Texas · UplandNorthern bobwhite quail

Northern bobwhite occurs in virtually every Texas county east of the Pecos River (TSHA's quail handbook), which is a real absence signal for the Trans-Pecos but leaves most of the state -- so TPWD's own annual roadside quail-index survey, broken out by ecoregion (Rolling Plains, South Texas Plains, Edwards Plateau, Cross Timbers and Prairies, Gulf Prairies, High Plains), is the sharper regional source. Two ecoregions consistently post the state's strongest numbers: the South Texas Plains, which TPWD biologists describe as 'a stronghold' where 'bobwhite populations appeared to increase the further south you go within the region' (12.70 birds/route in 2025, up from 9.13 the prior year), and the Rolling Plains, traditionally the state's highest-density bobwhite range (16.50 birds/route in a recent survey against a 15-year mean of 11.75, though populations there are more rainfall-volatile than South Texas). TPWD's own high-plains-region bobwhite management page states this directly: 'higher populations of quail are traditionally found in the rangelands of the Northern Rolling Plains than in more arid rangeland characteristic of the High Plains,' and in the eastern Panhandle, bobwhite is 'replaced by the Scaled Quail in more xeric uplands' -- i.e. the two species partition western Texas by moisture/vegetation type rather than sharing one range uniformly.