We, humanity, have removed the natural predators of deer. This being the case, if contraceptive measures are not taken (a new alternative), the deer breed until there are too many deer for the land to support in the way of food. If the hunters didn't come in, you would have seen a sadder, slower death for many of the deer - starvation.

When I was a kid, I remember driving through wetsren upstate NY one time in the winter, and there were gaunt deer trying to graze through the snow by the side of the interstate. And here and there were dead deer, obviously starved, that had just collapsed on the hillside and died. It is an awful, awful thing, trust me. Dad explained to me then that we killed or drove out wolves, coyotes and other natural predators that would have kept the population better in check, so it is now our responsibility to do it ourselves if we do not want to see starving, dying deer.