BTK,
Ah, a good question. Much of the wildlife in this country was extripated (killed off) by wanton waste, over harvest and market hunting at the turn of the last century. Also, habitat was being converted to farmland at a remarkable rate. A few conservationist (almost all hunters including Teddy Roosevelt) enacted laws to prevent the endless slaughter of wildlife and also set aside large areas of land for conservation. Eventually most of the wildlife came back, but a few didn't (passenger pigeon). A lot of effort has gone into transplanting and reintroducing wildlife to it's former range as well. Through all this effort,almost entirely funded by sportman, wildlife has made a tremendous comeback in our country. Now, we are faced with a different dilemma, too much wildlife in some instances. For example, canada geese. I actually helped with transplanting them in Oklahoma many years ago, now they're like flying rats. Everywhere. The same can be said for deer populations in many states. Once hardly any deer, now too many. Wildlife has a way of occupying a niche if given half a chance.