Woodpeckers belong to the family Picidae, which also includes sapsuckers and flickers. More than 300 species of woodpeckers are known throughout the world, and 22 species inhabit the United States. Seven species are common to Pennsylvania, and a few others visit the state in winter.
Woodpeckers are unique among birds because they drill into trees, primarily to find food, to nest, and to communicate with other members of their species. This behavior is also used by the birds to establish territories and to attract mates. Special physical adaptations, such as short legs, two sharp-clawed, backward-pointed toes, and stiff tail feathers, allow these birds to cling easily to a structure while pecking. They have stout, sharp beaks and a long tongue that can be extended a considerable distance. The bird's bill loosens bark and the tongue dislodges insects from the wood.
The flight of woodpeckers is undulating. The bird pumps its wings a few times, and then folds its wings against the body before another burst of wingbeats.
Most species can be easily identified by their prominent markings. Following are descriptions of the seven woodpeckers commonly seen in Pennsylvania.
With the exception of the extremely rare ivory-billed woodpecker, the pileated is the largest American woodpecker. About the size of a crow, it is easily distinguished from other woodpeckers by its solid black back and the appearance of a flashing white underwing during flight. Both sexes have conspicuous flaming red crests, white cheek patches, and white neck stripes. The female has a black forehead and lacks the red moustache of the male. The bird's distinctive drilling sound is loud, slow, and then softer at the end. Its call is a series of notes, never single. Pileated woodpeckers inhabit mature coniferous and mixed-hardwood forests where dead trees abound. A mainstay of their diet is the carpenter ant, but they also feed on beetles, wood-boring larvae, and wild fruits. These powerful birds are noted for the large oval to rectangular holes they cut in dead trees, live conifers, and utility poles.
This woodpecker, which is 8 to 9 inches long, is easily recognized by its zebra-patterned back, red cape, and white rump. Red covers the crown and nape in the male and the nape only in the female. The juvenile's head is brown. "Red-bellied" seems an inappropriate name because the vague reddish patch on its abdomen is difficult to see and appears almost pink.
Although it is found mainly in dense forests, this bird has adapted well to wooded suburbs. Unlike most other woodpeckers, the red-bellied prefers acorns, beechnuts, hickory nuts, and many kinds of berries to insects. It has become a popular bird at backyard feeders in Pennsylvania. It has a low, hoarse call and also produces a rattling sound.
This is a medium-sized bird, 8.5 to 9.5 inches long, and the only eastern woodpecker with an entirely red head. (The juvenile's head is brown.) Both sexes have similar black and white plumage. The large, rectangular white patches on the wings make the lower back appear white when the bird is at rest. Like the flicker, it is sometimes seen feeding on the ground. It also stores acorns in tree cavities during the winter. Its call is a raucous "kwrrk."
Left to right: Red-bellied Woodpecker, Northern Flicker and Red-headed Woodpecker
At one time this bird was called the yellow-shafted flicker to distinguish it from its western relative, the red-shafted flicker, but both are now considered the same species. The flicker is a large bird, 12 to 14 inches long, that flashes yellow under the wings and tail in flight. It displays a black patch across the top of its spotted breast and a red crescent on its nape. The male has a black moustache. Flickers are often seen on the ground feeding on insects. The call is a loud "wick, wick, wick" and sometimes a squeaky "flick-a, flick-a."
Hairy and downy woodpeckers
These two birds are easily confused. Differing only in body size and bill length, they have almost identical plumage. These are the only Pennsylvania woodpeckers that have a white back. The wings are black with white spots. The tails are black with white outer feathers on the hairy and speckled outer feathers on the downy. Both species have a white head with black crown and eye mask, and the males have a red patch on the back of the head.
The hairy, 8.5 to 10.5 inches long, is larger than the downy, 6 to 7 inches long, and its beak is as long or longer than the width of its head. The downy's beak is shorter than the width of its head. The call of the hairy is a loud, sharp "peek." The downy's call is a much softer "pik," and it also produces a rattle of descending notes. The downy is very common in Pennsylvania, the hairy less common.
Left to right: Hairy Woodpecker, Downy Woodpecker and Yellow-bellied Sapsucker
The sapsucker, which is 8 to 9 inches long, is among the smallest of the common Pennsylvania woodpeckers. The bird's finely mottled back allows it to blend into a tree's bark. The longish, white wing patch and red forehead patch are good field marks. The male has a red throat patch, whereas the female's throat is white. Immature birds are brown. Sapsuckers are noted for drilling orderly rows of small holes in trees for sap. The birds return later to feed on the sap flowing from the holes. They also roll insects, especially ants, in sap, creating a sugar-coated bolus, which they feed to their young. Their voice has a nasal, mewing sound. Their distinctive drilling sound consists of rapid thumps followed by slow rhythmic ones.
Description of damage
Although a woodpecker's ability to peck into trees when in search of food is well known, many species drill into wood where no insects exist. This behavior, known as "drumming," is a rhythmic pecking sequence. It is used by the birds to establish territories and to attract mates. Drumming is generally performed on resonant dead tree trunks or limbs; however, buildings and utility poles are also used on occasion.
Because woodpeckers are dependent on trees for shelter and food, wooden houses in forested suburbs or in rural, wooded countrysides are most apt to suffer damage. Two distinct peaks in the incidence of damage occur in spring and fall. When damage is noticed, control measures should be taken immediately, because with time the birds can become very persistent and difficult to move.
Biologists believe that woodpeckers often choose houses for drumming because houses serve as resonators and amplifiers of the drumming sounds. Infestation of insects is occasionally the cause of damage to houses by woodpeckers.
Certain types of grooved plywood siding, however, appear to be susceptible to insect damage. When the plywood is grooved to give the appearance of vertical boards, tunnels within the plywood are exposed. Insects enter the tunnels and lay eggs. This attracts woodpeckers. When any damage to wood occurs, it is best to check for insects. Some insects can overwinter in the spaces found in wooden siding, and other insects can bore into the wood. If a woodpecker discovers the insects, it will treat the house just as it would an insect-infested tree. If more than one woodpecker is visiting your home, you should probably suspect insect infestations.
Woodpecker holes may be drilled into wooden siding, eaves, or trim. Cedar, redwood, and plywood siding are most frequently damaged. Grooved plywood siding and board and batten construction with cedar can be very susceptible to drilling by woodpeckers.
In addition to inflicting structural damage to the building, woodpeckers frequently drum at dawn on downspouts, chimney caps, and antennas, as well as siding. The noise created by this activity can be a source of severe annoyance.
Prevention of damage
Researchers at Cornell University tested a number of products, including Irri-Tape Bird Repellent Ribbon, Prowler Owls, the Bird-Pro Sound System, and Scare-eyes, to determine their effectiveness in reducing woodpecker damage. All reduced damage to some extent, but none were able to completely eliminate damage. The most effective deterrent was Irri-Tape Bird Repellent Ribbon. The most expensive and least effective of the group was the Bird-Pro Sound System, which broadcasts bird distress calls. Researchers also found that houses stained with earth tones were more likely to be damaged than brightly painted houses.
One of the most effective methods of preventing woodpeckers from damaging wooden siding is to cover the area with lightweight plastic, nylon webbing, or plastic storm window material. The material should be at least 3 inches from the wall so that the bird cannot grasp the wall through the material with its sharp claws. It should be attached to the eaves or rain gutters so that it stands away from the wall. Sometimes a board must be installed along the top of the wall, to which the material can then be attached.
Small-mesh hardware cloth or welded wire can be used to cover pecked areas to prevent further damage. The repaired area should be painted to match the color of the building. Damaged areas on houses should be repaired or covered as soon as possible, because other woodpeckers will be attracted to the damaged site. If panels have to be replaced, it may be wise to add additional insulation to deaden the resonance.
Chemical treatments are limited. There are no registered toxicants for woodpecker control. Sticky repellents, such as "Tanglefoot" and "Roost-No-More," are difficult to use on siding but can be effective on rain gutters, antennas, and chimney caps. Consult an exterminator if an insect infestation is suspected.
Ornamental and shade trees
Healthy trees are rarely damaged by woodpeckers. When damage does occur, the yellow-bellied sapsucker is usually the culprit. This bird drills hemlocks, pines, and other conifers for sap in spring and also taps mature elm, maple, and hickory trees. During fall migration, sapsuckers may drill apple, hackberry, maple, and hemlock trees. Characteristically, the bird drills five to seven holes, cutting through the bark to make the sap flow. These holes are arranged horizontally and extend vertically down the trunk of the tree.
In the forest, sapsucker-pecked trees are most often those that should be culled. In orchards, apple trees may be extensively scarred by the sapsucker holes, but the shallow drilling soon heals over, and damage is not permanent. However, extensive summer drilling in birch trees, which yield high sugar sap, may kill branches or trees. Wrapping a 0.25-inch-mesh hardware cloth or burlap around the affected area is recommended to discourage sapsuckers from feeding on a favorite tree. Sticky or tacky bird repellents smeared on limbs or trunks where sapsuckers are working also discourage the birds.
Woodpeckers are classified as migratory, nongame birds and are protected by federal and state laws. Woodpeckers can be legally killed only under permits issued by the U.S. Fish and Wildlife Service and the Pennsylvania Game Commission. Any birds killed under a depredation permit must be turned over to a representative of the U.S. Fish and Wildlife Service. Woodpeckers are an ecologically beneficial group of birds with considerable aesthetic value. Killing offending birds should always be a last resort and is almost never warranted.
Prepared by Jack M. Payne, former extension wildlife specialist
Illustrated by Rae D. Chambers