MtDNA Analysis of Sexual Dispersal Among Glacier National Park Grizzly Bears (Ursus arctos)

Abstract

This study compared 369 base pairs of the hypervariable control region of mitochondrial DNA in 137 brown bears (71 males, 66 females) of Glacier National Park to investigate dispersal patterns between the sexes. Since females establish home ranges close to their birth sites, we hypothesized a stronger phylogeographic pattern among females. Contrary to our expectations, males exhibited stronger phylogeographic patterning with one haplotype in males occurring exclusively in northern regions of the park, while a second occurred exclusively in the south. No phylogeographic patterning was observed among females. Male dispersal patterns could be influenced by gene flow from regions contiguous to the park. All brown bear haplotypes in Glacier National Park belong to clade IV of earlier studies and suggest a recent establishment of brown bears in this region.