Proceedings of the Vertebrate Pest Conference

Locally overabundant deer herds, particularly those inhabiting fenced or other enclosed areas in urban or suburban settings, are presenting serious problems for wildlife managers, landowners, and the general public. Traditional methods of population control, such as regulated harvest by licensed hunters, often are impractical or illegal in such settings. The development of safe and effective wildlife contraceptives is needed to control locally overabundant populations in situations where traditional management tools cannot be employed. During July 2004, we initiated a field study of GonaCon™ Immunocontraceptive Vaccine, developed by research scientists at the National Wildlife Research Center in Fort Collins, Colorado. This vaccine had previously been tested successfully as a contraceptive in captive animals including white-tailed deer, feral and domestic swine, and wild horses. The two-year field study was prompted by the need to manage an enclosed, overabundant population of white-tailed deer that had caused considerable ecological damage to a 662-acre, federally-owned, forested site in Silver Spring, Maryland. The U.S. General Services Administration, which manages the property, conducted an environmental assessment, which concluded that sharpshooting followed by immunocontraception would be the most appropriate deer management strategy. After 214 deer were removed from the site by sharpshooters, we set up and tested an automated radio telemetry system for tracking deer and monitoring their mortality. Twenty-eight does were then captured, equipped with ear tags and radio telemetry collars, and injected with GonaCon™ vaccine. Fifteen additional does were captured, marked, and released without vaccination as untreated control animals. Reproductive behavior and fawn production by the vaccinated and unvaccinated does will be monitored and compared for two years, and will be used to determine the efficacy of GonaCon™ as a wildlife contraceptive agent. Data from this study will be used to support EPA registration of GonaCon™ as a wildlife contraceptive agent.