Survival and Dispersal of White-tailed Deer in an Agricultural Landscape

Abstract

White-tailed deer (Odocoileus virginianus) are a keystone species throughout their range in North America. The recent presence of diseases such as chronic wasting disease and bovine tuberculosis in Midwestern North America dictates the examination of influences of those diseases on deer populations, and survival and dispersal rates are important parameters when modeling potential disease spread. We quantified survival and dispersal rates of 105 deer in agriculturally-dominated east-central Illinois during 2005-2009. We used Program MARK to estimate rates of annual survival, seasonal survival, and dispersal for fawn, yearling, and adult age-classes. Male and female seasonal (winter/spring [16 Dec–14 May], summer [15 May–30 Sep], and fall/winter [1 Oct–15 Dec]) survival ranged from 0.56-0.95 and 0.84-0.96, respectively. Male survival was lower than female survival during the fall/winter season. Dispersal rates for yearling and fawn males and yearling and fawn females were 0.44 ± 0.07 and 0.41 ± 0.07, respectively. The dispersal rate of adult males was 0.46 ± 0.15 and no adult females dispersed. Deer survival appears to be higher than previously reported in the region, with important implications for potential disease spread. Furthermore, the observation of long-distance dispersal (42–96 km) combined with greater estimates of survival may impact current chronic wasting disease modeling efforts.