Foraging ecology of coyotes (Canis latrans): the influence of extrinsic factors and a dominance hierarchy

Abstract

We examined the influence of intrinsic (age, sex, and social status) and extrinsic (snow depth, snowpack hardness, temperature, available ungulate carcass biomass) factors in relation to time–activity budgets of coyotes (Canis latrans) in Yellowstone National Park, Wyoming. We observed 54 coyotes (49 residents from 5 packs, plus 5 transients) for 2507 h from January 1991 to June 1993. Snow depth, ungulate carcass biomass, and habitat type influenced the amount of time coyotes rested, travelled, hunted small mammals, and fed on carcasses. Coyotes decreased travelling and hunting and increased resting and feeding on carcasses as snow depth and available carcass biomass increased. Age and social status of the coyote influenced activity budgets. During times of deep snow and high carcass biomass, pups fed less on carcasses and hunted small mammals more than alpha and beta coyotes. Pups apparently were restricted by older pack members from feeding on a carcass. Thus, pups adopted a different foraging strategy by spending more time hunting small mammals. Coyotes spent most of their time hunting small mammals in mesic meadows and shrub–meadows, where prey densities were highest. Prey-detection rates and prey-capture rates explained 78 and 84%, respectively, of the variation in the amount of time coyotes spent hunting small mammals in each habitat in each winter. Our findings strongly suggested that resource partitioning, as mediated by defense by older coyotes, occurred among coyote pack members in Yellowstone National Park.