How to Tell the Difference Between a Downy and Hairy Woodpecker

Assess the size of the woodpeckers. Hairy Woodpeckers are approximately one-third longer than their Downy counterparts. While this may be the quickest mean to differentiate between the two species, it requires having already seen multiple woodpeckers, preferably side by side.

Assess the bill size. On Downy Woodpeckers, the bill measures roughly half the length of its head. The bill of a Hairy Woodpecker, on the other hand, is thicker and as long as the head.

Scrutinize the tail. Downy Woodpeckers possess black barring on the sides of its outer tail feathers. The tail feathers of the Hairy Woodpecker, on the other hand, are often pure white. This rule, however, is less than foolproof, because of regional variations, you may find some black barring on a Hairy, or a Downy with almost none at all.

Listen to the call. Downy Woodpeckers drop their song by a pitch, and sound almost like the whinny of a miniature horse. The call of the Hairy, on the other hand, maintains the same pitch throughout its call--a strong "woikawoikawoika."

Listen to the drumming (the sound of the pecks). Downy Woodpeckers often drum on smaller branches and with a higher pitch. Hairy Woodpeckers are louder but lower-pitched.

Pay attention to where they feed. A Downy, with its shorter bill, tends to feed right under the surface of the bark. A Hairy, with a longer bill, makes and feeds from deeper holes.