One of the most interesting birds that I’ve ever photographed is the Acorn woodpecker. [Marie Read, Photographer] And I found a population of woodpeckers in a suburban park in southern California. I noticed this tree with thousands and thousands of holes in it, each of which had got an acorn stuffed into it. Acorn woodpeckers, I think, are among the busiest birds. And what this tree’s called is granary tree. This is where the group of Acorn woodpeckers that lives together, this is where they store their winter food supply. It’s a tree that’s been used over the generations. Multi-generations of these woodpeckers have been using the same tree, adding to the number of holes over the years. So they don’t drill them all at once, each winter they drill a few more and add some more acorns to them. No other woodpeckers in North America will have this special method of storing in specifically drilled holes. So that makes Acorn woodpeckers pretty special in the bird world. Many people describe Acorn woodpeckers as having a clown-like look. They’re very colorful woodpeckers – they’ve got glossy blue-black back, they’ve got red and pale-yellow and black markings around their heads and faces, and their eyes are, in fact, kind of a pale whitish color, they really stand out. And you can tell the males from the females by the fact that the females have a little band of black between the red and the pale-yellow and in the males the red and yellow are next to each other. So when you find one Acorn woodpecker you’re most likely going to find a group of them, because their highly social birds. They live in social groups year-round, up to a dozen individuals or more. And one of the commonest sounds you’re likely to hear when a group gets together is the wacka wacka call. And often they’re also displaying at the same time, making this dramatic and very, very wonderful wing spread display. So you’ll get one bird landing on the granary tree then others will join it and they’ll be displaying and calling away. There’s nothing more fun than heading out to some park and hang out and wait for some Acorn woodpeckers to show up at their tree. You’re bound to be entertained, it’s one of the funniest things I like to do. I really like to go and watch them and photograph them.

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With their sharp, powerful beaks, Acorn Woodpeckers excavate custom holes into trees that are the perfect size to hold an unusual food—acorns. Each Acorn Woodpecker group works together to maintain and defend its acorn collection. The same tree, called a “granary”, is reused over generations to store the winter food supply. As dependent as Acorn Woodpeckers are on this communal food resource, it is not surprising that they are also highly social birds. They live in stable groups of roughly a dozen individuals and have evolved an unusual polygynandrous mating system in which multiple males and females share a single nest cavity and communally raise chicks.