Habits. This comparatively new Warbler was first met with by Townsend, and described by Audubon in the last volume of his Ornithological Biography. It has since been found to have a wide range throughout the western portion of North America, from Cape St. Lucas to British America, and from the Plains to the Pacific. It has also been obtained at Choapan in the State of Orizaba, Mexico, by Mr. Boucard, and in Guatemala by Mr. Salvin, who states that throughout the district between the volcanoes of Agua and Fuego this was a common species, frequenting the outskirts of the forests and the edges of the clearings. It breeds in abundance in Utah, Montana, Idaho, Oregon, Washington Territory, and probably also in Northern California.
Townsend first met with it on the banks of the Columbia. He states that it was mostly solitary and extremely wary, keeping chiefly in the most impenetrable thickets, and gliding through them in a cautious and suspicious manner. Sometimes it might be seen, at midday, perched upon a dead twig, over its favorite places of concealment, at such times warbling a very sprightly and pleasant little song, raising its head until its bill is nearly vertical.
Mr. Nuttall informed Mr. Audubon that this Warbler is one of the most common summer residents of the woods and plains of the Columbia, where it appears early in May, and remains until the approach of winter. It keeps near the ground, and gleans its subsistence among the low bushes. It is shy, and when surprised or closely watched it immediately skulks off, often uttering a loud click. Its notes, he states, resemble those of the Seiurus aurocapillus. On the 12th of June a nest was brought to Mr. Nuttall, containing two young birds quite fledged, in the plumage of the mother. The nest was chiefly made of strips of the inner bark of the Thuja occidentalis, lined with slender wiry stalks. It was built near the ground in the dead, moss-covered limbs of a fallen oak, and was partly hidden by long tufts of usnea. It was less artificial than the Yellow-Throat’s nest, but was of the same general appearance. On his restoring the nest to its place, the parents immediately approached to feed their charge.
Dr. Suckley found this Warbler very abundant between the Cascade Mountains and the Pacific coast. Like all Ground Warblers it was entirely insectivorous, all the stomachs examined containing coleoptera and other insects. He did not find them shy, but as they frequented thick brush they were very difficult to procure.
Dr. Cooper found this species very common about Puget Sound, frequenting the underbrush in dry woods, occasionally singing a song from a low tree, similar to that of the Yellow-Throat. He found its nest built in a bush, a foot from the ground. It was of straw, loosely made, and without any soft lining. Dr. Cooper found this species as far east as Fort Laramie, in Wyoming. They reach the Columbia River by the 3d of May.
The same writer noticed the first of this species at Fort Mojave, April 24. He regarded their habits as varying in some respects from those of the Trichas, as they prefer dry localities, and hunt for insects not only in low bushes but also in trees, like the Dendroicæ. Dr. Cooper twice describes their eggs as white, which is inaccurate. He thinks that some of them winter in the warmer portions of California. He regards them as shy, if watched, seeking the densest thickets, but brought out again by their curiosity if a person waits for them, and the birds will approach within a few feet, keeping up a scolding chirp.
The nests of this species obtained by Dr. Kennerly from Puget Sound were all built on the ground, and were constructed almost exclusively of beautifully delicate mosses, peculiar to that country. They are shallow nests, with a diameter of four and a height of two inches, the cavity occupying a large proportion of the nest. Its walls and base are of uniform thickness, averaging about one inch. The nests are lined with finer mosses and a few slender stems and fibres.
Mr. Ridgway found these Warblers breeding in great numbers, June 23, 1869, at Parley’s Park, Utah, among the Wahsatch Mountains. One of these nests (S. I., 15,238) was in a bunch of weeds, among the underbrush of a willow-thicket along a cañon stream. It was situated about eight inches from the ground, is cuplike in shape, two inches in height, three in diameter, and somewhat loosely constructed of slender strips of bark, decayed stalks of plants, dry grasses, intermixed with a few fine roots, and lined with finer materials of the same. The cavity is one and a half inches in depth, and two in diameter at the rim.
The eggs, four in number, are .75 of an inch in length and .50 in breadth. Their ground-color is a pinkish-white, marbled and spotted with purple, lilac, reddish-brown, and dark brown, approaching black. The blotches of the last color vary much in size, in one instance having a length of .21 of an inch, and having the appearance of hieroglyphics. When these spots are large, they are very sparse.
“This species,” Mr. Ridgway writes, “inhabits exclusively the brushwood along the streams of the mountain cañons and ravines. Among the weeds in such localities numerous nests were found. In no case were they on the ground, though they were always near it; being fixed between upright stalks of herbs, occasionally, perhaps, in a brier, from about one to two feet above the ground. The note of the parent bird, when a nest was disturbed, was a strong chip, much like that of the Cyanospiza amæna or C. cyanea.” He also states that it was abundant in the East Humboldt Mountains in August and in September, and also throughout the summer. A pair of fully fledged young was caught on the 21st of July.