What aspect of the woodpecker generally shows wide variation between species, contrasting with their uniform feeding mechanics?

Answer

External appearance, pattern, and color

While the physical mechanics for climbing and feeding are remarkably uniform across the family, external features like plumage size and color vary widely, often influenced by factors like sexual selection.

What aspect of the woodpecker generally shows wide variation between species, contrasting with their uniform feeding mechanics?
birdanatomyphysical characteristicwoodpeckerbeak