In his Report of the birds observed in the survey under Lieutenant Williamson, Dr. Heermann mentions finding this species abundant, and, in the fall season, as associated with Molothrus pecoris and A. tricolor. Its nest he found built in the willow bushes and tussocks of grass above the level of the water, in the marshes. There were but a few pairs together, and in this respect they differ from the tricolor, which prefers dry situations near water, and which congregate by thousands while breeding. The nest was composed of mud and fine roots, and lined with fine grasses. The eggs, four in number, he describes as pale blue, dashed with spots and lines of black.
Neither this nor the tricolor was detected by Dr. Coues in Arizona.
These Blackbirds were found by Mr. Ridgway abundant in the marshy regions of California, but they were rarely met with east of the Sierra Nevada. A few individuals were collected in Nevada in the valley of the Truckee. A few pairs were found breeding among the tulé sloughs and marshes. The nests found in the Truckee Reservations were built in low bushes in wet meadows.
A nest procured by Dr. Cooper from the summit of the Coast Range was built of grass and rushes, and lined with finer grass. The eggs are described
as pale greenish-white, with large curving streaks and spots of dark brown, mostly at the large end. They are said to measure one inch by .75 of an inch.
Eggs of this variety in my cabinet, taken in California by Dr. Heermann, are of a rounded-oval shape, nearly equally obtuse at either end, and varying in length from .90 of an inch to an inch, and in breadth from .70 to .80. Their ground-color is a light blue, fading into a bluish-white, marked only around the larger end with waving lines of dark brown, much lighter in shade than the markings of the phœniceus usually are.
Agelaius tricolor, Bonap.
RED AND WHITE SHOULDERED BLACKBIRD.
Icterus tricolor, “Nuttall,” Aud. Orn. Biog. V, 1839, I, pl. ccclxxxviii.—Nuttall, Man. I, (2d ed.,) 1840, 186. Agelaius tricolor, Bon. List, 1838.—Aud. Syn. 1839, 141.—Ib. Birds Am. IV, 1842, 27, pl. ccxiv.—Heerm. X, S, 53 (nest).—Baird, Birds N. Am. 1858, 530.—Cooper, Orn. Cal. 1, 1870, 265.
Sp. Char. Tail nearly even. Second and third quills longest; first a little shorter than the fourth. Bill slender, not half as high as long.