Cotton rats and bobwhite booms seem to be closely linked. Pardon this grainy image (it was taken using a thermal rifle scope during a hog hunt in south Texas [Karnes County] in November) but it shows many cotton rats under this deer feeder.
Cotton rats are at very low abundance in west Texas. If this picture is representative of other sites in south Texas, perhaps that (partially) explains why quail populations there have remained robust relative to west Texas. If you’re in south Texas, and going through game camera pictures, please note if you’re seeing cotton rats (in abundance) under those deer feeders. Please forward your observations to me (firstname.lastname@example.org)