A preliminary evaluation of deer body size trends across Georgia

Odocoileus virginianus (white-tailed deer) are vital elements in ecosystems across Georgia. In addition, given their prevalence, white-tailed deer also provide the opportunity to ask evolutionary questions about the relationship between resource availability and body size distributions. Bergmann’s rule suggests that body size varies with latitude as a result of localized resource availability, yet it remains to be tested with large datasets with robust spatiotemporal resolution. In this study, we use body size data from over 13,000 white-tailed deer harvested from Wildlife Management Areas across Georgia to evaluate spatiotemporal trends in body size. Our analyses indicate a heterogeneous pattern of body size trends across the state. Specifically, we find that older male deer (2.5 years of age) display a significant body size trend across the state with larger deer at higher latitudes. In female deer, this trend is much less pronounced. We also find that male deer body size varied in relation to the timing of the Covid-19 pandemic, indicating that the deer body size varied in relation to hunting pressure across the state. Overall, these data suggest that body size in white-tailed deer potentially adhere to the patterns associated with Bergmann’s rule. In the future, we plan to incorporate similar data from other states across varying latitudes in North America to further evaluate the preliminary trends presented here.