Deer, birds, and cute rodents are prey species. They surely know this, and breed prolifically to compensate. Most will be chased and killed within a year or 2 of birth. If we don't harvest them, another predator will, and probably not as humanely. If not predated, they will very soon overpopulate, and many will succumb to starvation, disease, and retrograde genetics.
I don't consider myself a hunter, but I destroy overpopulated prey on my farm. I don't eat the meat, because I don't need it. I let the night animals get their easy meal, and they are happy.
