Effects of immunocontraception on a suburban population of white-tailed deer Odocoileus virginianus

Abundant populations of white-tailed deer (Odocoileus virginianus) in North America have altered the structure of some forest communities and caused serious conflicts with farmers, gardeners, and motorists, encouraging the search for novel techniques to control populations of deer and other wildlife. We administered the porcine zona pellucida (PZP) immunocontraceptive vaccine to female white-tailed deer living on the 233-ha campus of the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, USA. Although some tested PZP preparations proved more effective than others, the number of fawns produced per female was significantly lower in treated than untreated females. Following the onset of contraceptive treatments, the population declined by an average of 7.9% per year, and population declines were larger following years when a higher proportion of females was treated. High mortality due largely to deer-vehicle collisions and low population fertility associated with high deer densities facilitated the observed population decline.