Picoides scalaris
ladder-backed woodpecker

From southwestern United States south to British Honduras (Lowther 2001).

Wooded canyons, cottonwood groves, pine and pine oak woodlands, desert scrub, and desert grassland dominated by mesquite. Elevation range is from sea level to 2,600 meters. A xeric adapted woodpecker that is found in diverse habitat including mangrove swamps in Honduras (Short 1982, Lowther 2001).

Black with white barring on face, male has red crown patch, female lacks red crown patch, forehead black, and wings black with white spots, back is black with white bars. Similar in appearance to Nuttall’s woodpecker that has a cleaner white breast, and less spotting on flanks, and wider white bars on upper back. Length is 18.8 mm, weight 30.3g, and wing length (chord) 64mm. Zygodactylic feet and stiff tail feathers for climbing (Kaufman 2000, Lowther 2001).

Chicks are nearly naked and helpless (altricial) and confined to the nest (nidicolous). No information is available on fledging stage, however based on observations of the Nuttallii’s woodpecker (Picoides nuttallii) they leave the nest 15 to 16 days after hatching, and parental care continues for two weeks after leaving the nest (Lowther 2000, Lowther 2001).

Breeding pair formation starts in late January and continues through March. Incubation occurs from April through May. Clutch size varies from 4 to 6. Egg shape is oval or oval short. There is no information on nest selection and building, however nest are cavities in Joshua trees, Willow, Walnut, Cottonwood, Oak, Hackberry, Pine, and Mesquite. There is no information on parental care, fledging stage, immature stage, or the break up of mating pairs. Molt occurs after breeding from July to October. Hybridization occurs with Nuttall’s woodpecker where their ranges overlap (Short 1982, Lowther 2001).

Longevity is 4.5 years based on banding. No data on adult survival rate. No known causes of mortality (Lowther 2001).

Ladder-back woodpeckers have a swift and undulating flight. They also move by walking, hopping, and climbing. Males and females roost in separate cavities. This species does not migrate (Lowther 2001).

Main foods are insects and arthropods found by probe, pick or glean, bill flick, pry, and excavate. Foraging accomplished mainly on trunks and limbs of trees some reports of ground foraging (Lowther 2001).

No known predators for the species, but snakes routinely raid woodpecker nests, primarily the bull/gopher snakes. Cooper’s Hawks (Accipite cooperii), other accipiters, falcons and owls regularly predate on woodpeckers (Koenig et al. 1995).

By eating wood boring beetles and other insects, they help to control insect populations and their effect on trees (Short 1982).