Although storing food for the winter is not unheard of among birds, the acorn woodpecker’s practice of carefully drilling holes in trees and stuffing them with hundreds of acorns is rather unusual. This industrious hoarder is undoubtedly one of the most fascinating birds because of its intricate feeding system and occasionally spectacular social behavior.
One of the 239 species of woodpeckers that make up the family Picidae is the acorn woodpecker. From the Oregon and California coasts all the way down to Mexico and Colombia, it may be found. These birds are more frequent in urban and suburban settings, but they prefer western oak and pine-oak woods at higher elevations. They are grouped in families of up to 12 people, so chances are if you encounter one, you’ll discover others shortly. The family units share a common nesting area and occupy a certain territory. Typically, dead trees with sizable cavities are used for their nests. Acorn woodpecker activities therefore take place in and around their tree and the area that their family occupies.
When there are several breeding females in a family group, all of the ladies deposit their eggs in one nest, which causes weird things to happen. Before each breeding female begins to lay eggs simultaneously, the family of an acorn woodpecker starts consuming any eggs it discovers in its nest. This is to guarantee that not just the oldest eggs have a chance to survive, claims Bill Schutt, professor of biology at LIU Post and research associate at the American Museum of Natural History. “It seems to reason that the eldest hatchling would have the greatest chance of surviving. The birds will continue to consume each other’s eggs until they both lay their eggs on the same day, which may take weeks, in an effort to eradicate this advantage.”
They will remain with their family for a few years after they reach adulthood to assist with the new babies. They will eventually go to the air to search for a new family. They typically replace an adult who just passed away. As soon as fall is almost around the corner, acorn woodpeckers start hoarding acorns for the colder winter months. The entire family spends a lot of time gathering and stockpiling acorns. They create a type of tree known as a “granary tree,” which they use to store the harvested seeds in tiny holes. Any tree will suffice, provided it has thick bark, although woodpeckers that dwell in suburban settings are also quite content to drill holes in wooden poles and store their acorns there.
It’s a significant operation that involves careful preparation to drill those holes. The acorns may fall out of their position if the holes are too large, or worse still, other birds may take the stored items. It’s dangerous to leave the hole too small since the acorn can crack or lose its quality. To select the best fit for the supplied acorn, the bird first gently presses the acorn into each hole in turn. Once the acorn is in position, it moves on to install another one, and so forth. But the task doesn’t end there. The family members must constantly care to the granary trees and be on the alert for prospective acorn thieves like squirrels or even other woodpeckers in order to protect their store. As a result, one of the group’s members is always watching after their tree.
Thousands of acorns are typically stored in a typical granary tree. Every square inch of the tree, which may be covered in holes from the bottom to the top, is used by the woodpeckers. 50.000 holes were ever documented on a granary tree, which was the labor of several generations of woodpeckers. Due to their high fat content, acorns are ideal for the winter, proving that their evolutionary plan has paid off. The woodpecker is the only bird that hoards food on such a large scale, yet this behavior does help the bird survive cold periods without having to fly to warmer climes.