This common desert woodpecker replaces ... hybridize at a few localities in southern California. Polytypic (about 8 ssp. in North and Middle America; birds north of Mexico are cactophilus).

Only about 500 California condors remain in the US south-west and Mexico. In the 1980s, fewer than two dozen birds remained in the wild, but conservation efforts have boosted their numbers in ...

and should be learned well as a reference point for less common species. The larger California (commonly occurs alongside the ring-billed in the west) is a 4-cycle gull with a stouter bill and ...