Natural History

Woodpeckers are 7 – 15 inches long, have short legs, and stiff tails. The woodpeckers diet consists mainly of insects, vegetable matter, berries and tree sap. Woodpeckers drum to mark territories, build nest cavities, attract mates, and find food. Woodpeckers are cavity nesters, excavating a nest in living or dead wood. Clutch size ranges from four to six eggs. Young hatch in 11 to 14 days. Young birds fledge the nest from 21 to 30 days. Woodpeckers and all other migratory birds are protected by federal, state, and local laws.

Human Conflict with Woodpeckers

Woodpeckers can cause property damage by drilling holes in wood siding and eaves. When attracting a mate, woodpeckers will often drum on wooden shingles, metal / plastic gutters, television antennas, light posts, and chimney caps. Drumming is most common during early morning and later afternoon hours, and usually ends by July 1st.

Control Methods for Drumming

Methods that have found to be successful include: mylar streamers (reflective strips 2 to 3 ft long), aluminum pie tins, and balloons. Hang any of these items above the area where the damage is occurring, and allow the wind to blow them freely.

Some research also suggests that mirrors frighten woodpeckers. Fastening mirrors flat against the wall next to the damaged area is believed to be effective when the woodpecker sees its own image and it thinks it is in another birds’ territory.

When woodpeckers are persistent, two or more visual repellents are recommended.

Control Methods for Cavity/Nest Excavating

Visual repellents can also be effective in discouraging woodpeckers excavating a nest. The most effective method to avoid damage yearly is to provide the woodpecker with a nest box. Placing cavity type nest boxes on buildings suffering from woodpecker damage has been very successful in the Larimer County area. Once established, nesting woodpeckers defend their territories and keep other woodpeckers away.

Nest boxes appropriate for woodpeckers must have a 2 1⁄2 - inch – diameter entrance hole 16 to 20 inches above the floor of the box. The inside dimensions should be about 6" X 6", and the total height should be 22 to 26 inches. The box should be packed with sawdust. The nesting bird will remove the sawdust, and be fooled into thinking it has just excavated its own nest.

Woodpeckers occasionally drill on houses to obtain the insects in the wood. Insect infestation is not common in well-seasoned wood. In Colorado, woodpeckers usually hammer holes to obtain insects primarily within the first two years following new home construction. Insecticides or wood preservatives may deter woodpeckers by killing the insects.