Sp. Char. Tail very slightly graduated. Upper part of the head and neck, back, wings, two central tail-feathers, line from base of bill through the eye to the black of the nape, and a line from the base of the bill running to a point on the throat, black. Under parts generally, sides of head and neck, forehead and line over the eye, rest of tail-feathers, rump, and upper tail-coverts, yellow-orange. A broad band on the wings, involving the greater and middle coverts, and the outer edges of the quills, white. Young male with the black replaced by greenish-yellow, that on the throat persistent; female without this. The first plumage of the young differs from that of baltimore in being more whitish beneath; lighter olive above, and without dark spots on back; white of middle and greater coverts connected by white edges of the latter. Length, about 7.50 inches; wing, 3.80.
Hab. High Central Plains to the Pacific; rare on Upper Missouri; south into Mexico. City of Mexico (Scl. & Salv. 1869, 362).
A closely allied Mexican species is I. abeillei of Lesson, differing principally in having the sides and rump black.
Habits. Bullock’s Oriole, the western counterpart of the eastern Baltimore, is found throughout the Pacific shore, from the great Central Plains to the ocean, and from Washington Territory to Mexico. It is not given by Sumichrast as occurring in Vera Cruz, where its place is taken, as a migrant, by the Baltimore. It was not noticed by Mr. Dresser on the Rio Grande, but in Arizona it was found by Dr. Coues to be a common summer resident. It was there seen to frequent, almost exclusively, the willows and cottonwoods of the creek-bottoms. To the small twigs of these trees its pensile nests were usually attached. It is said to arrive in Arizona late in April, and to remain there nearly through September.
In the survey of the Mexican boundary Dr. Kennerly met with this species in passing through Guadaloupe cañon, where it was often seen, but it was observed at no other point on the route. It seemed to prefer the low bushes on the hillside to the large trees. In its motions it was quick and restless, passing rapidly from bush to bush.
In Washington Territory this species is stated by Dr. Suckley to be more abundant in the sparsely wooded districts of the eastern base of the Cascade Mountains than in the Coast Range. He found it exceedingly abundant at Fort Dalles and along the eastern base of Mt. Adams. They arrive about
the 15th of May, and were very common among the low oaks of that region. He speaks of its song as very pleasant, and especially melodious early in the morning, when the bird is generally perched on the sunny side or top of an oak.
At Puget Sound, according to Dr. Cooper, these birds do not arrive until the beginning of June, and are at no time very common there. He describes their habits as similar to those of the spurius, they being shy and difficult to discover among the foliage. Their song is more like that of the Baltimore, loud, clear, and varied.
In his Report on the birds of California, Dr. Cooper states that these birds arrive at San Diego, from the south, about March 1; but at Fort Mohave, one hundred and sixty miles farther north, he saw none until a month later. Like the Baltimore Oriole, they resort to the open roads, gardens, and orchards, putting themselves under the protection of man, and repaying him both by their sweet melody and their usefulness in destroying insects. They keep chiefly in the trees and rarely descend to the ground, except to collect materials for their nests. These are suspended from the end of a branch, and are constructed of fibrous grasses, horse-hairs, strings, bits of rags, wool, hempen fibres of plants, etc. At times only a single material is used, such as horse-hair. These nests are neatly and closely interwoven in the form of a deep bag or purse, and are suspended by the edges from the forks of a branch, near its end. They have usually a depth of about four or five inches, and a diameter of about three or three and a half. In most cases they are largely made of the flaxen fibres of wild hempen plants, and by strings of this are firmly bound around the ends of the twigs to which they are suspended. They are lined within with fine, soft vegetable down. In some nests the inner bark of the silkweed largely predominates.
Dr. Cooper states that the eggs of Bullock’s Oriole are, in number, from four to six. He describes them as bluish-white, with scattered, winding streaks and hair-lines of black and reddish-brown near the larger end, measuring .98 by .60 of an inch. In the southern half of California they are laid in the first or second week of May. At Santa Cruz, in 1866, he did not observe any of this species until April 3.