Deer movement and habitat selection in Ontario and the implications for disease transmission

Background/Question/Methods

Understanding the movement patterns of wildlife has implications for understanding zoonotic and potentially zoonotic disease transmission. White-tailed deer (Odocoileus virginianus) are the most abundant ungulate in Ontario, Canada and overlap extensively with the human population. White-tailed deer also are susceptible to several zoonotic or potentially zoonotic diseases including Lyme disease, chronic wasting disease (CWD) and SARS-COV-2. Understanding patterns of transmission of these diseases requires fundamental understanding of the movement and space-use patterns of deer. We aimed to assess these patterns in white-tailed deer, with the original intention of informing potential future outbreaks of CWD, which currently does not exist in deer in Ontario. Because similar, though not identical, transmission patterns are expected for SARS-COV-2, as deer are competent hosts for the novel coronavirus, this project also can inform the current spread of this disease in the deer population. We captured and deployed global positioning system (GPS) radio collars with integrated proximity loggers on >60 deer in the winter of 2022 in a study area in central Ontario. All deer were assayed for both SARS-COV-2 virus and antibodies. We examined fine-scale interactions among, and broad scale movement and space-use patterns of, deer to assess the potential for spread of disease.

Results/Conclusions

Movement data revealed much larger seasonal movements of deer than anticipated. Proximity loggers suggested high individual variability in direct contact among deer, likely related to group membership. Deer space use was highly concentrated around private deer feeding activities and the potential for both direct and indirect transmission of disease is likely extremely high at these sites. These results are suggestive of the potential for rapid transmission of CWD and SARS-COV-2 followed by large-scale spatial spread of disease through seasonal migrations of infected individuals (for CWD primarily). Effective management of disease transmission in this deer population could require aggressive strategies aimed at rapidly reducing the potential for direct and indirect contact among individuals.