232 Birds of Colorado 



in El Pa3o co., April 5th and 15th, and there is an example taken 

 September 10th in the same county in the Aiken collection. On the 

 western slope it occurs at Grand Junction in spring. 



Habits. — ^The remarkable dissimilarity of the two 

 sexes in this Woodpecker, caused them to be at first 

 regarded as two different species. The male was known 

 as *S^. williamsoni, the female as S. thyroideus. Henshaw 

 (74) first found the two supposed species breeding together 

 at Fort Garland, and solved the difficulty w^hioh had 

 always been felt in regard to them. In most respects 

 Williamson's Sapsucker resembles the Red-naped, but 

 is apt to be somewhat shyer and more wary. It feeds 

 on insects and their larvae, but whether it bores for 

 sap like the other form, appears to be rather uncertain. 

 I have found no undoubted evidence on the subject. 

 It has rather a shrill cry, " Huit, huit." Gale says : 

 " This species affects generally old pine or spruce trees, 

 and stumps that are rotten and easily worked, frequenting 

 the same tree for several years, but making a fresh hole 

 each year. It occasionally chooses aspens, but if it 

 excavates for itself it chooses a rotten tree. Sometimes 

 it uses an old hole of a Red-naped Sapsucker." 



The male does most of the work, both of excavation 

 and incubation ; when the female is on the nest, he sits 

 on a branch near by and warns her of danger by a special 

 tapping. The eggs, five or six in number, are laid from 

 about May 30th to June 15th. They are white and 

 often somewhat pyriform in shape, which is unusual 

 in this family. They average "95 x "68. 



Genus PHLCEOTOMUS. 



Of large size — wings 8 to 10 ; bill stout, longer than the head, with 

 well marked culminal and lateral ridges ; head conspicuously crested ; 

 toes four, the outer posterior (fourth) shorter than the outer anterior 

 (third) ; plumage chiefly black with a red crest. 



Only two closely allied subspecies found in the United States. 



