588 The Roller-like Birds 



at the base of a trunk and ascend slowly, often in a spiral manner, prying into 

 crevices, knocking off pieces of bark, or digging deeply into decaying limbs, until 

 they reach the higher branches, when they repeat the process on the next tree 

 that comes handy or otherwise attracts their attention. The ground -feeding 

 species subsist largely on ants, and when they have discovered a fresh nest, usually 

 clean it up pretty thoroughly. The food of the arboreal species consists very 

 largely of insects, especially the larvae of wood-boring beetles, but most of the 

 species take a greater or less amount of vegetable matter in the form of berries, 

 seeds, acorns, or the tender inner bark of trees, while a few forms known as Sap- 

 suckers subsist, to some extent at least, on the sap of trees, causing thereby some 

 damage, since they often pierce rows of holes about the trunks or larger limbs. 

 A few species are known to store up food for the proverbial rainy day. The 

 Red-head and the California Woodpecker store acorns, beechnuts, and some- 

 times grasshoppers, in the crevices of fence rails, trunks and limbs of trees, etc., 

 in the latter case often boring regular rows of holes for the purpose, each con- 

 taining an acorn. 



Notes. The notes of Woodpeckers are rather loud and harsh, though not 

 altogether unmelodious. Especially in spring, but at other seasons as well, the 

 male, and perhaps the female also, executes the so-called "drumming," which 

 consists of rapid blows delivered on a dead limb or piece of loose bark, the 

 sound being audible often for the distance of a mile. 



In the passage between near-by trees the flight of most Woodpeckers resembles 

 the swaying of a pendulum, being downward and then upward just before alight- 

 ing, but when it is for some distance the flight is undulating and is in general so 

 characteristic that it is possible to distinguish species at some distance. 



Nests and Eggs. The nesting habits of Woodpeckers are very uniform, 

 since all deposit their eggs in cavities, either in trees or in banks. A natural 

 cavity is apparently rarely selected, but one is excavated by the birds themselves. 

 Usually the site chosen is an upright dead or decaying trunk "or large limb, 

 though some species select a perfectly solid trunk. A circular hole is first made 

 which extends in for several inches, then turns abruptly downward for a varying 

 distance, sometimes several feet, but usually not over eighteen inches. Appar- 

 ently both birds work at its construction in turn, and they are usually careful 

 to remove the chips to a considerable distance, since their accumulation at the 

 base of a tree would serve to call attention to a nest that might be otherwise un- 

 observed. The cavity is slightly enlarged at the base and is never lined, the eggs 

 being deposited on a few chips at the bottom. The eggs, which vary somewhat 

 in number with the different species, are always pure white and very glossy. 



The Woodpeckers constitute a large, almost cosmopolitan, group, of about 

 seventy genera and over four hundred species, " ranging over almost all of the 

 temperate and tropical regions, but absent in Madagascar, Australia, and 

 Polynesia." The New World is especially rich in forms, while the African 

 and Indian regions are also centers of distribution. The Woodpeckers are 

 divided into two well-marked groups, often denominated as subfamilies, in the 

 first of which the tail is spiny, all the shafts being stiffened and employed in 



