White-tailed Deer Population Dynamics and Fawn Survival in Cook County Forest Preserves

White-tailed deer respond well to urbanization, and often become locally overabundant. At times, their numbers can cause ecological degradation to natural habitats and present a threat to human safety through collisions with vehicles.

To manage deer populations, many agencies use mathematical models to make management decisions for local deer populations, but one critical component of those models — fawn survival — is often unknown. With the rise of coyotes within the Chicago region, it is possible that coyote predation may affect deer recruitment in urban preserves.

We began monitoring fawns and adult deer in Cook County forest preserves in 2013 as part of a long-term project to estimate survival of fawns and identify the primary causes of mortality.

Photo by Alex Garcia

Photo by Alex Garcia