White-Tailed Deer Group Composition Over Time in Elm Creek Park Reserve and Implications for SARS-CoV-2 Spread
SARS-CoV-2 was discovered in free-ranging white-tailed deer (WTD) populations in 2020. To determine the potential of WTD as reservoirs for SARS-CoV-2, the USDA developed a targeted surveillance network across 7 states, including Minnesota. Within Minnesota, Elm Creek Park Reserve (ECPR) is a study site. Although researchers are currently using Global Positioning Collars and serial testing to quantify the reservoir potential of WTD, additional information regarding the group size and composition would aid transmission modeling efforts. To empirically parameterize group size and composition, we used motion-activated camera-trapping across ECPR over the summer and fall. We then modeled group size with a zero-truncated negative binomial regression model, with sex and temperature as predictor variables. While doe groups had a higher average size than buck groups, no significant association was detected between group size and temperature or sex. Additionally, there were no significant changes in group sizes observed between the summer and fall. These findings suggest that WTD grouping behaviors do not differ dramatically across sex, temperature, or season in ECPR. Future studies could utilize double observer camera setups and artificial intelligence identification methods, which might more accurately quantify WTD group size.