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Fauna Series No. 4






Population and Mortality







Other Larger Mammals

Small Mammals


Misc. Diet



Fauna of the National Parks — No. 4
Ecology of the Coyote in the Yellowstone
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Grass.—Eighty-eight droppings contained grass, usually consisting of broad blades, some of which appeared to be a coarse sedge. Many droppings consisted entirely of grass, while others contained lesser amounts. It makes up a definite part of the regular diet.

Pine nuts.—The nuts of Rocky Mountain white pine (Pinus albicaulis) and limber pine (P. flexilis) were found in 51 droppings. Often almost the entire dropping was composed of pine nuts. Most of these were, no doubt, eaten in winter, even though the droppings containing them were gathered in early spring and summer. However, two fresh droppings containing pine nuts were found in early spring. O. J. Murie (1935, p. 22) writes: "Herb Whiteman, successful trapper in northern Jackson Hole, stated that in winter he has seen coyotes far back in the mountains digging down through rather deep snow for these nuts."

Fruit.—Berries are not abundant in Yellowstone National Park, which accounts for the scarcity of this item in the diet. Where fruit is available, it is often eaten in large quantities. Some of the droppings contained large amounts of rose seed, and a few taken close to an apple orchard near the Game Ranch consisted almost entirely of apples. In 1938, 16 of one batch of about 100 droppings collected in Pelican Meadows contained strawberries. A number of fruits, such as serviceberry, mountain ash, and sarsaparilla, are much relished by coyotes in other areas.

Mushrooms.—Remnants were found in four droppings. This item disintegrates considerably during digestion so that its presence is probably often not recognized.

Dandelion roots.—On November 18, 1938, a coyote was seen in a plowed field near the Buffalo Ranch, feeding off the ground in various places and vigorously chewing the material it was eating. I examined the spot and found that it had been feeding on the fleshy roots of six or seven dandelions turned up and exposed by the plow.


Forty-eight droppings, found mainly near the Buffalo Ranch in the spring of 1937, contained nearly 100 percent horse manure. I believe most of it had been eaten during the winter. Food was scarce so that the coyotes in this region probably ate more of this material than ordinarily. O. J. Murie kept a tame coyote in Jackson, which, even when well fed, would often consume horse manure, so that apparently this material may be eaten by choice even when other foods are available.

Many analyses showed that coyotes had frequented garbage piles and camp grounds to feed on refuse. Even in midsummer when food is plentiful I have noted that the animals had eaten large rags and canvas gloves and, at a time when carrion was plentiful, part of the leather of a cast-off boot. This indicates that the presence of items of little or no food value do not necessarily indicate that the animal is starving. The botfly larvae found in seven droppings were probably attached to ingested mice or gophers.

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

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