FLYCATCHERS 259 



at nostril. Young : with buffy or brownish wing bars. Length : 6.20-6.75, 

 wing 3.15-3.55, tail 2.50-2.95, exposed culmen .44-51, width of bill at base 

 .27-.S2, tarsus .49-.56. 



Remarks. In richardsonii the wings and tail are slightly longer than 

 in C. virens. 



Distribution. Breeds in Transition and Upper Sonoran zones from the 

 Plains to the Pacific, and from the interior of British America to Lower 

 California ; migrates to South America. 



Nest. Saddled on horizontal limb of orchard or forest tree, 6 to 40 

 feet from the ground ; made of wood, plant fibers, down, inner bark, sage, 

 and grass tops, rarely lined with a few feathers, and sometimes covered 

 with spider's web. Eggs : 2 to 4, white, irregularly wreathed around the 

 larger end with blotches and minute specks of brown and purple. 



Food. Flies and other insects, with a few wild berries. 



In the lower Canadian zone forests the western wood pewee is 

 frequently met with, and in the Murray pine meadows of the Sierra 

 is one of the commonest birds seen. It sits with its long thin body 

 erect, and as it watches for insects gives its quiet call, well rendered 

 by Dr. Merrill as tweer or deer. In Arizona its setting is altogether 

 different, mesquite and yucca stalks being its principal perches. 



GENUS EMPIDONAX. 



General Characters. Wing less than 3.25, not more than 

 five times as long as tarsus. 



Fig. 335. 

 KEY TO ADULT MALES. 



1. Under parts buffy. Arizona and New Mexico . . py gmaeus, p. 263. 

 1'. Under parts whitish or sulphur yellow. 



2. Width of bill at nostrils decidedly greater than half the 

 exposed culmen. 



3. Under parts wholly yellowish or brownish. 



4. Under parts darker, washed with brown . . difficilis, p. 260. 

 4'. Under parts lighter, with little or no brown wash. Santa Bar- 

 bara Islands insulicola, p. 260. 



3'. Under parts partly white. 



4. Wing 2.30-2.60 ; tail distinctly emarginate. Rocky Mountains 



to Atlantic minimus, p. 261. 



4'. Wing 2.60-3.00 ; tail even or slightly rounded. 



5. Colors weaker ; bill longer and narrower . . traillii, p. 260. 

 5'. Colors stronger ; bill shorter and broader. Eastern. 



alnorum, p. 261. 

 2'. Width of bill at nostrils not greater than half the exposed culmen. 



3. Bill narrower hammondi, p. 262. 



3'. Bill broader. Fig. 337. 



4. Under mandible blackish . . . wrightii, p. 262. 



4'. Under mandible flesh-colored, tipped with black. Fig. 338. 

 Mountains of southern Arizona griseus, p. 263. 



