Is it appropriate to judge animal welfare by human standards?

It is inhumane to see a human starve to death. We must intervene.

But is it inhumane to let animals in our wilderness preserves to starve to death? Should we intervene there? What about on large farms that are stocked with wild animals? During harsh winters when there are huge die-offs, should we have sharpshooters go in and kill the weaklings before they have a chanced to starve?

If so, can we reliably know which animals will not make it through the winter and therefore should be shot?

Or is this all a human emotional problem that has nothing to do with ethical treatment of animals?