Damage and Damage Identification

Red-headed woodpecker, Melanerpes erythrocephalus (left); downy woodpecker, Picoides pubescens (right).

Woodpecker damage to buildings is a relatively infrequent problem nationwide, but may be significant regionally and locally. Houses or buildings with wood exteriors in suburbs near wooded areas or in rural wooded settings are most apt to suffer pecking and hole damage. Generally, damage to a building involves only one or two birds, but it may involve up to six or eight during a season. Most of the damage occurs from February through June, which corresponds with the breeding season and the period of territory establishment.

The following species of woodpeckers are most generally involved in damaging homes or other wooden, human-made structures:

Woodpeckers can be particularly destructive to summer or vacation homes that are vacant during part of the year, since their attacks often go undetected until serious damage has occurred. For the same reason, barns and other wooden outbuildings may also suffer severe damage.

Damage to wooden buildings may take one of several forms. Holes may be drilled into wood siding, eaves, window frames, and trim boards. Woodpeckers prefer cedar and redwood siding, but will damage pine, fir, cypress, and others when the choices are limited. Natural or stained wood surfaces are preferred over painted wood, and newer houses in an area are often primary targets. Particularly vulnerable to damage are rustic-appearing, channeled (grooved to simulate reverse board and batten) plywood with cedar or redwood veneers. Imperfections (core gaps) in the intercore plywood layers exposed by the vertical grooves may harbor insects. The woodpeckers often break out these core gaps, leaving characteristic narrow horizontal damage patterns in their search for insects.

If a suitable cavity results from wood-pecker activities, it may also be used for roosting or nesting.

The acorn woodpecker, found in the West and Southwest, is responsible for drilling closely spaced holes just large enough to accommodate one acorn each. Wedging acorns between or beneath roof shakes and filling unscreened rooftop plumbing vents with acorns are also common activities.

Relatively new damage problems are arising where damage-susceptible materials such as plastic are used for rooftop water-heating solar panels or where electrical solar panels are used. Woodpeckers have also reportedly damaged elevated plastic irrigation lines in several vineyards in California.

Widespread damage from nest cavities and acorn holes in utility poles in some regions has necessitated frequent and costly replacement of weakened poles. Similar damage to wooden fence posts can also be a serious problem for some farmers and ranchers. Occasionally, woodpeckers learn that beehives offer an extraordinary food resource and drill into them.

Drumming, the term given to the sound of pecking in rapid rhythmic succession on metal or wood, causes little damage other than possible paint removal on metal surfaces; however, the noise can often be heard through-out the house and becomes quite annoying, especially in the early morning hours when occupants are still asleep. Drumming is predominantly a spring-time activity. Drumming substrates are apparently selected on the basis of the resonant qualities. They often include metal surfaces such as metal gutters, downspouts, chimney caps, TV antennas, rooftop plumbing vents, and metal roof valleys. Drumming may occur a number of times during a single day, and the activity may go on for some days or months. Wood surfaces may be disfigured from drumming but the damage may not be severe.

Sapsuckers bore a series of parallel rows of 1/4- to 3/8-inch (0.6- to 1.0-cm) closely spaced holes in the bark of limbs or trunks of healthy trees and use their tongues to remove the sap. The birds usually feed on a few favorite ornamental or fruit trees. Nearby trees of the same species may be untouched. Holes may be enlarged through continued pecking or limb growth, and large patches of bark may be removed or sloughed off. At times, limb and trunk girdling may kill the tree.

Figure 2. Yellow-bellied sapsucker, Sphyrapicus varius.

On forest trees, the wounds of attacked trees may attract insects as well as porcupines or tree squirrels. Feeding wounds also serve as entrances for diseases and wood-decaying organisms. Wood-staining fungi and bacteria may also enter the wounds, reducing the quality of the wood when cut. Woodpecker damage to hardwood trees can be costly. Wounds cause a grade defect called “bird peck” that lowers the value of hardwoods. Damage occurs to both commercial hardwoods and softwoods. Certain tree species are preferred over others, but the list of susceptible trees is extensive.

As mentioned previously, vegetable matter makes up a good portion of the food of some woodpeckers, and native fruits and nuts play an important role in their diet. Cultivated fruits and nuts may also be consumed. Birds involved in orchard depredation are often so few in number that damage is limited to only a small percentage of the crop. The crop of a couple of isolated back-yard fruit or nut trees may, however, be severely reduced prior to harvest.

In recent times, controls against wood-peckers to protect commercial crops have only rarely been necessary. Published accounts suggest that these isolated instances occurred mostly in the fruit-growing states of the far West where the Lewis’ woodpecker (Melanerpes lewis), whose flocks may number several hundred, is most often implicated

Legal Status

Woodpeckers are classified as migratory, nongame birds and are protected by the Federal Migratory Bird Treaty Act. The red-cockaded woodpecker (Picoides borealis) and the ivory-billed woodpecker (Campephilus principalis) are on the Endangered Species list and are thus offered full protection. When warranted, woodpeckers other than the endangered species can be killed but only under a permit issued by the Law Enforcement Division of the US Fish and Wildlife Service upon recommendation of USDA-APHIS-Wildlife Services personnel. Generally, there must be a good case to justify issuance of a permit. Woodpeckers are commonly protected under state laws, and in those instances a state permit may be required for measures that involve lethal control or nest destruction. Other methods of reducing woodpecker damage do not infringe upon their legal protection status. Threatened or endangered species, however, cannot be harassed.

Economics of Damage and Control

Little has been published on the economics of damage to buildings and other human-made structures. Most of what does exist relates to damage to utility poles because companies keep good records of these losses and the cost of replacements. For example, from 1981 to 1982 the Central Missouri Electric Cooperative replaced 2,114 woodpecker-damaged poles in their system at an estimated cost of $560,000. Economic losses to the timber industry in terms of damaged trees and reduction in wood quality have also been documented in several regions. Such published information is of a localized nature; the extent of damage on a nationwide basis is unknown. Little is published on the economic damage to buildings, although it is known to be substantial in some instances. In a survey of woodpecker damage to homes, Craven (1984) reported an average loss of $300 per bird incident. Damage to homes was estimated at $50,000 to $500,000 annually in Michigan, a conservative $50,000 in Louisiana, and over $100,000 in Wisconsin.

The economics of control are relatively unknown because in most situations it is difficult to predict what the damage might have been if no control was undertaken.