By Dan Reinking
Among the most common and most widespread of North America's Woodpeckers, the Downy and Hairy are also among the most similar. Both have in common white underparts, mostly black wings with white spots, mostly black tails, and a white back that shows as a vertical white bar on a perched bird that is set off by the folded black wings. Both have similar head patterns as well, with a black crown and cheek outlined by white lines behind the eyes and below the cheeks. Males of each species have a red patch on the back of the head, and juveniles have reddish foreheads (something to look for in summer). Both species occur across nearly all of the United States and forested Canada, though they are scarce to absent in parts of the southwestern U.S. Of the two, Downy's are more common in most locations, and occur in a somewhat wider variety of habitats.
Most birders rely on size to instantly distinguish between these two very similar species, though we'll get to other differences between the two shortly. Hairy Woodpeckers are considerably larger than Downys, though size can be a very difficult thing to judge when looking at a lone bird. Perhaps the best feature to key in on when evaluating the size of a lone bird is the bill. Downys have a very small, short bill that may even be difficult to see if the bird is distant. Hairys have a much larger bill, both in length and diameter, something that is noticeable even at a distance.
Voice is also helpful in distinguishing the two species, and voice may often be your first clue that one or the other of these species is present. The call of the Downy Woodpecker is usually describes as a "pik", while that of the Hairy is usually described as a "peek", a distinction that doesn't mean much unless you are also told that the call of the Downy tends to be rather gentle compared to the louder, stronger call of the Hairy. A few instances of observing a calling bird whose identity you know should help you learn the difference between the calls.
There are a few subtle plumage difference between these two species that you may wish to look for, though this issue is complicated by several races of each species that very geographically from west to east. Generally speaking, Downy Woodpeckers show more white spotting on the wing coverts that do Hairy Woodpeckers. Downy Woodpeckers often show some black spotting or barring on the white outer tail feathers, while these areas are plain white in Hairys. Downys may have a more noticeable fluff of feather at the upper base of the bill than do Hairys.
Behavior can also be helpful in assigning the identity of a bird to one or the other species. Being larger, Hairy Woodpeckers prefer to forage in mature trees and do not visit very slender branches or weed stalks. While Downy Woodpeckers do forage in mature trees, they will also utilize corn stalks, weed stems, and very small trees or branches. This behavioral difference may help you identify with confidence even a very distant woodpecker seen on a weed stem.
Beginning birders often find these two species a challenge to tell apart, but with a little practice the difficulty is greatly lessened. Fortunately, the wide range of both species means that nearly everyone can observe them without traveling very far, perhaps even at a backyard feeder.
Dan Reinking grew up birding in northwest Iowa after a December visit by his uncle, an active birder, left him with a passion for birds. He has since turned bird study into an occupation, having conducted or participated in research in South Dakota, Minnesota, California, Oklahoma, Arkansas, Texas, and Venezuela. Employed with the George M. Sutton Avian Research Center in Oklahoma since 1992, he recently coordinated the Oklahoma Breeding Bird Atlas Project. He is also a member of the Oklahoma Bird Records Committee and president of the Oklahoma Ornithological Society.