THE WHITE-HEADED WOODPECKER. 73 



I consider the White-headed Woodpecker a rather silent and more sedate 

 bird than most of the other members of this family, the only note I have heard 

 it utter being a sharp, clear "witt-witt" as it passes from one tree to another. 

 During- the winter its food consists principally of spiders and insects and their 

 larvae; and in summer, as Mr. Charles A. Allen, of Nicasio, California, informs 

 me, "It feeds its young on the large black ants with which all the dead pines 

 and stumps are covered at that time of year." 



Nidification usually begins about the middle of May and continues through 

 June. The sexes relieve each other in the preparation of the nesting site, which 

 is usually located in a dead stub of a pine or fir; one that is partly decayed 

 seems to be preferred as it rarely excavates one in solid, hard wood. The nesting 

 sites are seldom situated over 15 feet from the ground, and sometimes as low 

 as 2 feet. The entrance hole is about IJ inches wide, perfectly circular, and 

 just large enough to admit the bird; the inner cavity gradually widens towards 

 the bottom, and is usiially from 8 to 12 inches deep, the eggs lying on a slight 

 layer of fine chips, in which they become well embedded as incubation advances. 

 Occasionally a rather peculiar site is selected. Mr. Charles A. Allen found a 

 nest of this species in a post in one of the snow sheds on the Central Pacific 

 Railroad, between Blue Canyon and Emigrant Gap, aboiit 40 feet from the 

 entrance of the shed, and some thirty trains passed daily within a few feet of 

 the nest, which contained six eggs when found. Incubation lasts about fourteen 

 days, and both sexes assist in this, as well as in the care of the young, which are 

 born blind and remain so until about half grown. 



The number of eggs to a set varies from three to seven, sets of four being 

 most common. There is only a single set of five in the United States National 

 Museum collection, taken by Mr. L. Belding, at Big Trees, California, on June 

 8, 1879; hnt Mr. Charles A. Allen writes me that he has found seven eggs in 

 one of their nests. These vary in shape from ovate to short ovate ; the shell 

 is pure white, fine grained, and only moderately glossy. When fresh and 

 unblown the}^ are of a delicate pinkish tint and semitranslucent, and the yolk 

 can be plainly seen; as incubation advances they become more and more 

 opaque. 



The average measurement of forty-one specimens in the United States 

 National Museum collection is 24 by 18.07 millimetres, or about 0.95 by 0.71 

 inch. The largest egg of the series measures 25.40 by 19.30 millimetres, or 1.00 

 by 0.76 inch; the smallest, 21.84 by 17.78 millimetres, or 0.86 by 0.70 inch. 



The type specimen. No. 19436 (not figured), from a set of four eggs, Ben- 

 dire collection, was taken by the writer, near Camp Harney, Oregon, on May 

 6, 1877. 



