464. Birds of Colorado 
The female resembles the male, but the crown is less distinctly 
slaty, and washed with olive; the throat and breast are pale slaty- 
grey ; the lores are not black, and the white eye-spots are smaller. 
An autumn male has the crown slightly tipped with brownish. A 
young bird has the crown olive-brown, not slate. 
Distribution.—Breeding in western America from British Columbia 
to Arizona and New Mexico, wintering from Lower California to 
Colombia. 
This is one of the commonest summer Warblers throughout Colorado, 
extending for a considerable distance out into the plains and to the 
western slope of the mountains, and breeding from the foothills up to 
11,000 feet. It reaches El Paso co. about the middle of May, and the 
higher elevations of the mountains towards the end of the month. 
It departs again in September. Henderson took one at 10,500 feet 
early in that month in Boulder co. 
It has been recorded as breeding in Estes Park (Chapman), near 
Gold Hill, Boulder co., 11,000 feet (Gale), Idaho Springs (Trippe), 
Middle Park (Carter), Manitou (Minot), San Juan co. (Drew), and 
La Plata co. (Morrison), and on migration at Loveland (Cooke), Denver 
(Henshaw), near Colorado Springs and at Limon (Aiken), Pueblo 
(Beckham), Fort Lyon (Thorne apud Cooke), Springfield, Baca co. 
(Warren), and Grand Junction by Miss Eggleston (Rockwell). 
Habits.—MacGillivray’s Warbler is a shy and retiring 
bird, and would generally be overlooked were it not 
for its song; it is commonest in thickets and bushes, 
along the banks of streams, but is also found among 
the scrub of the steep hill-sides. It spends a good deal 
of its time on the ground searching for insect under 
dry logs and among dead leaves, while its song “ Chee- 
chee-chee-chee,”’ is short and sweet, and not easily 
distinguished from that of the Pileolated Warbler. 
The nest is generally placed low down in bushes at 
six inches to two feet above the ground, but Minot 
found one on June 21st near Manitou in scrub-oak, about 
five feet up. It was a bulky structure built of shreds. 
of stalks and grass and lined with hair. The eggs, 
four in number, were white, finely marked with lilac 
and various browns, generally forming a wreath; they 
average "71 x °52. 
