Western Gnatcatcher 513 
The eggs, generally eight in 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 Ist to 30th, and believed 
that a second brood was often raised in July. 
Genus POLIOPTILA. 
Small slender birds—wing under 2-5, with w 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 cerulea obscura. 
A.0.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; tarsus -70. 
The female is slightly duller in colour above and lacks the black 
frontal band ; young birds are very like 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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