Well, the over-population of racoons is largely due to the racoon being pretty "opportunistic", and getting into pet food like that. That does a couple of things; 1-The racoon population gets larger than the land would normally support, 2-The racoons predate on other critters more because there are more of them.
Of course it's all a lot more complicated than I can articulate in a couple of sentences, but the whip-poor-wills did pretty well until we drained the swamp (so to speak), but it's happening all over the country. There are several other ground nesting birds that are endangered in other places.
We have tons of California Quail here, they usually run around in groups of a dozen or so. Every now and then you'll see a smaller group; I guess it's because a Bobcat or Coyote had a mini-feast.
The GlueGuy