White-tailed deer population dynamics and adult female survival in the presence of a novel predator
Recent localized declines in white-tailed deer (Odocoileus virginianus) populations in the southeastern United States have been linked to increasing predation pressure from coyotes (Canis latrans), a novel predator to the region. Studies have documented coyotes as the leading cause of mortality for neonates, and 1 study documented coyotes as a mortality factor for adult females. However, no study has used field-based vital rates to conduct sensitivity analyses or model deer population trajectories under potential harvest or predator removal strategies. We used low, medium, and high values of fawn survival, adult female survival, and fecundity data collected from Fort Bragg Military Installation, North Carolina to demonstrate the current declining population trajectory for deer (ë = 0.905; low ë = 0.788, high ë = 1.003). Consistent with other studies of ungulates, we determined adult female survival was the most sensitive and elastic vital rate. Further, for 3 potential management (“what if”) scenarios, we projected the population for 10 years using estimated vital rates. Reducing adult female harvest (ë = 0.935; low ë = 0.875, high ë = 1.002) and coyote removal (ë = 0.995; low ë = 0.898, high ë = 1.081) reduced the current population decline, whereas combining both approaches (ë = 1.024; low ë = 0.898, high ë = 1.141) resulted in population increases. Our data indicate that for low-density deer populations with heavy predation pressure on neonates, protecting adult females from harvest may not completely offset population declines. Coyote removal might be a necessary strategy because it could possibly increase very low fawn survival, which appears to be the most important vital rate influencing ë in our study. However, managers may have to start with reductions in adult female harvest because coyote removal would have to be continuous and consistently effective, making it an impractical management approach by itself. © 2015 The Wildlife Society.