Hab. Eastern North America to shores of Arctic Ocean, and along northern coast from Labrador to Kodiak, breeding in immense numbers between the mouths of Mackenzie and Coppermine. West to Fort Yukon and Missouri River States. Winters south to Costa Rica. Chiriqui, Salvin; Cuba, Gundlach.
As originally described, this species differs from swainsoni in larger size, longer bill, feet, and wings especially, straighter and narrower bill. The back is of a greener olive. The breast and sides of the head are entirely destitute of the buff tinge, or at best this is very faintly indicated on the upper part of the breast. The most characteristic features are seen on the side of the head. Here there is no indication whatever of the light line from nostril to eye, and scarcely any of a light ring round the eye,—the whole region being grayish-olive, relieved slightly by whitish shaft-streaks on the ear-coverts. The sides of body, axillars, and tibiæ are olivaceous-gray, without any of the fulvous tinge seen in swainsoni. The bill measures .40 from tip to nostril, sometimes more; tarsi, 1.21; wing, 4.20; tail, 3.10,—total, about 7.50. Some specimens slightly exceed these dimensions; few, if any, fall short of them.
In autumn the upper surface is somewhat different from that in spring, being less grayish, and with a tinge of rich sepia or snuff-brown, this becoming gradually more appreciable on the tail.
A specimen from Costa Rica is undistinguishable from typical examples from the Eastern United States.
Habits. This species, first described in the ninth volume of the Pacific Railroad Surveys, bears so strong a resemblance to the Olive-backed Thrush (T. swainsoni), that its value as a species has often been disputed. It was first met with in Illinois. Since then numerous specimens have been obtained from the District of Columbia, from Labrador, and the lower Mackenzie River. In the latter regions it was found breeding abundantly. It was also found in large numbers on the Anderson River, but was rare on the Yukon, as well as at Great Slave Lake, occurring there only as a bird of passage to or from more northern breeding-grounds.
In regard to its general habits but little is known. Dr. Coues, who found it in Labrador, breeding abundantly, speaks of meeting with a family of these birds in a deep and thickly wooded ravine. The young were just about to fly. The parents evinced the greatest anxiety for the safety of their brood, endeavoring to lead him from their vicinity by fluttering from bush to bush, constantly uttering a melancholy pheugh, in low whistling tone. He mentions that all he saw uttered precisely the same note, and were very timid, darting into the most impenetrable thickets.
This thrush is a regular visitant to Massachusetts, both in its spring and in its fall migration. It arrives from about the first to the middle of May, and apparently remains about a week. It passes south about the first of October. Occasionally it appears and is present in Massachusetts at the same time with the Turdus swainsoni. From this species I hold it to be unquestionably distinct, and in this opinion I am confirmed by the observations of two very careful and reliable ornithologists, Mr. William Brewster of Cambridge, one of our most promising young naturalists, and Mr. George O. Welch of Lynn, whose experience and observations in the field are unsurpassed. They inform me that there are observable between these two forms certain well-marked and constant differences, that never fail to indicate their distinctness with even greater precision than the constant though less marked differences in their plumage.
The Turdus aliciæ comes a few days the earlier, and is often in full song when the T. swainsoni is silent. The song of the former is not only totally different from that of the latter, but also from that of all our other Wood Thrushes. It most resembles the song of T. pallasi, but differs in being its exact inverse, for whereas the latter begins with its lowest notes and proceeds on an ascending scale, the former begins with its highest, and concludes with its lowest note. The song of the T. swainsoni, on the other hand, exhibits much less variation in the scale, all the notes being of nearly the same altitude.
I am also informed that while the T. swainsoni is far from being a timid species, but may be easily approached, and while it seems almost invariably to prefer the edges of the pine woods, and is rarely observed in open grounds or among the bare deciduous trees, the habits of the T. aliciæ are the exact reverse in these respects. It is not to be found in similar situations, but almost always frequents copses of hard wood, searching for its food among their fallen leaves. It is extremely timid and difficult to approach. As it stands or as it moves upon the ground, it has a peculiar erectness of bearing which at once indicates its true specific character so unmistakably that any one once familiar with its appearance can never mistake it for T. swainsoni nor for any other bird.
The nests measure about 4 inches in diameter and 2¾ in height. The cavity is 2 inches deep, and its diameter 2½ inches. They are unusually compact for the nest of a thrush, and are composed chiefly of an elaborate interweaving of fine sedges, leaves, stems of the more delicate Equisetaceæ, dry grasses, strips of fine bark, and decayed leaves, the whole intermingled with the paniculated inflorescence of grasses. There is little or no lining other than these materials. These nests were all found, with but few exceptions, on the branches of low trees, from two to seven feet from the ground. In a few exceptional cases the nests were built on the ground.
Occasionally nests of this species are found constructed with the base and sides of solid mud, as with the common Robin (Turdus migratorius). In these, as also in some other cases, their nests are usually found on or near the ground. So far as I am aware neither its occasional position on the ground, nor its mud frames, are peculiarities ever noticeable in nests of T. swainsoni.
The eggs were usually four in number. Their color is either a deep green tint, or green slightly tinged with blue; and they are marked with spots of russet and yellowish-brown, varying both in size and frequency. Their mean length is .92 of an inch, and their mean breadth .64. The maximum length is .94 and the minimum .88 of an inch. There is apparently a constant variation from the eggs of the T. swainsoni; those of the aliciæ having a more distinctly blue ground color. The nests are also quite different in their appearance and style of structure. The Hypnum mosses, so marked a feature in the nests of T. swainsoni, as also in those of T. ustulatus, are wholly wanting in those of T. aliciæ.
This bird and the robin are the only species of our thrushes that cross the Arctic Circle to any distance, or reach the shore of the Arctic Ocean. It occurs from Labrador, all round the American coast, to the Aleutian Islands, everywhere bearing its specific character as indicated above. It is extremely abundant on and near the Arctic coast, between the mouth of the Mackenzie River and the Coppermine, more than 200 specimens (mostly with their eggs) having been sent thence to the Smithsonian Institution by Mr. MacFarlane. In all this number there was not a single bird that had any approach to the characters of T. swainsoni, as just given. From the Slave Lake region, on the other hand, T. swainsoni was received in nearly the same abundance, and unmixed during the breeding season with T. aliciæ.
Turdus swainsoni, Cabanis
OLIVE-BACKED THRUSH; SWAINSON’S THRUSH
Turdus swainsoni, Cab. Tschudi, Fauna Peruana, 1844-46, 188.—? Sclater & Salvin, Ibis, 1859, 6 (Guatemala).—Sclater, P. Z. S. 1858, 451 (Ecuador); 1859, 326.—Ib. Catal. 1861, 2, No. 11.—Baird, Birds N. Am. 1858, 216; Rev. Am. B., 1864, 19.—Gundlach, Cab. Jour. 1861, 324 (Cuba).—Ib. Repert. 1865, 229.—Pelzeln, Orn. Brazil. II. 1868, 92 (Marambitanas, Feb. and March).—Lawr. N. Y. Lyc. IX, 91 (Costa Rica).—Ridgway.—Maynard.—Samuels, 152.—Cooper, Birds Cal. 6.—Dall & Bannister. Turdus minor, Gmelin, Syst. Nat. I, 1788, 809 (in part). Turdus olivaceus, Giraud, Birds L. Island, 1843-44, 92 (not of Linn.). (?) Turdus minimus, Lafresnaye, Rev. Zoöl. 1848, 5.—Sclater, P. Z. S. 1854, 111.—Bryant, Pr. Bost. Soc. VII, 1860, 226 (Bogota).—Lawrence, Ann. N. Y. Lyc. 1863. (Birds Panama, IV, No. 384.)
Sp. Char. Upper parts uniform olivaceous, with a decided shade of green. The fore part of breast, the throat and chin, pale brownish-yellow; rest of lower parts white; the sides washed with brownish-olive. Sides of the throat and fore part of the breast with sub-rounded spots of well-defined brown, darker than the back; the rest of the breast (except medially) with rather less distinct spots that are more olivaceous. Tibiæ yellowish-brown. Broad ring round the eye, loral region, and a general tinge on the side of the head, clear reddish buff. Length, 7.00; wing, 4.15; tail, 3.10; tarsus, 1.10.
Hab. Eastern North America; westward to Humboldt Mountain and Upper Columbia; perhaps occasionally straggling as far as California; north to Slave Lake and Fort Yukon; south to Ecuador and Brazil. Cuba, Gundlach; Costa Rica, Lawr.
Specimens examined from the northern regions (Great Slave Lake, Mackenzie River, and Yukon) to Guatemala; from Atlantic States to East Humboldt Mountains, Nevada, and from intervening localities. The extremes of variation are the brownish-olive of eastern and the clear dark greenish-olive of remote western specimens. There is no observable difference between a Guatemalan skin and one from Fort Bridger, Utah.
Habits. The Olive-backed Thrush, or “Swamp Robin,” has very nearly the same habitat during the breeding season as that of the kindred species with which it was so long confounded. Although Wilson seems to have found the nest and eggs among the high lands of Northern Georgia, it is yet a somewhat more northern species. It does not breed so far south as Massachusetts, or if so, the cases must be exceptional and very rare, nor even in Western Maine, where the “Ground Swamp Robin” (T. pallasi) is quite abundant. It only becomes common in the neighborhood of Calais. It is, however, most widely distributed over nearly the entire continent, breeding from latitude 44° to high Arctic regions. It winters in Guatemala and southward as far as Ecuador and Brazil.
In its habits this thrush is noticeably different from the T. pallasi, being much more arboreal, frequenting thick woods; rarely seen, except during its migrations, in open ground, and seeking its food more among the branches of the trees.
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, Nuttall
OREGON 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 wit-wit t´villia, and wit-wit, t´villia-t´villia. His call when surprised was wit-wit.
All the nests of this species that have fallen under my observation are large, compact, strongly constructed, and neat. They measure about 5 inches in their external diameter, with a depth externally of 3; the cavity is comparatively shallow, being rarely 2 inches in depth. The external portions are constructed almost entirely of Hypnum mosses, matted together and sparingly interwoven with dry leaves and fine fibrous roots, and are lined with finer materials of the same kind. These nests most nearly resemble in their material and in their position those of Swainson’s Thrush.
Mr. Hepburn found these birds very abundant about Victoria. It does not usually breed there before the last of May, though in one exceptional instance he found a nest with young birds on the 24th of that month.
The eggs vary in size and shape, ranging from .77 to .94 in length, and from .65 to .69 in breadth. They also vary in their ground color and in the tints of the spots and markings. The ground color is light green or light blue, and the markings are variously yellowish-brown and lilac, or dark brown and slate.
Mr. Grayson found this thrush very abundant in the month of January, in the thickest of the woods, in the islands of the Three Marias, on the Pacific coast of Mexico. They were very timid and shy, more so than any bird that he saw on those islands. It frequently uttered a low plaintive whistle, and seemed solitary in its habits.
Turdus pallasi, Cabanis
RUFOUS-TAILED THRUSH; HERMIT THRUSH
Turdus pallasii, Cabanis, Wiegmann’s Archiv, 1847 (I), 205.—Baird, Birds N. Am. 1858, 212.—Ib. Rev. Am. B. 1864, 14.—Sclater, P. Z. S. 1859, 325 ??.—Ib. Catal. 1861, 2, No. 7.—Ridgway.—Maynard.—Samuels, 148. Turdus solitarius, Wilson, Amer. Orn. V, 1812, 95 (not of Linnæus).—Sclater, P. Z. S. 1857, 212. Turdus minor, Bon. Obs. Wilson, 1825, No. 72. Turdus guttatus, Cabanis, Tschudi, Fauna Peruana, 1844, 187 (not Muscicapa guttata of Pallas).
Additional figures: Aud. Birds Am. III, pl. cxlvi.—Ib. Orn. Biog. I, pl. lviii.
Sp. Char. Tail slightly emarginate. Above light olive-brown, with a scarcely perceptible shade of reddish, passing, however, into decided rufous on the rump, upper tail-coverts, and tail, and to a less degree on the outer surface of the wings. Beneath white, with a scarcely appreciable shade of pale buff across the fore part of the breast, and sometimes on the throat; the sides of the throat and the fore part of the breast with rather sharply defined subtriangular spots of dark olive-brown; the sides of the breast with paler and less distinct spots of the same. Sides of the body under the wings of a paler shade than the back. A whitish ring round the eye; ear-coverts very obscurely streaked with paler. Length, 7.50 inches; wing, 3.84; tail, 3.25; tarsus, 1.16; No. 2,092.
Hab. Eastern North America. Mexico? Not found in Cuba, fide Gundlach.
In spring the olive above is very much that of eastern specimens of swainsoni; in winter specimens it is much browner, and almost as much so as in fuscescens. Young birds have the feathers of the head, back, and wing coverts streaked centrally with drop-shaped spots of rusty yellowish.
Habits. Until quite recently the “Ground Swamp Robin,” or Hermit Thrush, has not been distinguished from the closely allied species T. swainsoni, and all accounts of writers have blended both in singular confusion. My colleague, Professor Baird, in the summer of 1844, was the first to suggest the distinctness of the two species. By the common people of Maine and the British Provinces this difference has long been generally recognized, this species being known as the “Ground Swamp Robin,” and the other as the “Swamp Robin.”
The present species is found throughout Eastern North America to the Mississippi, and breeds from Massachusetts to high arctic regions. It is only occasionally found breeding so far south as Massachusetts; through which State it passes in its spring migrations, sometimes as early as the 10th of April; usually reaching Calais, Maine, by the 15th of the same month.
It is a very abundant bird throughout Maine, where it begins to breed during the last week of May, and where it also probably has two broods in a season.
The greater number appear to pass the winter in the Southern States; it being common in Florida, and even occasionally seen during that season as far north as latitude 38° in Southern Illinois, according to Mr. Ridgway.
It rarely, if ever, sings during its migrations; appears in small straggling companies, frequents both thickets and open fields, and is unsuspicious and easily approached.
The song of this species is very fine, having many of the characteristics of that of the Wood Thrush (T. mustelinus). It is as sweet, has the same tinkling sounds, as of a bell, but is neither so powerful nor so prolonged, and rises more rapidly in its intonations. It begins with low, sweet notes, and ends abruptly with its highest, sharp ringing notes.
Taken from the nest they are easily tamed, and are quite lively and playful; but their want of cleanliness renders them very undesirable pets. When their nest is visited they make no complaints, but retire to a distance. Not so, however, when their natural enemy, the hawk, appears; these they at once assail and seek to drive away, uttering loud and clear chirps, and peculiar twittering sounds.
The nest of this thrush is always built on the ground, most generally either under low bushes or in the open ground, rarely, if ever, among thick trees, and for the most part in low swampy places. Both nest and eggs closely resemble those of Wilson’s Thrush (T. fuscescens). In Parsboro, Nova Scotia, I found one of the nests built in the very midst of the village, close to a dwelling, though on a spot so marshy as to be almost unapproachable. The nests are 3 inches in height and 5 in diameter, with a cavity 3¼ inches wide by 1¾ deep. They are composed of decayed deciduous leaves, remnants of dried plants, sedges and grasses, intermingled with twigs, and lined with finer grasses, sedges, and strips of bark.
The eggs are of a uniform bluish-green color, and range in length from .88 to .94, with an average of .63 of an inch.
Turdus pallasi, var. nanus, Audubon
DWARF HERMIT THRUSH
Turdus nanus, Aud. Orn. Biog. V, 1839, 201, pl. cci.—Baird, Birds N. A. 1858, 213; Rev. Am. B. 1864, 15.—Sclater, P. Z. S. 1859.—Ib. Catal. 1861.—Dall & Bannister.—Cooper, Birds Cal., p. 4. Turdus pallasi, var. nanus, Ridgway, Rep. Kings Exped. V, 1872. ? Turdus aonalaschkæ, Gmelin, S. N. I, 1788, 808. ?? Muscicapa guttata, Pallas, Zoög. Rosso-Asiat. II, 1811, 465.
Sp. Char. Above with the clear dark olive of swainsoni, but this even purer and more plumbeous. Upper tail-coverts (but not lower part of rump) becoming more rufous, the tail abruptly darker, richer, and more purplish-rufous, approaching to chestnut. The clear olive of the neck passes into brownish-plumbeous along sides; pectoral spots more sparse and less pure black than in T. pallasi. The white beneath is of an almost snowy purity, appreciably different from the cottony-white of T. pallasi. Wing, 3.30; tail, 3.00; bill, .36; tarsus, 1.07.
A very tangible and constant character possessed by this bird is the more slender and depressed bill, as compared with that of T. pallasi. Specimens vary only in intensity of colors; these variations very limited, and corresponding with those of T. pallasi. In all cases, however, their precise pattern and peculiar distribution is retained.
Hab. Western Province of North America, eastward from Kodiak to Cape St. Lucas. Arizona, Coues.
Habits. This small race of the Hermit Thrush was first noticed by Dr. Pickering, and described by Mr. Audubon from an imperfect skin. It has since been obtained abundantly on the Pacific slope, and Mr. Ridgway procured a specimen as far east as the East Humboldt Mountains, which he considers its eastern limit.
In its habits it is said to be, like T. pallasi, almost exclusively terrestrial. Dr. Heermann mentions finding it abundant in California, and breeding among the stunted oaks covering the sand-hills of San Francisco. Dr. Coues found it in Arizona, but speaks of it as rare and migratory, occurring chiefly in spring and autumn, and as a shy and retiring species. Dr. Cooper, in his Report on the Birds of California, describes it as shy and timid, preferring dark and shady thickets, feeding chiefly on the ground, running rapidly, and searching for insects among the leaves.
Near San Diego they began to sing about the 25th of April. The song, consisting of a few low ringing notes, resembles that of Wilson’s Thrush (T. fuscescens), and also that of T. ustulatus, but is not so loud. Their note of alarm is a loud and ringing chirp, repeated and answered by others at a long distance.
At Santa Cruz, on the first of June, Dr. Cooper met with several of their nests, which, though probably erroneously, he supposed to belong to the Dwarf Hermit Thrush. They were all built in thickets under the shade of cottonwood-trees. Each nest was about five feet from the ground, and all contained eggs, from two to four in number, in differing stages of incubation. The nests were built of dry leaves, roots, fibres, grasses, and bark, without any mud, and were lined with decayed leaves. Their height and external diameter measured 4 inches. The diameter of the cavity was 2½ inches and the depth 2¼. The eggs measured .90 by .70 of an inch. They are of a pale bluish-green, speckled with cinnamon-brown, chiefly at the larger end.
The nest, supposed to be of this species, supplied by Dr. Cooper, is large for the bird; constructed of a base loosely made up of mosses, lichens, and coarse fibres of plants. It is a strong and compact structure of matted leaves, put together when in a moist and decaying condition; with these there are interwoven roots, twigs, and strong fibres, surrounding the nest with a stout band and strengthening the rim. In fact, it corresponds so well—as do the eggs also—with those of T. ustulatus, that it is extremely probable that they really belong to that species. The only observable difference is the absence of the Hypnum mosses characteristic of northern ustulatus.
Dall and Bannister mention in their list of Alaska birds that the species is not common there. It was also taken at Sitka and Kodiak by Bischoff.
The fact that this thrush builds its nest above the ground, and lays spotted eggs, if verified, would at once warrant our giving it independent rank as a species, instead of considering it as a local race of pallasi.
Turdus pallasi, var. auduboni, Baird
ROCKY MOUNTAIN HERMIT THRUSH
Turdus auduboni, Baird, Rev. Am. Birds, 1864, 16.—Ridgway, P. A. N. S. 1869, 129.—Elliot, Illust. (fig.). Merula silens, Swainson, Philos. Mag. I, 1827, 369 (not Turdus silens of Vieillot, Encycl. Méth. II, 1823, 647, based on T. mustelinus, Wils. = T. fuscescens).—Ib. Fauna Bor.-Amer. II, 1831, 186.—Baird, Birds N. Amer. 1858, 213, and 922.—Sclater, P. Z. S. 1858, 325 (La Parada), and 1859, 325 (Oaxaca).—Ib. Catal. Am. Birds, 1861, 2, No. 9.
Sp. Char. Colors much as in Turdus nanus, but the upper tail-coverts scarcely different from the back. Tail yellowish-rufous. Length of wing, 4.18; tail, 3.60; bill from nostril, .45; tarsus, 1.26.