Preliminary analysis of habitat use of sympatric rattlesnakes in West Texas

• In Event: Terrestrial Ecology & Management Oral Session 2 & Section Meeting

Abstract

Western diamondback rattlesnakes (Crotalus atrox), Mojave rattlesnakes (Crotalus scutulatus), and prairie rattlesnakes (Crotalus viridis) are common in the southwestern United States and it is often hard to distinguish one from another where they occur sympatrically. Similar, and sometimes ambiguous, morphological characteristics are commonly used to identify these species, such as differences in tail banding and number of intersupraocular scales. Crotalus atrox x and C. scutulatus have hybridized in captivity but rarely in the wild. Evidence for hybridization is limited for C. atrox and C. scutulatus in Arizona, New Mexico, and Texas. A narrow hybrid zone was distinguished in Hildalgo County, southwestern New Mexico of C. scutulatus x C. viridis. Crotalus atrox also occurs in this hybrid zone, but previous genetic analysis provided no evidence of hybridization with the other two species. Hybridization of rattlesnakes has not been analyzed in west Texas since the 1970s. This study serves to confirm the lack of hybridization between the three species using modern molecular techniques, and to analyze habitat use. It is predicted that lack of hybridization is due to differences in habitat preferences among the species which decreases interactions.

Authors

• Jaimie Michelle Lawhorn, Sul Ross State University

• Sean Graham, Sul Ross State University