The vulnerability of a species to extinction is driven largely by several factors: its genetic capacity to adapt, its ability to disperse, and the rapidity with which its habitat is fragmented or decomposed. These can be gaged in a study species by evaluating its contemporary molecular diversity and dispersal patterns, the modeling of its environmental niche and the manner by which these match future climate projections. Here we examine genetic diversity in the Arizona Black Rattlesnake (Crotalus cerberus) by evaluating 100 individuals from across its range using 852 bp of mtDNA ATPase 6 & 8. We compiled geospatial data from these and another 302 museum specimens and employed 19 North American bioclimatic variables (i.e. yearly trends, seasonality, and extreme environmental conditions at 2.5’ spatial resolution; WorldClim) to derive an environmental niche model. These data reveal a restricted distribution during the last interglacial, an expansion during the last glacial maximum, a recession post-Pleistocene, and a northwestern shift driven by projected future climate change, with Grand Canyon a barrier to dispersal. The Arizona Black Rattlesnake is a high elevation woodland specialist associated with riparian areas, and its available habitat has been (and will continue to be) compressed by wildfire. Furthermore, its niche conservatism will promote altitudinal rather than latitudinal range shifts. These aspects, coupled with its shallow genetic divergence, will exacerbate the impacts of a changing climate and promote its potential extirpation.
|Original language||English (US)|
|Title of host publication||2014 Joint Meeting of Ichthyologists and Herpetologists, 31 July - 3 August 2014 Chattanooga, Tennessee|
|State||Published - 2014|