Читать книгу A History of North American Birds, Land Birds. Volume 1 - Robert Ridgway - Страница 9

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.

Genus PHYLLOPNEUSTE, Meyer & Wolf

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

ALASKA WILLOW WARBLER

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): total length, 4.60; wing, 2.40; tail, 2.00. Exposed portion of first primary, 0.42; of second, 1.56; of longest (measured from exposed base of first primary), 1.85. Bill: length from above, 0.38; from nostril, 0.29; along gape, 1.55. Legs: tarsus, 0.66; middle toe and claw, 0.55; claw alone, 0.16; hind toe and claw, 0.36; claw alone, 0.20.

Hab. Northeast Asia (China, East Siberia); adjacent to Behring’s Straits and Alaska.

This species, in general appearance, apparently comes nearer to P. trochilus than to any other of its congeners. It is, however, more olivaceous-green above, and more yellow beneath, and has a distinct band across the wing. The superciliary light stripe is more distinct and longer; the bill and legs are darker, and the toes not sensibly different in color from the tarsus. The proportion of the quills is much the same, except that the interval between the tips of the fifth and sixth quills is greater, and the second is almost inappreciably longer than the latter, not reaching nearly midway between the two. The first or spurious quill is rather shorter.

A single specimen of this species was obtained August 16, 1866, on St. Michael’s Island, in Norton Sound, Alaska, by Mr. Charles Pease. Mr. Bannister met with no other specimen in that locality, and from this it is inferred that this is not an abundant species there. It was described as a new species under the name of P. kennicottii (Baird), but has been ascertained by Mr. Tristram, to whom it was sent for examination, (Ibis, 1871, p. 231,) to be identical with P. borcalis of Blasius.

Dr. Blasius also states (Naumannia, 1858, p. 303) that a specimen of this species has been obtained on the island of Heligoland, showing it to be also an accidental visitant to Western Europe.

Habits. Mr. R. Swinhoe, who describes this among the birds of Formosa as P. sylvicultrix, states it to be a summer visitant to Southern China, passing in large numbers through Amoy in its autumnal migrations southeastward, probably to the Philippine Islands, touching at Southwestern Formosa and Twaiwanfoo, where he found them abundant. This was for a few days in October, but he neither saw any before nor afterwards, nor did he meet with any at Tamsuy (Ibis, 1863, p. 307). The same writer (Ibis, 1860, p. 53) speaks of this bird as very abundant in Amoy during the months of April and May, but passing farther north to breed.

We have no information in reference to its habits, and nothing farther in regard to its distribution. As it bears a very close resemblance to the Willow Wren of Europe, P. trochilus, it is quite probable that its general habits, nest, and eggs will be found to correspond very closely with those of that bird.

The European warblers of the genus Phyllopneuste are all insect-eating birds, capturing their prey while on the wing, and also feeding on their larvæ. They frequent the woodlands during their breeding-season, but at all other times are much more familiar, keeping about dwellings and sheepfolds.

The P. trochilus is a resident throughout the entire year in Southern Europe and in Central Asia. That species builds at the foot of a bush on the ground, and constructs a domed nest with the entrance on one side. Their eggs are five in number, have a pinkish-white ground, and are spotted with well-defined blotches of reddish-brown, measuring 0.65 by 0.50 inch, and are of a rounded oval shape.