SCENT-MARKING BY COYOTES, CANIS LATRANS - THE INFLUENCE OF SOCIAL ANDECOLOGICAL FACTORS

We observed 49 coyotes, Canis latrans, from five resident packs for 24 56 h and five transient coyotes for 51 h from January 1991 to June 199 3 in the Lamar River Valley, Yellowstone National Park, Wyoming, U.S.A . During these observations we recorded 3042 urinations, 451 defecatio ns, 446 ground scratches and 743 double-marks. The rate of scent-marki ng (via urination) was influenced by the social organization (resident versus transient) to which the coyote belonged, the social class (alp ha, beta or pup) of the animal and the time of the year. Transient coy otes scent-marked at a lower rate than did members of a resident pack. Within the resident packs, alpha coyotes scent-marked at a higher rat e than beta coyotes (adults and yearlings subordinant to alphas, but d ominant over pups) and pups. Alpha coyotes increased their rate of mar king during the breeding season; beta and pup coyotes performed scent- marks at a relatively constant rate throughout the year. There was no influence of social class or time of year on the rate of defecation. T he rate of double-marking was highest among alpha coyotes with a peak during the breeding season. Alpha coyotes ground-scratched at a higher rate than did beta and pup coyotes. Alpha and beta coyotes scent-mark ed more than expected along the periphery of the territory compared to the interior; pups marked in the interior and edge in proportion to e xpected frequencies. Double-marking and ground-scratching were higher than expected along the periphery of the territory. The distribution o f defecations was not different from expected along the edge Versus th e interior of the territory. Pack size did not influence the rate of s cent-marking performed by individuals in the pack or by the alpha pair . We concluded that alpha coyotes were the primary members of the resi dent pack involved in scent-marking. The large coyote packs and the hi gh rate of marking by the alpha pairs were parallel to the scent-marki ng behaviour displayed by wolves, C. lupus, to a greater extent than p reviously reported. Scent-marks appear to provide internal information to the members of the resident pack (internal map of territory, breed ing condition, reproductive synchrony) and enhance demarcation of terr itorial boundaries. (C) 1997 The Association for the Study of Animal B ehaviour.