I just heard on the radio yesterday that they are looking at introducing sterilized wolves (I'm assuming they mean wolves that have been "fixed" versus being germ-free) into Wind Cave National Park here is South Dakota to control the elk overpopulation. They talked about having an elk hunting season to control the elk population, but nope, that's not how the National Park Service does things so instead of generating income and food for folks they are going to have to spend money to have fixed wolves come in and hunt elk. (Of course, these fixed wolves will only elk and nothing else and will not stray from the national park).