A time-series analysis of winter shelter ingress and egress in Western Diamondback Rattlesnakes (Crotalus atrox), Suizo Mountains, Arizona

Karl, Kaitlin M

Department of Evolution, Ecology, and Behavior

School of Integrative Biology

University of Illinois Urbana-Champaign

Champaign, Illinois USA

Collaborative Conservation Genomics Laboratory

Illinois Natural History Survey

University of Illinois Urbana-Champaign

Champaign, Illinois USA

Martinez, Amanda

Department of Evolution, Ecology, and Behavior

School of Integrative Biology

University of Illinois Urbana-Champaign

Champaign, Illinois USA

Collaborative Conservation Genomics Laboratory

Illinois Natural History Survey

University of Illinois Urbana-Champaign

Champaign, Illinois USA

Davis, Mark A.

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 85719, USA

Schuett, Gordon W.

Department of Biology | Neuroscience Institute

Georgia State University

Atlanta, Georgia USA

Chiricahua Desert Museum, Rodeo, New Mexico USA

Long-term studies of individual organisms are critical for understanding movement patterns, behavior, and responses to environmental change. Despite their relevance, longitudinal field studies of long-lived reptiles remain limited, especially in the context of shifting climatic conditions. In this study, we examined the seasonal movements of a population of Western Diamondback Rattlesnakes (Crotalus atrox) in the Suizo Mountains of southern Arizona over a decade (2001–2010). Specifically, we focused on the seasonal timing of ingress and egress (the entry and exit from winter shelters) in relation to climatic variables, including daily temperature and precipitation. By analyzing seasonal ingress and egress dates, in concert with individual body temperature data for the snakes on days of recorded movement, we examined several environmental factors that might influence the timing of seasonal shelter ingress and egress. Preliminary findings indicate sex-based differences in body temperature associated with the type of seasonal movement (egress vs. ingress), suggesting males and females may adopt distinct strategies influenced by reproductive roles, physiological demands, or seasonal activity patterns. Given increasing concerns of climate variability, we also sought to determine whether phenological changes in the timing of ingress and egress were correlated with increasing average temperatures over time. We employed a time-series analysis to assess how trends in the timing of seasonal movements may reflect broader behaviorial and/or physiological responses to changing climatic conditions, thus providing insights into the resilience and adaptive responses of C. atrox in the face of ongoing environmental change.