The sight of a woodpecker drilling into a tree or the sound of its rapid drumming can alarm homeowners concerned about their landscape. Woodpeckers are a familiar sight, but the holes they create raise questions about potential lasting damage to trees. Understanding this interaction requires determining the woodpecker’s motivation and assessing the severity of the resulting holes.
Why Woodpeckers Drill Into Wood
Woodpeckers engage in pecking and drilling for three reasons, each resulting in a different mark on the wood. The most frequent motivation is foraging, where the bird excavates the bark and wood to hunt for insects, larvae, and other arthropods. These holes are typically small, irregularly spaced, and indicate the tree already contains a food source, such as wood-boring pests. A second reason is creating a nesting or roosting cavity, which involves drilling a single, large, deep hole. This behavior is usually aimed at dead wood or wood with compromised structural integrity, but it can occasionally target living trees or wooden structures like siding.
The third behavior is “drumming,” a rapid, rhythmic pecking used as non-vocal communication. Drumming is primarily used to establish territory or attract a mate, especially during the spring breeding season. This activity usually creates only minor, shallow dents in the wood, as the goal is sound production rather than excavation.
When Does Woodpecker Activity Become Harmful
Foraging pecks are scattered and shallow, causing little harm to a healthy tree. A healthy tree can effectively seal off these minor wounds, preventing the entry of disease. The presence of numerous insect-foraging holes often suggests the tree is already stressed or infested, with the woodpecker acting as a natural pest control agent.
The most significant threat to tree health comes from sapsuckers, a specific group of woodpeckers that feed on sap. Sapsuckers create distinct patterns of small, precise, circular or rectangular holes, known as sap wells, to access the tree’s sugary fluid. These wells are made in horizontal and vertical rows, and the bird returns repeatedly to drink the flowing sap. If a sapsucker creates rings of these sap wells that completely encircle the trunk or a branch, the tree can become “girdled.” Girdling severs the vascular tissues beneath the bark, disrupting the flow of water and nutrients.
Practical Ways to Stop Woodpecker Damage
Because woodpeckers are protected under federal law, deterrence methods must be non-lethal and focus on discouraging the bird from returning. The most effective approach is to first identify the motivation behind the pecking (foraging, nesting, or drumming). If foraging is the cause, reducing the underlying insect population is the most complete long-term solution. Physical barriers offer an immediate way to protect a tree trunk or structure. Wrapping the affected area with materials like burlap, hardware cloth, or fine mesh netting prevents the bird from gaining access.
Visual deterrents can also be employed, particularly for drumming or nesting activity, as these rely on startling the bird. Hanging reflective, shiny objects, such as Mylar strips, aluminum foil, or old CDs, creates unpredictable movement and light flashes that scare the birds away. These deterrents should be installed as soon as the activity is noticed, before the woodpecker establishes a strong habit or territory.