Factors Influencing Survival of White-tailed Deer Fawns in Coastal South Carolina

Abstract

Abstract The social and environmental pressures exerted on white-tailed deer Odocoileus virginianus in the southeastern United States are dynamic. Understanding factors that contribute to neonatal white-tailed deer mortality is vital to population management. To determine survival rates and causes of mortality, we captured and radio-monitored neonate white-tailed deer in the coastal plain of South Carolina. Using date of birth, mass, sex, age, and year as predictor variables, we created a candidate set of survival models to evaluate which factors influenced daily survival rates. We captured and monitored 210 fawns and recorded 68 total mortalities (32.3%). We recorded few mortalities in 2006 (n  =  5; 12.8%) and 2007 (n  =  5; 12.5%), but we observed a significant increase in mortality in 2008 (n  =  18; 37.5%), 2009 (n  =  28; 53.8%), and 2010 (n  =  12; 38.7%). Predation accounted for the majority of mortalities (n  =  29; 42.6%). We found that male fawns were more than twice as likely to survive as females, and older fawns were more likely to succumb to predation than younger fawns. Overall survival in our study was higher than estimates recently reported in the southeastern United States. Recent increases in coyote predation have been cause for concern in some parts of the Southeast, but our results indicate that although it appeared coyote predation increased over the course of our study, predation did not reach levels that have been reported elsewhere, possibly due to predator-control activities on our study site. Close monitoring of the deer population at Brosnan Forest allowed managers to adequately adjust harvest prescriptions to maintain deer populations at the desired level despite an apparent decline in fawn survival.