Personally think the decline of birds is multifaceted. Since the bleeding hearts in holleywood started throwing red paint on fur coat wearers the populations of nest predators has risen exponentially. Farming practices and habitat have also changed a ton in about the same amount of time as there are a lot fewer weeds (forbs) and stubble in croplands now. Also aerial spraying pasture to kill broadleaf plants (seed producing forbs). And... disease such as avian flu is much more widespread now. AND... pesticides are reducing certain bug populations that poults need. AND... there are now a lot more birds of prey than before.

With all that said I've focused my efforts on habitat improvements and nest predator removal. As you know a guy can only do so much.

Here's what you need to know about killing coons according to the State. You could also follow the triple S rule (not that I advocate that).
https://ksoutdoors.com/Hunting/When-to-Hunt/Furbearers