Left foot of an American three-toed woodpecker (<i>Picoides dorsalis</i>). By the numbers it can be seen that the hallux is absent. All three species in genus <i>Picoides</i> have this anatomy, and apart from two species in genus <i>Sasia</i>, they are the only woodpeckers to have three toes.<br>Color key to North American birds, by Frank M. Chapman ... with upward of 800 drawings by Chester A. Reed, B. S.
Chapman, Frank M.; Reed, Chester A.
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