If I remember right the article I read about the decline in bird populations in general were partly due to chemicals that farmers use on crops.
I could see where that would play a big part in population declines. But what makes me wonder about the chemical theory is that I ocassionly will see two or three quail when i am cutting or brush hogging fields that I usually spray from time to time.
We don't have wild pheasants here. 40 years ago we had a fair amount of quail. It wasn't unusual to see big covies of quail. Alot of people quail hunted back then too.
Back then you could hear quail whistling just about anywhere you went during the day. Now when you hear one whistle it is mostly going to be in wooded areas. Seems like they thrive there better for some reason.
It is a mystery to me as to what has happened to their decline. I think since their aren't many people trapping that probably has a little to do with their decline.
I assume you are blaming the raccoons, etc. for the decline in game birds, like quail. Long before people came to the Americas and began killing small predators (not to mention birds) in huge numbers, the birds and predators were doing just fine together.
The decline in all birds is primarily due to the declines in the small insects that the hatchlings eat, if they hatch, and failure of the eggs to hatch. The pesticides that are killing the insects at an alarming rate, including pollinators which we people need to pollinate our food plants, are also causing game bird (and other bird's eggs) not to hatch and if they do, the hatchlings can't find enough small insects to survive. The lack of insects is also causing migratory song birds to die of starvation. The birds get a double whammy, not enough insects, especially for their young ones and one seed coated with one of the most deadly insecticides, Imidacloprid, causes a song bird to either die soon after eating it or have their brain affected so they get lost, especially during migration, usually resulting in death. In the U.S., the insects have declined by about 65% in the last 50 years and the birds have declined by slightly more.
The same insecticide that kills the birds, Imidacloprid, was found to cause underdeveloped facial bones and reproductive malformations on white-tailed deer that were deliberately exposed. I doubt that it is a coincidence that cattle, goats, sheep and bison, llama and other camelids, horses and other equines, dog, cats and newborn children all began having the same birth defects. And that it was in the same year as the white-tailed deer and other wild grazing animals began being born with those birth defects. Imidacloprid was registered for use in 1994 and was quite widely used that year, especially in Washington, Oregon, Idaho, Texas and Florida. The birth defects on mammals, reptiles and birds began in spring of 1995 and became more prevalent as more neonicotinoids like Imidacloprid were used.
You all should type an animal like "domestic goats underbite images" on Google and see all the photos of goats with underbite. Do the same with domestic calves underbite images and lots of photos of calves with underbite are shown. Same with horse foals or other domestic animals, dogs, cats. Or try children underbite images. I taught grade school in the 1970s and there were no children with underbite, autism, missing limbs, etc. in any of the classes in the schools where I taught. Those birth defects became common in newborn children beginning in 1995, but no one seems to care about the children and no one will do anything about the birth defects on the domestic animals. Livestock owners don't seem to care if their animals are born with underbite or overbite or weird looking male genitalia, so the toxins responsible keep being used.