Young birds (as in 1,120) differ in a tinge of reddish-fulvous on the upper parts; the wing-coverts, secondaries, and inner primaries margined more or less broadly with a brighter shade of the same. The gray of the under parts is also washed with this color, especially on the chin and across the breast. The hooks of the edge of the wing have not yet become developed.
(No. 32,269 ♂, fresh specimen before being skinned.) Total length, 5.40; expanse of wings, 12.20; wing from carpal joint, 4.50.
(No. 32,269 ♂, prepared specimen.) Total length, 5.20; wing, 4.50; tail, 2.25, depth of fork, .15; difference of primaries, 2.28; length of bill from forehead, .40, from nostril, .24, along gape, .56, width of gape, .43; tarsus, .45; middle toe and claw, .57; claw alone, .19; hind toe and claw, .41; claw alone, .16.
Hab. Whole United States (exclusive of Northeastern States?) south to Central Mexico.
Habits. The Rough-winged Swallow was first met with by Audubon, in Louisiana, but described by him from specimens afterwards procured near Charleston, S. C. He knew nothing in regard to its habits, and its distribution was equally unknown to him. It has since been found, but nowhere very abundantly, in various parts of the United States. It has not been met with on the Atlantic coast farther to the north than New Jersey and Pennsylvania. On the Pacific coast it is more common. Dr. Suckley speaks of it as quite abundant both in Oregon and in Washington Territory. Dr. Cooper, in his Zoölogy of Washington Territory, speaks of it as common about the sandy cliffs of the bays and inlets of that coast, arriving near the Columbia in May, and remaining only until the middle of August, when all these Swallows go southwards, though their last brood is hardly able to fly. He says that they burrow holes in the soft sandy banks near the tops of cliffs, and have generally the same habits as the common Bank Swallow. They have no song, only a few chirping calls.
Dr. Cooper, in his Report on the birds of California, further states that this Swallow, in summer, is found throughout the lower portions of that State. He saw them at Fort Mojave as early as the 27th of February, and as he has met with them at San Diego in November, and also in January, he thinks they may winter within the State. He describes their burrows in the sandy banks of rivers as being to the depth of three feet, crowded very near together, and near the upper edge of the bank, in no wise different from the nesting of the common C. riparia. The nests are composed chiefly of dry grasses, with a few feathers, and contain five white eggs. Occasionally, however, they resort to natural clefts in the bank or in buildings, and to knotholes in trees. In the fall they congregate in great numbers about certain favorite spots, and keep much together in flocks. At night they roost in
their burrows. In Arizona, according to Dr. Coues, they are summer residents, breeding abundantly, arriving late in April and remaining until nearly the last of September.
At Eagle Pass, Mr. Dresser met these birds, arriving from the South, on the 21st of February. There, and also at San Antonio, they were very common, breeding in the towns, making their nests under the eaves and in holes in the old walls, depositing their eggs by the 25th of April. Dr. Kennerly also found this Swallow very abundant along the Colorado River in February. Its flight seemed to him to be like that of the common Barn Swallow. Dr. Heermann frequently met with this species during the journey from the junction of the Gila and Colorado Rivers through Mexico, New Mexico, and Texas, to San Antonio. In the latter place he found them breeding almost entirely in crevices in the walls of houses.
In the vicinity of Washington, Dr. Coues found this Swallow a summer resident, but rather rare, arriving in the third week of April, and leaving about the middle of September.
Mr. Ridgway speaks of this bird as one of the most abundant Swallows of the West, inhabiting the river valleys, and breeding in holes in the banks of the rivers. He says that in Southern Illinois it is much more abundant than the C. riparia, though both nest in the same banks.