_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.
Dr. Coues also found this Swallow in Arizona, where it was the most
abundant and characteristic Swallow of the pine regions of that
Territory. It is a summer resident at Fort Whipple, where it arrives
about March 20, and remains until late in September.
In the Province of Vera Cruz, Mr. Sumichrast found this Swallow
resident, not only in the hot belt of the coast, but also in the
temperate region and throughout the plateau, at almost all heights,
and was almost everywhere very common.
Mr. Salvin also states that early in March great numbers occur near
Duenas, Guatemala, where they remain for a short time. During that
time they are to be found flying over the open land to the south of
the Lake of Duenas.
Mr. Hepburn states that this Swallow has quite an extensive range
along the Pacific coast, but is restricted as to the localities it
inhabits. At the Pulgas Ranche, near San Francisco, it is even more
common than the _bicolor_, while a few miles from thence not one is to
be seen. He has also seen it on the banks of the Fresno, near its
junction with the San Joaquin River, and again in the Yosemite Valley,
without meeting with a single specimen in the intervening country.
About Victoria this was the prevailing species. These Swallows, so far
as Mr. Hepburn observed, always build in holes of trees. Their nest,
he states, is formed of a few fine dry stems of grass, placed at the
bottom of the hole, covered over with a thick mass of feathers. The
eggs, he adds, are pure white, large for the size of the bird,
measuring .81 of an inch in length by .50 in breadth. These Swallows
have two broods in a season. In 1864 he noted their arrival in San
Mateo County on the 28th of March.
Mr. Ridgway writes that he first met with the Violet-green Swallow in
May, on the islands in Pyramid Lake. He there found it very abundant
among the cliffs of calcareous tufa of which the island was composed.
They were seen to enter the fissures of the rock to their nests
within, which it was found impossible to reach. They were again seen
in July among the limestone cliffs along the cañons of the East
Humboldt Mountains, associated with the White-throated Swift, building
like them in the small horizontal crevices or fissures on the face of
the precipice. He was not able to get at more than two of their nests,
the first in a horizontal fissure just wide enough to admit the hand,
and about eight inches from the entrance. It contained five young. The
nest was similar to that of the Bank Swallow, and was composed of
sticks, straws, and feathers. In the other the female was dead on her
nest, and the eggs were broken. They were white, like those of the _H.
bicolor_.
In its flight this bird is said to greatly resemble the White-bellied
Swallow, but is distinguishable by the contrast of the three colors of
its upper plumage. These two species are rarely to be seen in the same
localities, the _bicolor_ preferring wooded, and this species rocky
localities.
Mr. Lord states that this beautiful Swallow was common from the coast
along the entire course of the boundary line, to the summit of the
Rocky Mountains. They were among the earliest visitors at Colville,
arriving in small flocks in March, but in greater numbers in May and
June. They build in June, making their nests in holes in dead trees as
high as they can get, and lay four or five eggs. The nest is made of
feathers and soft hair. They assemble in large flocks before migrating
in September. Mr. Lord felt pretty sure their nesting-holes were
excavated in the soft wood by themselves, though their soft beak seems
ill adapted to perform such labor.