Part 10 (1/2)

[Ill.u.s.tration: FIG. 28. Adult male Western Woodland Caribou (_Rangifer caribou sylvestris_) (No. 235361, U.S. Biol. Surveys Coll.). Stony Mountain, about 27 miles S. of Fort McMurray, Alberta, October 22, 1920. (U.S. Fish and Wildlife Service.)]

On October 30 tracks indicated that half a dozen Caribou had swum across Little River near its mouth, breaking through a 10-foot rim of ice on the near side. When a herd of 2,000 or 3,000 crossed Windy River during an October night about 1944, as reported by Charles Schweder, they broke three channels through the thin ice that covered the river.

Once Charles saw a buck cross the 100-yard-wide Nahiline Rapids on Kasmere River, where it drops about 40 feet in a quarter of a mile; yet the animal did not seem to be carried far downstream. When about 10 Caribou (mostly big bucks) crossed the Windy River at our camp on June 24, the last two, I noted, were pointing almost upstream in the 6- to 8-mile-per-hour current.

The usual formation in which a small number of Caribou cross a bay or a quiet stretch of river is a single file, but a larger band is likely to make the pa.s.sage in several simultaneous files. The fawns, in particular, follow as closely as possible behind their mothers.

Although the Caribou are strong and speedy swimmers, the natives are able, in canoe or kayak, to overtake and spear them. In 1947 several fawns were speared in Windy Bay by Anoteelik.

Other notes on swimming may be found in the sections dealing with _Migrations_.

_References._--Back, 1836: 367; Simpson, 1843: 76, 310; Rae, 1850: 27; Richardson, 1852: 290; Schwatka, 1885: 68, 71-72; W. J. McLean, 1901: 6; R. M. Anderson, 1913b: 503; Blanchet, 1925: 34; Birket-Smith, 1929 (1): 109-110; Seton, 1929, +3+: 107; h.o.a.re, 1930: 27, 31; Jacobi, 1931: 216; Clarke, 1940: 88-90; Downes, 1943: 256; Harper, 1949: 227, 229, 230; Banfield, 1951a: 21.

_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 sh.o.r.e 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 circ.u.mstances. 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 pa.s.sing 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 flas.h.i.+ng 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 s.e.xes. 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 flas.h.i.+ng 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 a.s.sumed 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 a.s.sume 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 sh.o.r.e 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 a.n.a.logy 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_