Conservation. When hunting, it means only hunting males of a species. So that females of the species can carry on and keep producing
For example, when you hunt pheasant or quail, you're only supposed to shoot the males of the species.
For bigger game like deer, since in many places the population has increased to such a point that the population is starving to death without natural predators, it necessary to cull the herd.
We take the place of natural predators to keep the herd from starving to death. Even those of us that don't want to hunt, we understand that we can take a deer and donate the meat to hungry humans.
Conservation means trying to keep things as they are. We like nature, we hate seeing nature mutilated or starving to death, and I'm the case of needing to kill, we want to feed those less fortunate.