"We have become so accustomed to associating Woodpeckers with big timber, that it strikes us as uncanny to flush a Cactus Woodpecker from a creosote bush at the edge of the desert, and to have it go plinking contentedly from one bit of dwarf vegetation to another. . . . [H]owever much it may forage over the creosote and cholla patches, on occasion, it requires something of more ample girth for a nesting site." —William L. Dawson, The Birds of California (1: 998).
The “Cactus Woodpecker” is an old name for a subspecies (D. s. cactophilus) of the Ladder-backed Woodpecker that inhabits the southwestern United States and adjacent Mexico. “Cactus” is an appropriate word to associate with this species, as it frequently forages on and nests in various species of cacti. Within the United States, the Ladder-backed Woodpecker “. . . is the standard small woodpecker of mesquite and cactus lands of the Southwest” (2: 524). More specifically, the species is found in deserts, desert scrub, and thorn forests in the southwestern United States and Mexico (Chihuahuan, Sonoran, and Mojave deserts) and in open pine and pine–oak woodlands Mexico and Central America (3, 4, 5). In plumage pattern and overall appearance, this small black-and-white woodpecker is very similar to the Nuttall's Woodpecker (D. nuttallii), though their ranges have little overlap. Ladder-backed Woodpecker best distinguished from Nuttall's Woodpecker by having less black on the face and upper back.
Observations on the biology of the Ladder-backed Woodpecker are limited, although many aspects are expected to be similar to those of other Dryobates woodpeckers, particularly Nuttall's Woodpecker. Lester Short's monograph (3) on this species provided an extensive, single-source reference as a catalog of behavior and vocalizations. However, observations on breeding biology are more limited and incidental, rather than results of directed efforts to assess demographic measures. Thus, despite its broad distribution, many aspects of the natural history of the Ladder-backed Woodpecker remain poorly known.