Friday, April 9, 2010

Woodpecker Wars

One morning, I woke up thinking our neighborhood was under attack. There was a deafening uproar like a particularly metallic-sounding Uzi. We leaped out of bed, but couldn’t immediately determine the source of the noise. The culprit turned out to be a woodpecker. Not being wise to woodpecker wiles, I thought, “He’s not going to find much to eat on that metal chimney flashing.” Actually, he was “drumming”-hammering loudly on a resonating surface to create noise, kind of like a heavy metal musician and for a similar reason. Since woodpeckers do not have a song, they use drumming as a territorial signal and to attract a mate. This goes on mostly in the spring and, as I can attest, in the early morning.

Most woodpeckers forage on tree bark, although Northern Flickers can be found feeding on ground insects such as ants. Woodpeckers have specialized beaks, long tongues and unique clinging feet with 2 toes directed backward to help the bird grasp branches and trunks. They move up a tree by hopping; they depend on their stiff tail feathers to support them. The woodpecker’s tongue can be as long as the woodpecker itself. I am not making this up.

Not all woodpeckers seek insects for food. A sapsucker is a woodpecker that prefers sap. This tricky character will also eat insects attracted to the sap. The United States Forest Service (see page 8) has determined that the yellow-bellied sapsucker kills trees. This bird is a serious tree pest and, being migratory, it affects trees throughout North America.

I’m not the only one to be perturbed by these pesky perpetrators; the Cornell Lab of Ornithology received so many pleas from harassed homeowners that they sought a grant to study the “ecophysiology and behavior of woodpeckers in suburban areas.”

Woodpeckers are beneficial when they eat harmful insects, but when habitat is scarce they can cause severe damage to wooden buildings and ornamental trees. Woodpeckers drill holes when drumming, to forage and to  build nesting cavities.

Woodpeckers roost and nest in cavities only slightly larger than the width of the bird. They prefer dead trees or snags that have a hard outer shell and a softer inner cavity, but some seem to find the soft cedar siding of houses to be ideal. So, once their drumming has paid off, they start excavating your home to make theirs.

If you want to minimize damage to your house or trees, once you are onto the woodpecker’s plan, you should take immediate action. Once established, they are not easily driven from their territory. There are multiple suggestions for deterrents and the best course of action may be to use more than one technique simultaneously. Use your chosen control for at least 3 days before switching to something else.

The most effective solution may be to exclude the birds from the area or tree at risk. Put hardware cloth, plastic netting, or metal sheeting around trees or on siding. Paint the materials to match the siding or tree color. Protect sites under the eaves by attaching hardware cloth or plastic netting to the eaves, angling it back and fastening it to the siding below the damaged area. If there is a specific landing site, tightly stretch heavy monofilament fishing line or stainless steel wire across it to exclude the bird.

You can make a deterrent from aluminum foil, which may be the most effective visual repellent. Cut strips of several inches wide and about 3 feet long. Attach one end of several strips to a 6-8 inch string. Nail small brads 2-3 feet from the damaged area. On a building, place the brads 6-10 feet apart. Attach each string to a brad so that the foil strips hang freely and move with the breeze. Sticky repellents like Roost-No-More®, Tanglefoot® and Bird Stop® can also be effective when smeared on the trunk and branches of high value trees.

Discourage drumming on the house by filling the hollow space behind the chosen area to deaden the resonance. Use a can of expanding foam insulation which you can spray into the hollow area. This can be purchased from hardware stores. Existing holes may serve as visual attractants. Promptly cover holes with aluminum flashing, tin can tops or metal sheeting, and paint to match the siding to discourage return visits.

It is against the law to kill a woodpecker without the proper permit because they are migratory birds and are protected by the Federal Migratory Bird Treaty Act. The permit requires proof that you have used other measures and that they have not been effective. Penalties may include fines as high as a $500 and 6 months in jail. Killing a red-cockaded woodpecker carries an even stiffer fine and jail sentence because is a federally endangered species.

For a description of the mayhem which ensued when a hapless West Seattle homeowner attempted woodpecker reprisal, read this blog entry. Try to win your war for peace by non-lethal means!

2 comments:

  1. i have an ugly tree in the front yard that is under attack by a sap sucker. i couldn't figure out what all those little holes were in the tree, and why the tree was always oozing... then i saw a documentary on wood peckers. so, i think the tree will die, and then i wont feel so bad chopping it down. :)

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  2. Be sure to read the comments, that is where all the mayhem is. Don't miss the comment left by the homeowner/vigilante.

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