358 Birds of Colorado 
very common. The males sit on the fence-posts or 
tall weeds, and pour out their weak but rather sweet 
little song while the females are busy on their nests. 
These are placed on the ground, generally flush with the 
surface, and concealed in the long grass to a certain 
extent. The eggs, four or five in number, are blueish 
white, spotted and blotched—sometimes so heavily as 
nearly to obliterate the ground-colour—with varying 
shades of brown. The date for fresh eggs is June or 
the beginning of July. Rockwell found it nesting 
commonly up to about 8,000 feet in Plateau Valley 
in May, June and July ; it raises two broods, and there 
the favourite nesting-site is in the alfalfa fields. 
Genus CENTRONYX. 
Small Sparrow-like birds generally resembling Passerculus, but 
with the tail longer in proportion, about -75 the length of the wing ; 
tail-feathers still narrower and distinctly pointed; inner secondaries 
elongated ; outer primary shorter than the fifth; edge of the wing 
white ; plumage streaky above and on the breast. 
This genus contains only the single species here described (see 
key, p. 355). 
Baird’s Sparrow. Centronyx bairdi. 
A.O.U. Checklist no 545—Colorado Records—Aiken 73, p. 236 
(C. ochrocephalus); Ridgway 73, p. 190; Baird, Brewer & Ridgway 
74, p. 510; Henshaw 75, p. 253; 86, p. 333; Coues 78, p. 1; Drew 
85, p. 16; Morrison 89, p. 37; Cooke 97, p. 101. 
Description.—Male—Sides and top of the head ochraceous-yellow, 
the crown and nape strongly streaked with black, tending to form two 
lateral bands of black ; upper-parts, wings and tail dusky with brown, 
light brown and often white edgings to the feathers ; edge of the wing 
white; outer pair of tail-feathers nearly white; below, the throat 
and chest with a pale wash of buffy, strongly streaked on the breast, 
sides of the throat and flanks with black ; tail-feathers narrow, attenu- 
ated and pointed; iris brown, bill brown, legs pale horny. Length 
5-0; wing 2-8; tail 2-15; culmen -40; tarsus -75. 
The above description is from a freshly moulted male, killed 
October 19th. The sexes are alike, and the young essentially like 
the adults. 
