Several ongoing studies are investigating the effectiveness of 

 GonaCon to hielp manage overabundant deer populations in 

 urban environments. (NWRC photo by Jim Gionfriddo.) 



NWRC has developed and tested many types 

 of wildlife contraceptives, including GonaCon™ 

 (an immunocontraceptive vaccine), which has 

 been effective in producing safe and reversible 

 infertility in captive white-tailed deer and in 

 other mammalian species, such as bison, wild 

 horses, domestic and feral swine, domestic cats, 

 California ground squirrels, and rats. GonaCon 

 is a one-injection formulation that is much more 

 practical for field delivery to free-ranging wildlife 

 than earlier, two-injection contraceptive agents. 

 NWRC regularly receives inquiries from concerned 

 citizens regarding the possibility of using GonaCon 

 to address local problems with overabundant deer 

 and other species of wildlife. 



Two major field studies of the efficacy of GonaCon as 

 a contraceptive for deer are underway in the United 

 States. The first study was initiated in Silver Spring, 

 MD, during July 2004, on a fully fenced, forested 

 site that is managed by GSA. Overabundant deer 

 were creating numerous conflicts with humans, 

 and WS was asked to resolve the problems. 

 NWRC scientists worked with Maryland-based 

 WS biologists to capture and vaccinate 28 adult 

 does with GonaCon. An additional 15 does were 

 captured, marked, and released without injections 

 as untreated control animals. 



After 1 year, 88 percent of the GonaCon-treated 

 does did not produce fawns, as indicated by 

 lactation. After two years, 47 percent of the 

 treated does did not produce fawns. Necropsy 

 observations and histological examination of 

 selected reproductive and other relevant tissue 

 samples taken from treated and control deer 

 identified no adverse effects associated with the 

 GonaCon vaccine except for localized, injection-site 

 reactions in 29 percent of treated deer. 



A second major field study of GonaCon as a deer 

 management tool began in the Morristown, NJ, area 

 during July 2005 on a completely enclosed, privately 

 owned, corporate office campus where overabundant 

 deer were damaging vegetation and creating traffic 

 hazards. NWRC scientists are collaborating on 

 this study with biologists from White Buffalo, Inc., 

 a nonprofit deer-management organization based 

 in Connecticut. This 2-year field study is similar in 

 design and scope to the Maryland study. Twenty- 

 eight adult does were captured and injected with 

 GonaCon, and 14 other does that are serving as 

 control animals were captured and given sham 

 injections before being released. As in Maryland, 

 the reproductive success of free-ranging treated and 

 control deer is being monitored and compared for 2 

 years to measure the efficacy of GonaCon as a deer 

 contraceptive under field conditions. 



After 1 year, 67 percent of the GonaCon-treated 

 does did not produce fawns, as indicated by 

 lactation. The reproductive performance of study 

 deer in New Jersey will be assessed again to 

 determine the second-year contraceptive efficacy 

 of GonaCon vaccine in free-ranging, white-tailed 

 female deer. 



Use of GonaCon To Control Black-Tailed Prairie 

 Dogs — Many prairie dog colonies exist across the 

 Western United States. In some areas, particularly 

 suburban settings, prairie dog colonies have 

 expanded to the point that they have denuded the 

 landscape. Conflicts have arisen in urban areas 

 between resource managers, who must manage 

 natural areas to maintain native plant life, and 

 residents who oppose lethal control of prairie dog 

 colonies. In October 2006, a study was initiated 



38 Developing Methods 



