Woodpeckers vs. the World | National Geographic

You probably recognize the sound of woodpeckers busy at work. But have you ever wondered why they're pecking away? And why they do it so, well, endlessly? Well, at least in the case of acorn woodpeckers in Carmel Valley, California, they're creating storage units. Thousands and thousands and thousands of storage units. See, these acorn woodpeckers are engaging in a behavior called hoarding. They're collecting far more food than they need for the winter by pecking holes into dead trees and stuffing them with their favorite food. Fat-filled acorns. This oak tree has been transformed into a storage site, or granary tree, for one extended family of acorn woodpeckers. This particular granary tree has been pecked with over 10,000 holes. Can you imagine how much work it takes to create all these holes? Then imagine how much work it takes to fill them. A woodpecker might gather over 100 acorns a day, and can only gather one acorn in each trip. A woodpecker can fly over 12 miles in one day gathering acorns. Then the acorn has to be pounded snugly into the hole. If the fit isn't just right, falling acorns aren't the only problem these woodpeckers face. They have to be wary of birds of prey, who pick off one in every five of the birds out here. Less deadly and more annoying are animals that raid their hard-won food supply. Ground squirrels love to let woodpeckers do all the work of gathering acorns, just so they can sneak in and steal them. Naturally, the woodpeckers don't think too kindly of this. When they find out, look out. When their food supply is threatened like this, you might say the woodpeckers go, well, nuts. One last threat, large portions of the acorn supply can rot. So even though hoarding may have negative connotations to humans, overstocking is necessary so the woodpeckers don't have to migrate to different food supplies. And all the acorns that get dropped in the hoarding process help regenerate all these oak trees, keeping the acorn woodpecker's circle of life intact.