Mary and I watched this coyote feed on a winter-killed bison - the remains left by the Lamar Canyon wolves. Wolf scent must have been everywhere. Every 15 seconds or so the coyote would lift his head from eating and look around. When he finally walked away from the carcass, he stopped often to scan. Vigilance is the key to a coyote's survival.
In Yellowstone, a fully protected, intact, natural ecosystem, free from human hunters, coyotes live in packs with up to seven members. Like a wolf pack, each has an alpha male, alpha female, and pups from previous litters. Old timers here tell me that before wolves were reintroduced, they saw coyotes travel and hunt in such packs. But they say that since the return of wolves, coyotes travel in singles and pair, like the coyote we watched. Keeping a low profile makes sense: forty percent of the deaths of adult coyotes come at the teeth of wolves.
But at night when packs reunite, I've heard howling from large choruses filled with many beautiful voices. That howling thrills me and explains why the coyote is called "song dog."