calculations be
made on the basis of the minimum of precipitation ex-
pected, rather than the average o r maximum, to prevent
guzzler failing during drought year s. Table 20.3 gives
the s ize of aprons in square feet needed to fill 2271 I ,
2649.5 I, 3046.5 I tanks at different minimum rainfall
rates.
General instructions for installation of a concrete guz-
zler are summarized as follows:
1. Select the site and clear the apron. Lay out the
excavation site for the guzzler. To square the outline,
measure diagonally from each rear corner to opposite
front corner and adjust stakes until these distances are
equal. Excavate the rear portion to required d epth and
slope ramp at front to ground level. Line excavation with
laminated Kraft paper.
2. Assemble reusable plywood forms for inner walls
and hang in position with 10.2-cm clearance between
forms and walls and floor. Level the forms and pour
371
Table 20.3. Size of apron nee ded for 600, 700, and 900 gal "guzzlers. "
Minimum Annual Square Feet of Collecting
Rainfall (inches) Surface Required
600g . 700g. 900g.
1 965 1,127 1,453
2 482 563 726
3 322 376 485
4 242 282 365
5 192 225 290
6 162 189 243
7 138 161 208
8 121 141 182
9 107 125 161
10 97 113 146
11 87 102 132
12 80 94 121
concrete between forms and walls of excavation. Tamp
and vibrate walls. Pour enough concrete to complete
floor and ramp. Trowel smooth, allowing 1.3-cm clear-
ance between edge of form and ramp.
3. Remove wall from carrie rs, assemble reusable roof
forms, place in pos ition and cover with 3 thicknesses of
Kraft paper. Place dishpan in position for manhole .
Cover roof with 7.6 em of con c rete, place 7.6 em of con-
crete inside the dishpan. Insert a loop of heavy wire or
0.6-c m reinforcing rod at center of manhole cover to
serve as a handle. Provide a 15.2-cm curb a t front end of
guzzler roof. Pour a 7.6-cm skirt 0.9 m wide in front of
guzzler ramp and provide a 15.2-c m trash wall.
4. Outline ap ron. Excavate a settling b asin 45.7 e m in
diameter and 20.3 em d eep in front of s kirt. Cover e ntire
apron and b asin with Kraft paper and pour conc rete 7.6
e m thick. Trowe l smooth and provide a 15.2-cm trash
wall around circumference of apron. Prov ide a hole of
7.6-cm diame ter through trash wall for screen ed inlet to
g uzzler. M ake holes for 1.3-cm-diame te r iron coyote
guard at 10.2-cm intervals across front of guzzler. Cover
all fres h concrete with pape r to e n sure prope r c uring.
5. Allow to set for 24 hr, remove paper a nd form s,
wash ins ide of guzzler with cement and water. Apply
asphalt e mulsion to apron. In st a ll coyote guards. Cover
roof with 25.4 em of dirt to st abilize tempe r ature within
cistern. If domestic lives tock graze the a rea, fence the
e ntire guzzler against stock so the r e will b e no c hance o f
damage to apron, tank, or lid. When g uzz le r is con-
s tructed a fter the ra iny season , it is b est to fill it with
w a te r to aid in c uring concre te and to d eve lop bird o r
animal accept ance.
Althoug h in corporating the sam e gen eral pri ncip l es as
the concrete guzzler describe d a b ove, the q ua il guzzler
illustrated in Fig. 20.22 is dissimilar in ma n y r espects.
This illustra tes the flexibility and diversity of d esign
that h as b een ch a racte ri s ti c of g uzzler development in
various regions. The iron roof s h o uld have a gentle slope
of around 5% for best perform ance a nd s h o uld be r e la -
tive l y smooth t o prevent water from standing o n s urface.
Apron Dime n sion in Feet
Square Circular
600g. 700g. 900g. 600g. 700g. 900g.
31
22
18
16
14
13
12
11
11
10
9
9
34 38 36 38 43
24 27 25 27 31
19 22 20 22 25
17 19 18 19 22
15 17 16 17 19
14 15 15 16 18
13 14 13 14 16
12 14 12 13 15
12 13 12 13 14
11 12 11 12 14
10 11 10 11 13
10 11 10 11 12
Runoff is caught at the bottom of the aprons and carried
in pipes to the storage container.
In some lo calities the storage tank has been closed at
all ends, or a s torage bag is used, and the water piped by
gravity flow to a small trough (Lauritizen and Thayer
1966). Here the flow is regulated by a float valve . Where
such a valve is in use , a r egular schedule of maintenance
is neede d to keep the valve functioning during the sea-
son when water is needed. Possibly the greatest value of
this design facility is that it directly allows wildlife to
u se the wate r in the storage tank. Thi s e liminates addi-
tiona l construction and maintenance cost s experience d
with additio nal ite m s such as troughs and flo at valves.
Although most g uzz le rs have been constructed for
game bird u se, their values to big game were well
a n a lyzed by Robe rt s (1977). H e r esearched the literature
thoroughly to identify the n eeds and values for antelope,
bighorn sheep, d eer, and e lk. Roberts' fin a l comment
was that water catchme nt d ev ices for big game a re a
practica l m ean s of increasing wildlife habitat and dis tri-
bution in arid areas.
Figure 20.23 portrays a guzzler adapted for bighorn
sheep. Similar structures h ave been d esigne d for and
u sed b y d eer. The catchment provides for a precipita-
tion collecting apron and unde rground st o rage tanks.
From the storage tanks the water proceeds to a tro u g h
w ith a control valve. The project is des igned to u se
water more e fficiently through e xcess s urface exp osure
causing high e vaportation. However, it can require a
hi gher maintenance fr eque n cy schedule and has a more
limited u se value for othe r species o f wildlife.
The install ation of prec ipitation cat chment facilities
on ranges lacking adequate water h as been s uccessful
for pronghorns (June 1965, Sundstrom 1968). Figure
20.24 provides specifi cati o n s for the catc hment used. At
fir st , a fence was constructed to contro l li vestock use;
however, this was late r dismantled w he n its need was
no lo nger jus tifi ed. This construction type of catc hment
was inst a ll ed. in a variety of habitat s and was u sed by
deer, e lk , sage grou se, doves, rabbits, ground squirre ls,
ol
II
" ,,
'I
372
Fig. 20.23. A water catchment constructed in the Southwest on a critical summer range inhabited by desert bighorn sheep. (U.S.
Bureau of Land Management photo by Jim Yoakum.)
and many other species of wildlife. Possibly its greatest
value is t hat it provides ready access of water to a tre-
mendous variety of wildlife. Not onl y was the water
used for dri nking, but it was used frequently for bathing
by songbirds, thereby qualifying as a genuine
multiple-use improvement!
DUGOUTS
As cattlemen moved into the West, they constructed
large earthen catchment basins to collect water for live-
stock. These excavations were commonly called "dug-
outs" by early pioneers and "charcos" by early settlers
a long the Mexican border. Lately, government agencies
have been constructing many of these charco pits on
public lands. Deer and antelope frequently make use of
such imp[ovements and rely heavily upon their use dur-
ing critical dry summer months. Bighorn sheep are not
frequent users of these projects but do benefit occasion-
ally during seasonal movements to and from their ranges
in rocky, mountainous terrain.
Dugouts may be located in almost any type of topog-
raphy. They are, however, most satisfactory and com-
monly used in areas of comparatively flat but well-
drained terrain. Flat slopes facilitate maximum storage
with minimum excavation. A natural pothole or intermit-
tent lake bed is often a good location for a dugout. Dug-
outs should not be located in wet or muddy areas be-
cause of the difficulty for large animals to get to the
water.
Fig. 20.25 shows a small rectangular dugout with
specifications. For larger dugouts the length, width, or
depth may be increased, but the side slopes should be
about the same. All sides should be sloped sufficiently
to prevent sloughing (usually 2: 1 or flatter) and 1 or
more relatively flat side slopes (4: 1 or flatter) should be
provided for livestock or big game entrances (U.S.
Bureau of Land Management 1964).
Modified Water Developments and Safety Devices
The habitat manager may construct water devel-
opments, such as tanks, troughs, or wells strictly for the
SITE LOCATED TO TAKE
ADVANTAGE OF SLOPE FOR
DRAINAGE
FIBERGLASS TANK COVER TO CUT
DOWN EVAPORATION AND IS EASILY
REMOVED FOR YEARLY CLEANING
PLAN VIEW
SIDE VIEW
BASIN
FENCE TO KEEP LIVESTOCK
FROM DESTROYING APRON
AND USING TANKS .
-
UP FROM EXC AVATION DIRT
SUPPOifT TANKS AND KEEP
IT FLUSH WITH THE GROUND LEVEL .
COVER a
BASIN
3 7 3
Fig. 20.24. A water catchment designed for ante lope use on the Re d Desert of Wyoming (adapte d fr o m June 1965).
b e n e fit of wildlife. More commonly, w ate r d evel-
opme nts w ill b e co n stru cte d fo r othe r purposes, i.e., fo r
livestock, campground wate r sto rage, a nd fire suppres-
si o n. O ft e n a s li ght m odificatio n o r additio n to s uch de-
velopme nts can be m ad e that w ill make wate r avail a ble
to w ildlife . M a nagers d esiring additiona l info rmatio n o n
sp ecifi cation s, p la n s a nd con struc ti on d e ta il s fo r wate r
impro ve m e nts will find the following sources o f value:
Range Im p ro vem e nt Standards Handbook (U.S. F o rest
Service 1960), Enginee ring Handbook and C on s tru c-
tion Manual (U.S . Bure au of Land Manageme nt 1967),
an d Vall e ntin e 's (1971) book: Range Development a nd
Improvem e nt.
Wh e re wate r is scarce in dry environs, wildlife often
readil y seek and use man-made wate r improvements.
Some o f these a re designed w it h out p r oper cons id -
erati o n s fo r w ildlife use and , consequen t ly, can become
a proble m b y e ntra pment and drown in g. T hi s is espe-
ciall y true for yo ung animals. The hazard of drowning
can b e r'.'!duced b y fl oat s, ra m ps, o r la dde rs that a ll ow
ave nues of e s c ap e . The best d esig n w ill incorporat e
s u c h escape facilities as a iJ art of th e improvem e nt.
I I
I''
METAL PIPE (MIN IMUM 24" DIAMETER)
CHARCO PIT
(
SILTING PON~
TOP VIEW
. ,':0..:'~~ ····--·-····
GAP GATE --~-~--'·-· . "'"'--·-----··· ·--.-------...... . -
Fig. 20.25. Schematic sketch of a "dugout" or charco pit use d in the west for providing water on the ranges for livestock and wildlife.
Nevada State Office, U.S. Bureau of Land Management.)
Where this has not been done, it b ecom es necessary to
improv ise. Any float, ramp, or ladder placed in a water
development s hould be r e lativel y maintenance free and
designed so that it n e ither interferes with nor can be
damaged b y li vestock. Wilson and Hannans (1977 ) s ur-
veyed~ subject of water d evelopment for li vestock
and listed the following guidelines:
1. Rare l y are li vestoc k water d evelopme nts located in
areas where terrain and cover conditions promote
maximum utilization by wildlife; the refore, separate
watering facilities for wildlife s hould b e provided in as-
sociation w ith the livestock development.
2. Fencing the wildlife water facility in a manner a l-
lowing wildlife use, but excluding livest ock, is nearly
a l ways necessary to preserve water quality and insure
growth of protecti ve cover.
3. Water should be avai lab le in a ll water devel-
opments at all t imes, except in those a reas where freez-
ing during the winter could result in damage to the proj-
ect.
4. Wherever ground-level wildlife drinking facilities
are not provided in association with other water devel-
opments, the height of livestock troughs or other con-
tainers must not exceed 50 .8 em (Fig. 20.26).
5. Consider installing safety barricades in all live-
stock watering developments to prevent accidental
entry and possible drowning (Fig. 20.27).
6. Consider installation of concrete blocks and/or
rocks to form escape ramps on all livestock water devel-
opments where water depth exceeds 50.8 em (Fig.
20.27).
7. When the lip of water troughs prohibits small
wildlife from the water, construct wildlife ladders which
allow the animals access. These ladders can be con-
structed of expanded metal or rebar and hardware cloth
and should be protected by posts or protective fencing
(Fig. 20.28).
8. An alternate method of providing small animal ac-
cess to the water from outside the trough is to construct
concrete ramps or rock ramps topped with cement (Fig.
20.28).
9. Large troughs posing survival problems inside the
facility need escape ladders. These escape ladders must
be constructed to intercept the line of travel around the
edge of the tank. They should be attached to the struc-
ture by a hinge or bracket. Wildlife escape ladders
should have a minimum slope of 30 degrees, but the
incline should not exceed 45 degrees. A minimum of 1
ladder should be installed per 9.14 linear m of trough
perimeter (Fig. 20.29).
In many livestock rangelands, large open water stor-
age tanks are used which are out of reach for many
species of wildlife (except birds and bats). For these
developments, a floating wildlife platform should be in-
stalled. Figures. 20.30 and 20.31 provide examples of
floating ramps.
375
WETLAND IMPROVEMENTS
Development of Water Areas
Techniques for improving wetlands will vary and a re
dependent to a large degree on the prior structural de-
velopment of the area, water quality, water level man-
agement, soil, climate, topography, and plant succes-
s ion. Sometimes wetlands can be manipulated by use of
biological and physical forces to deve lop an improve d
environment for wildlife.
A biological need should be established before any
plans for wetland improvements are made. The ch i e f
use o r uses of the area s hould be the prime considera-
tion in judging its potential development, although
these uses are also largely determined by the location of
the area and physical characte ristics . Some areas may
best be developed primarily for waterfowl, others for
muskrat or other fur production. There will be other
areas where these 2 features can be combined. The
habitat manager can often use various practices to c reate
interspersion of open water w ith marshland, interlace
ditches and high spoil lands, plant vegetation for food
and cover, and thereb y c reate wetlands favorable to
ducks and geese, beaver, muskrats, mink and warm-
water fishes. For the habitat manager se riousl y con-
cerned with techniques of preserving, managing, or
manipulating wetlands, we recomme n d the Techniques
Handbook of Waterfowl Habitat Development and
Management published by the Atlantic Waterfowl
Council (1972). A sizable porti on o f thi s book is devoted
to inaking preliminary evaluations prior to development
in order to establish need. There are also sections on
improvement techniques, many of wh ich are incorpo-
ra ted in this Chapter.
Fig. 20.26. A w a ter trough financed for lives-
tock use; however, a w ildlife habitat manager
added the following specifi cations for w ildlife
requirements: (1) that the trough be placed
low to the ground for easy wi ldl ife access; (2)
that water be available for wildlife during crit-
ical dry seasons even though livestock are not
in area, and (3) that an escape ramp (right
distance end covered in part by vegetation) be
installed for small wildlife. (U.S. Bureau of
Land Management photo by Jim Yoakum.)
.
srll'-
:: I
Ill I
i• ~~~~
II
lj I
'iJIJI
376
A. When trough height is 20 in or less wildlife have better access to water
' ' '
DIAMETER LOG
' I
', I -'!----
LEVEL
B. Possible barricade development depending
on livestock trough configuration
GROUND
LEVEL
BELOW
GROUND LEVEL
20/N
ROCKS OR CONCRETE
SIDE VIEW
C. Placing of rocks, concrete blocks or other ramp facilities provide on escape
route for wildlife where the water depth exceeds 20 inches
Fig. 20.27. Design modifications beneficial to wildlife for water troughs constructed for domestic livestock (adapted from Wilson
and Hannans 1977).
A. Concrete ramps or rock ramps capped by concrete into
livestock trough
ROCK STACKED
OUTSIDE OF TROUGH TO
ALLOW SMALL WILDLIFE
ACCESS TO WATER
LEAVE CONCRETE
6ROOV£D AND ROUGH
REBAR
LADDER CONSTRUCTED BY USING
21N BY 41N LUMBER FOR FORMS
B. Details for a triangular shaped wildlife ladder
MESH IS ATTACHED TO
REBAR WITH "-.
GALVANIZED WIRE
FORM TO FIT
SIDE OF T~H
\
30" ANGLE NOT TO
EXCEED 45"
BRACKET OR HINGE BOLTED TO TROUGH
WELDED JOINTS /UP (see next page for bracket design)
I'>< 1/ I. /4 TO J2 IN HARDWARE CLOTH
(also known as hardware wire)
I ~IN REBAR
REBAR IS HEATED AND BENT
THE PROPER ANGLE
Fig. 20.28. Construction details for adapting a livestock water trough for wildlife use (Wilson and Hannans 1977).
377
SHALLOW MARSHES
Marshes provide nest sites, cover, and food for water-
fowl and for muskrats and other furbearing mammals,
such as mink and otter. Herons, cranes, rails, plovers,
and sandpipers are the chief bird families that require
marshes. Many forms of reptiles, amphibians, and fish
complete the vertebrate fauna. A marsh should have
open water areas if it is large, or an adjacent pond, if
small, for maximum wildlife value.
Artificial impoundment is a common practice used to
improve existing marshes or to create new ones. The
objective is not merely to flood an area, but to control
378
--
A. Fencing and post arrangement to protect wildlife ramp leading into a
l ivestock watering facil ity.
TOP VIEW
SIDE VIEW
B. Details for constructing a wildlife ladder.
WILDLIFE LADDER
IN TROUGH -~----
-TROUGH
TOP VIEW
Fig. 20.29. Plans for modifying a livestock water trough by providing both an outside and inside w ildlife ladder (Wilson and
Hannans 1977).
379
TOP VIEW
Y• TO Y.z IN HARDWARE CLOTH
FLOATING PLATFORM
""'
GRAPE
2"x6"x48'' LUMBER
NYLON ROPE ~".,-\
~ <"m. ~~
CAP SECURED BY CEMENnNG
\_)
""' CONCRETE ANCHOR
Fig. 20.30. Floating wildlife platform recommended for large open water storage tanks (Wilson and Hannans 1977).
water levels after impoundment as a method of manag-
ing food and cover conditions. Stoplog controls should
be designed so that water level can be manipulated,
including complete drawdown when needed. In most
instances the average water depth should be 45.7 to 61
em depending on site condition and amount of edge.
Ditching marshes increases the variety of h abitat for
furbearers as well as waterfowl. Deeper water in ditches
helps animals find food and cover during dry periods.
The spoil banks, on the other hand, offer dry resting
sites, feeding areas, and shelter during flood periods.
Ditches also facilitate access for hunters, trappers and
maintenance crews.
Dredging has been found superior to blasting as a
method of ditch construction. Blasted ditches tend to be
shallower and loosened muck along the edges of the
ditch is highly susceptible to wave and wind erosion.
The lack of high spoilbanks desired for waterfowl nest
sites and muskrat dens further reduces the value of
blasting.
In constructing improvements in shallow marshes, the
use of scoops, draglines, bulldozers, or combinations of
the 3, are recommended so that the material removed
may be piled along the edges. The high areas should be
planted to a grass-brush cover.
POTHOLES, SUMPS, PONDS
Potholes may be defined as small, shallow, open
water retention areas or basins with surface areas usu-
ally under 1.6 ha in size. These areas, when developed
in conjunction with large, permanent water areas, can be
a particularly valuable tool in w~terfowl management.
The purpose of making potholes is to create or increase
water area lost to geological change and plant succes-
sion. An ideal wetland for waterfowl has one-third open
water and two-thirds marsh.
Draglines and bulldozers have been used in construc-
tion of potholes, but they are of most use when ditching,
damming, and diking are required. The use of a blasting
agent is the most expeditious and economical method to
employ in creating new small potholes. Recent experi-
ence has shown ammonium nitrate to be a very effective
agent. It is less expensive and safer than dynamite. Best
results are obtained with commercially prepackaged
ammonium nitrate fuel oil charges (U.S . Forest Service
1969). In pastured areas potholes should be fenced .
Fences should be located at least 7.6 m and preferably
12.2 m or more back from the waterline (Mathiak 1965) .
. Beavers, when skillfully managed, can create much
desirable habitat. Their ponds in intermediate stages of
. ,.
1, •.
"'
380
36" SQUARE OPENING
FOR OVERFlOW PIPE
12" X 2" REDWOOD
PlANKING FOR
FlOAT BOARD
WINDMILL AND WATERING TANK
NOTE:
1. THE OBJECTI VE OF FlOAT
BOARDS IS TO HElP CUT DOW N THE
W ATER EVAPOR ATION IN THE TANK.
2. TO G IVE GAME BIRDS IN THE
PROCESS OF OBTAI NING DRINK ING
WATER , A STRUCTURE W HICH MAY
HElP THEM ESCAPE SHOUlD TH EY
FAll INTO THE TANK.
2" X 4" REDWOOD
WATER lEVEl
FlOAT BOARD
TOP VIEW
%"= 1'·0"
36" 16 GAUGE METAl
, .. SQUARE I TANK
.. "" .... -
1W' GAlVANIZED OVERFlOW PIPE
TO COME WITH IN 2 INCHES OF
TANK TOP.
SIDE VIEW
%"=1 '-0"
Fig. 20.31 . The simple round float board illustrate d in these drawings h as s aved hundreds of w ild b irds by p roviding an area fo r
them t o drink at ro und water troughs. One su ch trough witho ut the b oard flat containe d 13 sage g rouse carcasses, h owever, a ft er the
"wildlife saver" had b een installed, n o furthe r mo rta lities were observed (Nevada State Office, U.S. Bureau of Land Managem ent).
d evelqpm e nt are m aj or attractions, not only for wate r-
fo w l, but a lso for othe r wildlife. But the typic al b e a ver
impoundme nt is a c hanging affair that evolves thro ugh
seve ral s tage s. For thi s r e ason, the manage r should not
be a s concerne d with maintenance of individual ponds
as he is with rot ati on of favorab le habitat e l e m e nts
within the entire area of b eaver infl uen ce .
During the past 25 years, the st ates o f Mai ne a nd New
Hampshire h ave d evelop e d a nd r e fin e d b eave r man-
a ge m e nt techniques as p a rt o f th e ir wa te rfo wl m a nage-
ment programs. Hundreds of hectares of selected
beaver-created impoundments, including problem
flowages which otherwise might have to be destroyed,
are preserved annually thro_ugh a program of beaver
population control and stabilization of water ievels.4
The life expectancy of a beaver-created impoundment
is determined by the available food supply and the
number of beaver utilizing the food. From a food suppl y
standpoint, a . beaver flowage in which the beaver popu-
lation is maintained at low numbers (2-3 beaver) will
r emain active for a much longer period of time than if
the same flowage were occupied by a full colony (10-
12) of beaver. Beaver populations in desirable fl owages
can be managed by annual trapping, live trapping and
transfer, and beaver sterilizati on techniques.
New Hampshire has developed a "beaver pipe"
(Laramie 1978) or water level stabi lization device which
can be used in a ll eviating flooding conditions caused by
beaver building dams in culverts or flooding va luable
timber, fields, or roadways. A "beaver pipe" is a 7.3-m-
long, 30.5-cm-sq wooden tube with 1 solid end and a
bottom of 5.1 x 10.2-cm w ire mesh. For ease of han-
dling, a "beaver pipe" is constructed in 2 sections which
are joined together at the installation site. When pushed
through or set on top of a beaver dam (wire side down
with the solid end extending out into the pond) and
secur ed by steel posts, water flows freel y through the
bottom of the pipe out over the dam. The pipe can be set
at almost any l eve l and the beavers' efforts to stop the
flow are usually futile. Experience has shown a
minimum of 0.6 m of water must exist between the bot-
tom of the upstream end of the pipe and floor of the
pond for the pipe t o work efficientl y.
In the case of a plugged culvert, the dam is removed
and a heavy wire mesh fence (15.2 x 15.2-cm #6 con-
crete reinforcing wire) is installed around the mouth of
the culvert and secured with st eel posts. When the
beaver build a dam on the fence, a "beaver pipe" can
then be placed through the fence to keep the water at a
desired level (Fig. 20.32).
For beaver flowages where no culvert is involved (a
situation where the water level must be maintained or
lowered) installation of a "beaver pipe or pipes" alone
will do the job. A single "beaver pipe" can handle the
normal runoff from a 8.7-sq-km drainage area and in stal-
lations hav e been made utilizing up to 3 pipes (Fig.
20.33). Beaver fl owages with drainage areas exceeding
26-28.8 sq km are not feasible to manage using "beaver
pipes."
The State of Maine in turn has developed a wat er
level control pipe (Boettger and Smart 1968) constructed
from aluminum culvert stock which they u se to achieve
and maintain optimum water levels in beaver flowages
and prevent damage through excessive flooding.
GREENTREE RESERVOIRS
Greentree reservoirs are bottomland hardwood areas
shallowly flooded for short periods during the dormant
growth period for the purpose of attracting waterfowl.
4 Material provided by Harold Nevers, New Hampshire Fish
and Game Department , Concord.
381
Fig. 20.32. Wire mesh fence to protect culvert from flooding
with a "beaver pipe" (H. Nevers, N. Hampshire Fish and Game
Department).
Fig. 20.33. Water level can be maintained or lowered in a
beaver flowage by installing a "beaver pipe" (H. Nevers, N.
Hampshire Fish and Game Department).
i ''I ,I
I
i
i•l
382
Short-term flooding makes possible attractive feeding
conditions on mast from various oaks (pin, willow, Nut-
tall, and cherrybark) supplemented by understory food
plants, such as wild millet and smartweed. Flooding
may be scheduled so as not to adversely affect tree
growth or plant succession.
Acorns are the staple wildlife food item for which
such areas are managed. Ducks (mallards and wood
ducks) are the principal target species; but greentree
reservoirs are also good for turkey, squirrel, deer, quail,
raccoon, other forbearers, and many species of nongame
mammals, birds, reptiles, amphibians, and fish.
Water depth of 30.5 to 45.7 em is considered most
suitable for "puddle duck" feeding. It is not necessary
that the ground be completely flooded; narrow ridges
may remain dry and still be utilized by waterfowl.
The selection of a site for a greentree reservoir should
be based on 3 main considerations:
1. The area should be flat and contain impervious
clay soils and be close to a low gradient stream to pre-
vent excessive diking cost.
2. There must be mast-bearing oak timber that can be
flooded and is adapted to flooding. The opportunity for
this appears to be largely limited to broad, geologically
old-age valleys such as those of the south central and
southeastern United States.
3. There must be an ample and dependable water
supply which can be removed from the area before tree
growth starts in the spring.
In the operation of a greentree reservoir, it is desir-
able to begin flooding sufficiently early in the fall to
attract early flights of waterfowl. Drainage of flooded
areas should be accomplished during late March to
mid-April to prevent loss or damage to timber stands.
An open marsh constitutes an ideal supplement to a
greentree reservoir. Such marshes add to the variety of
habitat conditions and probably increase nesting and
brood rearing values. Marshes may be improved by the
methods suggested in the "Shallow Marshes" section of
this chapter. Technical engineering guidance and plan-
ning are needed for all proposed greentree reservoirs. A
detailed plan of the area to be flooded should be made
prior to construction including proposed water levels,
soil samples, and location and design of levees and di-
version channels or dams. Engineering features that
should be included in the plan include:
Levees
a. Levees should be wide enough for small vehicles,
a minimum of 1.2 m wide at top.
b. Levees should have a 3 to 1 slope downstream, 4 to
1 slope upstream.
c. Levees should be seeded or sodded to permanent
vegetative cover including wildlife food plants.
Borrow Areas
Are~ere soil is taken should be outside the green-
tree reservoir, preferably on high ground where the
spillway will be located. Taking soil from within the
greentree reservoir creates a deep water hazard for
hunters.
Spillways and Drainage
a. The borrow area, if properly located, may be in-
corporated into the spillway. The spillway should flow
onto undisturbed earth.
b. When a system of levees is needed to make flood-
ing possible or to divide large areas into management
units, the spillway may be incorporated into the struc-
tures.
c. Spillways built into levees must be stabilized by
using soil, cement, concrete, or paving material.
d. Flooding of the feeding range may be accom-
plished by several methods, all of which require use of
low contour levees with control structures.
Retention of Rainfall or Flood Waters
This method is best adapted to flat bottoms with low
gradient. It requires minimum investment and is eco-
nomical to operate. This method depends on rainfall for
flooding at the proper season. Since soils on these sites
generally are heavy clay and difficult to drain, sites
should be chosen which will allow draining the im-
poundment early in the spring to guard against loss of
tree growth.
Diversion of Injlowing Streams
This method may be used where small streams enter
terraces and well-drained bottomlands. It consists of a
gate-type structure in the stream to permit diversion of
the stream-flow into the diked area at the proper time.
Initial cost is largely governed by the size of the diver-
sion structure and extent of facilitating levees. Flooding
by this method, however, is not dependent on rainfall.
Pumping
Pumping is used where groundwater is readily avail-
able and where other water ·sources are unreliable.
Flooding, of course, is completely controlled, but re-
quires a relatively fixed annual cost for pumping. Pump-
ing costs usually range from $2.03 to $4.05 per 1000 ma.
Habitat Manipulation Practices
WATER LEVEL CONTROL
Production of submerged aquatic vegetation will gen-
erally require stable water levels. Actual depths will
depend upon topography, clarity of the water, plants
used, and species of wildlife involved. Operating depths
will usually vary from 0.5 to 3. 7 m with the optimum
being about 1.2 or 1.5 m. Water levels of 0.3 or 0.6 m
during the production season for submerged aquatics
proved most beneficial to waterfowl on the Montezuma
National Wildlife Refuge. Depths greater than this were
of little value to dabbling ducks. Water levels should be
managed so as not to allow freezing to occur in the bot-
tom soils. It should be pointed out, too, that where suffi-
cient water level control is possible to permit growth of
wet-soil plants, food production usually exceeds that of
~:.
submerged aquatics. In all improvement projects,
means should be incorporated in the control structures
to allow maximum flexibility in manipulating water
levels.
For management of emergent vegetation, the draw-
down practice of water level controls is used in areas
where waters are acid, turbid and light penetration is
inhibited, and also where soils are of low quality. Pe-
rennial and annual food plants may be managed by
drawdown dependent upon whether the objective is to
encourage permanent muskrat populations, or to pro-
vide needed habitat requirements for waterfowl. Draw-
down should be as late as possible yet still early enough
to allo~ seed production for such fast growing aquatics
as wild millet, rice cutgrass, and annual smartweeds
which may become established on moist mud flats. The
drawdown date will vary according to latitude. In the
Middle Atlantic states, June 20 is the approximate
drawdown date. Reflooding is usually done by Sep-
tember I in order to serve early migrating waterfowl.
If the impoundment is in an estuarine area, tide gates
should be in operation during the period of drawdown
to prevent ingress of saline waters. For most marshland
plants drawdown is to meadow level in order to fu~ish
subirrigation waters. For millet, the water level should
be raised above meadow level after the growing millet
has attained a height of I5.2 em or more. As the millet
grows, water levels can be raised accordingly, but in no
case should the water be allowed to flood over the top of
the growing plants. Preventing overflooding has the ad-
vantage of inhibiting the growth of undesirable and pe-
rennial plants.
Reservoir drawdown is an effective method of ma-
nipulating cover around waterfowl impoundments.
Species composition of cover can be controlled by time
and length of drawdowns. If the soil remains wet, cattail
and bulrush are favored. If it is allowed to dry, sedges
and such species as woolgrass are likely to invade. Late
spring and early summer drawdowns favor submerged
plants; mid and late summer drawdowns favor weedy
growth. In some regions, willow and red-osier dogwood
may invade rapidly where the drawdown is sustained
for 2 years or more. Drawdowns also improve the growth
of submerged aquatic plants once the area is reflooded
because of both physical and chemical improvement of
soils.
In Ohio, drawdowns during May in a managed marsh
were the most successful in producing plant successions
beneficial to waterfowl (Meeks 1969). Semiaquatic
species such as rice cutgrass and nodding smartweed
were abundant after May drawdowns. In addition,
drawdowns in May did not impair duck nesting and did
not limit muskrats to single litters as occurred following
drawdowns in March, April, or June.
Although water drawdowns are a valuable tool in
marsh management, they must be used with care, and
should be predicated on knowledge of physical and
biological characteristics of the marsh. Bottom topog-
raphy, soils characteristics, existing plant communities,
current waterfowl use and productivity, and seasonal
water supplies all are important factors that will affect
the decision to use drawdown as a habitat manipulation
technique.
383
PLANTINGS FOR FOOD AND COVER
Efforts to propagate plants for waterfowl food should
be undertaken only after thorough survey of existing
conditions. The important native species first must be
identified and inventoried. Consideration needs to be
given to the distribution and environmental require-
ments of all the important duck food plants that are, or
should be, present on the area. Planting, the last step in
the program, is done only when it is known that impor-
tant species are missing and that conditions for their
i~t~oduction are right. A very important first step in pro-
VIdmg food plants for waterfowl is covered in this Chap-
ter under "Shallow Marshes." This is to create the kind
of shallow, marshy-edged type of impoundment that en-
courages the favored flora. A constant, stabilized water
level is very important for growth and reproduction of
most aquatic life, whether it be plant or animal. This is
especially true during late spring and summer.
Artificial introductions are of most value to small areas
where the site can be managed and controlled inten-
sively. Planting of large marshes, river bottoms, or ex-
tensive impoundments is frequently very costly. When
starting a planting program, small plantings should be
made, thereby determining the adaptability of test
species for the site.
To realize best results from the planting program, the
work must be conducted at the proper period of the year,
usually during spring or early summer months. Second,
the planting site must be of a nature that promotes
growth. If the site is already supporting a cover there is
little reason to expect planting success, as the plants
growing on the site will be much more adapted than
introduced species (Singleton 1965). ·
The job of the habitat manager is similar to that of the
farmer as he implements the principles and practices of
crop production. In order to insure successful growth,
the crop producer first removes all competing growth
from the land and tills the soil in an effort to create
conditions favorable to the growth and production of the
target crop. Recommended sources of good information
pertaining to plantings, especially for waterfowl, in-
clude the following: for the Gulf states (Singleton 1965);
for the eastern states (Atlantic Waterfowl Council1972);
for the Pacific Northwest (Scheffer and Hotchkiss 1945);
for the Great Lakes areas (Pimit~ 1935); for the Pacific
Southwest (Miller and Arend 1960, George 1963); and in
general for North America (Addy and MacNamara 1948).
For immediate reference, the following are some of
the more important food plants for waterfowl and
suggested techniques for planting them:
Pondweed
Pondweeds can best be introduced into new waters
by transplanting of the rootstock early in the spring sea-
son. Whole plants should be pulled or dug, the roots
balled with mud, and immediately transplanted. Soft,
muddy bottoms make the most satisfactory growth sites.
Smartweed
Smartweed is best propagated by transplanting
rootstocks. Successful establishment has also been· ac-
384
complished by 30.5-cm long stem cuttings. About one-
half of each cutting should be stuck into mud bottoms in
shallow water. Rootstocks or cuttings should be trans-
planted during late winter or early spring.
Duck J?otato
This species may be established by transplanting the
entire plants in the spring or early summer. The trans-
plants should be set in water equally as deep as that
from which they were collected. Soft, muddy bottoms
make the best growth sites.
Spike Sedges
Rootstalk or entire plants can be propagated. All
transplanting should be completed in the spring or early
summer months.
Duckweeds
Transplant the entire plant. This is done simply by
collecting the floating plants in a bucket or basket and
then scattering the material in the site to be planted.
Duckweed makes its best growth in sites having emer-
gent vegetation which will protect the duckweed from
excessive wind or wave action.
Coontail
New plants grow from fragments of coontail stems.
The stem fragments may be planted at any time during
the growing season and can be transported whenever it
may be gathered, either from the masses oflive plants in
the fall or by rakes and drags used on the bottom in
winter or spring. They may be planted in packages or
merely pushed by hand into the soft soil.
Grasses
There are hundreds of grasses, both natural and
domesticated grains, used by waterfowl in North
America. Two native species commonly planted are
wildrice and wild millet. Wildrice is broadcasted and
requires no covering, for each good seed sinks at once
and becomes embedded in the bottom soils. Best plant-
ing sites are those that have shallow, fresh, nonstagnant
water, mud bottoms, and are open to the sunlight. A
great deal of wildrice seed has been wasted in water too
deep for the young plants to reach the surface or on
sludge bottom into which the seed worked down too
deep by means ofits tiny slanting barbs.
Wild millet, or watergrass, will not sprout if the water
depth exceeds 15.2 em. Usually no seedbed preparation
is necessary if the wetlands are newly formed on ag-
ricultural land or on annual grassland. The seed can be
broadcast and the pond flooded. The same treatment can
be gi-\Lell bare pond bottoms. However, a seedbed must
be prepared if the bottom is covered with cattails, tules,
and saltgrass, or rushes and spikerushes, since millet
cannot compete with these plants. In such cases the soil
must be plowed or disced 2 or 3 times and then har-
rowed to break the sod. The seed may be planted by a
field broadcaster, airplane application, or by use of grain
drills. When using drills, plant the seed no more than 0.6
em deep since deeper plantings often fail to germinate.
The usuai pianting rate is 22.4 to 33.6 kg of seed per ha.
May and June plantings produce the best yield. Millet
germinates rapidly when soaked and must not be left
dry afterwards or the germ will die (Miller and Arend
1960).
Alkali Bulrush
For many of the southwestern salt wetlands, alkali
bulrush may be established. Generally seedbed prepa-
ration is not needed unless competition is severe with
other plants such as cattails, tules, and saltgrasses.
Spring seedings are recommended at a rate of 33.6 kg
per ha. Seed may be aerially broadcast (seed should be
presoaked for 5 days) for large areas or a standard 20 x 6
grain drill used for operations smaller than 10 ha. If
drilled, be sure not to cover the seed more than 1.27 em
otherwise germination will be retarded or lost. Very
small areas (ofless than 0.4 ha) can be hand transplanted
by digging up the entire plant, including rhizomes and
tubers.
Proper water management is exceedingly important to
establish this species. First, as much of the field as pos-
sible should be preflooded to a depth of 2.5 to 7.6 em.
After seeding, the water should be held at this 2.5-to
7.6-cm level for 2 to 3 weeks, then the water should be
drawn down to a mud flat stage for 2 or 3 days. This
allows the seedlings to emerge and firm their rudimen-
tary root systems. The wetland should then be reflooded
to the original depth (2.5 to 7.6 em) and maintained at
this depth until the plants have full mature seed heads.
After this plant has become established, it may be
flooded to almost any depth without adverse effects
(George 1963).
RESTING SITES
Often it is necessary to create loafing islands or nest-
ing sites on wetland development projects for water-
fowl. Brood-rearing territories can be increased on im-
proved marshlands exceeding 0.8 ha by partitioning the
tract. Partitions are made by ridging or building chains
of islands across the project. Ridges and islands can be
constructed with a bulldozer or dragline during dry
periods or by depositing rocks and boulders on the ice in
winter. Snow fences strung across potholes is another
practice to serve as temporary partitions (Atlantic Water-
fowl Council 1972).
Floating "islands" can be anchored in shallow low
water ponds. Metal barrels are sometimes attached un-
derneath to adjust the height of flotation. The "islands"
can be constructed from green logs with rough mitred
corners made by a chain saw and held together with lag
screws. Each "island" should be landscaped with grass
or willows to provide shade and protection from pred-
ators (Shomon et al. 1966). Loafing and resting places
may also be made by anchoring a couple of logs or
1.2 x 1.2-m rafts in open water, or by stacking rocks, old
straw or hay bales in shallow water.
NEST STRUCTURES
For suggested techniques on nest boxes, nest plat-
forms and cones, see "Nesting Cover" and "Specialized
!".Jest Struct-uresn in this Chapter.
MAN-MADE ISLANDS
During the past hundred years, over 2,000 man-made
islands have been constructed throughout U.S. Coastal,
Great lakes, and riverine waterways. These islands have
created new habitats for many species of wildlife, espe-
cially colonial birds. Landin (1978) provided an evalua-
tion of these structures and listed some 50 references
documenting the use of man-made islands by wildlife.
Most man-made islands are constructed with dredged
materials. They vary greatly in size and characteristics
and range in age from newly formed to 50 years. Com-
mencing in 1976, the Dredged Material Research Pro-
gram's Habitat Development Project located at the U.S.
Army Engineers Waterways Experimental Station,
Vicksburg, Mississippi, initiated studies of these struc-
tures. Most results published to date relate plant succes-
sion to bird utilization of islands. One report (Soots and
Landin 1978), provides helpful information pertaining
to the development of avian habitat through dredged
material islands.
Small man-made islands were attractive, relatively
safe nesting sites for mallards and Canada geese in
prairie wetlands {Johnson et al. 1978).
Constructing Water Control Devices
There are various development structures used to
control water to improve wetlands for wildlife. A gen-
eral list of techniques is presented here with references
on construction methods and specifications. The impor-
tance of working with expert engineers in developing
construction requirements cannot be overemphasized.
DIKES AND EMBANKMENTS
All discussions relating to earthen water impounding
embankments are limited to fills 3 m high or less. If
higher embankments are required, detailed soil studies
must be undertaken in order to design and construct a
safe structure for the most reasonable cost.
385
For a well-documented review of principles and
methods of making dikes or impoundments, see the ex-
cellent Techniques Handbook of Waterfowl Habitat
Development and Management compiled by the Atlan-
tic Waterfowl Council (1972). The material presented
here was obtained from that book. The handbook de-
scribes the following types of embankments:
Simple Embankments
Simple embankments are those consisting of rea-
sonably uniform material throughout. They are gener-
ally located in marsh or swamp areas where on-the-site
soils must be used. They generally involve the least ex-
penditures for construction and in many instances are
the only feasible type to use (Fig. 20.34).
Core Type Embankments
Core type embankments are those whose central por-
tion or core is constructed of selected soil, usually the
least pervious material. The outer surface is comprised
of on-the-site, more pervious soils. This type of em-
bankment seldom is used on low-head fills unless the
supply of less pervious materials is readily available or
unless the soils of different permeability are separated
naturally by distinct layers, readily available. to the
earth-moving equipment being used. However, on-the-
site soils can be so poor that stability of the embankment
will be questioned by competent engineers. In such
cases it may be economically sound to haul the core
material from some distant borrow pit (Fig. 20.35).
Diaphragm Type Embankments
Diaphragm embankments are those which incorpo-
rate a relatively thin section of concrete, steel, or wood
to form a barrier to percolating water. The "full dia-
phragm" type has the barrier extended from the level of
the impounded water down to a seal in an impervious
foundation. A "partial diaphragm" or cutoff wall type·is
one which does not meet the conditions of the full type
(Fig. 20.36).
Although the need for complete, detailed investiga-
tions of the properties of soils and' subsurface conditions
is less on the low-head fills, on-site inspections must be
Fig. 20.34. Plans for construction of a homogenous fill typical dike (Atlantic Waterfowl Council 1972).
i
i i
386
STONE PAVING AND
GRAVEL BASE IF
DOWNSTREAM POOL
IS FORMED
LOAM AND
SEEDING
ROADWAY
Fig. 20.35. Plans for construction of a typical clay core dam (Atlantic Waterfowl Council 1972).
made and "rule-of-thumb" criteria based on experience,
must be used in designing the embankment and select-
ing the type of earth moving equipment for the job.
All earthen embankments should meet the following
recommended criteria:
The dam shall be designed so that destruction through
erosion is prevented. In order to meet this condition: (l)
the spillway should have sufficient capacity to safely
pass the expected peak flow for the drainage area, and
(2) freeboard should prevent overtopping by wave ac-
tion at maximum high water. The final top elevation of
the embankment, after settlemerit, in areas of runoff
water should be designed by adding to the maximum
high-water elevation (resulting from flood flows) an
amount at least equal to the wave height plus wave run
up the slope. These amounts are determined by stand-
ard construction formulas. In areas of deep frost, an ad-
ditional amount must be added to allow for damage from
frost action. The elevation so determined considers
overtopping by water originating upstream from the
embankment.
For construction of sites in tidewater areas, overtop-
ping by storm waters from outside the impoundment
should be given consideration. The type of management
within the impounded area, type of material available,
and the cost of construction will have to be weighed to
determine whether or not embankments in these loca-
tions will be constructed to exclude such storm waters.
If it is decided not to exclude them, provisions must be
PREVIOUS FILL
l
SUITABLE SUB-GRADE
made in spillway and control structure sizes to admit the
storm water into the impoundment in such quantities
that the water surface elevation within the impound-
ment rises at approximately the same rate as the water
outside. Then, when overtopping occurs, dike erosion
will be reduced to the minimum.
For some wildlife management purposes, extremely
low fills may be desirable to temporarily impound shal-
low water. Under these conditions, a comparison of con-
struction plus annual maintenance costs must be made
between dikes which would allow for overtopping and
those which would prevent overtopping.
The foundation should be able to support the load
imposed by the embankment and live loads placed on it.
Foundation soils will usually be stable enough to sup-
port the load of the embankment and live loads for lpw-
head fills. In some areas, however, the soils may be
highly plastic so special precautions must be taken to
insure stability. If such soils are not too deep they c,an be
removed and replaced with more stable material. In
other areas, however, it may not be feasible to remove
and replace them and some method of treating them in
order to realize stability will have to be devised. Rows of
sheet piling or round piling can be used, but the cost per
meter of dike is high. If extensive areas of such unsuita-
ble foundation soils are encountered, it may be wise to
abandon the site.
The resistance of the embankment and foundation to
the passage of water is dependent on the impervious-
WATER LEVEL
EXISTING GROUND
Fig. 20.36. Plans for construction of a typical diaphragm embankment (Atlantic Waterfowl Council 1972).
ness and compaction of the material used. Loss of water
is not dangerous if the supply retained in the impound-
ment is sufficient for operational needs and the seepage
of water does not cause flotation of soils. Care must be
taken to establish the minimum siopes and top width of
dike which will provide this embankment safety and
bury the seep line. A 3.5 or 4 to l slope is considered the
minimum for maintenance because tractor mowing
equipment usu~lly cannot safely operate on steeper
slopes. Any embankment used for travel or maintenance
mowing should have a minimum 2.4 m crown width
with 3.1 m preferable.
The sites for habitat impoundment projects cannot
always be limited to those having suitable foundation
and fill materials. It is frequently necessary to compen-
sate for poor onsite material by safe design and construc-
tion of the embankment. However, under such condi-
tions, the initial construction cost and future annual
maintenance costs will increase proportionately with
the decrease in soil stability. In all cases, the typical
section (slopes, crown width and freeboard) should be
such as to keep the impoundment seep water line within
the fill. Wet spots on the downstream slope of any em-
bankment could indicate the seepage line is not covered
and remedial action should be taken. The type of em-
bankment will be governed by the depth of water to be
impounded, the materials available, and costs of both
initial construction and later maintenance. All of these
factors are interrelated but any one of them can out-
weigh the others on the specific project.
SPILLWAYS
Spillways are provided in major wetland devel-
opments to release surplus or floodwater which cannot
be contained in the impoundment basin. Inadequate
design of the spillway structure may result in failure of
the retaining dam and possible downstream damage.
The spillway design should be considered in relation to
the management potential of the marsh and to draw-
down or stable pool operation. A spillway design of
maximum flexibility of water levels will, in most cases,
be the best suited to the management of a wetland im-
poundment. Flexibility should be carefully judged
against its benefits as related to structural costs. Stand-
ard types of spillways include the following:
Free Overfall or Straight Drop
This type is used most frequently in the Northeast in
low-head design, common to most large shallow area
impoundments. It is necessary to provide artificial pro-
tection below the spill crest, as scouring and structural
damage is likely to occur. A concrete or plank apron
combined with cutoff walls is, therefore, an integral part
of the free overfall design. The free overfall spillway of
reinforced concrete or wood planking is usually de-
signed for fixed water level impoundments. In low-head
waterfowl impoundments, the design is usually mod-
ified to provide for drawdown or limited increase in
storage capacity.
The reinforced concrete spillway is usually the most
satisfactory design. The initial cost of concrete design is
387
higher than log cribbing or Wakefield piling, but main-
tenance of the structure is minimized since concrete
longevity is much greater than other materials. The loca-
tion of the impoundment site and availability of material
may warrant use of materiai other than concrete. The
spillway should be designed for access so structural
maintenance can be performed.
Ogee
The ogee spillway, usually designed of reinforced
concrete, has a weir that is ogee or (S) shaped in profile.
The flow is over the crest and along the profile of the
structure with minimum interference and therefore at-
tains near maximum discharge efficiency. In many
low-head designs for waterfowl, storage of water is im-
portant and discharge efficiency is not a factor limiting
design. The ease of construction and cost-related con-
siderations may limit construction of ogee spillway de-
sign. In cases where ogee designs are contemplated for
waterfowl impoundments, consideration should be
given to incorporating drawdown features. This may in-
volve drop boards, gates, or valves, so that water levels
may be dropped below normal operational levels.
Drawdown features should be considered even where
management planning is based on stable pools. The in-
stallation cost of a drawdown feature may well pay for
itselfby improving the future maintenance of the prime
structure.
Natural
This spillway is one that provides for impoundment
runoff over natural undisturbed ground. A spillway of
this type is unusual in a large fresh water impoundment
design. The possibility of locating a natural spillway
with runoff capacity, soil type, and vegetative cover that
will meet design criteria is unlikely. If a design can take
advantage of such a spillway, substantial savings in de-
velopment cost may result. It should be noted that main-
tenance of this type spillway may in some instances be
rather high. The obvious disadvantage is that unless this
type is supplemented with gates or other mechanical
devices, it is not possible to proyide for drawdown or
drainage.
Pipe or Culvert
A culvert spillway is a simple type spillway with the
inlet opening placed either vertically or inclined up-
stream, with a uniform profile grade. The approach to
the conduit may have flared or tapered sidewalls with a
level or sloping floor. Conduits are usually metal, with a
bituminous coating, and may have paved inverts. Con-
crete or fiberglass conduits have been used some. In
low-head design, this type spillway is adaptable for
either part or full capacity operation. Construction is
simple and economical.
There are disadvantages, however, in the use of
culvert-type spillways in managed wetland impound-
ments. The capacity does not increase greatly with in-
creased head, and there are limitations imposed in
drawdown unless a gate valve is incorporated.
388
Log Crib
The log crib spillway used in wetland impoundment
is limited to locations where the use of permanent mate-
rials would be too costly. Logs should be selected that
have uniform taper and are highly resistant to deterio-
ration. Logs treated with preservatives such as coal tar,
creosote, or pentachlorophenol solution are desirable
where longevity is important. The abutments and spill-
way are usually faced with 7.6 em treated planking. The
maintenance of this type spillway is often very high in
relation to cost of a more permanent type installation.
Because standard design plans are not often used in
these structures, it is important that a plan be designed
to meet local needs. The plan should be based on com-
petent engineering standards. In general log spillways
are constructed of toe piling driven on the upstream face
of a bed log with the spillway having a maximum incline
of 30". All bark should be peeled from logs not com-
pletely underwater. It may be desirab~e to include a
stoplog section if drawdown is a consideration in the
impoundment.
Drop Inlet
A drop inlet is one in which the water enters over a
horizontal positioned lip, drops through a vertical box or
shaft, and is discharged through a pipe or conduit. In
waterfowl impoundments, a concrete drop inlet in con-
junction with reinforced metal pipe may be suited to
small drainage areas. The most usual design is a
monolithically reinforced concrete box, with stoplog
slots on the upstream side. Provisions may be made for
trash screens to prevent pipe constriction. Emergency
spillways are incorporated in the design.
Stop Planks
Stop planks provide a means of adding flexibility to an
ungated spillway. These are planks spanning horizon-
tally between grooved recesses in supporting piers. Stop
planks may be removed during floods to pass excess
waters or when partial or complete drawdown of the
pond is desirable. This type control is the most econom-
ical and provides adequate area to pass debris. The pas-
sage space should be a minimum of 1.2 m wide on larger
dam structures. A lifting type device may be desirable if
the stop planks are to be removed frequently since man-
ual removal may entail considerable time and work. If
water loss is to be minimized, stop planks should be
planed on all4 sides and free from warp. Leaks between
planks can be easily sealed by placing soft coal ashes in
small quantities (handful) immediately upstream and
over the leak. Dry cinders are best as they float more
quickly into the leak. Planks should be naturally resis-
tant or specially treated, and a minimum width of 5.1
em.
Gates
~~ are used in spillways where higher frequency
and greater control of drawdown may be desirable. Lift
gates span horizontally between guide grooves in sup-
porting piers. Gates are usually cast iron or steel and
raised or lowered by an overhead hoist device. Radial
gates are usually constructed of steel (prefabricated).
Water thrust operates the radial type of gate which may
be set at a predetermined level so as to operate automat-
ically. Cost of the installation of radial gates may be
appreciably higher than lift gates, stoplogs, or drop inlet
installations. If continual drawdown in the impound-
ment is contemplated, gate installation should be con-
sidered.
LEVEL DITCHING
Level ditching means constructing upgraded ditches
on lands having a high water table. These ditches are
installed to improve water distribution, provide open
water for waterfowl, furnish nesting sites, and aid in
increasing or maintaining aquatic food and cover plants
for waterfowl and furbearers (Mathiak and Linde 1956).
This practice is applicable on wetlands where soils are
suitable for ditch construction and require a minimum of
maintenance for a long period of time. Suitable soils
include peats, muck, clays, and silt. Sands, sandy loam,
and clay high in salt content generally are not suitable.
Generally, ditching is applied to marshes exceeding 0.8
ha.
It is helpful to consult with soil scientists, hy-
drologists and agricultural engineers for planning level
ditching. On large wet areas, an aerial photo or topo-
graphic map is useful in locating natural drainage pat-
terns and in laying out ditch systems. A sufficient
number oflevels should be run to determine the general
slope of the wet area. Where slopes exceed 0.5% the
ditches must be laid out on the contour level. The ditch-
ing pattern is designed to avoid interception of natural
channels except where desirable for circulating systems.
Usually blocks are left between level ditches and the
natural channels, but these are designed to allow flood
or high tide flows into the ditches or else water circula-
tion is regulated by means of control devices. As a rule,
level ditches are installed at approximate right angles to
natural channels.
Level ditches are generally constructed with a drag-
line or with ditching dynamite. Occasionally a backhoe
or a bogharrow may be used. In the use of ditching
dynamite, the supervision of a licensed and experienced
explosive expert is recommended. When a dragline is
employed for ditching, spoil material is stacked 3 m
from the ditch edge in piles alternated from side to side
at 15.2 m intervals. This spoil serves an important func-
tion in providing nesting areas. The breaks between
piles are said to reduce nest predation. In small marshes
ditching usually is done in straight lines or, where there
is a slope, on the contour. Whether straight or curved,
these ditches must not have a fall. On flat marshes ex-
ceeding 4 ha, the ditch is constructed in zigzag pattern,
with each reach about 30.5 m long. Such a design re-
duces influences of wave action during high winds.
Multiple ditches are laid out with parallel reaches 61 to
121.9 m apart.
Minimum dimensions recommended for level ditches
are 1.2 m depth and 3. 7 m top width. Such ditches pro-
vide, at intervals given above, about 275.5 square m of
open water per ha.
PLUGS
Plugs are usually recommended for marshes where
diking is not a feasible management tool due to either
improper physical conditions of the area (size, location,
water, or terrain) or economic reasons.
Plugs can prevent the fluctuation of water levels in
existing water areas or increase the water area in the
marsh. Various types of plugs as defined by the Atlantic
Waterfowl Council (1972) include the following:
Nonspilling earth plugs are usually used to repair
marsh damage caused by mosquito or other marsh
drainage projects. The same principles are used as in
building a dike across a tidal creek. The plug must be
keyed in to both sides of the ditch and a good bond must
be made between the fill material and the bottom of the
ditch.
Nonspilling wooden plugs serve the same purpose as
the earth plug type. Wakefield piling of creosoted
lumber is used. Care must be taken to use piling long
enough to prevent undercutting and the wing walls
must be of sufficient length to prevent water from cut-
ting around the end of the plug.
Spilling gut plugs are designed to reduce water fluc-
tuations due to tidal action and thereby to make more
food available to waterfowl for longer periods. The most
common material used in this type of construction is
creosoted lumber.
STRUCTURAL IMPROVEMENTS AND FACILITIES
Modern society creates a variety of structural im-
provements and facilities that affect wildlife popula-
tions. Most of these are built for other than wildlife
management objectives, e.g., fences to control domestic
livestock, bypasses for vehicular access on highways,
etc. Since these structures are being built continually
and design specifications can adversely or beneficially
affect wildlife populations, techniques are provided
stating how they can best be implemented with consid-
erations for wildlife. Then too, there are certain prac-
-tices needed in wildlife management, such as fences to
control wildlife access.
Fences
Most fences are constructed today to control domestic
livestock. However, fences are also constructed to re-
strict vehicular access on highways and other reasons.
Fences have had their most serious impact on big game;
consequently, techniques are listed on how best to con-
struct fences to (1) allow wildlife movement through
fences built to control livestock, and (2) design specifi-
cations that will control wildlife access.
LIVESTOCK FENCES AND PRONGHORNS
Fences constructed to control domestic livestock
often have been documented as a problem to the free
movement of antelope on western rangelands. Caton
(1877) first noted this problem a century ago. More re-
cently, wildlifers report (Martinka 1967, Sundstrom
.1970, Oakley 1973) that fences can be major obstacles
389
where antelope mobility is restricted to procure food
and water, or escape deep snows.
During the 1960's, there was an accelerated increase
in livestock fences constructed on western private and
b 1' l .J Th _a: c"s _r..-. ___ e l'--c--w·--·L1e pu JlC range anuS . .I.J € cu€ l U.l UJt::~ .ltU "t:S a:; U
subject for an in-depth research project conducted in
Wyoming during 1963 and 1964. Results from this re-
search provided scientifically designed and tested data
regarding the interrelationships between pronghorns
and livestock fences. However, the true importance of
fencing to antelope mortality was not well accepted into
the 1970's; consequently, a regional workshop pertain-
ing to the problem was conducted during March 197 4, in
Cheyenne, Wyoming. Some 150 people representing
state, federal, and private workers met to establish
guidelines for the construction of fences in relation to
the pronghorn's welfare (U.S. Bureau ofLand Manage-
ment 1974).
There are 2 major interagency conferences that
periodically meet to exchange information and provide
recommendations on pronghorn management. Relative
to fences, each of these conferences documented their
findings and recommendations in the following publica-
tions: Interstate Antelope Conference (1962) and An-
telope States Workshop (1974).
It can, therefore, be stated that the controversy be-
tween livestock fences and antelope has been a long one
with many studies and recommendations. Recognizing
these interrelationship problems, the following are
basic principles that should be considered during the
planning of all fences in pronghorn habitat:
1. Any fence has the potential of becoming a problem
to antelope welfare if the fence restricts access to food
and water or causes physical injury through entangle-
ment. These potential biological problems should be
recognized during the initial planning justification for
all fences in pronghorn habitat.
2. How the fence is specifically designed will deter-
mine the true effects the fence will have on the antelope
population. A fence can be designed to allow no an-
telope movement; it can be designed to allow limited
antelope movement; or it can be designed to allow easy
movement for most antelope.
3. The design of the fence shoulp allow for movement
of all antelope age groups in order to maintain healthy
populations. This is particularly important for fawns.
4. Fences that are constructed on migration routes or
seasonal movement areas can be especially deleterious.
Antelope traditionally need to have freedom of access
from areas with deep snows. Likewise they need unre-
stricted access for seasonal movements to obtain water
and preferred forage. They also need unrestricted routes
to seek traditional fawning grounds.
5. Keep fenced areas as large as possible to allow an-
telope to obtain basic habitat requirements. Pronghorns
maintain best populations on ranges where there
is an abundance of forage and water with no undue
movement restrictions.
6. Existing or planned fences constructed through
traditional antelope migration routes or important sea-
sonal movement areas should contain an alternative to
use "lay-down panels" during time of antelope use. The
choice of such an alternative decision means that these
!!It•
390
panels must be properly maintained; otherwise, they
may be ineffective and could be even disastrous to a
population if not functioning during a crisis (e.g., ex-
treme early season deep snowfall).
7 . ,.\lt.'~-wugh a number of devices known as "antelope
passes" have been recently developed, they are a
mitigating alternative and have limited value in provid-
ing move m e nts for all aged pronghorns. This mitigating
alternative needs t o be recognized in the initial plan-
ning and justification of the fence project.
Net or Woven Wire Fences
Antelope workers are adamant in the ir professional
opinion that net or wove n wire fences are a serious r e-
s triction to movement of pronghorns. Such fences can be
the primary cause of death for individua l animals when
deprived of access to waters or forage, or restricting herds
when inclement weather conditions result directly in
mortality. Therefore, it is strongly recomme.nded that no
woven wire fence s be constructed in antelope h abitat.
This is especially true for the so called "wolf-proof"
fe nces on domes tic sheep ranges in New Mexico and
Texas. These fences are constructed of woven wire (of
which 15.2 to 45.7 em is buried unde rground) and top-
ped with 2 to 4 stand s of barbed wire. Fence heights
average 1.4 to 1.8 m. The objective is not to allow coyote
access under, through, or over such fences. They also
are 100% effective in preventing pronghorn access .
Barbed Wire Fences
1. The bottom wire sh ould be at !, ast 40.6 em from
the ground.
2. Because ante lope generally go under barbed wire
fences and the barbs can cause injury, it is recom-
mended that this wire be smooth.
3. No stays should be placed between fence posts to
provide a more flexible fence for ante lope attempting to
go between wires.
4. Spillett et al. (1967) documented that 81 em high
fences contained most livestock on rangelands. It is
therefore recommended that this fence height be con-
structed on antelope rangelands. Antelope can and do
jump fences in some areas, and the lowe r the top wire
the better. This would also hold true for other wildlife
such as deer, elk, and moose.
5. Based on findings of the "Regional Fencing Wo rk-
shop" (U.S. Bureau of Land Management 1974), the fol-
lowing specifications for barbed wire fe n ces on lives-
tock ranges (see Fig. 20.37.) are provided:
Type 1: Ranges occupied by cattle only
-
Type II:
3 strands of wire spaced at intervals of:
-bottom wire 40.6 em from ground
(smooth wire only)
-next wire (barbed) up 27.9 em
-top wire (barbed) up 27.9 em more for a
total wire height of96.4 em from ground
Ranges occupied by domestic sh eep only
4 strands of wire spaced at intervals of:
-bottom wire 25.4 em from ground
(smooth wire only)
-2nd wire (barbed) up 17.8 em
-3rd wire (barbed ) up 17.8 em
-4th wire (barbed) up 20.3 em for a totai of
81 em from ground
Type III: Ranges occupied by domestic sheep and
cattle
4 strands of wire spaced at intervals of:
-bottom wire 25.4 em up from ground
(smooth wire only)
-2nd wire (barbed ) up 22.9 em
-3rd wire (barb ed) up 22.9 em
-4th wire (barbed) up 25.4 em for a total of
96.6 em from ground
Antelope workers would be quick to evaluate these
fence s pecifications and to note that types II and III
could provide limitations to easy movement of certain
antelope age groups.
Antelope Passes
Standard cattleguards will a llow the movement of
adult antelope. Fawns, however, have difficulty in
c rossing them. They must be placed where antelope can
r eadily locate them. Advantages h ave been realized by
placing cattleguards in fence comers. The fences then
act to "drift" the antelope to the pass opening. In long
sections offences, it is he lpful to build a jog in the fence
line for placement of the cattleguard. Care needs to be
taken in locating the p lacement site to minimize the
cattleguards filling with debris and silt.
Structures describe d as "antelope passes" were de-
veloped and tested in the Wyoming sheep-antelope-
fe n ce study (Spillett et al. 1967). Unfortunately few of
these s tructures have been tested unde r range condi-
tions. More recently, Mapston and ZoBel! (1972) field
tested one such structure in Wyoming. Their conclusion
was that antelope passes are used but they have limited
value in r e lation to p roperly planned and full y im-
plemented range fences such as Type I in Fig. 20.37.
Figure 20.38 depicts a 4-5 month fawn pronghorn
n egotiating one of these facilities. Figure 20.39 provides
detailed plans for constructin g ante lope passes. After
s tudying the effect s of passes on antelope movements
under field conditions, Mapston a nd ZoBell (1972) pro-
vided guidelines as to when they are advantageou s and
whe re they have limited values. Antelope passes can
facilitate antelope movement through fences, but only
when properly located and installed. For maximum ef-
fectiveness, passes should be placed in fence comers or
offsets (see Fig. 20.40) and supporting fence post braces
kept to a minimum. Although antelope have an innate
jumping ability, it takes considerable time in certain
areas for pronghorns to learn to use passe~. The authors
emphasized that passes have limitations and should not
be viewed as a substitute for fences that permit ready
passage of pronghorns. The manager responsible for
making the decision as to whether a livestock fence
should or should not be con struct ed should also con-
sider the fence's effect.
391
= <D ~
~ ., ""' ' ' ' -
I ,I ~ CD ,,
10
:
-r---I -'· I .
I I -'• .... :CD -
l L~ I ·-.--J ....
..... ---TYPE I-CATTLE
"'
1'9. CD I A . ~
:
' j
1 .
I • -= N
' I---" 10 • ' I _.JI.,j
=gt l -' ... ~ .. lr,_ ~
..... ----~,._.A-TYPE JI-SHEEP
TYPE :m -CATTLE 8 SHEE?
Fig. 20.37. Details of specifications for livestock fe nces constructed on antelope ranges as
recommended by the Regional Fencing Work sh op (U .S. Bureau of Land Management 1974).
Fig. 20.38. A 4 -5 month fawn pronghorn leaps through a break
in a livestock fence known as an "antelope pass" (U .S. Bureau
of Land Management photo by Ray Mapston).
LIVESTOCK FENCES AND DEER
The interrelationships of domestic livestock fences
and native deer h ave n ot raised the political furor that it
has for the American pronghorn. However, throughout
North America w here livestock fe nces have been built,
they have undoubtedly caused a far greater mortality
problem to deer than they have to antelope. Deer are
more s ubject to being v ictimized on a n individ ual basis
whereas antelope at times are entrapped in large winter
concentrations. Then too, deer are frequently caught in
fences in isolated areas not readily witnessed, whereas
antelope mortalities in wide ope n country a re easy to
observe.
Deer characteristically j ump ove r fences ar.d this
often leads to the ir demise. While the adult deer is
jumpi ng, its hind feet can become entangled between
the top 2 wires of range fences. Such a case ge nerally
results in eventual dea t h. A case inves tigated in north-
·-~~
392
3~2'~3~2"•~" 1 ~1 ~" 1•'1." :..."L 's : ~J~=============f917-2 • 2 •'le ANGLE_
IRON-~===========~
+;;--
L
6o.c.
r----0 _' --------------------o=-1---
.... ~~L-C3/~'HoLE-----------------ll ~-_J
I I II ~ '--..
1 5 6 .,. T IMBER
PLAN
Fig. 20.39. Antelope pass specifications and recommended method of install a tion (Mapston and
ZoBell 1972).
west Colorado disclosed a major d eer d eath loss due to a
combination 81-cm net wire and 2-stranded barbed wire
fence. The 1.6-km-long fence was placed across a tradi-
tional migration route. For years the winter snows were
not deep and no problems were recorded. Then during
1974, h eavy snows fell. The deer migrated through the
are-;-as they normally did. However, the short yearl in g
class of deer did not have the ability to negotiate the
fence with a result of 12 perishing in the fence and some
50 others succumbing through entrapment.
Guidelines for Barbed Wire Fences
Nevada has experienced many cases where deer have
become entangled in barbed wire fences. Recognizing
this problem, state and federal wildlife managers de-
s igned a barbed wire fence best adapted for deer ranges.
It stresses 2 major points : (l ) keep the bottom wire up to
a ll ow movement of fawns, and (2 ) keep the top w i re
down to allow ease for jumping over. Figure 20.41 pro-
vides a schematic drawing for this specially designed
A. Recommended corner
location B. A fence wino to improve
effectiveness of fence II ne posses.
393
Min. of 30 yds.--oot
C. Method of lnstallino paired offsets.
D 0 ftset pass i nsta Jlot ion. . E .
t----20'---oot
Optional offset pass
Installation.
Fig . 20.40. Recommended methods for installing antelope passes (Mapston and ZoBelll972).
deer fence. Note these specifi cations designed for deer
requirements:
l. Bottom wire up 40.6 em from ground -thus a llo w -
ing for movement o f fawns.
2. Only 3 strands of wire required. Fences were con-
s tructed on large open rangelands where li vestock were
not restricted. Under these circumstances, 3 wires are
all that were needed to control cattle.
3. Top w ire is smooth and 91.4 em from ground, thus
a ll owing deer greater ease in jumping over the fence.
4. Stays are placed between fence posts. Since deer
frequently become entangled when the top 2 wires twist
....
iol!i'
..
lllltti
....
394 r 16'-s" c.c. ~
I ~ T~TED WIRE STAY
~[" .7:~~-!....:: ...... -•ijt!,_,-:_•~--_-.....,A---~-=--:..-+•_-_-=.Jt-i._ -*_•-:_-:_-• .._•_• =:.:::=~~~~=·~·==~SMOOTH WIRE
I I I I I I I I
LJ L~
Fig. 20.41. Recomme nded s pecifications for construction of a barbed w ire fe nce for cattle control allowing deer access.
around the legs, the stays make a more rigid fence ,
thereby allowing the animal a better c hance to wiggle
out of the fence.
Managers should recognize that these fence sp ecifica-
tions are adequate to contro l livestock for open range
conditions . Where livestock concentrate around water or
adjacent fields of lush, preferred forage , these specifica-
tions will b e minimal and not always adequate; how-
ever, most range fences do not fa ce these problems and
therefore the specifications can b e applied in more cases
than not. Because deer cha racteristically jump over
fences and frequentl y become entangled in the top wire ,
a smooth wire would decrease physical injuries.
Two fences w e re t ested with these specifications in
Nevada for the past 6 years. In each case, the fence
ade quately controll ed li vestock and decreased the inci-
dence of deer entrapment. Based upon information
gained from thi s field management study, othe r fe n ces
with these specifications to control lives tock on impor-
tant dee r ranges have b een constructed on wes tern
rangelands b y the U.S. Bureau of Land Manage me nt.
FENCES FOR CONTROLLING DEER
Properly construc t ed fences can provide good protec-
tion against deer depredations t o various a g ricultural
crops, high conce ntration winter ranges, and areas of
timber reproduction (Longhurs t et a!. 1962). Although
the initial cost of ins tallation of fencing for depredation
contro ls i s often high and continued mainte nance is
necessary, the expen se can, in many cases, b e justifie d.
F e nces can provide economic protection against dam-
age that deer can cause to high-value crops. Deer co ntrol
fen ces are also b e ing constructed for the purpose o f
rotating deer u se of fo rage in range p as tures on c riti cal
winter ranges in California, Colorado, and Was hington.
Under mos t circumstances the upright st y le of fe n ce has
proven most sati sfact ory, but unde r some conditio n s th e
slanting fe nce is cheaper to constmct and is advanta-
geous b ecau se of its lower h e ig ht. Specifications for
both fenc e types a re presented here as ad apted from
Long hurs t e t a !. (1962). Th e use of e lectrical fences h as
been a third tec hnique used to a limited d egre e in deer
habitat contro l. -Upright
While a h e ight of 1.8 m is usually adequate for u p right
fe nces on level ground, a 2.4-m fence may b e necessary
against larger d eer (Fig. 20.42). D ee r normally will not
jump a 1.8-m fence for food, but if pressed they can jump
a 2.4-m fence on level ground. When fences are located
on sloping ground, it m ay be necessary to build the m 3
m or 3.3 m h igh to guard against deer jumping from
above.
Woven mes h wire is preferable for the full height of
the fence; if economy is necessary, 2 or more strands of
9-or 10-guage s mooth wi re can be s tretched at 10.2-to
15.2-c m spacings above a 1.5-m mesh wi re. There is no
advantage in us ing b a rbed w ire for this purpose, and it i s
more costly. Welded m esh w ire is less expensive than
woven, but it is to o rigid to conform readily to ir-
regularities in the ground s urface and is most u seful on
even ground. Wire lighter than 12112 gauge is n ot rec-
ommended. Vertical stays s hou ld not b e over 15.2 t o
20.3 e m apart, a nd line wires not ove r 10.2 to 15.2 em
apart. Because deer will c rawl under a fe nce w h e n p os-
s ible, mesh wire s hould be secured and kept close to
ground level. An ex tra strand of barbed wire s tre tched
along the ground will help prevent them from crawling
under. In any depressions between posts, wire s hould
be staked firml y to the ground or depressions s h ould b e
filled with m a t erials w hich will not deteriorate o r wash
away. A 0.9-1.2-m piece of angle -iron post makes a
good permanent stake to hold wire close to the ground.
Wooden o r s teel posts may be used, the choice d e -
pending on availability and cost s . Wo od e n posts are
usually somewha t cheaper, w i th sawed ones being more
expensive tha n split p ost s . Th e i r di men s ions at the ends
should not b e less than 10.2 to 12.7 em across . Iffe n ces
are to b e moved from t ime to time, s teel post s are prefer-
able because of the greater ease with wh ic h t hey can b e
ins talle d and removed. Steel p ost s can be purc hased in 3
types: T-s hape d, c hanne l , and angle. The T-type is more
rigid and is perhaps preferable, w ith c h an nel next and
angle last in ord er of s tre ng t h; prices also d ecrease in
that o rde r. Pos ts should gen erall y be set about 3 to 3 . 7 m
apart, but ex t ra p osts may be necessary to hold the w i re
t o the contou r of uneven ground. When bu ild i ng w ith
s teel posts it is o ft e n a d visable to int e rsperse the m with
wood en p ost s in o rde r to s tre ngthen t he fence -1
wood en post fo r every 3 to 5 steel post s is the appro xi-
mate ratio . Prope r b racing alo ng fe n ce lines is important
to gi ve su ffi cient stre ngth. Wooden corne r posts should
b e a t least 15.2 em across the e n ds and are preferable to
s t eel posts un less t h e latter are in conc rete and are we ll
braced.
395
ALLOWABLE MESH SIZES. 4" X 4"-6" x 8"
POSSIBLE MESH AND SMOOTH WIRE COMBINATIONS
A. 7' OF MESH (AS SHOWN)
B. 6' OF MESH AND 3 SMOOTH WIRES (AS SHOWN)
12~ GA. OR LARGER W IRE MESH .
6"X6" MESH SHOW N .
C. 5' OF MESH AND 6 SMOO TH WIRES (NOT SHOWN)
rm tH
fTJ
Jill ru ru
7' ru ru
I .
.
.
I I
I I
I I
I I
LJ
l ~ ,,,;,:,:r
-·
r:::::::.J nn
t&l
[U
-1
:: ..
:: •'
'I' I I"
I I
I I
LJ
9 11 GA SMOOTH WIR ES j 4;, SPACiNG.
10' or 12'
-r-::,_:_]
1<-'-:'1
TTI
IHl I
H :J
t":;.'::)
MJ
Tfl
IJ]
Tfl
I l
I I
I I
LJ
6'
Fig. 20.42. Drawing showing 2 methods of using wire, either mesh above or combinations of mesh and smooth, to construct an upright
fence for controlling deer damage (Longhurst et aL 1962).
With upright fences the gate height should be approx-
imately equal to fence height. Weight should be kept to
a mini mum. A light wooden frame over which mesh
wire is stretched is often satisfactory. If factory-made
aluminum gates are used, metal exten sions may be
bolted or welded on and mesh wire stretched over them.
It is a lways advisable to sink a metal or treated wooden
base frame in the ground below the gate 'to give a uni-
form surface and to prevent deer from working under
the gate.
In Colorado, a 3-m-high upright fence was con-
structed to control deer movements on a rotational basis
for a key w in t e r range . The fe n ce was effective in con-
trolling both deer and elk movements . The fence was
al so effective in increasing plant diversity and abun-
dance t hrough controll ed use of big game foraging (J.
Clark, pers. comm.).
Overhanging or S lanting
This type of fencing is l ess expensive to construct than
upright fencing because fewer a nd sh orter posts are
needed and li ght er gauge wire can be used. S lanting
fences are particularly suitable for temporary fencing, as
the few posts can easily be removed and the wire more
readily rolled . This type of fencing is also suitable for
locat ions where an upright fen ce would be unsi g htly or
otherwise unsuitable.
Sl anting fences are beli eved to be effective because
they act primarily as a psychological barrier to d eer.
D eer usually first try to crawl under such a fen ce and
then, finding this impossible and with the wire ex-
tended above them, they are discouraged from jumping.
For this reason s lanting fences are effective in 1 direc-
tion on ly. Overhanging woven wire mesh fences are not
recommended in heavy snowfall a reas since the fence is
subject to being crushed by the settling snow pack.
Under such c ircumst ances the fence can be modified by
using smooth wires stret c hed horizontall y at 10.2-cm
spacings.
The basic design for the s lanting fence consists of ap-
proximately 1.8 m of mesh wire supported by a guy wire
stretch ed between widel y spaced post s (Fig. 20.43). The
high side of the fence is the side away from the area to
be protected.
For te mporary ins t a ll ations, light chi cken w ire or
stucco mesh may be used. For permanent installation,
w ire n o lighte r than 12Vz gauge is advisab le. If woven
wire is used, vertical s t ays s h ould not be over 15.2 to
20.3 em apart and h orizont al line wires s hould not be
over 10.2 to 15.2 em apart with 1.8-m st eel posts r ecom-
mended and spaced up to 9 to 12 m apart.
A hinged gate is needed if the re will be considerab le
traffic. Adequate side w ings should be provided (Fig.
20.44). If little traffic is expected, a pan e l consisting of a
li g ht wooden frame with wire mesh stretched over it is
often satisfact ory. For easy access where no gate is
needed, a stile is simple to construct.
The Cali fornia D epartment of Fish and Game (Blais-
dell and Hubbard 1956) used this type fence to control
deer use of game range vegetation study p l ots. They
found s lanting fences (also termed outrigger type deer
fence) cont rolled deer e ntry whereas regular barbed
wire was inadequate. The a uthors s uggest that this fence
technique could have values for protecting haystacks,
orchards, gardens, and other places whe re extensive
... "1
,,~
;:tJ::
hil•.
*''"'" ..
t1'"
I~Ul'
••
396
PANEL GATE WHICH CAN BE LIFTED ASIDE.
FRAME OF GATE SLIGHTLY LONGER THAN OPENING.
BRACE
7'
II ,,
II
II u
/
30'-40'
4'-4"
Fig. 20.43. Typical slanting deer fencing w ith examples of placing the gates either slanting or vertical (Longhurst eta!. 1962).
fencing is not n eeded. Fig. 20.45 depicts an outrigger
fence o n site to control deer access on key winter ranges
near Bishop, California.
Working in South Dakota, Messner eta!. (1973) mod-
ified the slanting fence described by Longhurs t e t a!.
(1962) with several major improvements (Fig. 20.46).
These changes included less mesh wire and shorter
posts, both contributing to a less expensive structure.
The authors also credit their design as blending well
into forest and meadow environment s and capable of
Fig. 20.4 4. Hinged gate for an upright deer control fence (U.S.
Bureau of Land Management photo by Jim Yoakum).
withstanding greater snow loads than other des igned
slanting deer fences. During 5 years of testing, white-
tailed deer and livestock were successfully exclude d by
thi s slanting fence.
Electric
Experience has s hown that electric fen ces can be u sed
for deer control. The stand a rd e lectric fence design used
for li vestock, however h as proven unsatisfactory at times
for big game control in parts of the West and Southwest.
This is generall y during the dry sea son when lack of
moi sture in the g round prevents good grounding of cur-
7' x 5" (Top)
Corner Post
7'x4"(Square)
Slanting Post
I
I
I I L __ )
397
Fig. 20.45. "Outrigger" fence used to control deer movement
on range lands in California (U.S. Bureau of Land Management
photo by Jim Yoakum).
rent. Researche r s in California found that the use o f 2
rows o f posts and ground wires with leads dee ply im-
bedded in the ground worked best (Longhurs t et al.
1962). Fig. 20.47 depicts how the double e lectric wire
fences were used in California.
Managers in Virginia had better experiences with
electric fences controlling deer damage to agricultural
crops. Here too, the conventional 1-wire fence used to
c ontrol lives tock was not effective for deer. However ,
with new designs specific for dee r management, the
e lec tri c fe n ce proved e ffective in re ducing deer foraging
(Myers 1977). Myer's recommendations for e lectric
fence a r e :
Barbed Wire
f
I I
I I
~~~r
Fig. 20.46. Modifica tion of slanting fen ce d eveloped in South Dakota (Messner et al. 1973).
~·
Itt!
11:1 •
398
G G
Fig. 20.47. Plans for double electric fence to control deer (Longhurst et al. 1962).
In construction, three strands of 12 or 14-gauge,
smooth type, galvanized wire is recommended.
Pos t s s paced approx imatel y 9 m apart can be of
e ither metal or wood with 1.5 m extending above
ground level. Corner posts need to be braced
properly and a ll posts must be p l aced deep
enough in the soil to hold w ires securely. Measur-
ing from the ground, the bottom wire is attached
45.7 em up on the post. The second wire is spaced
45.7 em up from the bottom w ire, and the third
wire another 45.7 em higher. This results in a
fence that is 137.2 em high from ground leve l to
the top wire. Either plastic or porce lain in su lators
can b e used. The porcelain insulator is recom-
mended, as the wire can b e wrapped around th e
in s ulator w hen neede d and does not cut through to
cause s horting out w h e n pressure is appli ed. All
three wires are c harged w ith a controlle r (o r box)
that operates from 110 vo lts which mus t b e prop-
erly grounded. An e lectric fence tester is also rec-
ommended for checking the fence to assure that it
is operating properly. The g round und e rneath the
fence has to be mowed and maintained to prevent
e l ectri cal sho rt circuits or grounds caused by
growing vegetation. Spring type gate hooks can be
used for access into the fenced area. It is al so rec-
ommended that the fence be set away from the
area to b e c ultivated to allow for th e operation of
equipme nt.
Gates
Sometimes it is desirable to permit deer to move
through a deer-prooffence in 1 direction only. An exam-
ple would be when a deer has entered a highway and
needs to get back through the right-of-way fences. To
meet this s ituation a "1-way deer gate" (Fig. 20.48) was
d eve loped and tested in Colorado (Reed 1971 ). The ra-
ti o n a l e for this gate is that dee r would jump through
heavy brush. Wh en tested in the field , several 1-way
gates on a major highway were used by deer a total of
146 times during the 1976 spring and fall migration.
The 1-way deer gate is now being used in various
parts of the country. Its value h as been vari ed d epend-
ing on-where the installations were made. One point i s
apparent to date -the device does have some limited
value in m eeting its objectives; however, in other areas
it has received very little use and s hould be so realized
when planning.
Fig. 20.48. A mule deer passes through a 1-way deer gate con-
structed in Colorado (Photo by Dale F. Reed).
Guards
At times it is necessary to allow easy access of vehicles
through deer-proof fences . This has resulted in recom-
mended deer guards similar to cattle guards constructed
on range fences for years. D eer guards are similar to the
cattle guards in structure, but generally are longer to
limit deer crossing (Longhurst et al. 1962). Working in
Colorado, Reed et al. (1975) tested deer use of3.7-, 5.~,
and 7.3-m guards. Their findings substantiated that little
advantage was gained by extending the length of guards
for deer; when these animals were motivated, they
walked, trotte d , or bounded across the guards. Conse-
quently, the use of modified deer-cattle guards to con-
trol deer movements appears to have limited value,
based upon structures designed to date.
interstate Highways
Movement of big game over country roads and low
standard highways has not been a serious problem.
Normally, barbed wire fences previously described are
used on most rights-of-way. Leedy e t al. (1975) pub-
lished 2lengthy voiumes containing extensive literature
r eviews on highway-wildlife relationships and
suggested research and management approaches to pro-
tect and enhance environmental quality for wildlife
habitats. These reports are especially timely b ecause
currently there over 10 million hec tares in highway
rights-of-way. The authors cited various reports on prac-
tices including fencing, underpasses , traffic warning
signs for animals, and other measures.
FENCES
With the creation of the federal interstate highway
system, a serious problem has developed. Highway con-
struction is cutting across important big game migratory
and access routes. lt'is important to maintain these big
game travel routes, yet the human hazard caused by
animals seeking to cross high-speed highways also must
be given consideration. When fences are constructed to
reduce hazard to life and property on super-highways,
alternate methods of allowing game to cross need to be
devised. Otherwise, highway fences can have a serious
detrimental effect on big game. In some instances, mi-
gratory habits may be impeded sufficiently to eliminate
a complete big game herd. Mitigation of wildlife losses
due to fence barriers must be done through state
wildlife agencies. The following approaches to the prob-
lem should be considered:
Traversable game fences are described in this section
in "Guidelines for Barbe d Wire Fences." These fences
will hold livestock but will allow game relatively free
crossing. They should b e used o nly in areas of light au-
tomobile traffic and in stretches where the re are no cen-
ter or island fences. They should be wide enough to
allow game to make crossings without entrapment.
There are many areas where game normally winter or
summer adjacent to interstate highways. While high-
ways present no barriers to wildlife, the 2.4-m high
woven wire fences -used in some areas not only block
game from crossing the right-of-way, but commonly e n-
trap animals that manage to get inside. Also, in narrow
canyons, interstate highways sometimes abandon the
separate opposite lanes of traffic and place roadways ad-
jacent to one another, separated by a chain-link fence to
reduce collisions and headlight glare. The fence may or
may not have a sp ace at the bottom and may exceed the
maximum height game animals can jump. This type of
fence not only creates an unnatural barrier to wildlife,
but a hazard to the driving public as well, because it
holds animals in the traffic zone. For such cases as this,
the manager may consider the "1-way deer gate" re-
ferred to under "Gates." Where chain link fences a re
used, a 10.2 em space should be left on the bottom to
allow small animals to cross . The maximum height
399
should not exceed 1.0 m where consistent with highway
needs.
Regelin et al. (1977) experimented with s nowfences to
relocate snowdrifts to infl uence forage availabi lity.
Snowfences reduced sno-w d eptt .. s in shrub stands so
that deer could use them and created drifts deep enough
to protect overused and newly seeded areas from graz-
ing by deer.
OVERPASSES
Underpasses and overpasses will need e ithe r natural
terrain or else wing fences to guide and funnel migrat-
ing animals to them . Research in Colorado showed that
underpass openings 4.3 m square wi th dirt floors were
accepted by mule deer (Reed et al. 1975). Small
skylights or artificial lights were not necessary for deer
to use the underpass. Overpass use by game shows a
marked reduction as the structures increase in length or
decrease in width. Fenced wings to guide big game to
these structures have been used with some success, but
more study is needed to discove r ways of improv ing
their effectiveness.
Power Lines and Raptors
The problem of hundreds of raptors being e lectro-
cuted by electric distribution lines became a national
conservation issue in the 1970's (Olendorff and Kochert
1977). The problem is greatest in the western United
States. Nelson and Nelson (1976) documented that for
1974, over 300 eagles were e lectrocu ted in the U.S. The
count s howed 98% were young birds just learning to fl y.
The young birds lacked skill necessary to l and smoothly
on power lines and were electrocuted.
Efforts to decrease this mortality problem were accel-
erated in the last decade. State and federal wildlife
agencies pooled their biological knowl e dge with power
company's engineering technical skills. The result was
the development of several guidelines on how best to
construct power lines to minimize electrocution of rap-
tors. These are well documented and available through
the U.S. Rural Electrification Administration (1972) and
the Raptor Researc h Foundation (n.d.). Since there are
many different power line desigl"\s and corrective mea-
sures need to b e specific to the problem line, the man-
ager should consult with these sources or other spe-
c ia li sts.
Two examples of habitat improvements recently de-
veloped to enhance power lines for raptors are nesting
platforms and wood perches. Nesting platforms a re dis-
cussed in detail under "Specialized Nest Structures."
Figure 20.15 is an example. Wooden perches are struc-
tures added 0.9 m above power lines. These have been
well used as preferred landing si tes by eagles and other
raptors (Nelson and Nelso n 1976). Figure 20.49 depict s
how these perches are mounted. It is estimated that 95%
of raptor electrocutions can be prevented by correcting
2% of power line poles. The authors also s tated that
power line poles properly constructed are a means of
improving raptor habitat, for they are often con structed
in vast open a reas of the West, lacking cliffs or trees .
Consequently, the raptors use power line poles for hunt-
ing, feeding, and nesting s ites.
[i' •
II •
11 '
""'I
400
ELEVATED PERCH CONSTRUCTION
~: x 1'-o•
2411
Fig. 20.49. Plans for perches on power lines to help reduce cases of raptor electrocutions (Nelson a nd Nelson 1976).
Study Exclosures (Big Game)
Exclosures are constructed for a number of purposes,
but are mainly used to exclude or control livestock or big
game use within the fenced area. These exclosures pro-
vide a basis for comparison of grazing or browsing with
that on adjacent open range. Exclosures also serve as a
method to determine proportionate use on ranges
grazed by both big game and livestock.
Permanent exclosures shou ld not b e less than 0.4 ha
in size-1 to 2 ha are frequently more desirable. Extra
strong construction is needed on all parts of the fence to
withstand heavy pressure by animals against these
small , fe n ced areas of better forage. Gates s h ould not be
constructed in ex clos ure fences. Stiles, s teps, or ladders
will prov ide access to the plot.
Three-way exclosures are often use d t o compare big
game_aEd lives tock use of vegetation in an area (Fig.
20.50 and 51 ). These exclosures are constructed with 2
fenced plots and l unfenced or open adjacent control
plot. They are generall y not less than 0.4 ha each. One
fenced exclosure (a) is game and livestock-proof; the
second livestock-proof (b) but readily accessi ble to
game. The third plot, (c) or control , is establi she d on
open range nearby. This unfenced control plot (c)
should be an equal-sized area marke d on the ground.
The fo ll owing sp ecifica tions apply to the fen ced plots.
A 2.1-m high fence u sually is adequate to exclude
both elk and deer. However , if the exclosure is so lo-
cated, or of such a size that it forms a barrier to con cen -
trated game movements, the fence s h ould be at least 2.4
m high. If areas subject to drifting s n ows cannot be en-
tire ly avoided, it is necessary to construct a higher fence
through the drift zone. F e n ces should not be located on
s t eep ground unless n ecessary. This w ill minimize the
influence of water drainage from outside the plot.
A square exclosure wi th w ire fe nce 2.1 m hig h w ith 64
m o n all sides, will e ncl ose about 0.4 h a and will require
the following materials:
20 comer wooden
posts
48 steel line posts
15.2-cm diameter at small
e nd and 3 m lo ng,
p eeled a nd p e ne tra ted
"T'' stud, 3 m long
16 line wooden posts,
8 braces, horizontal
8 braces, diagonal
2 spools , barbe d wire
No. 9 smooth wire ,
ga lvanize d
9 .1 kg staples
A
15.2-cm diameter at small
end and 3.0 m long,
peeled and penetrated
12. 7-c m diameter at small
end and 2.4 m long
12. 7-cm diameter at s mall
end a nd 3.1 m long
80-rod (401.6 m) s pool
91.4 m
3.8cm
1.8 kg nails
hog wire
Rabbit-proof wire
200 hog rings
401
40 d.
1.1 m, galvanized, 256m
5.1 x 10.2 em, galvanized,
256m
Heavy duty, galvanized
The livestock-proof plot (b) will be enclosed with LO-
rn fencing; 4-m spacing between posts (64 m to a side).
On livestock range, 4 barbed wires sha ll be spaced 12.7,
28, 45.7 and 66.1 em from the ground with a smooth wire
on top, 25.4 em above the top strand of barbed wire.
1 ACRE lOTS
----"tl
c
LIVESTOCK AND
WILDLIFE EXCLUDED
LIVESTOCK EXCLUDED
WILDLIFE USE ONLY
FOR BOTH LIVESTOCK
AND WILDLIFE USE
(NOT FENCED)
1 0' WOODEN POST
._, __ 10' STEEL POST
SEE DETAIL #1 SEE DETAIL #3
6' METAL POST FOR
LOCATION OF ACRE ~
LOT. (TWO CORNERS)
~~~~~--~~~~--~-+~~~-------------
TOP VIEW
HORIZONTAL BRACE
HOG WIRE
RABBIT PROOF
GALVANIZED WIRE
DETAil #1
NOTE:
1. PLACE AN 8'-0" HORIZONTAL WOOD
BRACE POST AND A 11 '-0"± DIAGONAL BRACE
POST ON EACH SIDE OF ALL FOUR CORNERS OF
LOT "A." THE SAME TYPE BRACING WILL BE
USED FOR LOT "B" EXCEPT THAT THE HORIZONTAL
BRACE WILL BE 6'-0" AND THE DIAGONAL BRACE
WILL BE 8'-6"±. IT WILL ONLY BE NECESSARY
TO BRACE SIX SIDES OF LOT "B" SINCE IT SUITS
UP TO LOT "A."
2. THE POSTS IN LOT "A " ARE TO BE PLACED
SO THAT THERE IS ONE WOODEN POST AND
THEN THREE STEEL POSTS. THE POSTS FOR
LOT "B" WILL BE PLACED ONE WOODEN POST
TO FOUR STEEL POSTS.
3. RABBIT PROOF FENCE TO BE BURIED
SIX INCHES IN GROUND
DETAil #2
5 STRAND WIRE, TOP
IS SMOOTH AND 4
ARE BARBED
DETAil #3
LADDER
SECTION A-A
Fig. 20.50. Plans and speci fi cation s for the install a tion of a 3-way wildlife-li vestock exclosure .
..... ..
~'I !..,
~I I
402
Fig. 20.51. Collecting forage production data on a 3-way
Wildlife life stock exclosure (U.S. Bureau of Land Management
photo by Jim Yoakum).
The following is a bill of materials for a livestock-
proof plot having 1 side in common with a game and
livestock-proof exclos ure:
8 comer wooden
posts
6 brace posts
6 wood line posts
36 steel line posts
2 spools barbed wire
2.3 kg staples
0.9 kg nails
No. 9 soft smooth
w ire, galvanized
15.2-cm diameter and
1.8 m long, peeled
and penetrated
15.2-c m diameter and
1.8 m lo ng
15.2-cm diameter and
1.8 m long
"T" stud, 1.8 m long
Standard (12-V2 gauge,
2 points), 80-rod (401.6 m)
spools
3.8cm
40 penny
24.4 m
A ladder should be constructed in 1 corner of the plot
with the high fence to facilitate workers access in and
out.
Consideration should be given to the co n s truction of a
large attractive sign denoting: (1) name of exclosure
plot; (2) brief s ta teme nt on purpose of plot; and (3) a list
of cooperating agencies respon sible for construction.
Plot (c) should have 2 steel 1.&-m s takes placed at the
2 exterior corners for location purposes. In some a reas, it
may be des irable to construct buck pole fences or worm
fences around exclosures.
SUMMARY
This c hapter on wildlife habitat improvements has set
forth-mtmerous ideas and suggestions on how to manip-
ulate food, water, cover, and living s pace for the benefit
of w ildlife. Techniques will, of course, vary throughout
the regions of North America; howeve r, below is a li st of
the main principles and methods:
1. Develop "edge" because many wildlife species
are a product of the places where 2 habitats meet.
Examples are the borders of woods, fields, ponds, or-
chards, meadows, rivers, potholes, marshes, brushlands,
clearings, and swamps.
2. Maintain mast trees. For oaks, 112 kg of mast per
ha is needed to sustain reasonable wildlife densities or
5.7-6.9 m 2 of basal area per ha for trees old enough to
produce seed (25.4 + em dbh). For hickory and beech
0.7-1.4 m 2 per ha has been recommended.
3. Encourage fruit trees; also woody cover in
hedgerows and fence rows.
4. Discourage fall plowing of harvested grain crops.
Encourage sharecropping agreements.
5. Favor trees and shrubs with high wildlife values,
especially heavy seed-, berry-, and fru it-producing
species like autumn olive, Russian olive, dogwood, and
thornapple.
6. Erect wood duck nest boxes in suitable sites, 5-9
per h a.
7. Erect 2-3 squirrel nest structures per ha in forests
and woodlots lack ing tree cavities but having a
minimum of 5-7 mast-producing trees per ha.
8. Erect nest structures for kestrels on barns and trees
near open fields, for screech owls erect nest structures
in parks or forest edges.
9. Favor tall trees, especially clumps of trees, for
eagles, ospreys, other hawks, a nd heron nest sites in
areas where these species are nesting.
10. Save 5 to 9 den trees per ha in wooded areas for
cavity nesting birds and mammals such as woodpeckers,
squirrels, and raccoons.
11. Construct brush piles where needed for protec-
tion and nesting sites.
12. Leave nesting cover undisturbed wherever prac-
tical, i.e., plow land before nesting; mow after nesting is
over.
13. Allow natural succession to revegetate areas not
suited for farming or plant them to trees, shrubs, and
permanent cover crops to intersperse cover types.
14. Maintain exis ting low-growing shrubs for natural
food and cover.
15. Establish living hedges around field boundaries
to reduce soil erosion and provide nesting cover, travel
lanes, and food. Use native plants when possible.
16. Establish windbreaks along roads, around home-
sites, and between fields and crop strips.
17. Establish and maintain openings in woodlands
and brushfields. Coordinate with other resource ac-
tivities when possible: tree harves ting, range improve-
ment, and fire control. Use prescribed burning, selec-
tive spraying, or sharecropping as often as possible.
18. Seed roadside ditches and waterways with suita-
ble grasses and legumes for nesting cover in intensively
cultivated areas. Maintain seedings by mowing in late
summer after nes ting is completed.
19. Encourage sedges and rushes in marshes and
s lough s.
20. Encourage the use of native plants for highway
borders, median strips, and interchanges, as well as
fence comers. In the Midwest native grass plantings can
be maintained by spring burns at 3-5 year intervals.
21. Keep certain fields open on old farmland by mow-
ing hayfields or keeping certain areas in cultivation.
22. Vary cover as much as possible . The more varied
the cover, the more wildlife.
23. Mix smaii plantings (0.4 ha) of evergreens with
hardwoods for cover; do not plant in extensive so lid
blocks and reserve the bottoms for hardwoods.
24. Control excessive weed growth in canals, streams,
lakes, and ponds.
25. Provide floating logs or rafts as loafing sites for
waterfowl.
26. Establish water holes at springs or in seepage
areas.
27. Provide potholes and other small open-water
areas for nesting or resting waterfowl.
28. Develop ponds and lakes for waterfowl, water
birds, and aquatic mammals.
29. Protect forests, marshes, swales, and fields from
uncontrolled fires. However, consider a "let bum" pro-
gram. Fir e is a natural force in many ecosystems and can
provide benefits for man and wildlife.
403
30. Avoid burning when vegetative habitat is critical
for nesting cover or food for young wildlife. In some
areas cool, late season burns can be used to rejuvenate
herbaceous species needed for wildlife food and cover.
Depending on successional trends and wildlife needs,
bums 'should be used on a 3-5 year rotation.
31. Perpetuate sand and small, natural gravel along
roads and trails to supply birds w ith grit.
32. In February-March, place mourning dove nest
cones 1.8-4.9 m above ground in suitable trees.
33. Fence woodlots and planted areas aga inst uncon-
trolled grazing to protect food and cover.
34. Stabilize streambanks with shrub and conifer
plantings. Fence livestock and wildlife away from
eroded streambanks where their use restricts recovery
of vegetation.
35. Reserve undisturbed buffer strips of riparian veg-
etation alone streams to provide shade, insect food for
fish, and dens for mammals.
36. Control water leve ls in marshes to favor habitat
for waterfowl and other water birds.