VIOLET-GREEN SWALLOW.
Hirundo thalassina, Swainson, Phil. Mag. I, 1827, 365 (Mexico).—Aud.—Brewer, N. A. Oöl. I, 1857, 102 (the fig. pl. v, fig. lxxiv of egg belongs to another species).—Baird, Birds N. Am. 1858, 311.—Lord, Pr. R. A. Inst. Woolwich, IV, 1864, 115 (Vancouver Isl.; nests in holes of trees).—Cooper & Suckley, P. R. R. Rep. XII, II, 185 (W. T.).—Cooper, Orn. Cal. 1, 1870, 107. Chelidon thalassina, Boie, Isis, 1844, 171. Tachycineta thalassina, Cab. Mus. Hein. 1850, 48. Hirundo (Tachycineta) thalassina, Baird, Rev. Am. B. 1864, 299. Petrochelidon thalassina, Sclater & Salvin, Ibis, 1859, 13 (Guatemala).—Ib. P. Z. S. 1864, 173 (City of Mex.).
Sp. Char. Tail acutely emarginate. Beneath pure white. Above soft velvety-green, with a very faint shade of purplish-violet concentrated on the nape into a transverse band. Rump rather more vivid green; tail-coverts showing a good deal of purple. Colors of female much more obscure. Length, 4.75; wing, 4.50; tail, 2.00.
Hab. Western and Middle Provinces of United States., south to Guatemala, east to the Upper Missouri. Breeds on Plateau of Mexico (Sumichrast).
Young birds are of a dull velvety grayish-brown, not unlike the shade of color of Cotyle riparia, but may be distinguished by the absence of the tuft of feathers at base of toes, and the gray (not white) bases of the feathers of under parts. There is only an ashy shade across the breast, not a pectoral band.
There is much variation among individuals regarding the distribution of the semi-metallic tints of the upper parts; generally the whole dorsal region is overlaid by a “dusting,” as it were, of soft brownish-purple; in specimens colored thus, the upper tail-coverts are pure dark-green, without a tinge of purple. In other specimens, on the contrary, the dorsal region is nearly pure green, that of the upper tail-coverts less golden, and mixed with a very beautiful rich soft violet.
Winter specimens from Guatemala and Mexico have the upper secondaries very sharply and broadly bordered terminally with pure white.
Habits. The Violet-green Swallow is a common bird, from the central plains of North America to the Pacific coast, and is found at different seasons from Washington Territory to South America. It has been found as far east as Nebraska, and in abundance at Fort Bridger, in Utah.
As observed, in Washington Territory, by Drs. Suckley and Cooper, it is said to arrive at Puget Sound early in May, and to frequent entirely the high prairies bordered with oak and other deciduous trees, in the knot-holes of which, or in deserted Woodpeckers’ holes, it breeds. Its song is described as pleasing and varied, but rather weak. They found it to be quite abundant in the interior of Oregon and of Washington Territory, and in its habits and mode of flight hardly distinguishable from the bicolor.
In California, according to the observations of Dr. Cooper, it arrives in Santa Clara Valley as early as March 15, where it chiefly frequents the groves of oaks along the sides of the valleys, across the whole Coast Range, excepting in the immediate neighborhood of the sea. Their nest, so far as known, is always in the knot-holes of oaks, and they have never been known to breed in the immediate vicinity of dwellings, excepting only when their favorite trees were so situated. It is generally in an inaccessible place, and their eggs are not often obtained. These are pure white, resembling those of the bicolor and the riparia. Townsend states that he found them nesting in the deserted nests of the H. lunifrons, but in this he may have been mistaken. The eggs he gave to Mr. Audubon as those of this species undoubtedly belonged to the lunifrons. They leave California for the south in September.