The issue with deer is that there are too few natural predators for them in many places on the east coast. The booming population has detrimental effects on the forests. Deer consume only certain plants so they end up causing lower diversity of eastern forests. When the decision is either cull them now or let the population starve until it gets back to a comfortable capacity, it's much better to cull them. This not only helps the surrounding ecosystem but also gives some people the chance to get large quantities of meat for almost no cost. Some people in the US really do still live off the land to an extent, meat is much cheaper when you kill and clean the animal yourself.

https://blog.nature.org/science/2013/08/22/too-many-deer/

We kill them, because we have replaced the apex predator in most ecosystems.

There are too few wolves, mountain lions, bobcats, coyotes, and bears to keep the population in check, so we do it.

>so the argument boils down to kill them because they're going to die anyway.

There's more to it than that. Overpopulation will cause damage to more than just deer. One of the biggest is the increase in the deer tick population and the subsequent increase in Lyme disease.

Instead of killing them ourselves, we could try to reintroduce predators, but why would a deer prefer being killed by a mountain lion to being killed by a human?

You'd have to bring back wolves and coyotes and bears to areas that currently only have deer to give deer the quality of life they 'deserve.'

I'm ok with that but I think you'd find that an untenable policy for most Americans.

Coyotes never really went anywhere; in fact, they seem to thrive in the same marginal suburban and semi-wild niches that deer do. Coyotes don't generally prey on deer, however, and hence they're not a perfect substitute for the lost wolves and bears. (Coyotes are too small and slow to take adult deer, except in snowy conditions.)

We have reintroduced wolves to national parks like Yellowstone, evidently with great success. I hope we do the same in other national parks if/where needed. Wolves do not prey on humans, contrary to popular belief, and generally keep a lot of distance from wandering hikers or campers.

Nature may not be "fair," but all things considered, I'd rather we let the wolves do the job of deer population control than humans. We are not as good at it, and we also pump the ecosystem full of heavy metals while we're shooting at the critters.

We should cull deer to preserve the forests. Deforestation caused by deer is becoming a very serious problem.

Wherever you see a forest where there is a deer problem, the trees you see today will not be replaced when they die.

Deer eat all the undergrowth and new saplings.

> I now suspect that just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer

Source: Thinking Like a Mountain by Aldo Leopold http://www.eco-action.org/dt/thinking.html

If you had the choice between death from a gun, death from starvation, death from the claw and tooth of a non-human predator, which would you choose?