124 BULLETIN 17 4, UNITED STATES NATIONAL MUSEUM 



extremes measure 23.6 by 18.1, 20.8 by 16.8, and 21.5 by 16.5 milli- 

 meters. 



Behavior. — The plumages, feeding habits, and general behavior of 

 this race do not differ materially from those of the species elsewhere, 

 but Maj. Allan Brooks (Dawson and Bowles, 1909) has given a good 

 description of a habit that seems to be shared by both species of 

 Pico ides and that has been referred to by others; he writes : 



When shot, even if instantly killed, three-toed woodpeckers of both species 

 have a marvelous faculty of remaining clinging to the tree in death. Where 

 the trunks are draped with Vsnea moss, it is impossible to bring one down, ex- 

 cept when winged — then they attempt to fly, and fall to earth ; but when killed 

 outright they remain securely fastened by their strong curved claws. * * * 

 The only chance Is to leave the bird and to visit the foot of the tree when the 

 relaxing muscles have at length permitted the body to drop — usually within two 

 days. Once I was fortunate enough to observe the exact position that enabled 

 the bird to maintain its grip. I had shot and killed an Arctic Three-toed Wood- 

 pecker on a low stump. On going up I found the bird's feet to be three inches 

 apart by measurement ; the tail was firmly braced, and the further the body was 

 tilted back the more firmly the claws held in the bark. 



Dr. Grinnell (1900) says: "In the fall and mid- winter these birds 

 are silent and seldom seen. But after the first of March their drmn- 

 ming on some resonant dead tree was heard nearly every morning. 

 This sound could be heard a long distance through the quiet woods, 

 giving notice of the whereabouts of the woodpeckers." 



PICOIDES TRIDACTYLUS DORSALIS Baird 



ALPINE THREE-TOED WOODPECKER 

 HABITS 



This race of the three-toed woodpeckers enjoys the most southern 

 distribution of any of the birds of this genus, ranging from northern 

 Montana to northern Arizona and New Mexico, in the boreal forests 

 of the Rocky Mountains. Ridgway (1914) characterizes it as "similar 

 to white-backed examples of P. a. fasciatus^ but larger; white mark- 

 ings on back usually all longitudinal (very rarely with any transverse 

 bars of black), white supra-auricular streak usually broader, forehead 

 usually with more black and less whitish spotting, white spots or 

 bars on inner web of innermost secondaries larger, and sides and 

 flanks usually less barred with black." 



The Weydemeyers (1928) say that in northwestern Montana, "un- 

 like arcticics, this species prefers dense, virgin forests to cut-over 

 woods and open w^oodland pastures. * * * in the higher eleva- 

 tions, this woodpecker may be found in white pine, lodgepole pine, 

 alpine fir, and Engelmann spruce forests. In the Transition zone, 

 it shows a preference for spruce woods, with larch and yellow pine 

 forests as second choice. In the Canadian zone, this species is some- 



