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.
Stelgidopteryx, Baird, Birds N. Am. 1858, 312. (Type, Hirundo serripennis, Aud.)
