A History of North American Birds, Land Birds. Volume 1. Robert Ridgway

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      Mr. Ridgway found this species very abundant among the Wahsatch Mountains, where it was one of the most characteristic summer birds of that region. It was breeding plentifully in the cañons, where its song could be heard almost continually. It inhabited an intermediate position between T. auduboni and T. fuscescens, delighting most in the shrubbery along the streams of the cañons and passes, leaving to the T. auduboni the secluded ravines of the pine regions higher up, and to the T. fuscescens the willow thickets of the river valleys. He did not meet with it farther west than the East Humboldt Mountains. The song, in his opinion, resembles that of the Wood Thrush (T. mustelinus) in modulations; but the notes want the power, while they possess a finer and more silvery tone.

      The song of this species has a certain resemblance to that of T. pallasi, being yet quite distinct, and the differences readily recognized by a familiar ear. It is more prolonged; the notes are more equal and rise with more regularity and more gradually, are richer, and each note is more complete in itself. Its song of lamentation when robbed of its young is full of indescribable pathos and beauty, haunting one who has once heard it long after.

      When driven from the nest, the female always flies to a short distance and conceals herself; making no complaints, and offering no resistance.

      These birds, in a single instance, have been known to reach Eastern Massachusetts early in April, in an unusually early season, but they generally pass north a few weeks later. They make no prolonged stay, and are with us rarely more than three or four days. Their return in the fall appears to be, at times, by a more inland route. They are then not so numerous near the coast, but occasionally are abundant.

      Their nests in Nova Scotia, wherever observed, were among the thick woods, on horizontal branches of a forest-tree, usually about five feet from the ground. Those observed in the Arctic regions by Mr. Kennicott were frequently not more than two feet from the ground.

      The nests average about four inches in diameter and two in height, the cavity being three inches wide by about one and a half deep. They are more elaborately and neatly constructed than those of any other of our thrushes, except perhaps of T. ustulatus. conspicuous among the materials are the Hypnum mosses, which by their dark fibrous masses give a very distinctive character to these nests, and distinguish them from all except those of the T. ustulatus, which they resemble. Besides these materials are found fine sedges, leaves, stems of equisetaceous plants, red glossy vegetable fibres, the flowering steins of the Cladonia mosses, lichens, fine strips of bark, etc.

      The eggs, which are four or five in number, exhibit noticeable variations in size, shape, and shades of coloring, bearing some resemblance to those of T. ustulatus and to the eggs asserted to be those of T. nanus, but are sufficiently distinct, and are still more so from those of T. aliciæ. They range in length from .83 to .94, with a mean of .88, their mean breadth is .66, the maximum .69, and the minimum .63. Their ground color is usually bluish-green, sometimes light blue with hardly a tinge of green, and the spots are of a yellowish-brown, or russet-brown, or a mixture of both colors, more or less confluent, with marked variations in this respect.

Turdus swainsoni, var. ustulatus, NuttallOREGON THRUSH

      Turdus ustulatus, Nuttall, Man. I, 1840, 400 (Columbia River).—Baird, Birds N. Am. 1858, 215, pl. lxxxi, fig. 1.—Ib. Rev. Am. B. 1864, 18.—Cooper & Suckley, P. R. Rep. XII, II, 1860, 171.—Ridgway, Pr. A. N. S. Philad. 1869, 127.—Dall & Bannister, Tr. Chic. Acad.—Cooper, Birds Cal., 5.

      Sp. Char. General appearance of fuscescens, but with pattern of swainsoni; the buff orbital ring as conspicuous as in latter. The olive above is more brown than in this, and less yellowish than in fuscescens, becoming decidedly more rufescent on wings and less observably so on tail. Pectoral aspect different from fuscescens, the spots narrower and cuneate, sharply defined, and arranged in longitudinal series; in color they are a little darker than the crown. Length, 7.50; wing, 3.75; tail, 3.00; tarsus, 1.12.

      Hab. Pacific Province of United States. Tres Marias Isl., Guatemala (winter), Mus. S. I.

      This well-marked race is to be compared with swainsoni, not with fuscescens, as has generally been done; the latter, except in shade of colors, it scarcely resembles at all; still greater evidence that such is its affinity is that the T. ustulatus builds its nest on a tree, and lays a spotted egg, like swainsoni, while fuscescens nests on or near the ground, perhaps never in a tree, and lays a plain blue egg. The song of the present bird is also scarcely distinguishable from that of swainsoni. Upon the whole, we see no reason why this should not be considered as a Pacific Province form of the Turdus swainsoni; at least it becomes necessary to do so, after referring to T. pallasi as geographical races, the T. auduboni and T. nanus.

      Habits. So far as we are aware, this thrush has a very limited distribution, being mainly restricted to the Pacific coast region from California to Alaska in the breeding season, though migrating southward in winter to Guatemala. Dr. Kennerly found it in great abundance breeding at Chiloweyuck Depot, July 3, 1859. Dr. Cooper also found it one of the most abundant of the summer residents in Washington Territory, arriving there in May and remaining until the beginning of September. Three specimens of this thrush were obtained at Sitka, by Mr. Bischoff. Mr. Ridgway met with only a single specimen east of the Sierra Nevada, though on that range he found it an abundant summer bird.

      In its general appearance it has a marked resemblance to Wilson’s Thrush (T. fuscescens), but its habits and notes, as well as its nest and eggs, clearly point its nearer affinity to Swainson’s Thrush (T. swainsoni), its song being scarcely different from that of the latter species. Like this species, it frequents the thickets or brushwood along the mountain streams, and, except just after its arrival, it is not at all shy. In crossing the Sierra Nevada in July, 1867, Mr. Ridgway first met with this species. He describes it as an exquisite songster. At one of the camps, at an altitude of about 5,000 feet, they were found unusually plentiful. He speaks of their song as consisting of “ethereal warblings,—outbursts of wild melody.” “Although its carols were heard everywhere in the depth of the ravine, scarcely one of the little musicians could be seen.” “The song of this thrush,” he adds, “though possessing all the wild, solemn melody of that of the Wood Thrush (T. mustelinus) is weaker, but of a much finer or more silvery tone, and more methodical delivery. It is much like that of the T. swainsoni, but in the qualities mentioned is even superior.”

      Dr. Cooper found its nests with eggs about the middle of June. These were most usually built on a small horizontal branch, and were very strongly constructed of twigs, grasses, roots, and leaves, usually covered on the outside entirely with the bright green Hypnum mosses peculiar to that region, which in the damp climate near the coast continue to grow in that position, and form large masses. The number of eggs is usually five.

      Dr. Cooper states that these thrushes sing most in the early morning and in the evening, when numbers may be heard answering one another on all sides. They do not affect the darkest thickets so much as the Hermit Thrush, but are often seen feeding in the gardens in the open sunshine.

      Dr. Suckley, who found them quite abundant in the neighborhood of Fort Steilacoom, on the edge of the forest, and in swampy land, describes the song as a low, soft, sad, and lively whistle, confined to one note, and repeated at regular intervals. Mr. Nuttall, the first to describe this form, speaks of it as shy and retiring, and as in the habit of gathering insects from the ground. His ear, so quick to appreciate the characteristics of the songs of birds, which showed a close resemblance between the notes of this bird and that of Wilson’s Thrush (T. fuscescens), enabled him to detect very distinct and easily recognizable differences. It is much more interrupted and is not so prolonged. The warble of this bird he describes as resembling СКАЧАТЬ