Coyote movements and social structure along a cryptic population genetic subdivision

Authors

Benjamin N. Sacks, Wildlife and Ecology Unit, Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California
Brian R. Mitchell, Department of Environmental Science, Policy, and Management, University of California
Christen L. Williams, USDA, Wildlife Services, National Wildlife Research Center
Holly B. Ernest, Department of Population Health and Reproduction, School of Veterinary Medicine, University of California

Date of this Version

January 2005

Abstract

A recent region-wide study determined that the central California coyote ( Canis latrans ) population was genetically subdivided according to habitat bioregions, supporting the hypothesis that coyotes exhibit a dispersal bias toward their natal habitat type. Here, we further investigated this hypothesis using radio-collared coyotes captured on a 150-km 2 study site on the border of (i.e. overlapping) two bioregions (Great Valley and Cascade Mountains). As predicted, most coyotes were assigned (based on a priori genetic criteria) to genetic clusters corresponding to one of these two bioregions. All of those assigned to the Great Valley genetic cluster were caught in (and for the most part, remained in) the Great Valley bioregion. However, contrary to expectations, the coyotes assigned to the Cascades genetic cluster occurred commonly in both bioregions. Nearly all resident individuals on the study site, regardless of the particular bioregion, were assigned to the Cascades genetic cluster, whereas a sizable fraction of nonresident (transient or dispersing) coyotes caught in the Great Valley bioregion were assigned to the Great Valley cluster. Even among resident coyotes, interrelatedness of packs was greater within than between bioregions, and packs with territories overlapping both bioregions were more closely related to those with territories completely within the Cascades bioregion than territories completely within the Great Valley bioregion. Finally, direct estimates indicated that gene flow was twice as high from the Cascades bioregion to the Great Valley bioregion than in the reverse direction. Collectively, these findings reveal the anatomy of the genetic subdivision as beginning abruptly at the bioregion boundary and ending diffusely within the Great Valley bioregion.