Rocky Mountain National Park, located in Colorado is home to over 3,500 elk. The optimum population is between 600 and 800. The elk have no predators, can eat, sleep, without having to roam too far. The park is then faced with having to thin the population. The herd has been culled, and birth control used on the cow elk. The problem is the elk typically stay in the meadows and are damaging trees that support other wildlife, so the park would like to drastically reduce the number. There have been discussions of reintroducing the gray wolf, with a maximum number of 14, so they would kill some of the elk, and also disperse the elk around the 415 square-mile park.
Use of "fertility control" would still require annual culling to keep the numbers down. The process to give the elk the birth control requires tranquilizing the elk, then vaccinating. The vaccination GonaCon was created for whitetail deer and lasts 2 years. Hunters outside the park were asked not to shoot at elk wearing collars, and animals treated with GonaCon wore tags advising hunters not to consume their meat since the vaccine may not have cleared their bodies.
From New West , “I’m always very wary when we try to do Mother Nature’s job better than she does,” says Jenny Powers, a National Park Service wildlife veterinarian and one of three lead scientists who participated in the elk research.