118 BULLETIN" 174, UNITED STATES NATIONAL MUSEUM 



water, and were in spruce, tamarack, pine, balsam, and cedar trees." 

 The nests of this woodpecker are not always so low down as those 

 mentioned above ; Col. John E. Thayer took a set, near Upton, Maine, 

 on June 9, 1898, that was 20 feet from the ground in an old dead 

 spruce stub; and the nests that Mr. Eaton (1914) found in the 

 Adirondacks "were situated in tamaracks and spruces from 25 to 

 40 feet from the ground." 



Eggs. — Four seems to be the usual number of eggs laid by this 

 woodpecker ; I can find no record of either more or fewer in complete 

 sets. The eggs are ovate, pure white, and only moderately glossy. 

 The measurements of 43 eggs average 23.32 by 18.01 millimeters ; the 

 eggs showing the four extremes measure 25.5 by 18.2, 23.8 by 19.6, 

 and 20.1 by 15.0 millimeters. 



Young. — The period of incubation is said to be about 14 days, 

 and it is shared by both sexes. Both parents feed and care for the 

 young, even after the young leave the nest, as family parties are seen 

 traveling about together in summer. 



Plmnages. — The nestlings are probably hatched naked and blind, as 

 with other woodpeckers, but the juvenal plumage is acquired before 

 the young leave the nest. In the juvenal plmnage, the young male is 

 similar to the adult male, but the yellow crown patch is smaller and 

 less sharply defined; the upper parts are duller, brownish black 

 instead of sooty black; the flanks are more heavily and more exten- 

 sively banded, or spotted, with sepia instead of clear black; the white 

 of the throat and breast is tinged with pale buffy. The juvenal 

 female is similar to the young male, but the yellow crown patch is 

 smaller, and the amount of yellow in it is very variable, sometimes 

 only a few scattered feathers and sometimes a well-defined, clear 

 patch. This plumage is worn at least through August and probably 

 well into fall. The only molting adults I have seen were taken in 

 August. 



Food. — The feeding habits of the American three-toed woodpecker 

 are almost identical with that of the Arctic three-toed. Prof. 

 F. E. L. Beal (1911) says: 



The largest item with both species is wood-boring coleopterous larvae. These 

 amount to 64.25 percent with arcticus and 60.66 with americanus. Caterpillars, 

 which in this case are mostly wood-boring species, amount to 12.88 and 14.45 

 percent for the two birds respectively. The total of wood-boring larvae, in- 

 cluding both caterpillars and beetles, is, 77.13 percent for arcticus and 75.11 

 percent for americanus, or more than three-fourths of the food of both 

 species. * * * 



Fruit skins were found in only one stomach of americanus and mast in but 

 one stomach of arcticus. Cambium was found in 10 stomachs of arcticus and 

 8 of americanus. This indicates that these birds do some pecking at the bark 

 of living trees for other purposes than getting insects, but no complaints have 

 yet been made, from which we infer that little or no damage is done; in fact 

 the amount contained in the stomachs is not large a little less than 10 percent. 



