The Population Genetics of Three Crotalus Species in a Sonoran Desert Habitat and the Effects of Anthropogenic Barriers

Abstract

The phylo-geography and population genetics of three Crotalus species in Southern Arizona (C. atrox, C. cerastes, and C. scutulatus) were examined using mitochondrial DNA genes and nuclear microsatellite DNA markers. My focus was twofold: (1) the phylo-geography and population structure in Southern Arizona and (2) possible genetic signatures of population fragmentation by linear barriers on rattlesnakes populations at Picacho Peak. My results show genetic signatures of geneflow restrictions in one species (C. atrox) which coincide with Interstate 10. I did not observe similar genetic effects in C. cerastes or scutulatus, possibly caused by smaller sample sizes and marker numbers. I found limited phylo-geographic and population genetic structure for all three species in Southern Arizona indicating large interconnected populations. This study provides wildlife management with a powerful genetic toolset and provides important baseline data for future assessment and monitoring efforts of important predators and their populations in the Sonoran desert habitat.