Acorn Woodpecker, Melanerpes formicivorus

Acorn Woodpecker, Melanerpes formicivorus formicivorus. Photograph taken within a residential community in Hereford, Arizona, June 2016. Photograph and identification courtesy of Bob Behrstock, Sierra Vista, Arizona (naturewideimages.com).

Acorn Woodpecker, Melanerpes formicivorus formicivorus. Photograph taken in the greater Santa Barbara area, Santa Barbara, California, September 2021. Photograph courtesy of Dr. Tom Bartol, Carlsbad, California.

Acorn Woodpecker, Melanerpes formicivorus formicivorus. Photograph taken in the greater Alamos area, Alamos, Sonora, May 2018. Photograph and identification courtesy of David F Smith, Alamos, Sonora.

Background and Identification

The Acorn Woodpecker, Melanerpes formicivorus formicivorus, is one of seven subspecies of Acorn Woodpecker, of which five are found in Mexico. They are a member of the Picidae Family of Woodpeckers, which has two hundred thirty-three members placed in thirty-three genera, and one of twenty-three global species of the Melanerpes Genus. They are known in Mexico as Carpintero Belloterois.

The Acorn Woodpecker is medium-sized in stature. The sexes are dimorphic. The adult males have solid red crowns while the females have a wide black band separating the red from the white forehead. Their underparts are white. They are black and white with a clown-like face that has a distinctive red crown, glossy black and white head, white underparts, a white rump and wing patches and a trace of yellow on the throat. They have a black patch around their eyes. Their bill is black, their gape is pinkish, their iris is white, and their legs and feet are black.

Habitat and Geographical Range

The Acorn Woodpecker is found near oaks within pine-oak woodlands in foothills and montane woodlands at elevations between 1,400 m (4,600 feet) and 3,300 m (10,800 feet). They primarily consume acorns and supplement their diets with flycatching, bark-gleaning, seed-eating, and sapsucking. They are known for their highly social habits and unique methods of storing acorns in storage trees. They are a cooperative breeder, cooperatively raise young and reside in family groups of ten or twelve individuals.

In Mexico, the Acorn Woodpecker is found in northeast Baja California and throughout the country in the central highlands south to eastern Veracruz and Oaxaca. The formicivorus subspecies is found throughout the country south to eastern Veracruz and Oaxaca. They are generally sedentary and will only move to locate food sources.

Common Misidentifications

The Acorn Woodpecker is a straightforward identification that is not easily confused with any other species, with the possible exception of the White-headed Woodpecker, Dryobates albolarvatus (lacks white underparts and a white rump).

Conservation Status

From a conservation perspective, the Acorn Woodpecker is currently considered to be of Least Concern with stable, widely distributed populations. Their long-term viability is threatened by habitat degradation by human development.