Woodpeckers vary in size from the small 6 1/2-inch downy woodpecker to the large 16- to 19 1/2-inch pileated woodpecker. Woodpeckers use their beaks to excavate holes in hollow trees when a natural cavity cannot be located in which to lay their eggs and breed their young. Many species of woodpeckers dwell in man-made birdhouses, although each species has its own nesting preferences and requirements.
Birdhouses must be constructed with the size of the woodpecker in mind. Different species require different floor size and height dimensions. For downy woodpeckers, floor size should be 4 by 4 inches and height 8 to 10 inches. Red-headed, red-bellied and hairy woodpeckers prefer a floor of 6 by 6 inches and a height of 12 to 15 inches. The yellow-bellied sapsucker prefers a floor of 5 by 5 inches and a height of 12 to 15 inches. Flickers require a 7 by 7 floor and height of 16 to 18 inches. Pileated woodpeckers require an 8 by 8 floor and a height of 16 to 24 inches.
Diameter of Opening
The diameter and location of the entrance hole varies between species. The entrance hole must be large enough to allow the woodpecker to enter and exit the nesting the box, but should not be too large, which invites other species or even animals to invade the box. The downy woodpecker requires a 1 1/4-inch opening located 6 to 8 inches from the floor. Red-headed, red-bellied, hairy woodpeckers and yellow-bellied sapsuckers prefer an opening located 9 to 12 inches from the floor, with a diameter of 2 inches, 2 1/2 inches, 1 1/2 inches and 1 1/2 inches, respectively. Flickers require an opening of 14 to 16 inches height and diameter of 2 1/2 inches. Entrance for pileated woodpeckers are 12 to 20 inches above the floor and 3 to 4 inches in diameter.
The preferred habitat for woodpeckers is woodland edge. Edge is the transition area located between deep woods and open areas. Edge generally has small trees and bushes along with grasses and weeds. Home gardens planted with trees of various heights and shrubbery create conditions resembling naturally occurring edge. Woodpecker nest boxes may be fastened to existing trees or mounted on a pole.
Different species of woodpeckers prefer to nest at different heights. Woodpecker houses should be placed at least 5 feet from the ground. Most species prefer higher locations, up to 20 feet from the ground. Pileated woodpeckers nest as high as 25 feet from the ground. When placing boxes, keep in mind your own accessibility to the house for cleaning and repair when necessary.