Habitat associations of desert bighorn sheep in Sonora, Mexico

Abstract

Desert bighorn (Ovis canadensis mexicana) have declined throughout Mexico, necessitating actions to inform habitat management and guide population restorations. We used a generalized resource-area-dependence analysis and univariate modeling of home range sizes to identify habitat quality for, and distribution v. availability (i.e., “habitat use”) analyses to further identify habitat associations of, 37 satellite/GPS collared adult desert bighorn in Sonora, Mexico. We found that sarcocaul shrubland and greater terrain ruggedness were most associated with desert bighorn home ranges. Sarcocaul shrubland was the only vegetation type related to home range size (i.e., habitat quality) of desert bighorn (adult females), and was also the only vegetation type significantly overrepresented in home ranges of both sexes. Similarly, greater terrain ruggedness was consistently associated with both sexes. Our results reflected availability of preferred foods and greater security for desert bighorn in Sonora. Our individual-based, telemetry-based data provide a rigorous basis for evaluating habitat potential and planning population restorations of bighorn in Mexico, and provide a quantitative guide for conservation of desert bighorn habitat and populations in Sonora and throughout arid Mexico.