Editor’s Note (August 2016): Maps, rich media, and text have been updated to reflect a taxonomic change/split for this species. This species account is still being edited and may contain content from an earlier version of the account.
The Northern Flicker is a common, primarily ground-foraging woodpecker that occurs in most wooded regions of North America, including the giant cactus forests of the Sonoran Desert and Baja California. It is a polytypic species comprising five subspecies groups, each readily distinguished by plumage coloration and also differing in size. Two subspecies, the Yellow-shafted Flicker (Colaptes auratus auratus) of eastern North America and the Red-shafted Flicker (C. a. cafer) of western North America, form a long, narrow hybrid zone on the Great Plains that parallels the rain-shadow of the Rocky Mountains and crosses the Canadian Rockies to reach southern Alaska. This hybrid zone has been of great interest to ornithologists and evolutionary biologists for more than a century. Hybridization occurs on a more limited basis between the Red-shafted Flicker and a third subspecies, the Gilded Flicker (C. a. chrysoides), which is the Sonoran Desert subspecies. The other two subspecies are allopatric; the Cuban Flicker (C. a. chrysocaulosus) occurs on Cuba and Grand Cayman Island, and the Guatemalan Flicker (C. a. mexicanoides) occurs in the highlands of southern Mexico south to northwestern Nicaragua.
The subspecies differ in several bright and contrasting plumage traits, which probably evolved via sexual selection. The most obvious of these is shaft color, from which the three North American subspecies derive their common names. The bright shaft colors are visible on the undersurface of the wings, which are flashed at potential mates or rivals during courtship and territorial defense. Other traits that distinguish the subspecies are the presence of a bright red nuchal (nape) patch in the Yellow-shafted and Cuban flickers (absent in others) and the color of the throat, ear coverts, crown, and malar stripe. The malar stripe, or “mustache,” is the only markedly dimorphic trait that distinguishes the sexes.
As its broad geographic distribution suggests, the Northern Flicker is a generalist in many respects, but in others it is a specialist. It is clearly a species of open woodlands, savannas, and forest edges. It eats mostly ants but also beetle larvae and—during late autumn, winter, and early spring—a variety of berries. The Northern Flicker is well adapted for human habitats, commonly breeding in urban as well as suburban and rural environments. Nevertheless, Breeding Bird Survey data indicate that the Yellow-shafted Flicker decreased 52 percent in abundance between 1966 and 1991 and the Red-shafted Flicker 19 percent between 1968 and 1991. Reasons for these declines are unclear, but likely explanations are loss of habitat and competition with the European Starling (Sturnus vulgaris) for nest cavities. Although the Northern Flicker remains abundant, this declining trend should be viewed with concern because the species plays a central role in the ecology of woodland communities where it excavates many of the cavities later used by other hole-nesting species.