There are 22 species of woodpeckers in the United States, including two that are endangered: the red-cockaded (
Picoides borealis) and the recently re-discovered ivory-bill (
Campephilus principalis). Most woodpeckers are year-round residents, but a few, notably the sapsuckers, are migratory.
All members of Picidae, the woodpecker family, share several characteristics that make them well-suited to their fascinating lifestyle. Their chisel-like bills and sharply-pointed, extra-long tongues are adapted to drilling and probing under tree bark, while their strong claws and stiff tail feathers help prop them up on tree trunks or branches as they work. Moreover, the feathers around their nostrils filter wood dust, and their thick skulls have special sacs that cushion the brain from impact. Interestingly, studies of this aspect of woodpecker biology have lent some insight into protecting humans from head injuries.
Most woodpeckers are residents of mature open woodlands and feed primarily on wood-boring insects, such as carpenter ants and bark beetles, which the birds dig out with their powerful beaks. They also eat gypsy moths, tent caterpillars, and grasshoppers. Some species favor a diet consisting of plant material, such as nuts, fruit, berries, or tree sap. During the winter, many woodpeckers are also readily attracted to birdfeeders stocked with suet or sunflower seeds.
Woodpeckers tend to concentrate their drilling energies on dead trees as opposed to healthy ones; by eating the insects in dead trees, they prevent those harmful pests from spreading to healthy trees. Woodpeckers are beneficial as well for many species of birds and mammals, who make ample use of woodpecker holes as dens or nests.
