Fauna Series No. 4

Fauna of the National Parks — No. 4 Ecology of the Coyote in the Yellowstone

CHAPTER XI:
BIRDS IN RELATION TO COYOTES

OTHER BIRD REMAINS

Remains which could be classified only as "bird" were found in 62 droppings. These included 55 "small birds," 18 "large birds," 5 immature sparrows, 1 sparrow, 2 Steller's (black-headed) jays, 2 warblers, 1 spotted sandpiper, 1 short-eared owl, 2 grebes, 10 large bird eggs, 7 small bird eggs, 3 domestic chickens (refuse), and 13 chicken egg shells (refuse). The domestic chicken and chicken egg shell were secured from garbage.

The jay was probably captured at a carcass. The grebe, eaten in the fall, probably was carrion since these birds would not otherwise be available to coyotes. At that time, otters in Yellowstone Lake were feeding considerably on grebes which they no doubt can capture in the water. The coyote may possibly have eaten a grebe killed by an otter.

Potential bird carrion aside from duck remains was represented by carcasses of two robins, one hermit thrush, and a magpie, whose carcasses were found intact, and an adult marsh hawk unable to fly. On September 22, 1938, a long-billed dowitcher was picked up at Yellowstone Lake with a wounded wing. Feather remains of two red-tailed hawks, one short-eared owl, one meadow lark, one bluebird, one magpie, and one Steller's jay, were noted, besides those of ducks, grouse, and other kinds mentioned elsewhere.

There is always some question as to how near a coyote must approach a bird on a nest before it scents the nest. On two occasions I found unmolested nests of the white-crowned sparrow about a foot above the ground in the brush bordering the trail over which coyotes were traveling regularly. On June 14 I found the nest of a spotted sandpiper 15 feet from the Lamar River. The bird tried to entice me away by acting wounded. Seven feet from the nest were fresh tracks of a coyote which had passed without noticing it. Four nests with eggs and two pairs with young were noted in June 1937. All of these were found along the streams much frequented by coyotes. The spotted sandpiper is common in the park.

On several occasions, coyotes were observed jumping after bluebirds and sparrows, but this apparently was done mainly in play. At times they may be successful in catching the birds.

At carrion it seems that the magpies would be vulnerable to coyote attack, for frequently upward of a dozen magpies were seen hopping over a dead elk or deer on which coyotes were feeding, completely ignored by the latter. Some have been seen feeding less than 2 feet away from the coyote's head. At times the coyotes chase the birds, but it seems this is done mainly to drive them away and not to catch them. There seems to be a sort of instinctive neutrality between coyotes and magpies (also magpies and hawks) at carrion. However, the magpies are always alert at a carcass and ready to avoid being seized. The coyote may have found by experience that it does not pay to try to catch these birds.

O. J. Murie (1935, p. 19) found that coyotes had frequently visited the base of a high cliff on which a colony of cliff swallows were nesting. On July 22, 1937, in Hayden Valley a young dead cliff swallow was found beneath a cluster of their nests.

The number of all bird items including ducks, geese, and grouse, and the egg remains, occurring in 5,086 scats is 273 or about 5 percent. Birds are usually taken accidentally.

Last Modified: Thurs, Dec 20 2001 10:00:00 pm PDT
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