Territoriality and breeding status of coyotes relative to sheep predation

Coyote (Canis latrans) depredation is a chronic problem for sheep producers in the western United States. Due to increasingly localized control effort s, behavior of individual coyotes in sheep-ranching environments is becomin g a more important consideration. We radiotracked 14 coyotes on a year-roun d sheep-ranching facility in north-coastal California during September 1993 -December 1995. Breeding coyote pairs used mutually exclusive territories ( maximum overlap between 90% adaptive kernel home ranges = 4%). Nonbreeding coyotes were transient or varied in their degree of fidelity to putative na tal territories but generally avoided cores of nonnatal territories. Breedi ng coyotes whose territories contained sheep were the principal predators o f sheep. In the 1994 lambing period (1 Jan-31 May), radiotelemetry indicate d that 1 breeding male was responsible for 71% of 65 kills. In the 1995 lam bing period, 4 breeding pairs were strongly implicated in 92% of 48 kills a nd were suspected of 85% of 26 additional kills; nonbreeders were not assoc iated with sheep depredation. Depredation was reduced only when territorial breeders known to kill sheep were removed. These results suggest the need for management to target breeding adults in the immediate vicinity of depre dation. Efforts to remove individuals >1 territory-width away from problem sites are unlikely to reduce depredation and may exacerbate the problem by creating vacancies for new breeders that might kill sheep.