World Bird List

Species factsheet
Acorn Woodpecker (Melanerpes formicivorus)

Order: Melanerpes formicivorus
Family: Woodpeckers (Picidae)

Voices can be found here (external link)
Subspecies and Distribution
Subspecie Distribution
bairdi Oregon (USA) to n Baja California (Mexico)
angustifrons s Baja California (Mexico)
formicivorus sw USA to se Mexico
albeolus e Chiapas (se Mexico) to Belize and ne Guatemala
lineatus Chiapas (s Mexico) to n Nicaragua
striatipectus Nicaragua to w Panama
flavigula Colombia