Sex differences in ecdysis cycles and shedding sites of adult Western Diamondback Rattlesnakes (Crotalus atrox) from the Suizo Mountains, Arizona

Amanda Martinez

amart230@illinois.edu

Karl, Kaitlan M.                                                                                                                                                  

Davis, Mark A.                                                                                                                                             

Department of Evolution, Ecology, and Behavior                                                                                      

Department of Integrative Biology                                                                                                                 

College of Liberal Arts and Sciences                                                                                                          

University of Illinois Urbana-Champaign                                                                                                  

Champaign, Illinois USA

Collaborative Conservation Genomics Laboratory                                                                                          

Illinois Natural History Survey                                                                                                                  

University of Illinois Urbana-Champaign                                                                                                

Champaign, Illinois USA

Repp, Roger A.                                                                                                                                                 

National Optical Astronomy Observatory                                                                                                       

Tucson, Arizona USA

Schuett, Gordon W.                                                                                                                                     

Department of Biology | Neuroscience Institute                                                                                           

Georgia State University                                                                                                                                

Atlanta, Georgia USA

Chiricahua Desert Museum                                                                                                                                

Rodeo, New Mexico USA

Ecdysis is the cyclic shedding of the epidermis and is a fundamental trait shared by many organisms, including all snakes and other squamates. It involves a synchronized series of cellular events that unfold simultaneously throughout the integument, and in snakes and several other squamate lineages shedding a whole epidermal cast occurs at a single point in time. The frequency and timing of ecdysis within individuals remain largely understudied in wild populations, limiting our understanding of its broader function across life-history contexts. Here, we leverage a long-term radiotelemetry dataset from a population of adult male (n=22) and female (n=28) Western Diamondback Rattlesnakes (Crotalus atrox) from the Suizo Mountains (Arizona) to investigate temporal and spatial patterns of the ecdysis cycle and shedding. The dataset spans 10 years (2001–2010) and includes geo-referenced records of individual shed events. By integrating spatial, physiological, and environmental data, we were able to identify population-level patterns of ecdysis and shedding. Specifically, our results reveal sex-based differences in the timing of the ecdysis cycle and location of shedding events, suggesting differential strategies tied to sex, seasonal activity, and reproduction.