Bird Watching: Acorn Woodpecker

The acorn woodpecker is a rather humorous-looking bird. In fact, it is often described as "clown-faced." Not only does it have an unusual look, the species also has some rather unusual habits.

The acorn woodpecker (Melanerpes formicivorus) is a medium-size woodpecker (about 9 inches). It has a glossy black and white head with very noticeable white circles around the eye. The red crown can look like a bad toupee. The male has red from the nape of the neck all the way to the white forehead, while only the rear of the crown is red on the female. The wings on both males and females are black with white patches. Juvenile acorn woodpeckers look like the males but have a dark eye instead of the white.

Acorn woodpeckers can be found in western portions of the United States. They range from southern Oregon into California, Arizona, New Mexico, and western Texas. They can also be found in the tropics. In fact their calls, which consist of drumming, a waka-waka-waka, and intermittent loud squawks, sound a lot like some tropical bird. They like open areas, especially open oak and pine-oak open forests. They can also be found in suburban areas and parks where there are oak trees.

The acorn woodpecker gets its name from its rather odd habit of gathering and storing acorns. These birds will drill holes in trees, which are called granary trees, in which they will stick an acorn in each hole. One granary tree can have as many as 50,000 holes in it. Acorn woodpeckers are not above using human structures as granary trees either. They have been known to drill holes in buildings, fence posts, and utility poles. Some have even used car radiators as storage for their acorns. Not only do they eat the acorns that they have stored, they also eat insects that they catch above the trees or that they find on tree limbs.

Acorn woodpeckers lay 2-8 white eggs during the breeding season. The young stay with the parents for several years and will even help to raise the young each year. There can also be a great deal of inbreeding within these family units that can have up to seven breeding males and three breeding females. In addition, the females share a nest cavity; and a female will destroy eggs in a nest before she lays her own eggs. Eventually, when all of the females are laying eggs, they will stop this behavior. Still, about a third of the eggs are lost during each breeding season. Nevertheless, there will be enough of this funny, clown-like bird around for you to observe. Just look for a tree with a bunch of holes in it that are filled with acorns. There will be an acorn woodpecker in the vicinity.

References:

Page, Jake and Eugene S. Morton. Lords of the Air: The Smithsonian Book of Birds. Avenel, NJ: Wings Books, 1995.

The Cornell Lab of Ornithology: All About Birds. Acorn Woodpecker.

whatbird.com: Field Guide to Birds of North America. Acorn Woodpecker.