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

INSECTS

GRASSHOPPERS AND CRICKETS: A total of 711 coyote droppings contained grasshoppers, and 123 Mormon crickets. Very often droppings held both forms. These insects are eaten from the time they become available in the summer until November when the cold weather has made them inactive. Many of the droppings were composed of a high percentage of grasshoppers and crickets, very often 100 percent. Even in November fresh droppings had more than 90 percent grasshopper remains. Many contained remains of from 75 to 100 grasshoppers.

On September 25, 1937, I watched three coyotes hunting mice and grasshoppers in the meadows along the Lamar River. Sluggish with cold the insects were not moving. It seemed that the coyotes were finding them by scent. One of the coyotes hunted them for an hour, moving slowly over an area 150 yards across, turning a step or two aside one way or the other to pick up a grasshopper. Each one was given three or four vigorous chews, jaws opening unnecessarily wide, it seemed, for such a tiny morsel. While I watched, an antelope buck came up to me, gave an alarm call, and dashed away, whereupon the coyote near me ran several yards, looking around for danger as he went, but almost immediately turned back to the grasshopper hunting. The latest date on which I watched a coyote hunt grasshoppers was November 6. At this time all grasshoppers were dormant, of course, but the coyote seemed to find many of them.

A coyote I watched hunting grasshoppers at Gibbon Meadows on September 28 had to move quickly to make each catch, for the bright sunshine had brought a return of summer activity to the insects. Sometimes the grasshoppers were caught with the paw, at other times it seemed that they were seized with the jaws. Some were retaken after they had once escaped.

On one occasion 25 grasshoppers were caught in 4 minutes, but others were captured before and after this period.

Grasshoppers and crickets are an important and highly palatable food, or they are eaten in large quantities at times when much other food is available. The lower incidence of crickets in the diet is probably due to more restricted distribution than that of the grasshoppers.

June beetles.—Remains which appeared to be some form of the June beetle were found in 14 droppings. A few of the droppings contained as many as a dozen.

Hibernating flies.—Ranger Gammill told me that he and Ranger Coleman near the Cooke City Ranger Station had observed a coyote track turn to one side and lead over to the bank of a stream. Here they found that the coyote had been eating flies which were hibernating under the bark of a tree branch and on the under side of a rock.

Figure 55— Mormon cricket feeding on rush. These, as well as grasshoppers, are relished by the coyote.
Horseshoe, July 6, 1938.

SNAKES, FISH, AND SNAILS

Snakes are not very abundant in the park, but the remains of garter snakes were found in nine droppings.

Fish remains were found in 12 droppings, in several of which only the bones of the head were present. This would indicate that the coyote had found the spot where a fisherman had cleaned his catch. The fish in the diet is no doubt mainly carrion.

Remains of snail shells were found in four droppings. One summer in Jackson Hole O. J. Murie and I found a concentration of snails in the trail and a few feet away two coyote droppings containing many remains of them. They seem to be relished when they can be found.

VEGETABLE MATTER

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.

OTHER ITEMS

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.