Early spring is the start of woodpecker courting season. And the secret to attracting a mate, if you are a woodpecker, is to make as much noise as possible. From dawn to dusk, you may hear their hammering, on resonant surfaces such as metal rain gutters as well as their more usual targets of trees.
Eight species of woodpeckers can be found in Maryland (approximately two hundred species exist worldwide). The largest is the pileated woodpecker, which can be up to 19 inches long with a 28 inch wingspan.
Woodpeckers are well-adapted for their hammering mission. They have strong neck muscles, and spongy, close-fitting bone shields their brains. The woodpecker’s long tongue, which may extend 4 inches, also curls around the brain and further cushions it. The woodpecker’s beak re-sharpens itself so it can peck up to 20 times per second, as many as 12,000 times per day.
You may be concerned that woodpeckers are killing your trees with all this activity, In fact, severe damage is relatively rare. Woodpeckers are more often a symptom of tree problems than a cause. Most species prefer to hammer on relatively soft dead wood (the exception are the sapsuckers, which commonly lick out sap from healthy trees).
If they are not courting or drilling a nest hole, woodpeckers are in pursuit of tasty insects that they have detected under the bark. They may be aiding trees by eating these insects; for instance woodpeckers have been shown able to destroy 85 percent of ash borer larvae in infested trees.
That said, holes left by woodpeckers can themselves open the tree up to insects and disease. If woodpecker bark damage goes completely around a branch or trunk and “girdles” it then the wood above the girdled area will die as water and nutrients can no longer reach it. An unusually persistent woodpecker can be a threat.
How to remove such a threat? It can be difficult as woodpeckers are strongly territorial once they become attached to a place. Don’t wait to act if you have concerns. A research study of different methods of repelling woodpeckers found that only hanging reflective strips to the tree was consistently effective. (Along the same lines, you could also try mirrors, reflective balloons, or old CDs.) Whatever you do, do not harm or kill the woodpecker. All species are protected by federal law.
How to treat woodpecker damage? If holes are 1 inch or less, leave them alone; the tree will heal itself. You may want to treat any larger areas of injury with a fungicide and wrap them with 1/4 inch plastic mesh, hardware cloth, or burlap. Using such coverings or similar small-mesh bird netting will also discourage woodpeckers from continuing to peck that area.
Questions about woodpeckers or other signs of tree problems? We welcome hearing from you.