Melanerpes formicivorus

It's not hard to see this bird in Yosemite Valley. The Acorn Woodpecker is a common denizen of California's oak woodlands. It's a highly social species, congregating in large groups and calling raucously. Around here they are known as monkey birds, because their call resembles that of a monkey screeching. They have no reservations about drilling holes into just about anything wood-based, including people's homes, which doesn't always yield friendly relations between them and humans. For my part, and perhaps partially because I'm houseless, I like them just fine.