NATIONAL PARK SERVICE Fauna of the National Parks of the United States No. 4 Ecology of the Coyote in the Yellowstone

BISON

BUFFALO (Bison bison bison) in the form of carrion furnish a source of food which at times may be highly important to the coyote. In March 1938 a heavy mortality among the buffalo occurred in Pelican Meadows according to a report by Ranger Watson. On March 20 three of the buffalo observed in Pelican Meadows seemed to be within a few hours of death and a number of others showed signs of extreme weakness. Four carcasses, were found, and seven coyotes were seen in the vicinity of one of them. Tracks of a coyote were found at an old calf carcass near Fern Lake cabin. The dead buffalo in Pelican Meadows furnished the coyotes of that region with food for a number of days, and may have been instrumental in carrying through the winter some of these which otherwise might have perished.

On November 4, 1937, in the Horseshoe, remains of a yearling buffalo were found in a treacherous water hole located in a sedge-covered bog. The buffalo had no doubt drowned. Coyotes were feeding on the carcass and a day later a bear had pulled most of it out of the water.

It is unlikely that coyotes kill many buffalo calves. Some kills have been reported in the park but the reports which have come to my notice have lacked proof that coyotes killed the animals.

Figure 44— A buffalo became mired in this "bottomless" water hole, in a quaking sedge bog, and was apparently drowned. Coyotes fed on part of the carcass and later a bear pulled out the remainder.
Horseshoe, November 1938.

MOOSE

Remains of moose (Alces americanus shirasi) were found in one dropping. For several years the moose population in the park has been officially estimated at about 700. Moose are present in such numbers that in some of the favorite summering areas the willows have been heavily browsed. In winter the moose generally move to higher ground, away from the willow tracts and borders of lakes and streams. Scattered over the park, so that they are seldom seen in winter, they subsist largely on Douglas fir, and various shrubs available in the particular areas used.

Since moose can travel quite readily in deep snow if it is soft, and since they are primarily browsers, they are not affected by snow to the same extent as are the elk. There is relatively little overlapping of moose and elk range in winter in Yellowstone National Park at the present time for few moose are found on the north side in winter. It may be true, of course, that more moose would be found in this area if it were not so badly over browsed.

Moose furnish coyote food mainly in the form of carrion. Near a deep water hole on Geode Creek, adjacent to another "bottomless" water hole in which several elk bad been drowned, I found the carcass of an old cow moose on May 16, 1938.

It is possible that occasionally a calf is found by a coyote. On June 19, 1937, one was made available to coyotes through an accident. In the morning some fishermen found a calf moose in water so deep that it had to stand to keep its head above the surface. It was thought that the animal had fallen off a steep bank. The mother remained near her offspring, preventing the fishermen from rescuing it. By afternoon, the calf had drowned.

DOMESTIC COW

The five droppings containing domestic cow were gathered near the Game Ranch not far from one of the ranches still within the borders of the park. The source of this food would undoubtedly be carrion. Such has been found to be the case so generally in studies on areas adjacent to Yellowstone National Park that it appears to be a safe conclusion. However, in other parts of the country, young domestic calves have been reported killed by coyotes under certain circumstances.

BLACK BEAR

Remains of bear (Ursus americanus cinnamomum) found in 43 droppings all represented carrion occasionally made available by the shooting of dangerous campground and roadside bears. Most of the droppings were found in the vicinity of areas where dead bears were known to have been left.

Figure 45— The black bear is primarily a vegetarian but takes anything that comes his way.
Occasionally he stumbles on an elk calf.
Tower Falls, June 10, 1938.

COYOTE

Coyotes (Canis lestes) feed readily on coyote carcasses even when other food is available. Remains were found in 13 droppings.

CARCASS FRAGMENTS IN COYOTE DIET

Bone.—Fragments of large bones were found in 47 droppings. These bones may be consumed together with the meat of a carcass, or chewed from a skeleton long after the meat has been removed. Immediately after an elk skeleton has been cleaned of flesh most of the ribs have only the tips chewed. The coyotes continue to visit the bones until often only a short stub of each rib, 2 or 3 inches long, remains. Processes of the vertebrae are also chewed off. Sometimes the ribs are chewed short in 2 or 3 days after feeding on the carcass has begun. Often weathered skeletons several years old are visited by coyotes, who stop to eat a little of the bone in passing. Old weathered bone is often eaten when food is plentiful so is not necessarily resorted to because of hunger.

On November 21, 1937, I followed a coyote's trail near Junction Butte and came to a spot where the coyote had chewed off vertebral processes of an old bull elk that had died during the previous winter. On January 13, 1938, a coyote was seen chewing on some gray and weathered vertebrae of a fawn. On January 25, 1938, near Deckers Flat, part of an old elk skeleton had been eaten. On October 1, 1938, near Tower Falls two coyotes were frightened from some bones of an elk that had died the previous winter. The tips of several ribs had been freshly chewed.

Antlers.—On several occasions shed antlers of deer and elk were found which had been chewed by coyotes. Some of these antlers were freshly shed while others had been shed at least a year previously. Deer antlers that had been recently chewed by coyotes were found on January 26 and 30, and February 12, 13, and 16. One antler chewed on February 12 was seen again February 13, and it was noted that during the night coyotes had almost removed one of the tines. On February 16 an old elk antler was found which had been much reduced by coyotes. Deeply grooved tooth marks, probably made by the canines, were left on some of these antlers.

Hoofs.—Bits of hoofs of deer and elk were frequently found in the scats. Several instances were noted in the field in which the coyotes had gnawed on a hoof. On November 22, 1937, while examining a bull elk skeleton from which the flesh had been eaten a day or two previously I noted that one-half of a hoof had been consumed. On January 15 a coyote was seen to stop at some elk remains and chew away part of a hoof, and on January 26 a deer hoof was eaten. On February 10, 1938, part of a hoof of an old ram was eaten although half of the meat of the carcass remained. On February 15 the hoof of a deer fawn was chewed.