It hadn't occurred to me that hogs may play a serious role in reducing gamebird populations, including those of troubled Texas quail.

Here is a quote out of today's Rolling Plains Quail Research Foundation October newsletter detailing on a scale of 1 to 10 the grim quail hunting outlook across west Texas counties:
Dr. Joe Pat Hemphill reports from Coleman County: “I would have to go with a "2". I have seen one covey of 7 juvenile birds—hopefully there are more somewhere. Science may prove me wrong, but I firmly believe that nest predation by feral hogs is a greater factor in our area than weather.”

Yup. They get the turkey nests as well.

quail are/were wiped out by fire ants in the 80s

Jeff, up here in the Rolling Plains they also suffer from the eyeworm parasite. Quail ingest the larvae from grasshoppers and other insects, and the larvae can locate and travel up the ocular nerve within 30 minutes of being swallowed. Both amazing and horrifying.

https://www.quailresearch.org/parasite-work/

There are a lot of factors playing out with quail. Too many to list here but what hurt us was lights on tractors! Farmer could and did work at night. Wiped out whole coveys. Changes in crop timing. Then quit row crops and planted coastal for hay.

There are few if any hogs in West Texas west of
about Del Rio and Id bet on drought being a problem on a dry year and drought runs for years in a row at times in that area..the quail always seem to survive..My sister in North DAllas was fire ants. now thats a real preditor , killing deer and hogs and livestock during the calving season..Quail need management trapping and setting pairs out over the ranch is your best bet or was with me..those large coveys of several hundred drew predators like fox, skunk, coyotes,snakes, our house cats, birds of prey and so forth, and lots of them..I recall when furs were high dollar, quail population seem to increase at least where I was ranching...I suspect its combination of all thats mentioned..I wonder why all this didn't take place on our places in west Texas growing up, we had lots of quail, moms pets that were not allowed to be hunted grew to hundreds..

My old hunting property here in Georgia always offered excellent deer, squirrel and turkey hunting until about 10 years ago when we started seeing sign of hogs. It took us quite a few years of trapping and actively hunting hogs to get a reasonable turkey population back. Hogs can really change the balance of nature.

All the more reason to hunt hogs. I hope to soon.