Conservation genetics of black bears in Arizona and northern Mexico

Because American black bears (Ursus americanus) are an important game species in Arizona and are endangered in Mexico, an understanding of the population structure, gene flow, and connectivity are important for effective management. Black bears inhabit coniferous and broadleaf deciduous woodlands in southern Arizona and northern Mexico, usually in sky islands (sky islands are mountains that rise from the desert and are isolated from each other). Because a single sky island is too small to support a viable bear population, black bears move through desert lowlands to reach other sky islands. My objective was to assess genetic structure, connectivity, and conservation implications for sky island black bears in southern Arizona and northern Mexico. I addresses 4 components of bear ecology and genetics: a literature review of genetic information available for black bears in North America; the use of 2 mitochondrial DNA genes (Control Region and ATP synthase protein 8) to study the phylogenetic relationship of black bears from the sky islands of southern Arizona and northern Mexico relative to all North America; the use of 10 microsatellite loci to detect the current genetic structure of black bears in the sky islands in Arizona and northern Mexico; and the use of noninvasive samples collected from the field to determine bear density and population size for black bear in Sierra San Luis, Sonora, Mexico. These studies provide information that can be used by biologists, land managers, and others to assist in the conservation of black bears and their habitat.