Woodpeckers are distinctive birds recognized for their characteristic pecking, a behavior that might seem puzzling at first glance. This rapid, rhythmic action is not random; it serves several specific purposes that are essential for their survival. Understanding these behaviors reveals the intricate adaptations that allow woodpeckers to thrive in their environments.
Foraging for Sustenance
A primary reason woodpeckers engage in pecking is to locate and extract food. They diligently excavate wood to find insects, such as beetle larvae, that reside beneath the bark or deep within the timber. The vibrations created by their pecking can disturb these insects, helping the woodpecker pinpoint their exact location.
Once an insect is located, a woodpecker uses its specialized tongue to retrieve the prey. This unique tongue can be remarkably long, often extending far beyond the beak, and is typically sticky or barbed to effectively grasp and pull out insects from narrow crevices. Some woodpecker species also create small holes to access tree sap, consuming both the sap and any trapped insects.
Crafting a Home
Woodpeckers also peck to construct cavities for raising their young or as roosting sites. These excavated holes provide protection from predators and adverse weather conditions. Unlike many other birds, woodpeckers do not bring nesting materials into these cavities; instead, the wood chips created during excavation form a soft bed for their eggs and young.
They often select dead, decaying, or diseased trees for cavity excavation, as the softened wood requires less effort to bore into. Trees affected by heart rot are favored because the softened interior makes chiseling much easier. The size and shape of these cavities vary by species, but they typically feature an entrance hole leading to a larger vertical chamber.
Sounding the Alarm
Beyond foraging and nesting, woodpeckers use a distinct form of pecking, known as drumming, for communication. This behavior is different from the slower, more deliberate pecking used to find food and is used to attract mates and establish territorial boundaries. Both male and female woodpeckers participate in drumming, especially during the late winter and spring breeding season.
Woodpeckers intentionally choose highly resonant surfaces to amplify their drumming sounds, allowing their messages to travel farther. While natural structures like hollow tree trunks are common, they also utilize human-made objects like utility poles or metal siding, which provide excellent amplification. The specific rhythm and speed of a woodpecker’s drumming can convey information about its species identity and even its individual identity.
Nature’s Shock Absorbers
The constant, high-impact pecking raises questions about how woodpeckers avoid brain damage. Their ability to withstand repetitive forces is attributed to anatomical adaptations. Woodpeckers possess strong neck muscles that help manage the force of impact.
Their skulls contain a thick, spongy bone that acts to dampen vibrations. A hyoid bone, which supports the tongue, wraps around the skull like a seatbelt, distributing impact forces and stabilizing the brain. Additionally, the relatively small size of a woodpecker’s brain contributes to its higher tolerance for deceleration, reducing susceptibility to injury from pecking forces.
When Pecking Touches Our Homes
Woodpeckers sometimes extend their natural pecking behaviors to human structures like houses or utility poles. This activity is typically an extension of their natural instincts rather than a malicious act. One common reason is foraging, as they may mistake the siding or trim for dead wood containing insects.
Another cause is drumming, where the birds use the resonant qualities of a house’s siding or metal to attract mates or declare territory, much like they would a hollow tree. In other instances, woodpeckers might attempt to excavate roosting or nesting holes in convenient spots on a building. Acorn woodpeckers may even create holes in homes to store acorns.