season of open water the latter may effect a ready escape by plunging
into the nearest river or lake and crossing to the other side. There is
reason to believe that islands provide a good sanctuary during the
summer (Seton, 1929, +3+: 108-109; Gavin, 1945: 228). In the winter the
Caribou must depend primarily on its fleetness of foot. Even the fawns
are reputed to be able to outdistance Wolves in a chase that is not too
prolonged. An adult, if brought to bay after a long chase, is probably
able to stand off a single Wolf indefinitely. Its powerful hoofs are its
principal means of defense. Even if the antlers are brought into play,
they are effective only during the limited period when they are
fullgrown, hard, and free of velvet. When two or more Wolves manage to
bring a Caribou to bay, the outcome is probably almost invariably in
their favor. Charles Schweder has never known a Caribou to kill one of
these predators in defending itself. In several cases reported by Fred
Schweder, Jr., the last stand was made on the ice of lakes. The Caribou
itself may choose such a place, as if aware that it may be more
sure-footed on the ice than its enemy.
After listening to wolf tales by residents of the frontier settlements
rather than by real men of the "bush," one might almost expect to see a
couple of these bloodthirsty animals harrying the rear of every band of
Caribou and keeping up a relentless pursuit. However, during a sojourn
of six months on one of the best Caribou ranges in Keewatin, where
trapping has very little effect on Wolves, I saw just one of these
animals alive, heard the howling on several occasions, and noted a
single Caribou that had probably been killed by them. It is far from a
common experience for the resident trappers to witness actual pursuit by
Wolves or even to find their kills. The following instances, related by
Fred Schweder, Jr., comprised his only direct observations on Wolves in
pursuit of Caribou up to and including 1947, when he was eighteen years
old.
During the northward migration in May, 1945, a silent black Wolf pursued
a band of 100 Caribou over the ice of Windy Bay. At one time it came
within 100 feet, but thereafter they forged ahead. After half a mile the
band split up, and the Wolf desisted. In October, 1946, Fred noticed a
Caribou fighting off two Wolves on the ice of Nueltin Lake near its
outlet. It used both horns and hoofs against its attackers. While one
Wolf was in front, the other would try to get in the rear of the Caribou
and hamstring it. This went on for two hours until darkness hid the
scene. The next morning the Caribou was dead and half eaten. On October
16, 1947, a white Wolf was seen in pursuit of four fast-moving Caribou
near Simons' Lake. It was about half a mile in their rear, and presently
halted, probably by reason of catching sight of Fred.
November 7, 1947, was a blizzardy day; the air was full of drifting
snow. Under these conditions a gray Wolf chased a buck and a doe right
into the dooryard of one of Fred's trapping camps 10 miles north of
Windy River. It was only about 30 feet behind them. When the buck broke
through the ice of a little creek, the Wolf went right past it in
pursuit of the doe. The latter nearly ran into Fred's toboggan, and he
shot it at a distance of 20 feet. The Wolf came within 40 feet, but by
the time it was recognized as not just another Caribou, it was 100 feet
away. Fred then shot but merely wounded it, the sight being off his
rifle. Meanwhile the buck escaped, but 3 miles away Fred met with it
again and secured it. He recognized it as the same animal because at
both encounters it was limping from a previous wound and was hornless as
well.
In late November Fred found two fullgrown bucks and a doe on the ice of
Windy Lake, where they had been killed by Wolves. The bucks were
antlered and had probably met their end several weeks previously. Yet
their flesh was so musky and unpalatable, in consequence of the rutting
season, that it had not been devoured. A long trail of blood and hair
led to the spot where the doe had fallen, apparently a couple of weeks
previously; it was still only half eaten.
In Fred's opinion, Caribou are apprehensive of sandy eskers as the haunt
of Wolves, and do not linger there.
On October 15 Charles Schweder pointed out the body of a Caribou in a
little pond in the delta area at the head of Simons' Lake. He considered
it killed by Wolves some weeks previously; its antlers were in the
velvet, and it had been eaten only about the head and hind quarters as
it lay in the water.
Joe Chambers, a trapper of Goose Creek (south of Churchill), stated that
Wolves select the fattest Caribou, and that during the winter of 1946-47
they had been devouring only such choice parts as the tongue and the
unborn young.
Caribou bodies are the primary bait for Wolves and Foxes on the Barren
Grounds. Two traps are commonly placed at each carcass.
Up to a couple of centuries ago, when the baneful effect of civilized
man began to be felt, the Caribou throve and multiplied to a point where
they probably strained the grazing capacity of the Barren Grounds.
Neither primitive man nor the Wolf had any serious effect on the size or
condition of the herds. The Caribou were numbered by millions, and they
doubtless owed their vigor and their success as a species in no small
measure to their friendly enemy, the Wolf. Through long ages the latter
had tended to eliminate the weaklings, the sickly, and the less alert
individuals, leaving the fitter animals to propagate their kind. Here
was a fine example of natural selection operating to the advantage of
the Caribou. Thus the Wolf may be safely considered a benefactor of the
species as a whole--a regulator and protector of its vitality.
There are only two regions of the world where Caribou (or Reindeer) have
not long shared their territory with the Wolf--Spitsbergen and the Queen
Charlotte Islands. And what sort of situation do we find there? Instead
of thriving in the absence of such a natural predator, the animals of
both regions are the runts of the whole Caribou-Reindeer tribe, and
those of the Queen Charlottes have become virtually or wholly extinct
(_cf._ Banfield, 1949: 481-482). Furthermore, the Newfoundland Caribou
suffered a very serious decline after the Newfoundland Wolf became
extinct at about the beginning of the present century. The lesson is
obvious: it is folly for man to imagine that he can benefit the Caribou
by eliminating the Wolves.
It is virtually axiomatic that no predatory species (other than modern
man) exterminates its own food supply. Long ago nature must have
established a fairly definite ratio between the populations of the Wolf
and the Caribou. Although a certain fluctuation of that ratio could be
expected from time to time, each fluctuation would be followed by a
return to more or less normal conditions. The trend of evolution has
doubtless been toward perfecting the Wolf in its ability to capture the
Caribou, but at the same time toward perfecting the Caribou in its
ability to escape the Wolf. Unequal progress of this sort on the part of
the two species would presumably have been rather disastrous to the one
or the other. But it is nature's way to have preserved a proper balance
between the abilities of the two species, and thus between their
populations. This balance (a rather delicate one) has probably been
upset to some extent by the advent of civilized man with his devices to
the Barren Grounds.
The Caribou "exemplify the survival of the fittest; none but the perfect
are allowed to live and breed, hence their perfection. We believe that
the wolf is in no small degree responsible for this high standard,
and that were he killed off the species as a whole would suffer."
(Critchell-Bullock, 1930: 161.)
"It is doubtful if the efforts of white or native hunters are of any
importance whatever in the control of wolves in the caribou country, or
could, under present circumstances ever be of any importance." (Clarke,
1940: 109).
_References._--Franklin, 1823: 242, 327, 344, 486, 487; John
Ross, 1835a: 402, 530, 534, 564; Back, 1836: 128-129; Simpson,
1843: 232; Armstrong, 1857: 395, 480-481, 488, 525; Osborn,
1865: 227-228, 231, 232; Kumlien, 1879: 53, 54; Gilder, 1881:
61; Bompas, 1888: 60; Collinson, 1889: 244; Pike, 1917 (1892):
56-58; Whitney, 1896: 239; Jones, 1899: 374-375; Preble, 1902:
41, and 1908: 214; Hanbury, 1904: 89; MacFarlane, 1905: 692-693;
Amundsen, 1908, +1+: 102; Seton, 1911: 225-226; R. M. Anderson,
1913b: 516; Stefánsson, 1913a: 93, and 1921: 248-249, 475-476;
Blanchet, 1925: 34; Mallet, 1926: 79; Birket-Smith, 1929 (1):
51; Seton, 1929, +1+: 344-346, and +3+: 108-109; Blanchet, 1930:
54-55; Critchell-Bullock, 1930: 159-162; Hoare, 1930: 22; Kitto,
1930: 89; Jacobi, 1931: 240-241; Harper, 1932: 31; Sutton and
Hamilton, 1932: 33, 35, 36, 81, 82, 84, 85; Ingstad, 1933:
157-159, 165-166, 207, 302-304, 306-307; Hornby, 1934: 106, 108;
Freuchen, 1935: 93, 120-122; Murie, 1939: 245; Clarke, 1940:
107-109; Manning, 1942: 29, and 1943a: 55; Downes, 1943: 262;
Young, 1944: 236-238, 243; Yule, 1948: 288; Harper, 1949:
230-231, 239; Banfield, 1951a: 37-41; Anonymous, 1952: 263-265.
_Relations to birds of prey_
These relations are not so much of the living Caribou as of their bodies
after death. The principal avian scavengers in the Windy River area seem
to be the Rough-legged Hawk (_Buteo lagopus sancti-johannis_), the
Herring Gull (_Larus argentatus smithsonianus_), the Canada Jay
(_Perisoreus canadensis canadensis_), and the Raven (_Corvus corax
principalis_). These birds are evidently attracted to the vicinity of
camps and trap-lines by reason of the numbers of caribou bodies lying
about. On their first arrival in late May or early June, before the
lakes have opened up and while food in general is scarce, Herring Gulls
seem particularly prone to assemble where Caribou have been recently
killed. For example, up to June 3 only a handful of these birds had been
seen about Windy River. On that day several Caribou were killed, and on
June 4 about 100 Herring Gulls had gathered at the scene. Their
scavenger activities make it especially necessary to protect the caribou
bodies in the way described in the section on _Relations to man_. In a
few days one of the bodies (apparently not so protected) had been almost
entirely consumed. The Herring Gulls operate locally only from May to
September, being absent during the rest of the year. A few Ring-billed
Gulls (_Larus delawarensis_) appeared meanwhile and attacked a caribou
carcass.
The Rough-legged Hawk is far less numerous than the Herring Gull and so
is a much less serious scavenger. Now and then, however, it may be noted
feeding on a caribou carcass. Even the Long-tailed Jaeger (_Stercorarius
longicaudus_) is reported in such a role. The Canada Jay and the Raven
are permanent residents and are undoubtedly helped through the
inhospitable winter by man-killed Caribou. On the other hand, a good
many Ravens fall victims to the fox traps placed about the bodies.
Charles Schweder has frequently seen Ravens following Wolves, as if in
expectation of a kill. Buchanan remarks (1920: 248) concerning the
Reindeer Lake region, that the Ravens "appear to remain in the vicinity
of the Caribou herds all th[r]ough winter." In the Windy River area the
Canada Jay became noticeably more numerous in August, after the Caribou
had returned from the north. The Ravens and the Rough-legs exhibited a
similar increase in September and October.
The depredations of these carnivorous birds result to the detriment of
the living Caribou in that they virtually force the hunters and trappers
to kill a larger number of the animals than would otherwise be
necessary.
_References._--Hanbury, 1904: 135; Stefánsson, 1913a: 93;
Seton, 1929, +3+: 108; Ingstad, 1933: 157-159; Downes, 1943:
228; Banfield, 1951a: 36, 42; Harper, 1953: 28, 60, 62-64, 72,
74, 76.
_Relations to miscellaneous animals_
The Schweder boys spoke of Arctic Hares (_Lepus arcticus andersoni_)
being in the habit of eating the stomach contents of Caribou after the
animals have been dressed in the field. This represents merely harmless
utilization of a normally waste product, although it serves some of the
natives as _nerrooks_ or "Eskimo salad" (_cf._ Richardson, 1829: 245).
Wolverines, Mink, Weasels, and Lemmings help to consume unprotected
caribou bodies. (In the Old World the Wolverine is regarded as a serious
enemy of live Reindeer [Jacobi, 1931: 243; Harper, 1945: 473].)
_References._--Pike, 1917 (1892): 56-58; Seton, 1911: 252, 1929,
+2+: 413, 424, 443, and 1929, +3+: 108; Harper, 1932: 23;
Ingstad, 1933: 157-159; Freuchen, 1935: 93, 99; Hoffman, 1949:
12; Banfield, 1951a: 36, 41; Harper, 1953: 40, 41.
_Relations to flies_
Flies of various kinds perhaps cause more wide-spread, year-round misery
to the Caribou than all other pests and enemies combined. It is safe to
say that not a single individual in the whole population escapes their
attacks, and some even succumb to mosquitoes (Gavin, 1945: 228). The
various biting and parasitic flies have already been discussed to some
extent in the section on _Influence of insects on distribution_.
Harassment by these pests is believed to be the leading cause of the
haste with which the Caribou are frequently seen passing over the
Barrens in summer. Downes (1943: 204) has commented on the habit of
Chipewyan hunters in the Nueltin Lake region of examining the legs of
Caribou for swellings caused by mosquito bites. In a buck secured on
August 17 the legs exhibited numerous little bumps of this sort;
furthermore, black flies covered the buck's body, while scarcely
troubling those of us who were preparing the specimen. Fortunately the
suffering from mosquitoes and black flies on the Barrens is largely
limited to the months of July and August.
Even at this season the Caribou are granted occasional relief from the
blood-sucking flies. The characteristic strong winds of that region help
greatly in keeping the insects in abeyance. Furthermore, both mosquitoes
and black flies become more or less inactive whenever the temperature
drops to the neighborhood of 45° (_cf._ Weber, 1950: 196), and this
happens fairly frequently even in mid-summer. Finally, the black flies
retire during the hours of darkness; and short as these hours are, the
relief they bring is very noteworthy. These conditions offer something
of a contrast to those surrounding the Woodland Caribou. It is difficult
to see how that animal can secure a moment's respite from mosquito
attacks, by day or night, through most of the summer. In its forested
habitat there is not sufficient lowering of the temperature nor
sufficient penetration of strong winds. Hard as the life of the Barren
Ground Caribou may be, it seems to have a few advantages not available
to the Woodland Caribou; and possibly it is these that have enabled it
to attain a vastly greater population than the other species.
Of 52 mosquito specimens brought back from the Windy River area, 39 were
_Aedes nearcticus_ Dyar, 2 were probably _Aedes fitchii_ (F. and Y.),
and the remaining 11 were of the same genus but not in condition for
specific determination (_cf._ Dyar, 1919; Weber, 1950: 196). _Ae.
nearcticus_ is holarctic in distribution; in North America it occurs
chiefly on the Barren Grounds, but is known from as far south as
Montana. _Ae. fitchii_ ranges through the northern United States and
Canada, north to the limit of trees. Of 26 black flies, all were
_Simulium venustum_ Say, which occurs in northern Europe, Alaska, and
Labrador, south to the Adirondacks, Illinois, Iowa, Georgia, and
Alabama. (Names and ranges supplied by Dr. Alan Stone, of the United
States Bureau of Entomology and Plant Quarantine.) These mosquitoes and
black flies were presumably the species attacking the Caribou in the
Nueltin Lake region.
The effects of the two parasitic flies are felt nearly throughout the
year. The adult warble fly (_Oedemagena tarandi_) is seen in the Windy
River area in August, when the Caribou are on their southward march. On
August 22 Fred Schweder, Jr., secured three of them on freshly killed
Caribou and another that alighted on himself--all on an island in Windy
Bay. His name for them is "deer fly." He reported seeing about 50 of
them on this day (more than ever before), although he sighted only 10
Caribou. As he remarked, these fuzzy flies look much like bumblebees.
Three days later, along Little River, something buzzed past me while a
band of Caribou were near. It was probably this species, although it
suggested a hummingbird almost as much as a bumblebee. On several
subsequent August days, while numbers of Caribou were passing very close
to me, I detected no more of the warble flies. In general, they might
well have escaped my notice owing to my preoccupation with photography;
but on August 30, when I looked for them on one of the nearest animals,
I saw none. Evidently they are not sufficiently numerous (like
horse-flies on cattle) to be constantly in attendance on each Caribou.
In fact, a comparative scarcity (or at least difficulty of capture) may
be surmised from the fact that the Canadian Arctic Expedition 1913-18
brought back only three adult females--one from Teller, Alaska, and two
from Bernard Harbour, Dolphin and Union Strait (Malloch, 1919: 55).
Weber (1950) collected no Oestridae in Arctic Alaska.
Apparently there has been scarcely any published study of the egg-laying
or other habits of the adult _Oedemagena_ in relation to _Rangifer
arcticus arcticus_, other than a few recent notes by Banfield (1951a:
31-32, fig. 17); but its behavior in relation to the Lapland Reindeer
seems to be fairly well known, and it is summarized by Jacobi (1931:
245-246). In the case of the Reindeer, the fly's eggs are laid (during
the summer) generally on the legs, belly, and tail region of the victim;
the larvae, on hatching, bore through the skin, travel widely through
the body, and finally (in the autumn) reach the place for further
development--beneath the skin of the back on both sides of the vertebral
column. Each one makes a breathing-hole through the skin, and uses this
as an exit when leaving the host in the following June. Only the younger
animals, from one to about four or five years old, are heavily infested;
those still older are spared, possibly having learned to guard
themselves better against the fly. Curiously enough, the fawns are said
to escape this parasitism entirely.
My own observations on the larvae were restricted to a few Caribou
specimens in June and in the autumn. As with the Reindeer, the Caribou
fawns in their first autumn showed no visible infestation, as I noted in
looking over some fresh hides on September 10, and as was noted again in
a fawn of September 26. Fred Schweder, Jr., made the remark that larvae
would be evident in the fawns by the following spring; this may indicate
that the larvae have not, in the autumn, completed their journey to
their final position on the Caribou's back. I learned of no immunity on
the part of old adults.
Fullgrown larvae still remained in bucks secured on June 3 (fig. 17) and
18. According to Charles Schweder, they drop out in June. In the buck of
June 3 there were perhaps several dozen warbles, each surrounded by a
mass of repulsive tissue; in another buck of June 18, there were
apparently more than 75. "It may be assumed," says Johansen (1921: 24),
"that the pupae lie on the ground for about a month before the flies
appear." He found (1921: 29) the adult flies abroad at Dolphin and Union
Strait by July 14.
In a buck of August 17 the new warbles (or perhaps merely warble scars
from the previous June--_cf._ Banfield, 1951a: 32) on the inside of
the skin were not very numerous. Some were medium-sized, but most were
so small that it was not deemed necessary to scrape them off; they had
comparatively little fatty tissue about them and were merely allowed to
dry up. The number of warbles (or warble scars) found in autumn
specimens varied considerably, up to a maximum of roughly 200. They were
situated mostly along the mid-dorsum, and more on the lower back or rump
than farther forward. The number appeared to be approximately 130 in the
skin of an adult doe that was nailed to the log wall of a cabin for
drying on September 15 (fig. 18). A doe of September 21 seemed to have
less than the usual number of warbles.
The nostril fly (_Cephenemyia_) is another serious dipterous parasite of
the Caribou. The life history of the European _C. nasalis_ (L.) (or
_C. trompe_ [L.]) and its effect on Reindeer are discussed by Bergman
(1917), Natvig (1918), and Jacobi (1931: 245) as follows.
This fly attacks the host from June to September, depositing its
viviparous larvae in the nostrils. The Reindeer attempts to fend off the
fly, striking at it with its hoofs and keeping its nostrils closed as
far as possible. Once deposited, the lively larvae crawl into the inner
nasal passages and as far as the larynx, where they fasten themselves
and live on the mucus. A Reindeer may harbor as many as 130 of these
parasites. They range from 6 to 26 mm. in length. Their particular
growth begins at the end of March, and they are ready for pupation up to
May. The host assists their exit by continual sneezing and snuffling. In
the last stages they are a great affliction for the host, and they
sometimes cause its death. Pupation takes place in or on the ground,
under some sort of cover, and it lasts for 15-19 days. The flies have
been found emerging from July 12 to 31.
The corresponding parasite of the Barren Ground Caribou is a similar or
perhaps identical species, with a parallel life history. Its chief
activity as an adult doubtless occurs in July and August. A number of
the mature larvae were found in the throat of the buck of June 3; two of
them that were preserved measure approximately 7 mm. in diameter and 27
and 30 mm. in length. A large mass of such sizable parasites in the
throat might easily become a serious obstacle to comfortable living or
even to survival on the part of the host. Presumably the larvae drop to
the ground at about the same period as those of _Oedemagena_. Fred
Schweder, Jr., remarked concerning the buck of August 17 that these
larvae are never found at that season, and Charles Schweder made the
same remark concerning a doe specimen of September 21. It would appear
either that they remain so small as to escape detection at this time or
that they do not reach the throat on their short journey from the
nostrils until some later period of the year. Johansen (1921: 24)
records larvae only 2-3 mm. long in the nasal passage at the end of May.
Since the bulk of the Caribou population has passed well to the
northward of the Nueltin Lake region by the time the larvae of
_Oedemagena_ and _Cephenemyia_ drop out of the bodies of their hosts to
pupate briefly on or in the ground (say in the latter part of June), one
is tempted to speculate on the possibility that the adult flies found
here in August may have followed their prospective victims for many
miles in their southward migration. However, Porsild remarks (1943: 386)
that they "apparently do not travel very far."
Certain kinds of behavior exhibited by the Caribou in attempting to fend
off the parasitic flies are discussed in the section on _Shaking off
moisture and insects_.
The adults of _Oedemagena tarandi_ (L.) were determined by Mr. C. W.
Sabrosky, of the Bureau of Entomology and Plant Quarantine; and the
larvae of _Oedemagena_ and _Cephenemyia_ by Dr. W. W. Wirth, of the same
bureau. The larvae of the latter genus are regarded as probably _C.
trompe_ (L.); they were new to the collection of the United States
National Museum.