Western Gnatcatcher 513 



The eggs, generally eight m number, are creamy-white 

 when fresh, pure white when blown, with a very fine 

 peppering of reddish-brown at the larger end ; some- 

 times this is so indistinct that the egg appears to be 

 plain white ; they measure "55 x "45 (Scott). Gale 

 found fresh eggs from June 1st to 30th, and believed 

 that a second brood was often raised in July. 



Genus POLIOPTILA. 



Small slender birds — wing under 2-5, with a straight bill rather 

 shorter than the head, broad and depressed at the base and a slightly 

 hooked tip ; nostrils exposed ; wings rounded, outer primary about 

 half the next ; tail exceeding the wing and distinctly graduated, the 

 feathers slightly club-shaped ; tarsus scutellate ; plumage chiefly ashy 

 with black and white, no bright colours. 



A genus of about twenty species and subspecies, confined to the 

 warm temperate and tropical regions of America. 



Western Gnatcatcher. Polioptila ccerulea obscura. 



A.O.U. Checklist no 751a — Colorado Records — Ridgway, 73, p. 179 ; 

 Drew 85, p. 15 ; Lowe 92, p. 101 ; Cooke 97, pp. 124, 169 ; Henderson 

 05, p. 421 ; 09, p. 241 ; H. G. Smith 08, p. 190 ; Rockwell 08, p. 179 ; 

 Cary 09, p. 184. 



Description. — Male — Above greyish-blue with a black V-shaped 

 band across the forehead to the eye ; wings dusky with whitish edgings, 

 especially on the inner secondaries ; tail and upper tail-coverts black, 

 the outer pair of tail-feathers largely white, but the black base extending 

 beyond the tail-coverts ; the second pair with the terminal third, the 

 third pair only tipped with white ; a white orbital ring ; below white, 

 washed with blueish-grey ; iris brown, bill black, legs dusky. Length 

 4-55 ; wing 2-05 ; tail 2-20 ; culmen -40 ; tarsiis -70. 



The female is slightly duller in colour above and lacks the black 

 frontal band ; young birds are very Uke the female, but rather more 

 brownish above. 



Distribution. — The drier portions of south-western North America 

 from the interior of northern California and Colorado to Colima in 

 Mexico. 



In Colorado the Gnatcatcher is a rare summer resident in the plains 

 and at low elevations up to about 7,000 feet. It arrives early in May, 

 and has been noticed at Pueblo on May 6th (Lowe), in Fremont co., 

 May 12th, and at Limon, May 23rd (Aiken coll.), and at Boulder, May 



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