Northern three-toed woodpecker
Picoides tridactylus
L 7½″
Habitat: This highly beneficial woodpecker is most common in coniferous forests of the West, but does occur occasionally in the Northeast.
Nest: The northern three-toed woodpecker excavates nest cavities each year in standing dead trees or in dead limbs of live trees with rotted heartwood (Jackman and Scott 1975). Their nest cavities have been reported in pine, aspen, spruce, and cedar trees (Bent 1939). In Arizona, we found two nests in ponderosa pine snags.
Food: The northern three-toed woodpecker is probably one of the most important birds in combating forest insect pests in the western United States. Massey and Wygant (1973) found that spruce beetles comprised 65 percent of their diet in Colorado. During the winter when other foods were scarce, the spruce beetle made up 99 percent of the food taken. West and Speiers (1959) reported that both species of three-toed woodpeckers in northeastern United States feed on elm bark beetles, which carry Dutch elm disease. Koplin (1972) estimated that 20 percent of an endemic and 84 percent of an epidemic spruce beetle population in Colorado were consumed by three species of woodpeckers, the most important of which was the northern three-toed. Other foods include ants, woodboring and lepidopteran larvae, fruits, mast, and cambium (Beal 1911, Massey and Wygant 1973).