Acorn Woodpecker

The Acorn Woodopecker, Melanerpes formicivorus is a species of woodpecker (Picidae).

Other names
California woodpecker.

Description
A black and white woodpecker. Black chin, yellowish throat, white cheeks and forehead, red cap. . Female has smaller bill than male and has less red on crown (top of the head). In flight, it shows a white rump and wing patches that are conspicuous.

Calls
Its most common call is waka repeated several times; or, according to Peterson (1961), whack-up, whack-up, whack or ja-cob, ja-cob.