The following information has been copied from The Great Backyard Bird Count webpage.

Northern Bobwhite, Colinus virginianus
Habitat: Brushy pastures, grassy roadsides, farmlands and open woodlands. Population Trend: Northern Bobwhite have been declining by almost 3% annually throughout their range since 1966, as shown by the red areas in the Breeding Bird Survey map below. Data from the Breeding Bird Survey (BBS) and Christmas Bird Count (CBC) show a very similar declining trend (below right).

Scaled Quail, Callipepla squamata
Habitat: Dry grasslands and brushy deserts. Population Trend: Scaled Quail are declining by 2.4% annually throughout their range, as shown by the red areas in the Breeding Bird Survey map below. Data from the BBS and CBC are closely matched for this species as well (below right).

Gambel's Quail, Callipepla gambelii
Habitat: Desert thickets and arid country. Population Trend: Although Gambel's Quail are decreasing in certain areas, overall their numbers seem to be increasing or staying level.

Montezuma Quail, Cyrtonyx montezumae
Habitat: Grassy and brush-covered ground in pine-oak woodlands. Population Trend: The status of Montezuma Quail cannot be accurately assessed using BBS or CBC data.