Individuals vs. Populations

I've been thinking a lot about individuals and populations lately. This has a lot to do with the fact that I've been reading a handbook (or a great big 3-inch ring binder-full of information) on wildlife rehabilitation and some to do with the fact that I've been talking to the game wardens.
A few years ago I was volunteering at the Game and Fish Department, stuffing moose licenses into envelopes. I had told the conservation officer that I'd really like to go along if he had any wildlife cases, and as it happened, a couple of hours later he did. I confess I was pretty disappointed. We'd been called out because a cat had gotten hold of a songbird in some body's front yard, and he seemes to be holding out hope that the bird could be saved. We took it to the local vet and had it euthanized, just because it was good public relations. When I told the warden the story, he countered that that was a lot of expense and wasted time, and that he would never tell anyone that there was anything he could do for the animal. Apparently he has been called some nasty names because he couldn't (or in the view of that particular person, wouldn't) save the animal.
There are people who save animals and return them to the wild. They're called wildlife rehabilitators. Yet even these people must euthanize animals when it is determined that they can never be functional in the wild again. It's just realism, plain and simple. I have no doubt that veterinarians would like to be able to save all their patients, and I've even seen some vets take some pretty extreme measures (like giving CPR to a dog). However, when that patient has a leg that's been partially detached by fishing line or two broken wings or has no suitable habitat in the area, it's crueler to release it as it will most likely die anyway, and in greater discomfort than it would be at a rehab center.
Nearly every government wildlife agency deals in populations, not individuals. As long as the population is healthy, the individuals comprising it will be, too. The cycle of life and death in healthy populations hinges on natural selection, something that humans have tried to combat with medications and hospitals and have been fairly successful with. There are six billion of us on the planet now, with more to come. This is going to sound extremely cruel, but I sometimes wonder what things would be like if we managed our population like we manage other populations. There would certainly be fewer of us if we just let nature take its course, and perhaps then there would be more room for the wildlife.
It may be an interesting pipe dream, but it's never going to happen. However, people have to becomne accustomed to the fact that fawns and adult deer are going to get hit crossing the road, legs and wings will be broken, things will feed on other things. Every so often someone will be killed after hitting a deer or an elk. Them's the facts. Sometimes we can rehabilitate the animal (or person) and sometimes we can't. That's life. But if the population survives there will be other deer and other people. Awful as it may seem, it's the reality we deal with on a daily basis. If we can keep the population alive, we've done our job.