Determining the potential for geographic range expansion of pitvipers at northern latitudes in the context of climate change


Hill, Jessica L.

jhill7021@sdsu.edu


Department of Biology

San Diego State University

San Diego, California USA


Grisnik, Matt

Tennessee State University

Department of Agricultural and Environmental Sciences

Nashville, Tennessee USA


Hanscom, Ryan

Department of Biology

San Diego State University

San Diego, California USA


Sukumaran, Jeet

Department of Biology

San Diego State University

San Diego, California USA


Higham, Tim

Department of Evolution, Ecology and Organismal Biology

University of California, Riverside

Riverside, California USA


Clark, Rulon W.

Department of Biology

San Diego State University

San Diego, California USA


Ecological niche modeling (ENM) is being increasingly used on a variety of taxa to predict both the current and future range of species under climate change conditions. Ecological niche modeling is a framework that predicts where viable habitat will be located using a combination of geographical presence points, environmental variables, and absence or background points. The ENMs we are currently working on are of Prairie Rattlesnakes (Crotalus viridis) and Ord’s Kangaroo Rat (Dipodomys ordii). These two species represent a predator-prey system, and they are co-distributed across the great plains of North America. This system is of particular interest in the face of climate change because rattlesnakes are ectothermic whereas kangaroo rats are endothermic. This mismatch leads to the prediction that changing temperatures will have a greater impact on the performance of ectothermic Prairie Rattlesnakes than endothermic kangaroo rats. Due to this asymmetry in the biotic interaction, we anticipate differences in the environmental predictor variables that best model their niches and in whether their geographic distribution expands or contracts. The models we will show in this talk represent a preliminary model of the niche of prairie rattlesnakes as well as a possible demonstration of how their range may shift in the face of different climate change scenarios. Additionally, these models are contextualized by being part of a broader study of this system using data collected in the field across a natural thermal cline. Data collected at our sites will allow us to compare the home ranges and activity patterns of these two species at different temperatures. By pairing these natural data with the predictive ecological niche models, we aim to create a clearer picture of how climate change may impact the predator-prey relationship and overall dynamics of prairie ecosystems.