Natural History, Variation and Distribution of the Strickland's Woodpecker
Davis J. 1965. Natural History, Variation and Distribution of the Strickland's Woodpecker. The Auk. 82(4):537-590
Among the New World members of the woodpecker genus Dendrocopos, two forms are sharply differentiated from their congeners in that they are brown and white rather than black and white. One form is widely distributed, extending from the mounta.ins of southeastern Arizona and southwestern New Mexico south in the middle and upper middle elevations of the great Sierra Madre Occidental of western Mexico to the state of Jalisco, and thence east in the mountains rimming the south edge of the Mexican plateau to east-central Michoacan. Separated from this wide-ranging form by an airline distance of about 50 miles is a more restricted series of populations of brown-backed Dendrocapos occupying high elevations in the mountains from the Michoacan-Mexico boundary east to Puebla and Veracruz. The populations of the north and west, characterized in typical form by medium brown coloration, immaculate or nearly immaculate dorsum, and spotted and barred underparts, have been considered by most ornithologists to be a distinct species, the Arizona Woodpecker (Dendrocopos arizonae). The more restricted populations of the south and east, characterized by very dark, sooty brown dorsal coloration, heavily barred dorsum and rump, and streaked and barred underparts, have been considered by most ornithologists to represent a second species, Strickland's Woodpecker (Dendrocopos stricklandi). This paper presents information on the natural history of these woodpeckers, describes their morphologic variation, and attempts to evaluate the relationship between the major components of the complex.