A REVIEW OF THE THREE-TOED WOODPECKERS 
OF NORTH AMERICA. 
BY OUTRAM BANGS. 
In North America, as is well known, two very different kinds 
of Three-toed Woodpeckers are found. These are the Picoides 
ardicus series (black-backed Three-toed Woodpeckers) , and the 
Picoides americanus series (black-and-white-backed Three-toed 
Woodpeckers). Both are boreal species and over a very large 
extent of country a representative of each occur together. Both 
species may be subdivided into geographical races — P. ardicus 
into two, P. americanus into four. Of these six races, one of 
P. ardicus, inhabiting the Cascade Mountains, and one of P. 
americanus , found in Labrador, have not before been recognized. 
There is furthermore a mistake in the synonymy of P. americanus 
which makes it necessary to give the form of northern New Eng- 
Both these Old World forms are larger than any of the P. 
americanus series, except P. americamis dorsalis, which sometimes 
nearly equals them in wing measurement. 
Synonymy. 
Picoides ardicus has escaped synonyms. It was described by 
Swainson, in 1831, as Picus (Apternus) ardicus (F. B. A., II, 
Birds, pp. xxvi and 313, pi. 57, 1831), from “a male killed near 
the sources of the Athabasca River, lat. 57 0 .” 
There are, however, two races — the typical one, extending 
from the northern Rocky Mountains to the Atlantic ; the other 
inhabiting the Cascades, and Sierra Nevada of California. 
Picoides americanus has a complicated synonymy. In most 
recent works one finds the name Picoides americanus dating from 
