The same happens with all of the rest of the animal world, too. One of them leaves a morsel and it is scarfed up by another. All of the left overs are taken care of in this manner except by humans.We throw away or dump any excess that has served its purpose to us - so much that the animals can't keep up with it.
Hunting and gathering used to be about survival for the two-legged co-inhabitants of the land. Now few people choose to hunt and gather. That's what grocery stores are for. Comparitively, there aren't as many aching bellies from hunger when food can't be hunted, either.There are still too many, but not as many as when the game animals went somewhere else in the early times.
A person could drive themselves batty trying to think how to improve the world around him. Personally, I think he should watch more rabbits and do what they do one belly at a time. The rabbits appear to be doing well without the use of their debit cards.