WOODPECKERS 207 



GENUS XENOPICUS. 



399. XenopicUS albolarvatus (Cass.). White-headed Wood- 

 pecker. 



Outer hind toe long-er than outer front toe ; bill with nasal groove ex- 

 tending nearly to tip ; terminal half of bill 

 not distinctly compressed ; tongue very 

 slightly extensile. Adult male: head and 

 neck white, whole body black except for white 

 patch on winys and red patch on back of head. ^^' 



Adult female: similar, but without red on head. Young male: similar, 

 but back and red on crown duller. Length : 8.90-9.40, wing' 5.00-5.10, 

 tail 4.00-4.05. 



Distribution. — Breeds in Transition and Canadian zones of the moun- 

 tains from southern British Columbia to soutliern California, east to the 

 Blue Mountains of Oregon, eastern Idaho, and along the eastern slope of 

 the Sierra Nevada. 



Nest. — Usually 4 to 15 feet from the ground in stub of pine or fir. 

 Eggs: usually ;{ to 7, white. 



Food. — Insects and larvse which are found under the scales of pine bark. 



In the Trausition zone forests of ]N[ouut Shasta and the Sierra 

 Nevada, one of the most striking birds is the white-headed wood- 

 pecker. Impossible as it would seem at first sight, I have found 

 that the snow-white head often serves the bird as a disguise. It 

 is the disguise of color pattern, for the black body seen against 

 a tree trunk becomes one of the black streaks or .shadows of the 

 bark, and the white head is cut off as a detached Avhite spot with- 

 out bird-like suggestions. On the other hand, when the bird is ex- 

 ploring the light-barked young Shasta firs or gray, barkless tracts 

 of old trees, the white of the head tones in with the gray and is lost, 

 the headless back again becoming only a shadow or scar. But the 

 most surprising thing of all is to see the sun streaming full on the 

 wliite head and find that the bird form is lost. The white in this 

 case is so glaring that it fills the eye and carries it over to the light 

 streaks on the bark, making the black sink away as insignificant. 

 All this applies, however, only when the bird is quiet ; in motion he 

 is strikingly conspicuous, and in fiight his white wing streak makes 

 another good recognition mark. Dr. ^lerrill noticed some interest- 

 ing phases of this disguise at Fort Klamath. There, he says, the 

 pines have stubs of branches projecting an inch or two from the 

 trunk which, lit by the sun, appear white them.selves and cast a 

 black shadow. In winter when a little snow has lodged on these 

 stubs the resemblance is still greater, often leading one to mistake 

 a stub for a bird. 



Xenopicits works with apparent indifference on trunks or branches, 

 Ijike the Nuttall woodpecki-i- he often lights upside down. In hunt- 

 ing over the bark he easily backs down the trunk, or if he takes the 



