Meet the acorn woodpecker: storage extraordinaire
By now you’ve probably seen the story: a pest control company doing routine work at a house in Glen Ellen discovered over 700 pounds of acorns in the walls! The photos are unbelievable—a mountain of acorns that came pouring out of a hole in a wall are piled high on a bedroom floor. The exterminator said he had never seen anything like it, but bird experts knew exactly what caused it—acorn woodpeckers!
Acorn woodpeckers are one of our most common woodpeckers in Sonoma County, and they are known to cache (or store) acorns in places like chimneys and vent pipes of homes, especially when their natural acorn storage trees, or granaries, have been removed. At this particular home in Glen Ellen, acorn woodpeckers had been placing acorns in the chimney of the house, probably over the course of a few years, until there was no more room for even one more acorn. I’ve also heard stories of acorn woodpeckers filling vent pipes on roofs of houses with acorns until they are overflowing. My neighbor recently discovered that acorn woodpeckers had filled the vent pipes on her roof with so many acorns that she needed a shop vacuum to get them all out. Luckily, a simple fix of screening the vent pipes solved the problem.
Acorn woodpeckers are beautiful black, white and red woodpeckers, known for their clown-like facial markings. They are social birds, meaning they live in large family groups, preferably in oak woodlands where they have access to an abundance of acorns and places to store them. If you’ve been anywhere in Sonoma County in proximity to oak trees, you’ve probably heard their distinctive call, which sounds like “jacob, jacob, jacob!” or observed their behavior as they swoop up from a branch to grab an insect. What makes acorn woodpeckers really fascinating is their social structure within their colonies—they all work together to find and store their food, as well as excavate nest holes and raise their young.
My favorite acorn woodpecker colony to watch is at Ragle Ranch Regional Park in Sebastopol. Ragle Ranch is full of oak trees, and therefore home to many acorn woodpeckers. There is a cluster of snags used as a granary behind the ranger residence, where you can find acorn woodpeckers working together to busily stuff acorns into the holes they’ve drilled. The snags are right next to the road, so if you’re quiet enough, you can observe the woodpeckers and their interesting behavior from just a few feet away.
Another amazing acorn granary is in Point Reyes, on the road to the Bear Valley Visitor Center. This granary is in a huge, aging Douglas fir, where acorn woodpeckers have drilled thousands of holes in one massive tree trunk, each with its own acorn stored inside. It is quite a remarkable sight!
Acorn woodpeckers are stunning birds to see, and always fun to watch. Next time you are outdoors in oak woodland habitat, keep your eyes—and ears—peeled for this fascinating woodpecker.
