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 efforts, behavior of individual coyotes in sheep-ranching environments is becoming a more important consideration. We radiotracked 14 coyotes on a year-round 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 natal territories but generally avoided cores of nonnatal territories. Breeding coyotes whose territories contained sheep were the principal predators of sheep. In the 1994 lambing period (1 Jan-31 May), radiotelemetry indicated that 1 breeding male was responsible for 71% of 65 kills. In the 1995 lambing period, 4 breeding pairs were strongly implicated in 92% of 48 kills and were suspected of 85% of 26 additional kills; nonbreeders were not associated 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 depredation. 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.