Survival and Movements of White-Tailed Deer in Suburban Chicago, Illinois

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Management of high-density suburban deer populations requires knowledge of survival and movement to predict population trends. However, natural and human-induced influences on survival and movement of suburban deer are poorly understood. Therefore, we marked 208 (60 bucks, 148 does) white-tailed deer (Odocoileus virginianus) from forest preserves in Chicago, Illinois, USA (1994-1998). Seasonal and annual survivorship was >0.80 for 114 does and 13 bucks. Deer-auto collisions produced the highest mortality rates, 0.10 (95% CI 0.06 to 0.14) and 0.17 (95% CI 0.0 to 0.37). Spring dispersal for does was 7% (3 of 41) for fawns and 6% (5 of 83) for yearlings and adults; and for bucks it was 50% (8 of 16) for fawns and 7% (2 of 30) for yearlings and adults. All dispersals were <9 km, except for I parous doe that moved 33.9 km. Doe home ranges averaged 51 (95% CI 40.5 to 61.5), 26 (95% CI 22.0 to 30.0), and 32 (95% CI 19.6 to 44.4) ha for winter-spring, summer, and fall, respectively. A priori, we developed a set of 10 logistic regression models for suburban doe survival relative to home range size and traffic exposure indices. Using Akaike's Information Criterion (AIC), the best models included covariates reflecting home range size and traffic exposure. Inference across a ≥90% confidence set of survival models indicated substantial spatial heterogeneity in mortality risk for suburban does. High survival and philopatry by suburban deer apparently contribute to their overabundance in metropolitan areas.