Coyotes use dens only for sheltering pups. At 12 weeks of age the pups begin to travel with the adults, and the pack abandons den life. Kazia Hatier, one of Crabtree's graduate students, found that the highest pup mortality occurs from mid June to early August as the pups enter the world beyond the den. Generally, only two pups from an average litter of six survive into adulthood. Much of pup success depends on food availability.
Alphas always eat first.
If nothing is left over, pups and betas may starve. Which suggests that the life of a predator, even in a place like Yellowstone, is not an easy one. Of 6,433 encounters between coyote and prey that Eric Gese, a doctoral student working on the coyote project, has tallied, only 1,545 concluded successfully for the coyote. Nevertheless, Crabtree's research has shown that coyotes as a species annually kill more elk than any other park predator. In the northern range, home to 20,000 elk, coyotes yearly take about 1,350 elk, grizzlies 780 and cougars 612.