Fauna Series No. 4

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

CHAPTER III:
HABITS BEHAVIOR AT CARRION

COYOTE-RAVEN RELATIONSHIPS

IN WINTER, when a considerable part of the diet both of the raven and the coyote consists of carrion, their similar interests draw these two species together. They are interested in each other's actions; the raven watches the coyote and the coyote watches the raven. If one has found a source of food he is sure to be joined sooner or later by the other. The coyote-raven relationship is an example of a loose symbiosis.

At a carcass, the raven, because of its wider view when in the air or on top of a tree, frequently warns the coyote of approaching danger or other intrusions. The coyote is usually occupied tugging at the carcass while the ravens are scattered about, some at the carcass, others soaring or sitting in nearby trees, so it is difficult for anything to escape their notice. The coyote takes their warning and becomes alert, but it may only look around briefly, and, seeing no danger, continue to feed. Some incidents may serve to show how closely ravens and coyotes observe one another when food is involved.

On May 12, 1937, in Pelican Meadows I watched a coyote hunting on a snowdrift. After a short period of intent watching it pounced. This was followed by a little digging in the snow and some more quick pounces. A raven flying overhead turned its course and lit on the snow 10 yards from the coyote. Here it remained patiently waiting for about 5 minutes while the coyote dug some more. The latter then took a few alert steps, only to return again to the same spot. When the coyote wandered off, the raven walked to where the coyote had been digging and gave the spot a thorough investigation.

On the morning of January 15, 1938, I saw a coyote trotting along the base of Mount Everts. on the margin of a wide flat. Near the opposite side of the flat a raven was standing on a snowdrift. When the coyote had trotted to a point opposite the raven and about 200 yards away it turned its course directly toward the raven on the snowdrift. The bird by that time had been joined by a second one which had alighted to feed on a tiny food morsel it had been carrying. When the coyote was somewhat less than 10 yards from the feeding raven it made a quick dash for the bird. The raven easily escaped and lit again a few yards to one side. The coyote sniffed the spot where the raven had been feeding and then made another dash for it. These tactics were continued for some time. It appeared that the coyote chased the raven in order to pick up some fragment of food that might be left behind because of the sudden departure. The coyote made six or seven dashes at the bird before it flew off about 250 yards. After peering at the departed bird, and seeming to hesitate whether or not to follow, the coyote trotted after it. When the coyote had covered half the distance the raven circled back over the coyote, which looked up at it as it wheeled 15 or 20 feet overhead.

The raven lit on the snow again to feed on its food morsel and the coyote trotted along as if to pass it, but suddenly turned to make another quick charge. These rushes, as before, were repeated five or six times. Once the coyote leaped high in the air toward the raven and rolled over twice when it hit the snow. The raven finally flew away along the river and coyote disappeared in a draw. It appeared that both animals were enjoying the fun, for the raven could easily have flown away to escape if it were annoyed, and it would seem that the coyote, which was probably well fed by the abundant carrion, would not have been so persistent unless he were enjoying the play.

In the winter of 1937—38 on the Federal Elk Refuge in Jackson Hole one of the men reported a coyote playing with a mouse. A raven was attending the coyote and would try to get the little creature when the coyote left it out of reach. Before the raven could get the mouse the coyote would retrieve it. This game continued for some time.

At the Mammoth dump on March 29, 1938, a raven and a magpie were perched a few yards from a coyote which was chewing vigorously on some food. The moment the coyote left, both birds and a second magpie flew at once to the spot and quickly picked up the crumbs. The crumbs left by the coyote were no doubt easier to eat than was most of the garbage. The alertness and watchfulness of the birds indicated that feeding on the small morsels left by them was a common practice.

On February 15, 1938, I witnessed an incident which showed that the ravens could be quite vexatious. A short distance above the mouth of Bear Creek several ravens were circling low and lighting on the ground, across the Yellowstone River from me. Through my binoculars I made out two coyotes tugging at a carcass lying on a bench sloping away from the river. About 15 ravens, the number varying because of continuous arrivals and departures, were near the carcass. Some were in the air, some perched in the nearby trees, and some on the ground by the carrion. Magpies, as usual, were also assembled and hopping about barely out of reach of the coyotes. Frequently during the hour that I watched, the coyotes made rushes at the magpies and ravens, not, it seemed, in any attempt to catch the birds, for they never followed through with their attack, but rather to drive them away. For about 20 minutes the coyotes continued feeding. I was on the bank of the river opposite the carrion and from this point it was just out of my view, and so, at times, were the coyotes feeding on it. One of the coyotes seemed small, with a scraggly light-colored coat. He had a lame left front foot which was used lightly and sometimes not at all. This lame member of the group presently started up the slope carrying the front leg and shoulder bone of a fawn deer with most of the hide attached. When he had gone up the slope about 10 yards a large dark coyote followed with a rush, causing him to drop his burden and retreat for a few yards. The dark animal, with back sharply arched, head held low, and lips drawn back from his teeth, returned to the carcass. The lame one cautiously retrieved the deer quarter and moved up into a small grove of Douglas firs. Six or seven ravens followed him as he went, circling a few feet above. In a few minutes the lame coyote emerged from the grove where he had cached the carrion. He looked back up the hill toward the grove where some ravens were lighting in the trees, apparently having some misgivings about the security of his cache. He then carried a second large piece of the meat into the grove and was followed by the dark coyote which was carrying a quarter with most of the meat removed but with much of the hide still clinging loosely. The dark coyote disappeared in the grove, but later crossed an opening higher up the slope, still carrying what remained of the deer quarter. He dropped his load on the snow and stood looking alternately at his burden and at the circling ravens which had been following closely. He was not so naive about making his cache as was the lame one, who did not seem to realize that potentially all the ravens in the region knew the location of his store. The dark one seemed much dismayed. He probed his nose into the snow, picked up the bones, looked up at the ravens, and walked into another grove. The ravens followed, perching on the trees along his route. The coyote moved a long way up the slope to still another grove where he again stood watching the ravens, seeming completely perplexed. When he moved into the woods I left the scene for I had been watching for more than an hour with the temperature about 30° below zero. As I left I caught a glimpse of a third coyote at the carcass. The caching of the remains shows why carcasses at times so quickly disappear.

Figure 7— Coyote and Raven at Play.
Sketched from Life by O. J. Murie

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