Effects of fragmentation on a rattlesnake community in a human-dominated landscape

Collaborator: Roger Repp, Past President Tucson Herpetological Society

Human-induced barriers and alteration of landscape have caused many terrestrial regions to become fragmented. Landscape change and its impact on species diversity and abundance is one of the primary challenges in conservation biology. Predominately sedentary species with specialized habitat requirements appear to be the most vulnerable. These characteristics are especially true for snakes, important top predators of the Sonoran Desert. Owing to the fact that most snake species are elusive and notoriously difficult to study in nature, we selected three non-endangered, comparatively abundant, and easily studied rattlesnake species (Crotalus atrox, C. cerastes, C. scutulatus) as our models. Ongoing studies show that these taxa exhibit different spatial patterns in a sahuaro-cholla dominated desert scrub ecosystem.  This habitat is divided by a four/six lane interstate highway and is further fragmented by new industrial and housing developments on one side of the interstate.

We will use radio-telemetry to study the dispersal and movement patterns of these snakes. To obtain insights into population structure, meta-populations, and gene flow, we will utilize a suite of molecular markers. This approach will allows us to identify historical events that had an impact on population structure and monitor current spatial and temporal population patterns.

This project has a strong educational component and offers a unique experience in the field and in a highly sophisticated molecular laboratory. Undergraduate students and volunteers will be encouraged to participate. University of Arizona students have the possibility to earn independent study credits.