Bluebird, but are so different as to be easily recognized; they are equally sweet and clear, but have much less power.
Neither Dr. Gambel nor Dr. Heermann found this species in California excepting during the winter, and were of the opinion that none remain there to breed.
Dr. Kennerly observed them at different points among the Rocky Mountains, where they frequented the vicinity of his camp early in the morning, at some times in pairs and at others in flocks of four or five.
Mr. J. K. Lord states that he found this Bluebird very abundant between the Cascades and the Rocky Mountains, where they arrive in June and leave in September. After nesting they assembled in large flocks, and fed on the open plains.
The eggs are of a very light blue, paler than those of the other species. They measure .89 of an inch in length by .66 in breadth.
Mr. Ridgway states that he found the Rocky Mountain Bluebird nesting in Virginia City in June. Its nests were built about the old buildings, and occasionally in the unused excavations about the mines. At Austin he also found it common in July, in similar localities. On the East Humboldt Mountains it was very numerous, especially on the more elevated portions, where it nested among the rocks and, though more rarely, in the deserted excavations of woodpeckers in the stunted piñon and cedar trees. He describes it as generally very shy and difficult to obtain, seldom permitting a very near approach. In its habits it is much less arboreal than either S. mexicana or S. sialis, always preferring the open mountain portions in the higher ranges of the Great Basin.
In regard to its notes Mr. Ridgway says: “The common note of this species would, from its character, be at once recognized as that of a Bluebird. Its autumnal note, however, lacks entirely the peculiar plaintiveness so characteristic of that of our Eastern species, and is much more feeble, consisting of a simple weak chirp. Like the S. mexicana, the S. arctica was also never heard to give utterance to anything resembling the lovely spring warbling of the S. sialis.”
Family SYLVIIDÆ.—The Sylvias
Char. Bill much shorter than head, slender, broad, and depressed at the base, distinctly notched and decurved at the tip. Culmen sharp-ridged at base. Frontal feathers reaching to the nostrils, which are oval, with membrane above, and overhung—not concealed—by a few bristles or by a feather. Rictal bristles extending beyond nostrils. Tarsi booted or scutellate. Basal joint of middle toe attached its whole length externally, half-way internally. Primaries ten; spurious primary about half the second, which is shorter than the seventh. Lateral toes equal.
The birds of this family are readily distinguished from the Paridæ by the slender bill, notched and decurved at tip; much bristled gape, sharp-ridged culmen, exposed oval nostrils, less adherent toes, etc. They are much smaller than the Turdidæ and Saxicolidæ, with much more slender, depressed bill, longer rictal bristles, etc. The short outer primary, with the primaries ten in number, distinguish them from the Sylvicolidæ.
The following synopsis will serve to characterize the American forms of their respective subfamilies. The species are all among the most diminutive in size with the exception of the Humming-Birds:—
A. Wings longer than the nearly even and emarginate tail. Scutellæ of tarsus scarcely or not at all appreciable. General color olivaceous above. No white on tail.
Nostrils naked. Scutellæ distinct on inner face of tarsus only. Head plain … Sylviinæ.
Nostrils overhung by bristly feathers. Scutellæ of tarsus not appreciable. Head with a colored central crest … Regulinæ.
B. Wings about equal to the graduated tail. Tarsal scutellæ distinct. Above bluish; tail with white spots or patches.
Nostrils uncovered. Head plain; either bluish or black above … Polioptilinæ.
Subfamily SYLVIINÆ
Char. Size and form of Sylvicolinæ, but with a spurious first primary about one third the second quill. Wings considerably longer than the nearly even or emarginate tail. Feathers of frontal region with bristly points; but not covering the nostrils. Tarsi scutellate anteriorly, but indistinct externally. (Characters drawn with reference to the American form.)
The introduction of this subfamily into the present work is required to accommodate a species of Phyllopneuste collected on the Yukon by the Russian Telegraph Expedition, the first known instance of the existence in North America of a group of birds characteristic of the northern parts of the Old World. Among the smallest of the class, they are eminently sociable, and feed entirely on insects, which they capture mostly on the wing, like flycatchers. The nest is placed on the ground, and is of an oval or spherical form with a round opening on one side. The sexes are similar, and the young differ very little from the parents.
Phyllopneuste, Meyer & Wolf, Taschenbuch, 1822.—Degland et Gerbe, Ornith. Europ. I, 1867, 543.
Phyllopneuste borealis.
45909
Gen. Char. Bill shorter than the head; straight, slender, and depressed, notched at tip. Nostrils open. Tarsi lengthened; exceeding the middle toe; scutellate anteriorly, but with the plates indistinct, claws short, much curved. Wings pointed, longer than tail, and reaching at least to its middle; spurious quill extending farther than the upper covert. Tail emarginate. Olivaceous above; yellowish or whitish beneath.
Phyllopneuste borealis.
For the purpose of distinguishing this genus from any other North American, it is enough to say that, of the general appearance of the warblers, it has a short spurious first primary, as in the Thrushes, and some Vireonidæ. The single species found as yet within our limits resembles at first sight an immature Dendroica æstiva, but is easily distinguished by the wing formula, the yellowish stripe over the eye, and the brown tail-feathers.
Phyllopneuste borealis, Blas. Ibis, 1862, 69. Phyllopneuste, Kenn., Baird, Trans. Chicago Acad. Sci. I, ii, p. 313, pl. xxx, fig. 2, 1869.
Sp. Char. (Description of specimen No. 45,909.) Plumage in August: above olive-green, with a slight shade of brown on top of head, rather lighter behind; beneath white, tinged with greenish-yellow; more olive on the throat and breast; and more yellow behind, inside the wing and on thighs; axillars purer yellow. A well-marked greenish-yellow line from nostrils over the eye to the nape (extending behind the eye nearly as far as from eye to tip of bill), beneath this an olivaceous streak through the eye, running into the mixed olive and yellowish of the cheeks. Quills and tail-feathers brown, edged with olivaceous; the outer edges of primaries more yellowish than those of secondaries; the greater coverts tipped externally with greenish-yellow, so as to form a distinct band across the wing. Bill rather dark brown; paler beneath. Legs dark olive; toes not sensibly different. Nest probably on ground, and domed. Eggs white, spotted with pink.
Spurious quill in length about one fourth the second, which about equals the sixth, or very slightly exceeds it; third and fourth longest; fifth a little shorter.
Dimensions (fresh specimen before being skinned): total length, 4.75; expanse of wings, 6.00; wing from carpal joint, 2.50.
Dimensions (prepared specimen):
