HomeMy WebLinkAboutWildlife of the North Slope a Ten Year Study 1969-1978Angus Gavin
Wildlife of the North Slope
A Ten-Year Study 1969-1978
On the cover
A juvenile golden eagle (Aquila chrysaetos) flexes its
wings menacingly as the photographer approaches its
North Slope nest. A not-so-concerned sibling
peers from behind.
Designed by Tom Yerxa
Photography by Bill Clark, Jack Sheedy and the author.
Angus Gavin
Wildlife of the North Slope
A Ten-Year Study 1969-1978
A pale summer sun provides scant illumination on Prudhoe Bay.
Introduction
In 1968, oil was discovered at Prudhoe Bay on
the North Slope of Alaska. Initial tests indicated
the discovery was a major one, but its location
among tundra and permafrost would pose
considerable problems in developing the field
and in getting the oil to market. Since very little
was known about this region of the North Slope,
Atlantic Richfield Company engaged the author
to conduct a comprehensive baseline study to
determine its ecological values. Some of the
objectives of this study were to:
1. Evaluate the effects of oilfield development on
the overall environment;
2. Inventory caribou using this region of the
Slope and evaluate the effects of oilfield
development on their numbers, distribution
and migrations;
3. Inventory waterfowl and other avifauna using
this region and evaluate the effects that
development might have on their populations,
distribution and migrations;
4. Inventory other wildlife in the area and
evaluate the effects of development on their
well-being;
5. Gather baseline data on fish using the rivers
and streams. Ascertain their migration times,
routes and spawning areas;
6. Conduct sampling of invertebrate fauna;
7. Conduct a baseline study of all
offshore islands.
This book is an informal summary of the results
of these studies. It is based on the observations
of Angus Gavin, compiled over a ten-year
period of work on the North Slope.
Contents
Introduction
Angus Gavin
The Study Area
The Brooks Range Province
The Foothills Province
The Coastal Plains Province
Weather and Climate
Permafrost
Tundra
Soils
Vegetation
Survey Methods Caribou studies
Waterfowl studies
Other wildlife studies Fish surveys
Offshore surveys
Waterfowl
Swans, Loons and Mergansers
Eagles, Hawks, Owls
and Other Birds
Mammals
Caribou
Summary
Study Area Map
10
11
12
13
14
15
18
23
26
30
36
42
44
Angus Gavin
Angus Gavin’s love of wildlife began at an early
age. He grew up on the family dairy farm not far
from Aberdeen, Scotland. The area abounded in
grouse, partridge, rabbits, salmon, trout and
song birds. And his love for animals was not
blunted by the fact that he was up at four o'clock
every morning to help hand-milk more than
100 cows!
When it came time for him to enter college, he
not surprisingly chose zoology, but when he was
graduated from Gordons College, a part of the
University of Aberdeen, he asked himself,
“What am I going to do with a degree in
zoology?” So, he returned to school at Kanes
College, also affiliated with the University, for a
master’s degree in engineering.
His first job? As a zoologist, of course! Friends
who had gone to Canada to work for Hudson’s
Bay Company returned on vacation filled with
exciting tales. Their stories stirred and intrigued
Angus, and so in 1929 he sailed for Canada and
a job with Hudson’s Bay. He was assigned to the
Dominion’s Western Arctic, where he was to
remain for six years. His only means of
communication with the outside was the
once-a-year supply boat.
His primary function was to check and report on
populations of fur-bearing animals in that
remote region, in order to give Hudson’s Bay’s
home office an approximation of the coming
year’s harvest. But he was many other things to
his Native friends — doctor, teacher, counselor,
whatever the moment might require. During his
arctic years, Angus compiled an English-Eskimo
dictionary which is still in use today. He also was
the first to locate the breeding grounds of the
elusive Ross’ goose.
In the early 1940s Angus spent two years
gathering information for the province of Alberta
on waterfowl and other wildlife in the Athabasca
Delta area. Then, in 1945, he joined Ducks
Unlimited, Canada, a conservation group, as
provincial manager for Saskatchewan. Part of his
responsibility was to plan and implement
wetlands projects to increase and improve
nesting grounds for waterfowl.
He remained with DU some 24 years, the final
two decades as general manager for all of
Canada. In 1969, he retired to catch up on his
golf, hunting and fishing, and to devote more
time to personal pursuits, which included a
sizable black Labrador retriever kennel.
But his retirement ended almost before it began.
Robert O. Anderson, chairman and chief
executive officer of Atlantic Richfield, was
instrumental in persuading Angus to survey,
study and report on wildlife and the
environment of Alaska’s North Slope. Equally
important, Angus was to recommend ways to
minimize negative impact of oilfield operations
there. Angus originally thought, “Well, Ill go up
for a year or so, make my report and
recommendations and get back to the golf
course.” It should come as no surprise that his
studies of the North Slope are continuing.
When Angus first went to the Slope that
summer of 1969, very little of substance was
known about the area’s wildlife and
environment. He has contributed heavily to the
store of knowledge of the North Slope and
shares that knowledge generously with others.
nders a question at East Dock
The Study Area
When gathering baseline data on any area, one
must have a working knowledge of its physical
and geographical features. The North Slope of
Alaska consists of three habitat types based on
vegetative life forms and physical characteristics
of the terrain. The habitat and physical
characteristics are known as “provinces” and
have been classified by Payne, et al (1951), as the
Brooks Range Province, the Arctic Foothills
Province and the Arctic Coastline Province. As
our study area lies within parts of each of these
provinces, some description is necessary to
provide perspective and understanding of the
complexity of gathering comprehensive baseline
data in an almost roadless area. (Map, page 44.)
Shallow rivers thread the North Slope tundra.
6
The Brooks Range Province
The Brooks Range Province includes a number
of high, rugged ranges reaching heights of some
8,000 to 9,000 feet, and in most instances these
ranges lie in a north-south direction.
Geologically, the range dates to Early Cretaceous
(90-135 million years). Exposed rocks are
limestone, conglomerate, chert and shale.
Several valleys or passes break through the
range and provide access for caribou movement
between summer and winter ranges. Although
glaciation was extensive during the Early
Pleistocene time (less than one million years
ago), there are few glaciers in the area today.
Some moraines and glacial outwashes are
noticeable along some valleys and mountain
slopes. Fragmentation or talus slopes are
common throughout this portion of the range.
Marine fossils can be found in some mountain
streams. Most slopes are sparsely vegetated.
Valley floors generally are alpine tundra-heath
covered, and where streams and rivers flow, the
banks are often fringed with willow, birch
and alder.
L
The Sagavanirktok River
et
meanders through the Brooks Range foothills.
~
The Foothills Province
The Foothills Province lies immediately north of
the Brooks Range and stretches to the open
plains of the Coastal Plains Province: In our
study area, it extends approximately 50 miles and
reaches heights of some 1,500 feet around the
White Hills area. Much of this province is a
rolling, hill-type terrain, broken here and there
by outcroppings of conglomerate, shale and
sandstone. Much of the area is covered by
tussock-heath and tundra dominated by cotton-
grass. Valleys and stream banks have extensive
stands of willow and birch.
The Foothills Province is the primary North Slope
8
habitat of moose (Alces alces).
The Coastal Plains Province
This province stretches from the Foothills to the
Arctic Ocean and, in our study area, extends
some 80 miles south to north. Its terrain
generally is low and flat, with very poor surface
drainage. Permafrost is continuous, blocking
internal drainage. The result is a great variety of
intermittent and permanent water bodies which
range from small ponds to large lakes. Some
relief is provided by bluffs along some of the
rivers and streams, and single conical hills called
pingos that dot the plains in a number of areas.
Several of these pingos rise to elevations of 200
to 300 feet, but the majority are well below that.
Most streams crossing the coastal plain rise in
the upper foothills and Brooks Range. Several
are quite large, although grades are low and
most follow meandering courses, often forming
wide alluvial deltas with a network of
different channels.
Winter sunlight illuminates the frozen Coastal Plains Province.
9
The weather and climate of the northern portion
of Alaska, although well known to the Eskimo
inhabitants, has not been documented to any
extent through official weather stations. These
stations are few in number and have been in
operation for a comparatively short time. We do
know that throughout the North Slope area the
climate is severe, characterized by long, cold
winters and short, cool summers. Winter, as a
rule, lasts for some eight months, with
subfreezing temperatures predominating from
October through May. Temperatures can reach
—60°F at times, although the mean for the
winter averages —20°F. Spring and summer
temperatures range from +30°F toward the end
of May to +70°F during August, dropping again
to freezing temperatures by the beginning of
September. Within the Brooks Range area, our
own records taken during many survey trips
show a 10°F to 15°F higher range throughout
much of the year.
Daylight on the North Slope is continuous from
late May to late July. During this time the sun
does not go below the horizon. Precipitation on
the Slope proper is very limited, averaging,
between six and eight inches a year, about
equally divided between rain and snowfall.
Visiting this area during the winter when a
snowstorm is blowing, one gets the impression
that a lot of snow is falling. Actually this is not
the case. Most times it is snow already on the
ground that is being wind-driven, giving the
illusion of a heavy snowfall. During these blows,
which can last for a week or ten days, wind-chill
temperatures can reach below —100°F.
Farther south, in the Foothills and Brooks Range
Provinces, snowfall and rainfall can be heavier,
with snow reaching depths of several feet in the
Brooks Range proper. Break-up of ice in the
major rivers on the coastal plain occurs between
May 25 and June 1, with an earlier break-up by
about ten days to two weeks occurring in the
rivers farther south in the Brooks Range.
Summer comes to the
0%
craggy peaks of the awesome Brooks Range.
10
Permafrost
Permafrost occurs where the temperature of
ground material remains continuously below 0°C
for one year or more, or is equated with a
ground thermal regimen that is perennially
negative —regardless of the condition of the
subsurface material. Permafrost or “permanently
frozen ground” is covered by an active layer that
thaws during the summer and freezes again
during the winter. This active layer varies in
depth from less than a foot in some areas to
three feet or more in others, depending upon the
type and degree of vegetative cover and the
makeup of the underlying soils. Permafrost can
be dry, containing no water at all, or wet,
containing up to 100 percent ice.
Although several forms of ice are present in
areas of permanently frozen ground, only two
have been established with any degree of
certainty. These are known as pingo and
ice-wedge ice. Pingo ice normally shows little or
no foliation and is composed of large,
translucent crystals of simple shape, while
ice-wedge ice has vertical or inclined foliation,
and is composed of small crystals. In areas
underlaid by permafrost, some unusual ground
patterns are to be found. The patterns are caused
by frost action within the active layer. The
movement, and subsequent freezing of moisture
in the active layer, produces swelling or frost
mounds, the largest of which are known as
pingos. As previously mentioned, some pingos
reach an elevation of 200 to 300 feet. Frost action
accompanied by other processes also produces
an assortment of other patterns. Patterned
ground or ice-wedge polygons are good
examples. The surface picture manifested by
these patterns of polygons is that of cracked,
dry mud.
Vegetation on the active layer plays a large role
in the energy exchange regimen. Vegetation acts
as an insulator and protects the permafrost
against the warm summer air and sun. This
vegetation cover also reduces the amount of
melting by impeding the flow of run-off water.
The process of transpiration decreases the
amount of water percolating through the soil,
and it also draws water from the soil, thereby
removing the heat held by the water. It is not a
simple matter, however, to say precisely how
greatly vegetation influences permafrost because
the vegetation is closely related to other factors
of climate and terrain.
In two adjacent areas, the permafrost conditions
may be the same, but the combinations of factors
producing them may be altogether different. Best
insulators are mosses, lichens and peat. During
the summer the surface of a layer of peat is
relatively dry and little heat is transferred
through it from the atmosphere to the soil. On
the other hand, wet peat has a higher thermal
conductivity, but that of frozen saturated peat is
much higher still. In winter, the amount of heat
transferred from the ground to the atmosphere is
therefore greater than the amount transferred to
the ground in summer. This imbalance therefore
favors permafrost.
One may assume that permafrost occurrences
can be related to those types of vegetation that
most effectively retard thawing, particularly
sphagnum (peat) mosses. Sphagnum holds
more water than vascular plants and draws
moisture from the soil in greater amounts, but
loses it readily to the atmosphere. However, the
difficulty in establishing precise relationships
between permafrost and sphagnum mosses is
that several other varieties of vegetation usually
grow along with it and the separate effects of
each may be hard to discern.
1
Frost action creates unusual ground patterns.
Tundra
The plains tundra area of the North Slope of
Alaska in appearance resembles the grasslands
of the mid-latitudes. However, vegetation in this
area, except for willows and birch along some of
the rivers and streams, almost never grows high
enough to hide even a ground squirrel. Most of
the mosses, lichens, herbs and forbs rise only a
few centimeters above the ground surface.
Almost all vegetation is perennial, most
reproducing by runners, tubers or other
vegetative means rather than seeds. Several
factors control the development of arctic
vegetation. Included are the short growing
season; the lack of water (or the superabundance
of it); low winter temperatures; intense
desiccation in winter; the mobility of the
materials in the active layer; the lack of available
mineral nutrients, such as nitrogen and
phosphorus; the cycling time; the low bacterial
activity in some soils and the high acidity
in others.
Wildflowers abound during the brief North Slope summer, although they rarely grow more than a few inches high.
12
Soils
Arctic soils, together with the arctic biota,
generally are young in comparison with other
regions of the globe. They also are poorly
developed, and they no doubt will remain so.
Principal soils of the North Slope are the upland
tundra soils of the foothills region and the
sphagnum bog-type soils of the coastal plain.
North Slope soils generally have a silt-loam
texture and, as a rule, are quite acid. Their
profile is extremely variable due to frost action,
and their colors range through browns, grays
and yellows. Gley soils occur in some poorly
drained areas, as do peat beds.
Sand dunes provide a startling contrast to the surrounding tundra in a number of North Slope
13
areas.
Vegetation
Vegetation on the North Slope varies
considerably. In our study area, it is alpine along
the Brooks Range, tussock-heath in the foothills,
and a sedge-grass, marsh-bog type over much of
the coastal plains. Over this latter area, where
elongated thaw lakes predominate, the major
vegetation is composed of aquatic grass, sedge,
cottongrass, marsh grass, mare’s-tail, along with
a variety of other plants that grow on the drier
peat and tundra hummocks and ridges. These
are often woodrush, moss, lichens, white
heather, yellow marsh saxifrage, brook saxifrage,
purple saxifrage, willow, buttercup, groundsel,
foxtail, bluegrass, cranberry, bladder-campion,
together with many other scattered grasses,
herbs, mosses and lichens.
In the foothills, where tussock-heath prevails,
the major vegetation is made up of tussock-
forming cottongrass, reindeer moss, and lichens,
along with such sedges as Carex bigelowii, C
lugens, and grasses like bentgrass and holygrass.
Shrubs of several species are also present,
including crowberry, cranberry, cloudberry,
Labrador tea, and others. Along the lake shores
of the foothills area, vegetation is much the same
as that found along lake shores on the coastal
area, with sedges, cottongrass and aquatic grass
being most abundant. The valleys and stream
banks hold fairly extensive stands of willows
and birch, with an occasional stand of alders.
Willows generally are Salix richardsonii,
S. alaxensis, S. reticulata, and S. arctica. The birch
species is Betula glandulosa. Farther south, along
the morainal deposits and talus slopes of the
Brooks Range, vegetation ranges from mosses,
grasses, lichens and herbaceous forbs to plants
such as mountain cranberry, saxifrages,
groundsel, woodrush, and ferns. While the
foregoing only covers the vegetation of this
region of the Slope on a very limited basis, there
are several excellent books available on this
subject. These include Porsild’s Illustrated Flora of
The Canadian Archipelago (1957) and Wiggins and
Thomas, A Flora of The Alaskan Arctic Slope (1962).
Both of these works have been used in the
identification of the vegetation listed in the text.
Cottongrass is frequently found in peaty soils of the Slope.
14
Survey Methods
Caribou Studies
Studies of caribou populations and their
movements were made to ascertain what effect
the development of an oil field might have on
their migrations, calving grounds, summer
ranges, etc. All major survey work was froma
helicopter or fixed wing aircraft. Our base of
operations was the Atlantic Richfield-Exxon
operations camp at Prudhoe Bay.
Population and movement studies were started
in 1969 and have continued each year since.
Observations of populations, movements and
patterns were commenced each spring toward
the latter part of April as the caribou began
moving from wintering grounds south of the
Brooks Range to calving grounds and summer
range on the coastal plains of the North Slope.
Surveys were continued through summer and
fall until the caribou left for their wintering
grounds. Most observations were carried out on
practically a day-to-day basis, except for a short
period at the end of May and beginning of June
when calving is at its height. Disturbance at this
time was kept to a minimum.
Waterfowl Studies
Like those on caribou, waterfowl studies were
carried out to determine if oilfield operations
would have any effect on numbers or use of this
part of the North Slope as a breeding, nesting,
rearing and molting area. During the first two
years of our survey, 1969-1970, counts were made
of all waterfowl on the coastal area between the
Colville and Canning rivers, stretching for a
distance of ten miles inland. The strip method
was used to cover the remainder of the survey
area. From 1971 through 1973, the strip method
was used for all coverage, with counts being
compared for accuracy against selected total-
count areas. Ground observations were made at
selected localities, including some brant, snow
geese and eider duck colonies.
Other Wildlife Studies
Observations of other wildlife on the Slope, such
as barren ground grizzly bear, wolves, foxes and
moose were made in conjunction with caribou
and waterfowl surveys. Although no specific
surveys were made, all observations were
recorded, which provided a fairly comprehensive
catalogue of information.
Lemming populations were observed on a
relatively wide and casual basis through spot
checks during other surveys, as was the
observance of the number of predators that rely
on lemming for much of their diet, i.e., owls,
foxes, jaegers and hawks. Avifauna, apart from
waterfowl, were recorded on a daily basis, and
many searches were made for nests and young
birds during the summer season.
16
Fish Surveys
Much of the information on fish was secured by
sample netting on the Sagavanirktok River, and
by test angling on many other streams.
Additional information was provided through
the courtesy of the Alaska Fish and Game
Department, whose personnel have done
considerable study work on the Sagavanirktok
River and other area streams.
Offshore Surveys
Most of our offshore surveys were carried out by
float-equipped helicopter. Offshore islands were
visited on a regular basis. Inventories of nesting
birds (as well as the gathering of other
information) were conducted primarily on foot
on these islands.
A 500mm lens helps in Angus Gavin's “note taking” of
North Slope wildlife. :
A caribou bull (Rangifer tarandus arcticus) strolls leisurely through the North Slope oil field
Area grace)
There have been fluctuations in overall
waterfowl populations in the Prudhoe Bay area
of the North Slope since the first of our annual
comprehensive surveys of the region was
undertaken in 1969-1970, but none has been of
any drastic nature, either up or down. Individual
species have varied from year to year, which is
natural and occurs wherever nesting waterfowl
are to be found. There also has been some
shifting in nesting densities from one area to
another, particularly in black brant geese (Branta
nigricans) populations. Some colonies of these
birds have moved from known nesting sites to
new locations for a year or so, and then have
moved back to their original locations.
There is no doubt that the high level of human
activities near some of these colonies was to an
extent instrumental in causing some of these
shifts. We also have noted that some colonies
have moved that were not in any way disturbed
by any of the activities connected with the oil
field. Although these movements have taken
place, the overall nesting populations of brant
geese within our survey area have remained
remarkably stable. Populations have ranged
from a high of 1,007 birds in 1973 to a low of 715
in 1978. Most years the numbers have been
between the 800 and 900 mark.
The white-fronted goose (Anser albifrons frontalis)
and the lesser Canada goose (Branta canadensis
minima) have shown remarkable adaptability to
all the various activities along this region of the
Slope. Populations of these birds have increased
considerably over the past years.
Throughout the field at Prudhoe Bay there are
many drillsite pads, storage pads, base camp
locations and a network of roads connecting
these various sites. All of these have been built
with gravel taken from either stream beds or
from borrow pits. Traffic along these roads and
around the drillsites and base camps generates
considerable amounts of dust, despite measures
being taken to avoid this as much as possible.
ra
oa A spectacled eider drake (Somateria fischeri) peers at his surroundings.
19
This dust becomes wind-blown and settles over
much of the oilfield area. With the coming of
spring, these dust particles, mixed with the
snow, gather and hold heat from the sun,
resulting in an earlier thawing process than that
occurring in most other areas along this region of
the Slope. The same situation applies to the
pipeline haul road, which stretches south from
Prudhoe Bay. Because of this early thawing
throughout the field and along the northern
portion of the haul road, an “oasis” has been
established. This has attracted many birds to the
Prudhoe Bay area, and at a much earlier date
than in other regions across the Slope. While this
“oasis” attracts many more birds than normally
would be in the region, it has not made much
difference in the number of nesting birds. There
always has been a good population of nesting
ducks and geese within the oilfield area, with
lesser Canada geese being the most abundant.
The small lake islands, and many points jutting
into the numerous lakes that lie within the field
area, are their favorite nesting locations.
The increasing number of birds attracted by this
early thawing use the area as a staging ground
from which they disperse to nesting sites farther
afield. Most noticeable has been the fairly large
increase in the numbers of white-fronted geese
coming here in the spring, and which are
showing up in our pair counts along some of the
more southerly transects. The birds that have
fluctuated most within our survey area have
been the snow geese (Chen caerulescens
caerulescens) that nest on Howe Island, lying off
the mouth of the Sagavanirktok River. They have
had an up-and-down existence since we first
discovered them nesting there in 1971. In some
years they have brought off a good hatch; in
others it has been extremely poor. What the
causes were for the poor hatches in some years
is difficult to determine with any degree of
accuracy; in other years the reasons have been
fairly obvious.
The years 1971, 1972 and 1973 were all good for
these birds; but in 1974 they failed to nest on
Howe Island and only an occasional nesting pair
were recorded at other points within our survey
area. Although these birds arrived on the island
and appeared to be settling down to nest, they
apparently were disrupted by a two-week cold
front that moved into the area. Temperatures
dropped to 20°F —with blowing snow freezing
everything over again. Although it is only
speculation, we felt that this long cold spell,
coming at a critical time, may have inhibited the
breeding cycle of these birds, preventing any
nesting for that year.
Although no nesting took place on Howe in
1974, the snow geese returned to the island in
1975 and again in 1976, with both years being
quite successful. In 1977 they were on the island
again at the start of the nesting season, but
never really got settled down. Drilling rigs to the
east were being supplied by helicopters and
their route to and from Prudhoe Bay was over
Howe Island. These steady flight disturbances,
we believe, were just too much for the snows to
handle, resulting in a desertion of the island for
that year. Some birds did attempt to nest on the
Duck Islands to the east of Howe, and some
were successful, although many were driven off
or had their nests destroyed by the large colony
of glaucous gulls (Larus hyperboreus barrovianus)
that also nest there. One nest we found on Duck
Island in 1977 had one snow goose egg and three
glaucous gull eggs and was being incubated by
the gull. We often wondered if the snow goose
egg hatched out, and what happened to the
gosling if it did.
In 1978, the snow geese came back to Howe
Island looking for a place to nest, but apparently
were driven off, along with a number of lesser
Canada and black brant geese that had also been
using this island as a nesting site. A den of
white fox (Alopex lagopus) appeared to be the
culprits this time. These animals would be a
constant harassment to any birds on the island
and would most certainly be a disrupting
influence to any nesting attempts. On a
reconnaissance flight we made over the island
on June 15, we noticed there were no nesting
birds, although there was a group of about 40
snows sitting on the west end of the island.
20
While on the high east end of Howe, we glassed
the Duck Islands to the east and, from this
vantage point, were able to ascertain that a
number of snows were again attempting to nest
on the Duck Islands despite the large colony of
gulls there. Some of the snows apparently were successful, as indicated by the number of
goslings seen during a survey of the
Sagavanirktok River delta on July 25. On this date, a group of 37 adult snows, along with 21
goslings, was recorded. Although other surveys
were made after this date, these were the only
birds recorded from this area.
Like the geese, there also have been some
fluctuations in the numbers of different species of ducks that generally come here to nest. The
most abundant of the duck species utilizing this
area during the spring and summer are the old-
squaw (Clangula hyemalis). Literally tens of
thousands of these birds gather amongst the
offshore islands and bays during the summer
and fall. Here is one of their moulting areas, and, from the numbers congregating here, the
birds must come from a wide region along this
coast, as the local nesting population certainly
does not come anywhere near the numbers that
are seen at times along this offshore area. The
largest onshore population of old-squaw
recorded during our surveys was in 1973, when
some 9,432 birds were tabulated. The smallest
population was in 1976, when only 4,200 were recorded during spring pair counts.
Of all the ducks and geese nesting in this region,
the old-squaw is the most difficult to tabulate as
to numbers of pairs. They nest later than some
of the other ducks, and when our pair counts are
being conducted in early June many are still in
the midst of courting, with a number of males
generally in pursuit of a single female. They
never seem to settle down in any one area at this
time; they are always on the move.
Although eiders are fairly numerous throughout
the region, they never seem to be very successful
in bringing off a hatch. Predation among their
nests appears to be quite high; and, when they
are successful in bringing off a brood, their
numbers average generally quite low, often only
two or three to a family. Most predation comes
from foxes, ravens, jaegers and gulls. An
example of how heavy the toll can be was very
evident in 1977, when, of 13 nests that were
recorded on one transect, none was successful.
All had been destroyed, most of them by foxes,
but gulls, ravens and jaegers also were the
culprits in a number of instances.
Four species of eider ducks nest along this part
of the coast: the common eider (Somateria
mollissima), the king eider (S. spectabilis), the
spectacled eider (S. fischeri), and Steller’s eider
(Polysticta stelleri). The most noticeable birds are
the male king and spectacled eiders, whose
bright-colored plumage, when viewed against
the drab tundra, is outstanding. Steller’s eider
have been recorded each year from this part of
the Slope, and a few nests located, but they are
not by any means plentiful.
Pintails (Anas acuta) are fairly abundant nesters
in most years; however, there are times when
large numbers seen in this area in the spring
belie the actual number of nesting pairs. 1977
was a good example of this. There was a large
increase in the overall population of pintails
within our survey area, and yet the nesting pair
counts showed only a minor increase. Most of
the additional birds that came here in 1977
appeared to be non-nesters, along with a very
high percentage of male birds.
Many mixed groups of pintails were seen during
our spring surveys, but they showed no signs of
pairing off to nest. Influxes of these birds, along
with numbers of some of the other southerly
nesting species, seem to come north when
conditions to the south are on the dry side. Over
the years, as well as having increases in pintails
during these times, there also have been
increases in the number of mallard (Anas
platyrhynchos), shoveler (A.clypeata), American
widgeon (A. americana) and green-winged teal
(Nettion carolinense). These latter four species are
not abundant in this region, only showing as a
trace in the overall percentages. But they do
become noticeable at times.
Also, greater scaup (Aythya marila), while found
nesting throughout our survey region, are by no
means abundant along this part of the Slope.
Scattered nesting pairs have been recorded each
year of our surveys, predominantly in the more
southerly of our transects, just north of the
foothills. Like the greater scaup, scoter
populations are quite light and are mostly
confined to the coastal zone. No nests of either
the white-winged scoter (Melanitta deglandi), the
surf scoter (M. perspicillata) or the American
scoter (Oidemia americana) have been located in
this region, although over the years broods have
been seen on different occasions during some of
our offshore surveys along the barrier islands. It
is assumed that some of these birds have
nested there.
Harlequin duck (Histrionicus histrionicus
pacificus), although not recorded on any of our
transects along the coastal zone, have been seen
fairly frequently during flights along the upper
reaches of the Sagavanirktok, Ivishak and
Canning rivers. They seem to prefer the
fast-water areas of these rivers as their main
habitat, and, as the presence of broods would
indicate, apparently must nest there.
22
Although fluctuations of both ducks and geese
have taken place within our survey area, overall
production figures have remained fairly
constant. However, some decline is shown in
production figures for geese; this despite the fact
that there has been an increase in their overall
numbers. Average duck broods have stayed in
the three-ducklings-per-brood range, while the number of goslings per brood has dropped from
3.5 in the years 1971 through 1974 to 2.5 over the
last few years.
Whether the drop in production figures is due to
the population of birds being too high for the
available nesting sites, or whether there is a
larger population of non-nesting birds coming to this region is difficult to determine with any
degree of accuracy. There has been a larger
percentage of grouped birds showing up in our
spring pair counts over the last few years and,
since it is not known how many of these birds
disperse to nest after our surveys are made, all
are included in our overall spring counts.
If, indeed, a large percentage of these grouped
birds are non-nesters, which we believe they
are, this, while giving a larger pair count in the
spring, would certainly tend to depress overall
brood production. We do know that more
nesting geese are beginning to show up on some of our more southerly transects, with no
noticeable shifting from any of those nearer the
coast. This increase is quite likely due to the
earlier thawing along the haul road, attracting
birds to the region.
Apart from these minor differences in
populations and percentages, the production of ducks and geese from this region of the Slope remains excellent and adds considerably to the overall waterfowl production from Alaska.
Swans, Loons and Mergansers
Notes have been kept on swans, loons and
mergansers during our waterfowl and other
surveys, but no attempt has been made to keep
a completely accurate inventory of these species
of birds as we have done with the main body of
ducks and geese. However, from these notes,
enough information is available to provide some
pertinent data on overall populations and
breeding success.
Whistling Swan (Cygnus columbianus)
It is a long way—3,000 miles—from Maryland
and the Carolinas to Alaska’s North Slope, but
that is where the majority of these birds come
from each spring to nest and attempt to raise a
family. Scattered throughout this region of the
Slope, numerous nesting pairs are to be found.
Their favorite nesting sites are on the Colville,
Sagavanirktok and Canning river deltas. Since
oil operations began at Prudhoe Bay, there have
been several pairs that have nested within the
oilfield area. One or two of the original nesting
sites have been abandoned because of
encroachment, but there are still a number that
continue to nest within sight of drill rigs,
campsites and other facilities, seemingly
unperturbed by all the activities going on
around them.
Since many of these birds are accustomed to
human habitation on their wintering grounds,
they probably feel a sense of security being in
close proximity to human activities. About the
only predator here is the white fox and, while
they can generally handle these, we have seen
some nests that foxes have been able to rob.
Generally this happens when lemming, the
foxes’ main diet, are scarce. During these times,
with a hungry litter of kits to feed, foxes can
become quite aggressive.
During the early 1970s we assisted Dr. William
Sladen of Johns Hopkins University in
neck-banding a number of whistling swan in the
survey area. At that time, since we were looking
for these birds, we got a fairly complete picture
of their numbers. Apart from the fairly high
density on the Colville and Canning river deltas,
there were between 35 and 45 nesting pairs
scattered throughout this region. Although, as
indicated, no complete inventories have been
kept on these birds over the last number of
years, there does not seem to be any significant
change in their overall numbers here.
Arctic Loon (Gavia arctica pacifica)
The arctic loon is a very prominent bird
throughout this region of the Slope. Many nests
were recorded during our surveys and, like a
number of other birds, they like to come back to
the same nesting site year after year. A case in
point is the pair that nests on a tiny lake island
within a couple of yards of the main Spine Road
opposite the Frontier Company’s base camp.
This pair has nested here for the last five years
and seems undisturbed by the high volume of
traffic which passes along the road above them
day and night.
Loons are quite late nesters and rarely have
more than one chick. More often than not, these
birds are caught in the fall freeze-up with the
youngsters unable to fly, resulting in a number
being lost. This, we suppose, is nature’s way of
keeping things in balance. Loons are not on the
hunter’s list of prime game birds, and rarely are
shot for food. Since our first surveys along this
region of the Slope in 1969, there does not seem
to be any change in the populations of the loon
nesting here.
24
Red-throated Loon (G. stellata)
The red-throated loon is a fairly common nester
over much of the Slope area, but not nearly as
plentiful as the arctic loon, although it prefers
much the same type of habitat. Being a late
nester, it also can get caught at times with its young unable to fly at freeze-up. Over the years
we have found several of the young of both the arctic and the red-throated loon frozen in the ice. They are generally picked up quickly by white foxes on the prowl.
Yellow-billed Loon (G. adamsii)
In the ten years of our surveys along this region
of the Slope, very few of these birds have been
seen and only two nests have been recorded.
One was on a small lake east of Sagwon, and
the other was in the Ugnu area. At times single
birds were seen coming to feed in Prudhoe Bay,
mostly in the evening. It is possible that other
nests were in this area, although none
was located.
Red-breasted Merganser (Mergus serrator)
The red-breasted merganser is very scarce in this area, with only a few birds having been recorded over the last ten years. A pair was seen ona
small pond near the Kuparuk River in 1973, but no brood was observed on any of our
subsequent surveys around the area. In 1977, a
brood was recorded on the Sagavanirktok River
near Franklin Bluffs, and it must be assumed
that a pair had nested somewhere in that area. The only other records we have of this bird are for single individuals that we have recorded
from time to time near the West Dock shore.
This graceful pair of whistling swans (Olor columbianus) has just arriv ved on the North Slope from wintering grounds in the Chesapeake Bay region 3,000 miles away.
Golden Eagle (Aquila chrysaetos)
Golden eagles, while generally favoring the
mountain-range type of country, are to be seen quite regularly throughout this region of the
Slope. Several nests have been recorded, and, while most of these have been located in fairly inaccessible spots along some of the higher cliff
faces, there have been a few that nested quite close to the ground. The golden eagle has a fairly
wide choice of food in this region, yet a close look at some of the aeries would suggest that their main diet during the nesting season is
ptarmigan and ground squirrels. They do,
however, take other animals, as we witnessed one kill an arctic fox near the East Dock in
August 1971. This bird was immature but certainly did not show that when it came to
making a kill.
Peregrine Falcon (Falco peregrinus)
The peregrine falcon is rather widely scattered
throughout this part of the North Slope. Like the
golden eagle, it prefers the higher country for
nesting. Peregrine falcon nests are to be found
along many of the river banks within this area, where cliffs and rugged terrain exist. Areas such
as the cliff banks along the Colville River, high
outcroppings on the Sagavanirktok, Ivishak and
Kavik rivers are favored nesting sites. There are
also a number of other areas where nests of
peregrine have been recorded, and although no
precise inventory has been taken, there does not appear to be any decrease in the number of
these birds utilizing this region of the Slope
during the nesting season.
Gyrfalcon (Falco rusticolus)
Not a plentiful bird in this region, a few pairs of gyrfalcons have been recorded each year nesting along the high cliff banks of the Colville River.
One pair was recorded on the Anaktuvuk River
in 1973 and one pair was seen on the upper
reaches of the Kavik River in 1977, but no nests were located. Single birds have been seen flying
around the Prudhoe Bay facilities, and one landed on top of the Central Compressor Plant
(CCP) on August 29, 1978. Another was seen
likely the same bird — August 30 near the base
camp. It, or both, were immature.
Rough-legged Hawk (Buteo lagopus) Rough-legged hawks are fairly common and
widely scattered throughout this region. Their
territory is the same as the peregrine, and they often nest in close proximity to one another.
Distribution and nesting numbers have changed
little over the past ten years. Most known
nesting sites have been occupied every year since our surveys began in 1969.
Snowy Owl (Nyctea scandiaca)
Each year there always are some snowy owls to be seen in the area lying between the Colville
and Canning rivers. Their numbers, however,
are governed by the abundance or scarcity of lemming and other rodents within the area.
Large numbers of these birds were recorded
from this region of the Slope during only two of
the last ten years. One was 1969, when they
were very plentiful everywhere, along with a
high population of lemming; the other was in
1972, when the area east of the Sagavanirktok
River held quite a high population. The numbers
of lemming within the area in 1972, however,
apparently were not sufficiently high to induce
these birds to nest, as only one was recorded. In 1975 there was a fairly large population of snowy owl in the Oliktok-Colville region, and a number
nested within this area. Since 1975, we have
seen some snowy owls each year, but no large numbers have been present anywhere.
27
Short-eared Owl (Asio flammeus)
Like the snowy owl, the population of the short-
eared owl fluctuates with the numbers of
lemming and other small rodents within its
range. Short-eared owls were plentiful over
much of the region in 1969, but scarce in 1970. They again were fairly plentiful in 1971 on the eastern part of our survey region. There was an
excellent population in 1972, especially along the foothills area; and they also were recorded along the coastal region. Fairly good numbers also
were present in the foothills in 1975, but since that time (although some birds have been seen every year) no large numbers have been present within this area of the Slope.
A snow goose egg being incubated in a glaucous gull nest posed an unsolved mystery: what happened to the gosling when it was hatched?
Other Birds: Families —Laridae, Scolopacidae, Charadriidae, Phalaropodidae, Tetraonidae, Corvidae and Fringillidae.
Many species of birds under the above family
groups come to the North Slope each spring to
nest and raise their young. A complete list of
these was contained in our “Wildlife of the
North Slope—A Five-Year Summary,” issued in
1974. This ten-year report, while making some
reference to a number of birds within these
family groups, will not necessarily contain
a full list.
Generally, the first migrant to appear on the
Slope in the spring, apart from some of the
hawks, which come very early, is the glaucous
gull (Larus hyperboreus barrovianus). This bird
often appears in early May while the country is
still hard in the grip of winter. Although the
glaucous is the main gull of the family Laridae in
this area of the Slope, Sabine’s gull (Xema sabini)
and the arctic tern (Sterna paradisea) are quite
common in some areas. Mew gulls (Larus canus)
have been recorded a number of times, and a
stray Ross’s gull (Rhodostethia rosea) was
observed in August 1975. Large colonies of
glaucous gulls nest along some of the offshore
islands—the Niakuk and Duck Islands
in Prudhoe Bay being two of their
favorite locations.
Shorebirds are also common in the region, and
there are a number of different species. Some are
quite plentiful, while others range from fairly
common to scarce. The most abundant are the
semipalmated sandpiper (Calidris pusilla) and the
pectoral sandpiper (C. melanotos). Some of the
others recorded within this area are the buff-
breasted sandpiper (Tryngites subruficollis), found
in fair numbers; Baird’s sandpiper (C. bairdii),
quite scarce; the solitary sandpiper (Tringa
solitaria), uncommon; spotted sandpiper (Actitis
macularia), uncommon; and the stilt sandpiper
(Micropalama himantopus), which appears in this
region as a straggler only.
Dunlin (Calidris alpina) and ruddy turnstones
(Arenaria interpres) are two fairly prominent birds
along this part of the North Slope. While they
are not as plentiful as some of the other
sandpipers or plovers, they are fairly common
over the entire coastal area. Long-billed
dowitchers (Limnodromus scolopaceus), while not a plentiful bird in the region during the breeding
season, migrate through this area in the fall.
Flocks of several hundred are often to be seen
feeding in the shallower marshes along the coast
during the latter part of August.
The three main species of the family Charadriidae
that frequent this part of the coastal slope are the
golden plover (Pluvialis dominica), the black-
bellied plover (P. squatarola) and the
semipalmated plover (Charadrius semipalmatus).
All three of these species, while not appearing in
large numbers, are sufficiently abundant to
be noticed.
Two of the most prevalent species of birds that
appear along the coastal regions of this part of
the North Slope are of the family Phalaropodidae.
These are the red phalarope (Phalaropus
fulicarius) and the northern phalarope (Lobipes
lobatus). They arrive here in large numbers in the
spring and are prominent nesters all along the
coastal region. In most areas, the red phalarope
is more plentiful during the spring and the
nesting season. In the fall, during migration,
very heavy movements of these birds are to be
seen along the offshore barrier islands. During
this period in the fall, the two species seem to be
in fairly equal numbers.
29
Of the family Tetraonidac, two members are to be
found within our survey area. These are the
willow ptarmigan (Lagopus lagopus alascensis) and
the rock ptarmigan (L. mutus nelsoni). Although
both are to be seen along the coastal regions, the
willow is by far the most prominent of the two
over much of the Slope. In the spring, just
before the breeding season starts, flocks of
several hundred are not uncommon, especially
along some of the river banks and valleys where
a growth of shrub willow is present.
One of the birds of the family Corvidae that has
been attracted in fair numbers to the Prudhoe
Bay area of the Slope has been the common
raven (Corvus corax). Numbers of these birds stay
around the base camp buildings and other
facilities, seemingly seeking the shelter they
provide, for they are often seen perched among
the buildings wherever there might be a suitable
ledge. In the field, their main diet is generally
carrion, although they will kill weakened smaller
animals. They are also very proficient at hunting
out nests of other birds. In the oilfield area at
Prudhoe Bay they are fairly heavy predators
among the local nesting birds.
When doing our survey work, they provide a
useful service in that they are generally always
first around a kill, whether it be natural or
caused by wolves or grizzly bear. Under normal
conditions these birds can be spotted a fairly
long way off, and on many occasions they have
led us to kills that probably we would have
missed otherwise.
Two birds which are always a welcome sight
come from the family Fringillidac. These are the
snow bunting (Plectrophenax nivalis) and the
lapland longspur (Calcarius lapponicus). Their
arrival heralds the approach of spring, and their
singing brings a new outlook to the residents of
the north after a long, cold winter.
Mammals
30
Caribou (see pages 36-40) constituted perhaps
the main subject of our research program around
the Prudhoe Bay region of the North Slope, yet
other animals inhabiting this area were noted
during our many surveys. Included were moose,
barren ground grizzly bear, polar bear, wolves,
wolverine, foxes, lemming, and an introduced
species, musk ox.
Moose (Alces alces)
Moose, the largest species of deer, appear within
the oil field proper at times; however, their main
habitat lies farther south, along the river bottoms
and valleys nearer the foothills. Areas of heavy
willow growth, such as that found along the
Colville River from the Big Bend area to Umiat,
at times carry some fairly heavy populations of
these animals. Along this stretch of the river, our
surveys have recorded highs of 15 animals to the
mile; they have been as low as two or three to
the mile.
Most of the streams and valleys along the
foothills lying between the Colville and Canning
rivers hold their quota of moose; however, their
numbers to a large degree depend on snow
conditions and willow growth. Pockets of fairly
high populations have been recorded at times
along the Itkillik, Kuparuk, Toolik and Echooka
rivers. We have observed as many as 15 moose in
small groups along some of these rivers in early
spring. A number of moose winter along the
valleys and streams leading through the
foothills, yet many move farther south into the
mountains, then come north again in the spring.
Quite a few drop their calves along the foothills
area, and it is not uncommon to record a number
of these during spring caribou surveys.
The majority of these animals generally stay
fairly close to the river bottoms among the
willows, but they do at times wander out onto
the flat country to feed on the succulent plant
growth in and along some of the nearby lakes.
We have also at times recorded some of these
animals right up on the coast, generally during
the middle of the summer when flies are
bothersome. In the fall of 1978 three moose came
into the oil-development area—a young bull and
a cow with a second-year calf. They were first
seen on September 5, grazing near Flow Station
1, and they stayed in the area of the Flow
Station, Drillsite 2 and Drillsite 5, for the better
part of three days before moving south along
the Sagavanirktok River. They did not seem
to be very much perturbed by the activities
going on around them and were little concerned
when we approached within 15 yards or so to
photograph them.
Moose populations within our survey region
have varied from area to area, and from year to
year, yet there always seems to be pockets of
fairly high density. Predation appears to be light,
with only a few of the animals falling prey to
wolves and grizzly bear. There is little hunting
by natives north of the Brooks Range, so this
certainly poses no problem at the present time.
Over the years of our survey, moose in this
region seem to be doing quite well, and under
present conditions they should continue to
do so.
Barren Ground Grizzly Bear
(Ursus horribilis)
The barren ground grizzly was a fairly frequent
visitor around the oilfield camps at Prudhoe Bay
during the early years of field development.
They were attracted there by the smell of food
and the availability of numerous food scraps.
With the installation of proper garbage disposal
units, however, very few bears are now to be
seen around the camps at Prudhoe, even though
the population of these animals within this
region of the Slope remains quite stable. This
was most evident during the building of the
pipeline haul road and the construction of the
pipeline south from Prudhoe.
There were many camps along the way during
this period of time, and bear were a problem at
practically all of them. There always seemed to
be several around each camp, looking for scraps
or a handout. With the completion of the road
and oil pipeline and the closing down of the
majority of the camps, there is now little to
attract them to these facilities, although we still
see bear in the vicinity of these camps during
our surveys. Most, however, have moved to
their more natural habitat and surroundings.
31
During the past two years the vast majority of
bear recorded have been seen along the river
bottoms and deeper valleys, with only a few
being seen out on the open tundra.
From our observations, although no complete
inventory has been attempted, there does not
seem to have been very much change in their
overall population since we first started regular
surveys of this region of the Slope. As indicated,
there was some shifting during the construction
of the haul road and pipeline; however, with
these completed, bear have now scattered back
over their more normal habitat.
Polar Bear (Thalarctos maritimus)
Polar bear, while preferring the sea ice and
offshore islands as their main habitat in this
region, have been observed along the shores of
the Slope during the last few years. During our
offshore surveys of the barrier islands, one or
two polar bear would nearly always be
encountered each year. In 1977, however, they
were more than plentiful; 14 animals were
tabulated from the islands and along the sea
coast. Most were females with cubs, although
there was also the odd single. During the
summer of 1977, a large pack of very heavy ice
was driven up against the offshore islands and
was held there for a number of days before a
wind shift took it back north. It is very likely that
the majority of these bears came off this pack
and were left on the islands when the wind
change took the pack ice out to sea again.
In 1978 there were a few polar bear seen along
this part of the coast, and one actually had a den
and two cubs practically within sight of the base
camps at Prudhoe Bay. The first indication we
had that a polar bear was in the vicinity was
fresh tracks of one discovered near the East
Dock. On a survey east along the coast during
the beginning of May, a bear with two small cubs
was spotted, and from a distance of about a
quarter of a mile they appeared to be sitting at
the entrance to a den. Not wishing to disturb
them, we made no attempt to proceed
any closer.
Moose (Alces alces) are seen frequently along the river bottoms and valleys near the foothills.
Although surveys were made along this area of the coast at a later date, these particular animals were not seen again. We must assume that the cubs were able to travel and that the sow took them out onto the sea ice where the availability
of food was much better.
At the time, seals were starting to sun themselves on top of the ice, and it would have been no problem for an expert hunter like a polar bear to secure enough of these animals to feed herself and her two cubs. After a period of semi-hibernation to give birth to her cubs, and with little or no food during the suckling period, she would have been more than ready fora good feed, and a freshly killed seal certainly would have been high on the “menu.” During the fall of 1978, several single bears were recorded along this part of the coast, mostly between Prudhoe Bay and the Canning River.
Wolf (Canis lupus)
Since the early 1970s the population of wolves recorded in this region of the Slope has been quite low. Small packs and single animals have been seen each year, and the occasional den
located, but they never seem to have recovered from the late 1960s when aerial hunters virtually eliminated them from this part of the Slope. Stories persist that hunting from aircraft is still going on, although this practice was banned a number of years ago.
During the early years of our surveys, there was also a much larger population of caribou throughout this region. During these springs and summers, the Arctic Herd was at its peak in numbers. With a larger population of caribou within the area, it is only logical to assume that more wolves would be attracted. Then the population of the Arctic Herd dropped drastically in the early 1970s. Whether this sudden decline in the overall caribou population caused some of the decline in wolf numbers is rather difficult to determine with any degree of accuracy.
Should the Arctic Herd build up again to its former numbers, and should it spread out onto this region of the Slope as it formerly did, and should a greater population of wolves return with them, then, of course, some of our questions would be answered. At the present time, however, we can only describe the wolf population here as being very low.
As indicated, we see only a few wolves each
year, and observe the odd kill with one or two wolves in attendance. But nowhere are there any large packs, or even family groups, to be seen. We did have a report from a highly reliable source that a pack of some 14 animals was seen in the spring of 1978 somewhere between Happy Valley and Galbraith. This certainly is quite possible, but it is surprising that the wolf pack did not follow the movements of caribou through this area as they traveled north towards their calving grounds.
There were a couple of wolves resident within the oil field during the winter of 1977-78, and they were responsible for a few kills near the West Dock, where a number of caribou had
spent the winter. These two wolves, one with somewhat of a limp, were still around the field until late spring, when they apparently moved farther west. The one with the limp was seen during calving-success surveys west of the Kuparuk River. A caribou kill was nearby and we assume that this wolf had been responsible for it, as no other wolf was seen in the immediate vicinity.
During our other surveys around this part of the Slope in 1978, only two other wolves were recorded. One was in the foothills area near the Ivishak River, and the other was seen on the east bank of the Canning River, just north of Shublik Island.
33
Wolverine (Gulo luscus)
The wolverine is an inhabitant of the Prudhoe Bay region, but is very rarely seen. It is a most secretive animal and will quickly take cover at the first indication of danger. It is quite vicious and dangerous if disturbed on a kill, for pound for pound it is one of the strongest and most aggressive animals on the continent. Trappers,
campers, prospectors and others are often chagrined and angered to discover that their caches have been robbed or destroyed by this animal. The natives prize wolverine because its fur makes excellent trimming for their parka hoods. The smooth hairs of this animal retain less of the frozen moisture from the breath of the wearer than the fur of any other animal.
During the years of our surveys of the area between the Colville and Canning rivers, a total of eight wolverine has been recorded. Three of these were sighted on the open tundra, with the others being sighted along some of the river bottoms and up on the foothills near the Brooks Range.
White or Arctic Fox (Alopex lagopus) The population of arctic foxes on the Prudhoe Bay area of the North Slope, as elsewhere across the arctic regions, is subject to extreme fluctuations. Their numbers are mostly governed by the abundance or scarcity of lemming. When these rodents are plentiful in an area, it generally follows that foxes also are plentiful, since they are dependent to a large degree on lemming for their main food supply.
The most abundant year that we have recorded for both white foxes and lemming was 1969. That year, foxes were to be seen everywhere and lemming were so abundant the tundra teemed with them. During the next four years, through to 1974, the fox population declined dramatically, although there were pockets of lemming in spots. This was particularly true in 1972, as evidenced by a fairly large population of snowy owl, another predator dependent on lemming for the major portion of its diet.
In the fall of 1974 foxes appeared to be on the upswing again, but an outbreak of rabies that winter very effectively reduced their numbers.
While fair numbers of these animals were in
evidence in 1975, another siege of rabies during
the winter of 1975-76 again reduced their numbers considerably.
Although regionally the fox population has
varied from year to year, there always seem to be a fair number within the oilfield area proper. This is most likely attributable to the fact that
there are a number of excellent denning sites within th field, and the majority of these are in use every year. In fact, with so many denning
sites in use each year, there is often conflict
between foxes and nesting birds, especially when lemming are as scarce as they have been in recent years. With few lemming, foxes turn to
raiding wildfowl nests, and, with litters of young to feed, they can wipe out practically
every nest within their hunting territories.
During 1977 and 1978, this was very evident on some of our transects; often 90 to 100 percent of nests were destroyed by foxes.
Lemming (Dicrostonyx groenlandicus and
Lemmus alascens)
There have been isolated areas throughout our survey region where lemming have at times been fairly plentiful, but there really hasn’t been a high population on a widespread basis since
1969. In 1969, lemming were to be seen practically
everywhere on the tundra from early spring
until well into the month of September, when
they just seemed to disappear. Foxes and snowy owls, which had been quite plentiful during this
same period, also dropped considerably in
numbers. There was some evidence that the lemming had migrated westward, but insufficient data gathered at that time precluded
any definite answer to this question. This pesky red fox (Vulpes fulva), its coat almost bleached white by the summer sun, raided common eider (Somateria mollissima) nests on Egg Island during the summer of 1979.
34
Generally, the numbers of snowy owls, foxes, jaegers and other predators give some indication as to the population of lemming within an area.
In 1972, during much of the spring and summer,
there was quite a large population of snowy owl and parasitic jaeger along this region of the
coast, indicating that there were sufficient lemming to hold these birds in the area. There was evidence of this from the numbers and signs of these little animals encountered during some of our walking surveys.
Both 1973 and 1974 were poor lemming years in
this area. Foxes were seen searching for bird
nests, at which they are very adept. And the jaegers were hunting small birds, their favorite
being those of the sandpiper family.
In 1975 there were some small pockets of
lemming within the region. One in particular
was around the Oliktok-Colville River area,
where snowy owls were quite plentiful and a number of nests were located. Some of these were apparently quite successful, as a good
number of young birds were seen in the fall.
From 1975 to 1979, there was little or no evidence
of lemming within our survey region. Foxes denning within the field area obviously were
living off bird eggs and any scraps they could
pick up. Being subject to very wide fluctuations,
however, it is quite possible that future years
could see cyclic movements of lemming into this region of the North Slope.
Blue Fox (A. lagopus)
The blue fox is actually a color phase of the
white or arctic fox. Both come from the same litter and the same parents. The frequency of blue fox kits within a litter of whites varies widely throughout northern Alaska and the arctic regions of Canada. Trading-post records of the Hudson’s Bay Company indicate that in furs brought in for trade, blue fox pelts average one for every one hundred white fox pelts. On the Pribilof Islands of Alaska, the blue fox has
become the dominant species, and every effort is made by the residents to keep it that way. White fox born on the islands or coming in off the ice pack are killed whenever possible in order to preserve the blue strain. The monetary value of the blue fox pelt is much higher than the white fox pelt.
In the Prudhoe Bay area of Alaska, a few blue foxes are to be seen each year, their numbers
rising or falling depending on the overall population of their dominant strain, the white or arctic fox.
Red Fox (Vulpes fulva)
During 1969, when lemming were plentiful throughout the North Slope, a number of red fox were recorded, mostly along the southern part of our survey region. Since then, one or two a year has been the maximum we have recorded.
35
Least Weasel (Mustela rixosa) The least weasel is the only weasel we have recorded from the Prudhoe Bay area of the North Slope. During 1969, when lemming were plentiful, several of these little animals were recorded at various points during our surveys. In 1971 and 1972 the animal was again seen, but since that time none has been recorded. There is no doubt that a number of these animals have been within our survey region each year; we just have not seen them. These fierce carnivores feed on lemming, mice and small birds. Like the larger species of weasel, the least changes its summer brown coat to white when winter comes. Apart from size, it is easily recognized by its short tail, which never has a black tip, as others of the species do.
Musk Ox (Ovibos moschatus) Although musk ox were indigenous to the northern part of Alaska some one hundred years
ago and ranged widely over northern Europe, Asia and North America during Pleistocene times, the only ones found on the Slope area of Alaska today are those that were planted there some ten years ago from stock raised on the Nunivak National Wildlife Refuge. These in turn were imported from Greenland in 1930. While the overall status of these planted animals is not
known, we did at times observe small groups during some of our caribou and other surveys. At least a number of the planted stock are breeding in their new surroundings, as several calves have been observed. Most groups seen have been in the Canning River delta and Kavik regions. The latest was in 1978 when a group of eight was sighted on the Canning River delta. Two of these were calves of the year.
Caribou
36
As has been happening for many years, a
number of caribou (Rangifer tarandus arcticus)
wintered on the Slope during 1977-78, although
not as many as we had expected. During our late
fall survey in 1977, a good percentage of the total
population seen during the summer of 1977 were
still on the Slope. Many of these, however, must
have moved south during the early part of the
winter, since our early spring surveys in 1978 did
not show any large numbers of animals
anywhere on the Slope area proper.
First surveys in 1978 were made on May 11,
when most of the area between the Colville and
Canning rivers was checked. Although there
were several hundred caribou scattered
throughout the region, there really were no large
groups in evidence. The largest numbers were in
the area west of the Kuparuk and in the Franklin
Bluffs region. Several small groups were noted
in the oilfield area, and, according to workers
there, they had been in the area all winter. Two
wolves were also noted within the field and had
managed to take several of the wintering
animals. From evidence I was able to gather, it
appears that most of the kills made by these two
wolves were from a small group of some 15
caribou that wintered in the West Beach area of
the field.
Although several surveys were made
throughout the area during the month of May,
there was little evidence of any large-scale
migration into this region. There were scattered
groups recorded coming down the Ivashak,
Sagavanirktok, Kuparuk, Kadler, Oshilik,
Shaviovik, Kavik and Canning rivers. The
largest movement was noted on the Canning
River May 29, when between two and three
hundred animals were observed. From trail
evidence it was apparent that they had come
from the east down the valley opposite Shublik
Island, then headed north along the banks of the
Canning River. First calves of the season were
recorded on May 29. Two newly born calves were
observed and photographed on the morning of
May 29 just east of British Petroleum (BP) drill
pad N. A cow caribou was seen lying down in
the same area, and, on checking the following
day, she also had given birth to a calf. During the
season, several other calves were born at various
points within the oil field. These were duly
recorded, and, wherever possible, photographs
were taken showing their location.
At least ten cows were known to have dropped
their calves within the oilfield area, and it is
quite possible that there were more, since on
one survey 15 cows with calves were counted.
Although it was possible to see cows with calves
at any point in the field during the calving
season, their favorite spots during this period of
time appeared to be the area from north of the
Central Compressor Plant, west along the Put
River to around Drillsite 7 and north to the east
side of the BP complex.
As has been our custom in past years, surveys to
ascertain calving success for the year were
carried out during the middle of June. Counts at
this time indicated a very successful calving
season, with the region west of the Kuparuk
River appearing to have had somewhat better
success than the area east of the Sagavanirktok
River. Calf/cow ratios west of the Kuparuk were
around the 60:100 mark, while those for the area
east of the Sagavanirktok registered around a
50:100 figure.
37
Total population surveys of the area lying
between the Colville and Canning rivers were
carried out from July 6 to 8. During this time
flying insects were out in force and were
extremely bothersome. When mosquitoes are
bad, Caribou tend to gather along the coastal
areas, herding up on river deltas and sandspits.
This makes counting of the total population
fairly easy. Checking was done from a helicopter
with two people counting. If there was any
marked discrepancy between one observer and
the other in the counts, the process was
repeated until we were sure the count was
correct. With a helicopter this process can be
done quite easily, since it can hover high enough
over the animals without disturbing them.
Total population recorded at this time is given in
the following table:
Cows Calves Yearlings Bulls Total
East of
Sag. River 1820 828 529 625 3802
West of
Kuparuk R. 1270 720 420 470 2880
Prudhoe
Field area 80 32 21 5 138
Totals 3170 1580 970 1100 6820
Calf/Cow Ratio—50:100
With the addition of barren cows, and cows that
had lost their calves during or after the calving
season, the overall calf/cow ratio had dropped
somewhat from the figures obtained during
calving success surveys. Omitted from the field
area count was a herd of approximately 150
caribou that was in the area west of Pt.
McIntyre. These, we feel, were part of a herd
that was on the Kuparuk River delta during our
count of that area, and had moved east during
the time we were counting farther to the west.
The trans-Alaska pipeline poses no barrier to caribou (Rangifer tarandus arcticus).
In 1978, the Alaska Fish and Game Department placed collars on a number of caribou so that their movements could be traced more accurately. Some of these are radio collars; other caribou were numbered and collared with different colors. During our surveys we recorded a number of these animals at different points across the Slope, with several having been seen within the oilfield area. Two of these were
recorded on July 7: a caribou identified as Red No. 63 was seen north of the Central
Compressor Plant in a small mixed herd; No. 16 was recorded in a band of 20 cows and calves near Drillsite 3, moving northeast toward
Flow Station 1.
During the spring and summer, numerous
groups and small herds of caribou were seen within the field area. As expected, the largest numbers were recorded during the height of the insect season. During the years of our survey work at Prudhoe Bay, the movements of these animals through the field have been recorded on maps of the area. In order to provide an idea of the numbers of animals that come into and pass through the field area, some quotes from my
field notes made in 1978 might be appropriate:
“July 6th. Beautiful clear morning. Temp. 45°F at
6:00 A.M. Light breeze from the west.
Numerous mosquitos around. Caribou moving around and through the field in small herds. Herd of about 50 animals (mixed) went east past Drillsite 9 around 10:00 A.M., heading east toward Sag River delta. Another small mixed herd moved along the Sag River around 11:00 A.M., passing through the lines from Drillsites 3
& 9, and also heading towards the Sag River delta. At about the same time a mixed herd of 42 animals, coming from the west and also heading
toward the Sag River delta, crossed over the East Dock Road. At 1:00 P.M. left with helicopter on
survey east of the Sagavanirktok River, arriving
back at 4:30 P.M. Around 5:30 P-M., a herd of some 60 animals moved into the flats between Drillsites 3 & 9, staying there for about two hours before moving east.
“July 7th. Another lovely clear day with
unlimited visibility. Very warm. Temp. 63°F at 6:00 A.M. Reached 75°F at height of day. Very light westerly breeze. Herd of about 100 caribou between sanitary landfill and Drillsite 4 at 8:00 A.M. These moved west towards the Put River at 9:00 A.M. and were north of Drillsite 5 when last recorded at 11:00 A.M. At this time there was
another mixed herd of animals over near the Deadhorse Airstrip. There were 84 animals in
this group, and they were moving east at the time of sighting. At 1:00 P.M. left with helicopter
to survey area west of Kuparuk River and the Prudhoe Bay field area.
“July 8th. Nice bright day, but cooler. Temp. 45°F at 6:00 A.M. Fairly strong easterly breeze. Dust blowing off sand dunes north of Surfcote. Small herd of about 100 animals, mostly bulls, seen north of Drillsite 5. Small band broke off from this group and moved over behind Flow Station 1, where they stayed for some time before moving back east.”
During the next number of days the weather stayed cool, with temperatures going down as low as 35°F. While there were some movements of caribou in and through the field at this time, no large numbers were involved.
“July 20th. Nice clear day with very light
westerly breeze. Temp. 45°F at 6:00 A.M. Numerous mosquitos around. Small band of 47 caribou along airfield and around Base Camp 2. These were a mixed group and they stayed between the Base Camp and Flow Station 2 for much of the day. Mixed group containing 21 cows, seven calves and ten bulls, with six yearlings, heading west toward Put River area, crossed over East Dock Road north of Surfcote at 6:00 P.M.
“July 21st. Dull, overcast morning. Light breeze from the west. Temp. 40°F. Numerous little bands of caribou noted in field today, the largest being a small group of about 40 animals north of Flow Station 2. Group of 30, mostly bulls, near airport road. Small group of nine cows, four calves and three yearlings near Drillsite 7. Fourteen animals just north of Drillsite 3 and two small groups totaling 32 animals along sand dunes north of Surfcote.
39
“July 22. Cooler today. Temp. 40°F at 6:00 A.M. Overcast but good visibility. Herd of roughly one hundred animals moved in around Drillsites 3 &
9 this evening. They were a mixed group, and they came in from the south and left around 9:00
PM., going back the same way. Herd of 39 animals, going west at around 9:45 P-M., crossed East Dock Road at Surfcote. There were 15 cows, eight calves and seven yearlings in this group.
“July 26th. Beautiful, clear, bright day. Unlimited visibility. Very little wind. Lots of mosquitos.
Temp 45°F at 6:00 A.M. Went up to around 60°F during the day. Numerous bands of caribou in the area today. The largest was a herd of some 200 in the CCP-West Beach area. This mixed
herd came in from the west, moved over to the
coast north of West Beach, then headed back toward the British Petroleum (west) side of the field around 10:00 A.M. In the afternoon another herd of about 150 animals came into the West
Dock-West Beach area and stayed around for some time before moving back to the west. In this group was a collared animal wearing Red No. 63. This same animal was recorded north of the CCP on July 7. Most were cows and calves, with only a very few bulls or yearlings
being noted.
“July 29th. Overcast, but nice morning. Temp. 51°F at 6:00 A.M. Lots of mosquitos. Herd of
some 150 animals in area between Drillsites 3 & 9 this A.M. They stayed there for the better part of the day before moving up past Drillsite 4 over to the sand dunes west of the Sag delta. At the same time a herd estimated at around 600 animals moved into the area between Drillsites 3 & 9 and down onto the Sag River flats opposite the ARCO airport. These animals came in from
the south, then moved over to the sand dunes
north of Surfcote, before heading toward the Sag
River delta. In this group there were a number of Fish & Game collared animals. The ones we were able to record were: Red No. 11, Red No. 61, Red No. 64 and Blue No. 7. Around 10:00 P.M., a group of some 50 cows and calves was recorded crossing over the East Dock Road and heading west past Flow Station 2. In this group was the red-collared animal No. 64.
“July 30th. Nice morning, although it had been
raining much of the night. Good visibility. Temp.
54°F at 6:00 A.M. Mosquitos still quite bad.
Small herd of 125 animals moved onto river flats
between Drillsites 3 & 9 around 10:00 A.M. They
came in from the southwest, and stayed around
this area for a few hours before most of them
moved to the east. Two blue-collared animals in
this group—Nos. 92 and 65. Around 5:00 PM.
another small herd of roughly 70 animals was
noted moving into the area immediately east
of Drillsite 9.”
From this date until the fall, there were
numerous groups of animals recorded in and
moving through the field. One point of interest
was the group that was recorded going west on
July 29, amongst which was a red-collared cow,
No. 64. While taking pictures with Jack Sheedy
on August 1, we recorded this same animal and
photographed it in a group of about 50 cows and
calves immediately west of Pump Station 1,
thirty miles away. By the first ten days of
August, a large percentage of the animals had
moved away from the coast and were slowly
wending their way south towards the foothills.
On a photographic flight to the Canning River
area on August 3, we observed numerous bands
of caribou moving south. One of interest was
along the valley leading into the Sadlerochit
Mountains. Although there were only 30
animals in this movement, there were numerous
trails along the valley, indicating that others had
moved this way. In the spring, a number of
caribou were recorded moving out of this valley,
heading north. Those seen on August 3 were
very likely some of the same animals moving,
back to their wintering grounds to the
east and south.
During the latter part of August, several surveys
were made around the Slope, and though there
were still numbers of caribou scattered
throughout the region at this time, most had
already moved south into the foothills area.
Many of the animals that had spent the summer
west of the Kuparuk River moved south along
this river in the fall. A fairly steady movement
was noted in this area during the first ten days
of August. Another movement of interest was
up along the Itkillik River. On August 2, while
on an inspection of the Itkillik Drillsite, we
observed a large number of animals moving
along the river. An estimated 500 caribou were in
this group, but the weather at the time was quite
foggy, with limited visibility.
From the area east of the Sagavanirktok River,
much of the movement south was along the
Sagavanirktok and the Shaviovik rivers, with
scattered other movements along the Kavik and
Canning rivers.
40
By the middle of August, a good percentage of
the caribou population from this region had
moved south, away from the coast. However,
there still were small groups of animals to be
seen throughout September. Most if not all of
these likely stayed and wintered on the Slope.
There were still a number around the field at this
time, including about a dozen animals that were
spending much of their time in the area around
Drillsite 7. In this group was a blue-collared
animal, No. 37.
For the caribou population, the year 1978, as a
whole, was a good one. They appeared to have
wintered well; they had a good calving season,
and, if coming winters are kind to them, they
should come back to the Slope in future years in
good shape and in increased numbers.
Breakdown of Estimated Caribou Population — Colville-Canning Areas (1978)
Cows Calves Yearlings Bulls Total
3170 1580 970 1100 6820
Calves per 100 Cows — Canning-Colville Area (1978)
50:100
June Survey of Caribou Within Field —1978
Cows Calves Yearlings Bulls Total
29 15 Z| 6 57 Note: Large number of animals in field due main! ly to the fact that many of them stayed in the field area during winter of 1977-78.
Calves per 100 Cows — Prudhoe Bay Area (1978)
50:100
Calves —1978
West of Kuparuk River Prudhoe Bay Area East of Sagavanirktok River Total
720 32* 828 1580
*Taken from July 7 Survey. Calves born in field (June Survey): 15
41
The Prudhoe Bay field lies in the area between
the Sagavanirktok and Kuparuk rivers and
stretches from the coast at Prudhoe Bay south
for approximately 12 miles. On an area basis, it
covers roughly 250 square miles.
From the date of discovery of oil in mid-1968 to
the present time, many changes have taken
place within the field area. Numerous wells have
been drilled, and base camps, flow stations,
injection plants, and many other facilities have
been constructed. A network of roads has been
built and a series of gathering lines laid. These
are all necessary and vital components needed
for the proper development and efficient
operation of the field.
While some of these activities may have
disrupted the overall environment to some
degree, the effects have not been of a drastic or
permanent nature. What limited environmental
changes there have been took place during the
years of heavy construction, when the pipeline
from Prudhoe Bay to Valdez was being built and
when many of the development and operating
facilities were being constructed. During this
time, thousands of men and machines were in.
the area, and it was only natural that some
changes, both environmental and ecological,
would occur.
With the pipeline completed and in operation,
and most of the major field facilities in place,
activity within the field has more or less settled
down to normal operating procedures, although
more construction is planned. Some have
expressed concern for the well-being of wildlife
that inhabit this region during various times of
the year. Systematic surveys conducted each
year since 1969 have not shown that the
development and operation of an oil field within
their domain has caused major changes in the
wildlife populations. There are natural
population trends where man has no control or
influence, one of these being the proliferation of
lemming, which is very cyclic in nature. Their
numbers within an area govern the population
of other animals and birds.
Since 1969 the caribou population utilizing the
field area of the Slope lying between the Colville
and the Canning rivers has fluctuated
considerably, from a high of more than twenty
thousand in 1970 down to roughly seven
thousand in 1978. This fluctuation, however, was
not caused by construction of the pipeline or the
field development. The prime cause was the
drastic decline in the population of the Western
Arctic Herd. This herd has gone from an
estimated 240,000 animals in the late 1960s to a
low of approximately 60,000 in 1973. This
tremendous drop was caused by a combination
of many things, including poor reproduction,
disease, predation, and over-harvesting. This
type of mortality among caribou herds has been
going on for hundreds of years and no
management techniques in use at present will
halt similar declines in the future.
During the early years of our surveys, 1969-1970,
when there were approximately 20,000 caribou
migrating into the region between the Colville
and Canning rivers, some 25 percent to 80
percent of them came into the area via the
Anaktuvuk Pass and, without doubt, were part
of the Western Arctic Herd. The remaining
animals, numbering around 5,000, came in from
the south via the Kuparuk, Sagavanirktok,
Shaviovak, Kadleroshilik and Kavik rivers, with
some movements at times along the Canning
River. These animals were not designated as
coming from any particular herd, but, according
to research done by Roland Skoog and later
confirmed by Cameron and Whitten, there
apparently is a small herd in the Central Brooks
Range, and this herd has been designated as the
Central Arctic Herd.
43
With the drastic drop in the Western Arctic Herd
population, its present range is confined to that
part of the Slope west of the Colville River.
Latest figures, however, indicate that the
population of this herd is increasing again and
has now reached the 100,000 mark. Should it
continue to increase in numbers, there is no
doubt that it will again extend its range into the
region between the Colville and Canning rivers
as it did in the late 1960s and early 1970s. In the
meantime, the major portion of the caribou
utilizing the area around Prudhoe Bay will come
from the Central Arctic Herd. This herd, despite
all the activities that have taken place within its
range, has stayed remarkably stable, ranging
between the 5,000 and 7,000 population mark.
Trends in some of the other wildlife in this
region have, like the caribou, varied from year to
year. Foxes have been up and down in
population, much of this dependent upon the
lemming population. There also have been a
couple of outbreaks of rabies, which quite
effectively controlled their numbers.
Wolves have never been plentiful in this region
of the Slope, even in the early years of our
surveys when caribou were more plentiful.
Aerial hunting in the late sixties practically
decimated the entire population from this part of
the Slope, and the wolves have not seemed
to recover.
Lemmings have not been recorded in any large
numbers within our survey region since 1969,
when they were truly abundant. There have
been localized areas where these animals have at
times been seen in fair numbers, but there has
not been any noticeable, widespread explosion
that periodically occurs among these animals.
Waterfowl are quite numerous throughout this
region of the Slope. They come here in a variety of species to nest and rear their young and have adapted well to the changes in environment.
Populations of a number of species rose quite
dramatically during the middle seventies, but
have now settled back to population levels
comparable to the early part of the decade, and
appear to be leveling off at this point. Within the
oil field proper, where numerous surveys are
conducted yearly, predation by foxes and ravens has been a big problem in some years. There are
quite a number of fox dens located within the
field, and when lemming are scarce these animals turn to raiding nests and hunting
young birds.
To facilitate the unloading and movement of large facilities and equipment shipped via barge from the south, it was necessary to build a long gravel-filled causeway out into Prudhoe Bay. There was some concern that this causeway might interrupt movements of fish. Surveys conducted by the Fisheries Branch of the Alaska Fish and Game Department indicate that this causeway is not proving to be a barrier to the free movement of fish.
Although the development of an oil field at Prudhoe Bay and the building of a pipeline to
Valdez, together with all the other attendant
activities, have at times disrupted and disturbed
some of the wildlife within the area, this should not have any lasting or detrimental effects. With major construction work over for the present,
more normal conditions now prevail, although our surveys over the years have shown that most species of wildlife adapt quite readily to changing environmental conditions.
44
% ae > ¥ “eh Canning e
Clockwise from upper left: long-tailed jaeger (Stercorarius longicaudus); barren ground grizzly (Ursus horribilis); lemming (Dicronstonyx groenlandicus);
caribou (Rangifer tarandus arcitus).
45
Clockwise from upper left: arctic ground squirrels (Spermophilis undulatus); pintail hens (Anas acuta); arctic fox kit (Alopex lagopus); musk ox (Ovibos moschatus).
46