How to Manage Pests
Pests in Gardens and Landscapes
Woodpeckers (Melanerpes spp.), sapsuckers (Sphyrapicus spp.), and flickers (Colaptes spp.) belong to an interesting and well-known group of birds in the family Picidae. There are 17 species found in California, 2 of which are California-listed endangered species. They are all referred to as woodpeckers.
IDENTIFICATION AND BIOLOGY
Woodpeckers vary in size and range from about 7 to 14 inches in length, usually with brightly contrasting coloration. Most males have some red on the head, and black and white markings are common on many species.
Woodpeckers have short legs with 2 sharp-clawed, backward-pointed toes and stiff tail feathers that serve as a support prop. Such physical traits permit them to cling easily to trees or wood surfaces. They have stout, sharply pointed beaks and a long tongue for extracting larvae and other insects from wood crevices. Because they are dependent on trees for shelter and food, woodpeckers are commonly found within or on the fringes of wooded or forested areas.
Part of a woodpecker's breeding behavior is a rhythmic tapping or repetitive drumming on hard surfaces using the bill. This drumming is a way of proclaiming breeding territory and social significance. Woodpeckers prefer drumming surfaces that resonate loudly. They frequently bypass wood and use metal gutters and downspouts, metal chimney caps, or metal rooftop ventilators. Both male and female woodpeckers drum. This activity may be annoying to household residents, especially if it starts in the early morning hours.
Woodpeckers come into conflict with people when they use human dwellings in their search of food, as a surface for territorial or social drumming, or for nest construction. These activities not only create disturbing noises but, more importantly, may cause structural damage. Pecking damage can occur on wooden siding, eaves, trim boards, or window frames. Some research suggests that houses with wood siding that are painted or stained with earth tones are more likely to suffer woodpecker damage than houses painted white or pastel colors. One study found that in wooded yards, stained houses suffered more damage than did painted or non-wood houses.
Cedar and redwood siding seem most vulnerable, especially rough-hewn veneer-type plywood. Reverse board-and-batten veneer plywood is particularly prone because of gaps created as a result of the manufacturing process. These gaps provide hidden spaces that harbor insects, which in turn, attract woodpeckers in search of food.
When searching for insects, woodpeckers leave a series of small holes all in a row, which is characteristic damage. Woodpeckers will also peck larger holes in wood siding to create nests in the wall cavity. Exploratory pecking is commonplace. The damage tends to be on houses in or near natural wooded areas and most often occurs in suburban or rural settings.
Gardeners and landscapers may notice a series of small holes in rows pecked through the bark of a tree trunk or tree limb by a sapsucker seeking food. Over time, this continuous activity extends the number of rows of holes, and the resulting loss of sap may weaken the tree and provide access for harmful insects or plant diseases. Woodpeckers may also remove the bark as they search for insects, creating a patchy design on the tree. Some species of woodpeckers feed on fruits, berries, and nuts, but crop damage rarely constitutes a significant problem.
Acorn woodpeckers place numerous acorns in holes they drill in buildings, wooden fence posts, utility poles, and old tree snags. The acorn woodpecker may also take a quicker approach and wedge acorns beneath wooden shakes or shingles and in the process be very destructive. Acorn woodpeckers may accumulate and store hundreds to thousands of acorns in a single season.
All woodpeckers are protected under the Migratory Bird Treaty Act of 1918 as migratory insectivorous birds and are classified as non-game by the State of California. Two California woodpeckers (Gila woodpecker, Melanerpes uropygialis and gilded flicker, Colaptes chrysoides) are California-listed endangered species and are offered greater protection. When warranted, woodpeckers other than endangered species can be killed, but only under a permit issued by the Law Enforcement Division of the U.S. Fish and Wildlife Service upon recommendation of the U.S. Department of Agriculture, Animal and Plant Health Inspection Service (USDA-APHIS) Wildlife Services personnel. Generally, there must be a good case to justify a permit and the permit process is time-consuming.
Control methods that do not harm the bird or its active nest are allowed except for the two endangered species. Those species cannot be harassed or bothered in any way. Physical exclusion, if installed before the endangered species is in the area, is allowed. For more information on these and other endangered species, see the website or contact the main office of USDA-APHIS Wildlife Services in your state.
Several methods have been used to prevent damage or to frighten woodpeckers from a site. Physical exclusion is by far the most effective. Don’t wait for a woodpecker to establish a pattern of behavior before you act. The sooner you implement one or more of the following management suggestions, the better chance you have of preventing further damage. Removing food attractants can help prevent a food-driven woodpecker problem from developing. Keep your wood finish, trim, and decking in good condition to minimize chances of an insect infestation. Caulking holes and cracks and applying a wood preservative may also help. More often than not, frightening devices or repellents fail to provide the desired result.
Woodpeckers, like many other birds, are so visible that little specific monitoring information is needed. In the case of woodpeckers, they may be heard pecking and drumming even before they are seen. Hearing their activity over several consecutive days is a cue for a visual inspection. Vacation homes in forested areas should be checked for damage several times during the spring and fall.
Bird netting is the most effective method to stop damage to a building. This prevents woodpeckers from gaining access to wood siding or other wood surfaces. The lightweight, 3/4-inch mesh can be stretched from the eaves to a lower point on the building. Alternatively, the netting can be stretched over any flat surface subject to damage, leaving at least 3 inches of space between the netting and damaged surface so that the birds cannot cause further damage through the mesh. If the appropriate type and color of netting is selected and properly installed, it is barely visible from a distance of a few yards and will offer a long-term solution to prevent subsequent damage. Remember that you may have to net the entire side of a building; otherwise, the woodpecker may move just beyond the netted area and continue its activities. Bird netting is available at many hardware stores, retail garden centers, and farm supply stores as well as from online sources.
When attaching the net, ensure it can be pulled taut. This prevents flapping in the wind, which looks unsightly and results in tangles or breakage at mounting points. The net should not have any loose pockets or wrinkles that could trap and entangle birds.
Netting can be attached using tape, staples, or hooks on the eaves and the side of the building. An advantage of hooks is that the net can be taken down for maintenance of light fixtures, painting, and other activities. If staples are used, use rust-resistant types to avoid unsightly rust stains on the building. When using hooks, a supporting framework of wooden dowels, wood laths, or metal rods along the netting edges will ease attachment and create uniform tension on the net. Netting may also be wrapped once or twice around wood laths and nailed directly to the building. It should extend from the edge of the outer eaves down the side of the building to the point where the eaves' protection from the elements is lost.
Extensive netting may be a bigger task than some residents want to assume, especially if it involves a 2-story building. In this case, it may be advisable to call a bird control or pest control professional for assistance in fitting the net. Netting is increasingly used to curtail woodpecker damage because it consistently provides the desired result.
Sections of lightweight sheet metal or 1/4-inch hardware cloth may also be fastened directly over the woodpecker-damaged areas. If done at the first sign of damage the bird may be discouraged and move on to another location. This metal sheeting or wire mesh can be painted to match the siding. This method is most useful where only one or a few relatively small areas have been damaged. If the woodpecker is doing territorial drumming, wrapping the chimney or metal vents with hardware cloth or chicken wire may help. If a sapsucker is damaging a tree, wire mesh, such as chicken wire, wrapped around the tree trunks or limbs will often persuade the bird to relocate. In most cases, it will be necessary to protect a large area with mesh because the woodpecker will move to a nearby area and begin pecking again.
Models of hawks, owls, and snakes are ineffective as frightening devices. Plastic twirlers, windmills fastened to the eaves, compact discs (CDs) hung by string, aluminum foil or brightly colored plastic strips hung from above repel by movement and reflection and have been used with some success. Various other gadgets or devices are marketed for frightening woodpeckers, some claiming they resolved a particular woodpecker problem. This is possible only if the woodpecker has not become well-attached to that particular location. Once established, woodpeckers are persistent and are not easily driven from their territory or selected pecking site.
Many chemicals with objectionable tastes or odors have been tested for repelling woodpeckers with little or no success. On buildings, sticky or tacky bird repellents such as Bird-X Bird Repellent Gel may help, but some have cautioned that they may damage trees if applied directly to the bark, stain surfaces, attract and hold dirt, or may coat birds’ feathers, which can harm them. Carefully read and follow label directions on any such products.
Other Control Methods
Fill all visible holes with putty or replace damaged siding to prevent woodpeckers from seeing the holes and using them as a visual clue that there may be insects. For cedar siding or log houses, check the building for insect infestation and treat as necessary.
Other methods that are sometimes suggested include feeding suet to the woodpecker in the hope of discouraging damage. Placing nest boxes on nearby buildings, poles, or trees has also been advised. However, research shows that placing food or nesting boxes in the area does not consistently reduce the problem. These methods may, in fact, attract more woodpeckers.
Some advise against removing dead trees near the house, as that may worsen problems with woodpeckers. If acorn woodpeckers are causing damage, setting up an old tree snag for them to store their acorns instead of using your house may help, but this is unproven.
Woodpeckers can be removed only with a permit specifying trapping or shooting as the control method.
Harding EG, Curtis PD, Vehrencamp SL. 2007. Assessment of management techniques to reduce woodpecker damage to homes. Journal of Wildlife Management 71:2061–2066.
Harding EG, Vehrencamp SL, Curtis PD. 2009. External characteristics of houses prone to woodpecker damage. Human–Wildlife Interactions: Vol. 3: Issue 1, Article 18. doi.org/10.26077/j5dd-pm32 [Accessed on March 16, 2022].
Salmon TP, Whisson DA, Marsh RE. 2006. Wildlife Pest Control Around Gardens and Homes, 2nd Ed. UC ANR Publication 21385. Oakland, CA.
Pest Notes: Woodpeckers
AUTHOR: Carolyn A. Whitesell, UC Cooperative Extension San Mateo-San Francisco Counties.
Based on a previous version by TP Salmon, UC Cooperative Extension, San Diego Co.; DA Whisson, Wildlife, Fish, and Conservation Biology, UC Davis; and RE Marsh, Wildlife, Fish, and Conservation Biology, UC Davis.
TECHNICAL EDITOR: K. Windbiel-Rojas
Produced by University of California Statewide IPM Program
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