A History of North American Birds, Land Birds. Volume 2. Robert Ridgway

Чтение книги онлайн.

СКАЧАТЬ streaks on the back confined to a mere streak along the shaft. There is less of an olive tinge across the breast.

      The proportions of the present race differ more from those of æstivalis than do the colors, the bill being more slender, and the wings and tail considerably longer.

      The resemblance to P. botterii (= æstivalis, var. botterii) of Sclater, from Middle Mexico (Orizaba, Colima, etc.), is very close; the difference being greater in the proportions than in the colors, the latter having a shorter wing and tail, with thicker bill, as in var. æstivalis. In botterii there is rather a predominance of the black over the rufous in the streaks above.

      Habits. This, in its general habits, nesting, eggs, etc., probably resembles the variety æstivalis.

Peucæa cassini, BairdCASSIN’S SPARROW

      Zonotrichia cassini, Woodhouse, Pr. A. N. Sc. Ph. VI, April, 1852, 60 (San Antonio). Passerculus cassini, Woodhouse, Sitgreaves’s Rep. Zuñi and Colorado, 1853, 85; Birds, pl. iv. Peucæa cassini, Baird, Birds N. Am. 1858, 485, pl. iv, f. 2.—Heermann, X, c, p. 12, pl. iv, f. 2.—Cooper, Orn. Cal. 1, 219 (not from Cal.).

      Sp. Char. (6,329 ♂, Texas; compared with type of species.) Ground-color of upper parts grayish-ash; the middle portion of each feather dull brown, in the form of a blotch, and with a black shaft-streak, the latter becoming modified on scapulars, rump, and upper tail-coverts, into transverse spots, those on the upper tail-coverts being large and conspicuous, and in the form of crescentic spots, the terminal margin of the feathers being lighter ashy in sharp contrast. Middle tail-feathers clear ashy, with a sharply defined shaft-streak of blackish, throwing off obsolete, narrow, transverse bars toward the edge; rest of tail clear dusky-brown, the lateral feather with whole outer web, and margin of the inner, dull white, all, except the intermediate, with a large, abruptly defined, terminal space of dilute brown (decreasing in size from the outer), the margin whitish. Upper secondaries broadly and sharply margined along both edges with dull ashy-white, the enclosed portion being clear dusky brown, intensified where adjoining the whitish. A very obsolete superciliary stripe of ashy, becoming whitish over the lore; auriculars more dingy, but without distinct stripe along upper edge. An uninterrupted but indistinct “bridle” along sides of throat. Lower parts dull white, without any ochraceous, but with a very faint ashy tinge ever the jugulum; flanks with broad, somewhat blended streaks of mixed brownish and dusky. Bend of wing edged with light yellow. Wing, 2.55; tail, 2.80; bill, .28 from nostril and .23 deep; tarsus, .68; middle toe, .55.

      Young. (45,277, Laredo, Texas, June 28.) Very similar, but with a few drop-shaped streaks of dark brown on the jugulum and along sides. The feathers above have a more appreciable terminal border of buff.

      Hab. Rio Grande region of Southern Middle Province; Kansas, breeding (Allen). San Antonio, Texas, summer (Dresser, Ibis, 1865, 489; eggs); ? Orizaba, temp. reg. (Sum. M. B. S. I, 551).

      In the Birds of North America, the specimen characterized on p. 637 of the present work as æstivalis, var. arizonæ, was referred to P. cassini, those specimens which are here retained as such being considered as in quite immature plumage. A more recent examination of additional material, however, has compelled us to change our view. In consequence of the similarity of the specimen in question to æstivalis, as noted in the article referred to above, the general acceptation of the name cassini has been that of a term designating a variety of the common species; but we have as the result of the investigation in question found it necessary to retain under the head of “cassini” only the typical specimens from the Rio Grande region, and refer the supposed aberrant specimen to æstivalis. In this Los Nogales specimen we find existing such differences in proportions and colors as are sufficient to warrant our bestowing upon it a new name, and establishing it as the Middle Province race of æstivalis, in this way connecting the South Atlantic and Mexican races (var. æstivalis and var. botterii) by a more similar form than the P. cassini, which must be set apart as an independent form,—in all probability a good species. Several facts are favorable to this view. First, we have of the P. cassini specimens which are beyond question in perfect adult plumage, and others which are undoubtedly immature; they differ from each other only in such respects as would be expected, and agree substantially in other characters, by which they are distinguished from the different styles of æstivalis. Secondly, the region to be filled by a peculiar race of æstivalis is represented by the var. arizonæ, which is undoubtedly referable to that species; thus we have in one province these two different forms, which therefore are probably distinct.

      The present bird is hardly less distinct from the races of æstivalis than is ruficeps; and we would be as willing to consider all the definable forms presented in the synopsis as varieties of a single species, as to refer the present bird to æstivalis.

      Habits. This Finch, in its general appearance, as well as in respect to habits, nesting, and eggs, is quite similar to Bachman’s Finch. It was first met with by Dr. Woodhouse, in the expedition to the Zuñi River, when he found it in Western Texas. He shot it on the prairies near San Antonio, on the 25th of April, 1851, mistaking it for Passerculus savanna, which, in its habits, it seemed to him very much to resemble, but upon examination it was found to be totally distinct.

      Dr. Heermann afterwards, being at Comanche Springs in Texas, had his attention attracted by the new note of a bird unfamiliar to him. It was found, after some observation, to proceed from this species. He describes it as rising with a tremulous motion of its wings some twenty feet or more, and then descending again, in the same manner, to within a few yards of the spot whence it started, and as accompanying its entire flight with a lengthened and pleasing song. The country in that neighborhood is very barren, covered with low stunted bushes, in which the bird takes refuge on being alarmed, gliding rapidly through the grass and shrubbery, and very adroitly and effectually evading its pursuer. He observed them during four or five days of the journey of his party, and after that saw no more of them. They seemed, at the time, to be migrating, though their continued and oft-repeated song also showed that they were not far from readiness for the duties of incubation.

      The Peucæa cassini is said, by Mr. Sumichrast, to be a resident species in the valley of Orizaba, in the State of Vera Cruz, Mexico, and to be generally distributed throughout the temperate region of that district. It is very probable, however, that he has in view the Mexican race of P. æstivalis (var. botterii), and not the present species.

      Mr. J. A. Allen, who considers this bird only a western form of P. æstivalis, mentions (Am. Naturalist, May, 1872) finding it quite frequently near the streams in Western Kansas, where its sweetly modulated song greets the ear with the first break of dawn, and is again heard at night till the last trace of twilight has disappeared. Mr. Allen also states, in a letter, that this bird was “tolerably common along the streams near Fort Hays, but very retiring, singing mostly after nightfall and before sunrise, during the morning twilight. When singing, it had the habit of rising into the air. I shot three one morning thus singing, when it was so dark I could not find the birds. The one I obtained does not differ appreciably from specimens from Mr. Cassin’s collection, labelled by him Peucæa cassini, collected in Texas.”

      Mr. Ridgway regards this record of the manners of this bird, while singing, as indicating a specific difference from P. æstivalis. The latter, in Southern Illinois, has never been heard by him to sing at night, or in the morning, nor even on the wing; but in broad midday, in the hottest days of June, July, and August, he often heard them singing vigorously and sweetly, as they perched upon a fence or a dead tree in a field, exactly after the manner of our common Spizella pusilla.

      Among Dr. Heermann’s notes, quoted by Mr. Dresser, is one containing the statement that he found this species not rare on the prairies near the Medina River, in Texas, where it breeds. Mr. Dresser also states that when at Howard’s Ranche, early in May, he found this bird by no means СКАЧАТЬ