Part 16

Shaking off moisture and insects

The long, dense fur of the Caribou holds so much moisture that when the animal emerges from swimming it endeavors to rid itself of the extra burden and cooling agency. This is effected to a large extent by a vigorous shaking of the body, head, and ears and a switching of the tail. The initial performance, lasting for perhaps a second or two, may be undertaken while the animal's lower extremities are still in the water; and it is likely to be repeated from one to several times as it moves over the shore and ascends the adjacent ridge. The cloud of spray flying off is a sight to behold (fig. 9). The action is very much like that of a dog under similar circumstances. The fur may remain wet for a least 10 or 15 minutes after emergence from the water. In driving rain on September 5, I noticed an individual in a band of 20 Caribou shaking itself and sending the rain drops flying off in spray, just as when one emerges from the water.

The Caribou also go through a very similar but perhaps still more strenuous performance for the obvious purpose of shaking off flies (perhaps primarily the warble flies, Oedemagena). On August 20 a buck passing along a ridge in the Barrens agitated the hide on its body several times with considerable vigor. A young animal (fawn or yearling) thus shook itself on August 28 as it approached the far side of Little River. I got the distinct impression that the hide was shaken horizontally in the case of moisture, but vertically in the case of insects; for the present, however, this is best considered as just an impression, and not a statement of fact. The muscles that agitate the skin of the sides should be particularly well developed through frequent practice with water and flies during the warmer part of the year.

At the mouth of Little River, on August 30, I heard one of the Caribou in a large band "blow its nose," so to speak, with vigor. The sound suggested that produced by a horse in vibrating its nostrils by forcefully expelling air through them. I suspect that the Caribou uses the same means, in an effort to fend off a nostril fly (Cephenemyia) bent on depositing its larvae.

Reference.--Harper, 1949: 230.

Signaling

Apparently the commonest method employed by the Caribou for indicating or communicating suspicion or alarm is erecting the stub of a tail to a vertical position. This brings its white under side into full view, as the silent flashing of a danger signal to other Caribou. However, a solitary animal will exhibit signaling behavior as well as one in a band. The tail remains erect, whether the animal stands to stare uneasily at a suspicious object or flees from it in alarm. The action is common to old and young of both sexes. It is so characteristic of a fleeing animal as to give significance to the expression, "high-tailing it." In normal, unalarmed progress the tail extends backward in a drooping curve (figs. 11, 12).

I was not fortunate enough to detect any flashing of the white throat, as described by Preble (1902: 42).

Another silent signal is a most peculiar sprawling posture of the hind legs, attained by thrusting one of them well out to one side and setting the foot down. The legs are not then symmetrically placed; the one not moved obviously bears most of the weight of the hind quarters. I managed to film this stance in a buck standing on a sky-line on August 24 (cover). On September 9 another buck assumed the posture while looking over our camp from a ridge on the opposite side of Windy River. According to Charles Schweder, this is an expression of suspicion or alarm, designed to communicate the same feeling to other Caribou. When the others notice it, they stop and assume the same pose; it may be observed in does and even fawns. Charles added that the tail is erected at the same time--a very natural accompaniment, though I failed to notice it.

In all the literature on the Barren Ground Caribou, I have found just one reference to this posture, and that a distinctly fragmentary one:

"While [the Caribou are] thus circling around I have often been amused at the manner in which they carry one hind leg. A novice in the hunting field, after having fired a shot in their direction, would think that he had broken one hind leg of each member of the herd." (A. J. Stone, 1900: 53.)

The author makes this observation just after mentioning a herd sighted near the shore of Franklin Bay. A virtually identical posture in the Norway Reindeer has been sketched by Seton (1929, +3+: 112, pl. 18), who labels it "surprize." An analogy to the posture of the Caribou might be found in a hand thrust out, with fingers spread, by a military scout as a signal of warning or caution to his fellow scouts. A sprawling leg is perhaps the nearest approximation to the human signal that a Caribou can attain.

As noted in the section on Gaits, an alarmed Caribou may set off by taking an initial leap into the air. According to Dugmore, such an act on the part of the Newfoundland Caribou plays an important role in its system of communications, not by means of sight or sound, but through the olfactory sense. He observes (1913: 89-90):

"For hours afterwards every Caribou, on arriving at the place where the frightened ones had jumped, has started violently, and has on nearly every occasion turned and run in a manner that showed every indication of fear, even though my presence was entirely unknown to them. My idea is that when the animal is suddenly frightened it expels a certain fluid from the glands in the foot, and that this fluid is a signal of alarm, a silent and invisible warning, but none the less so positive that none dare ignore it."

As for the foot click--a presumptive means of communication (cf. Seton, 1929, +3+: 69; Jacobi, 1931: 212-216)--I must confess that I was always so engrossed with photography whenever the Caribou were close at hand (up to within a dozen feet) that I had no thought of this phenomenon and did not detect it.

References.--Richardson, 1829: 242; A. J. Stone, 1900: 53; Preble, 1902: 42; Seton, 1929, +3+: 105; Murie, 1939: 245; Harper, 1949: 230; Banfield, 1951a: 19, 27.

Food

The ground lichens (including the various species of Cladonia) in the Windy River area in 1947 did not seem, for the most part, to have a height of more than 2 or 3 inches. The average length of several local specimens of Cladonia is approximately 51 mm. This condition was in considerable contrast to the great spongy masses I had noted in the Tazin River basin, between Athabaska and Great Slave lakes, in 1914. I have no means of knowing whether the condition in Keewatin represented severe cropping by Caribou in past years and subsequent slow recovery, or whether it is a normal condition. According to Charles Schweder, the growth depends upon rain, and so varies from year to year. During the warmer months, from June to September, the local Caribou seemed to me to be feeding very largely on the higher vegetation, such as willow, dwarf birch, alder, and sedges. I had no definite evidence of their consuming lichens during that period. By early October the species of Cladonia seemed to have attained a somewhat fuller growth than they had exhibited several months previously. Perez-Llano discusses (1944: 29-30) the utilization by Reindeer of various lichens. Dix has reported (1951) on a collection of lichens from the Windy River area.

Some miscellaneous observations along Windy and Little rivers follow: June 16, 20 Caribou feeding apparently on patches of crowberry (Empetrum) and dwarf birch (Betula glandulosa) on a ridge; June 29, a Caribou feeding apparently on dwarf birches; June 30, a buck grazing in a sedge bog; August 26, several bucks browsing on willow tops (probably Salix planifolia) in a riverside thicket, and some does on dwarf birch and perhaps tall grass or low willow; August 27, numbers feeding largely on willow and dwarf birch; August 28 and 30, low alders, willow, and dwarf birches nibbled off. By early October the leaves of the three last-mentioned shrubs were no longer available, having dropped off. During the summer they had seemed to be preferred above the lichens. Cabot has remarked (1912: 46) on the fondness of Rangifer arcticus caboti for dwarf birch in Labrador.

Charles Schweder reported as follows on the food of Caribou. In summer they live chiefly upon leaves, especially those of dwarf birch, and to some extent upon "grass" (probably largely sedges). Toward the last of June a Caribou was killed with fat an inch thick on its haunches--perhaps the effect of recent feeding on the fresh green vegetation. In August and September the animals also eat mushrooms and get very fat on them; they seem to be especially fond of a certain red kind, which Charles has found in their stomachs. The Eskimos' name for mushrooms signifies "deer food." The Caribou feed upon dead "grass" (perhaps mostly sedges) in the fall, but not in the winter. Charles has seen them digging through 4 feet of snow to get at the reindeer lichens; but for the most part their winter feeding in this region is on the tops of the hills, which remain bare. They also eat tree lichens, especially in the winter time.

Charles has seen Caribou chew the cud while standing as well as while lying down. He once saw a buck thus occupied while standing on a hill for half a day in a breeze that kept the mosquitoes down.

Among the hundreds of Caribou observed at the river crossings and elsewhere, I do not recall seeing a single one pause to drink.

The Influence of food supply on distribution of the Barren Ground Caribou has been discussed in a previous section.

References.--Hearne, 1795: 317; Franklin, 1823: 242; Richardson, "1825": 329, and 1829: 243; Godman, 1831, +2+: 284; Richardson, in Back, 1836: 498, and 1861: 275; Murray, 1858: 202; B. R. Ross, 1861: 439; Kumlien, 1879: 54; J. B. Tyrrell, 1894: 441; Russell, 1898: 226; J. W. Tyrrell, 1908 (1898): 80; Lydekker, 1898: 49; Elliot, 1902: 276; Stone and Cram, 1904: 53; Buchanan, 1920: 105-106, 131; Hewitt, 1921: 61; Blanchet, 1925: 33; Seton, 1929, +3+: 107-108; Kitto, 1930: 87; Jacobi, 1931: 223; Harper, 1932: 30; Sutton and Hamilton, 1932: 84; Weyer, 1932: 39; Hornby, 1934: 105; Murie, 1939: 245; Clarke, 1940: 106-107; G. M. Allen, 1942: 299; Soper, 1942: 143; Downes, 1943: 228; Porsild, 1943: 383; R. M. Anderson, 1948: 15; Manning, 1948: 26-28; Rand, 1948a: 212; Harper, 1949: 230; Banfield, 1951a: 11, 19-20, 28-29; Barnett, 1954: 106.

Scatology

The pellets of the Caribou are small, more or less blackish, very irregular in shape, somewhat compressed, and generally deposited in little piles, in which the individual components do not stand out very distinctly, being pressed against each other. They are quite unlike the oblong, curvilinear, comparatively symmetrical scats of the White-tailed Deer and the Moose. I did not observe, nor learn of, any particular seasonal variation in the shape or other characters.

References.--Sutton and Hamilton, 1932: 81; Manning, 1943a: 50.

Voice