ACORN WOODPECKER (Melanerpes formicivorus) – (See images below)
NOTES: As with many other woodpeckers, the acorn woodpecker has two forward and two backward toes, which allows better grip when climbing vertically on tree trunks. In addition, their tail feathers have stiff ends to provide more support.
Drumming: A behavior that is unique to the woodpeckers including this one, is their drumming on metal surfaces (preferably) for territorial and courtship purposes, and the louder the better. The drumming can then be heard from a good distance. Woodpeckers will not shy away from drumming on buildings, on hollow metal parts, for example, that brings them a good loud sound. For more information on drumming, you can click here.
SIMILAR SPECIES: Pileated Woodpecker
REFERENCES: (Texas Breeding Bird Atlas)

Acorn Woodpecker – Sonoma, CA – photo by Roberta Palmer
Acorn woodpecker, Roberta Palmer