The Rough-winged Swallow 
Nesting. — Nest: In crevice of cliffs at end of tunnels of earth, or sand-banks, 
or in crannies of bridges, etc.; of leaves, weed-stems, grasses, feathers, and the like; 
bulky or compact according to situation. Eggs: 4 to 8; white. Av. size 18.8 x 13 
(.74 x .51). Season: May, June, according to altitude; one brood. 
General Range. —United States at large, and southern portions of Canada; 
breeding north to Connecticut, southern Ontario, southern Minnesota, British Colum¬ 
bia, etc.; south to southern border, and in Mexico south to Jalisco. Winters from 
central Mexico to Costa Rica. 
Distribution in California. —Of general occurrence during migrations; locally 
common as a breeder, chiefly in the Lower and Upper Sonoran zones. Less common 
in the humid coastal regions. Has occurred in winter, but probably only as an early 
migrant: San Diego, Jan. 27 (J. G. Cooper); Potholes, Feb. 8, 1912. 
Authorities.—Heermann, Jour. Acad. Nat. Sci. Phila., ser. 2, ii., 1853, p. 261 
(Calif.); Cooper, Orn. Calif. 1870, p. no (San Diego, Nov. and Jan.); Cones , Birds 
Col. Val., 1878, p. 438 (syn., habits, desc., etc.; see also p. 364); Tyler, Pac. Coast 
Avifauna, no. 9, 1913, p. 93 (San Joaquin Valley, nesting habits); Grinnell, Univ. 
Calif. Pub. Zook, vol. xii., 1914, p. 186 (Colo. Valley; nesting habits, etc.). 
IT NOT infrequently happens that some oversight, or want of dis¬ 
crimination, on the part of early observers condemns a species to long 
obscurity or unending misapprehension. The Bank Swallow was at 
once recognized by the pioneer naturalists of America as being identical 
with the well-known European bird, but it was not till 1838 that Audubon 
distinguished its superficially similar but structurally different relative, 
the Rough-wing. Dr. Coopery writing in 1870 under the caption “Bank 
Swallow,” says: “This species . . . seems rather less common on 
this coast than the next [i. e., the Rough-wing] and resembles that so close¬ 
ly that they cannot be distinguished without examination of specimens. 
Their habits being exactly alike, I will describe those of both under 
one heading.” And this the good doctor proceeds to do, under the 
caption of Rough-winged Swallow, to the great confusion of all suc¬ 
ceeding literature. 
Of course the two species are perfectly, if not easily, distinguish¬ 
able a-wing; and of course their habits do show marked differences. 
It may be easier, however, to take the Bank Swallow as a basis, and 
to say that our subject differs from that species by thus and so. 
In the first place it has those curious little hooklets on the edge 
of the wing (especially on the outer edge of the first primary)—nobody 
knows what they are for. They surely cannot be of service in enabling 
the bird to cling to perpendicular surfaces, for they are bent forward, 
and the bird is not known to cling head-downward. It is easy to see 
how the bird might brace its wings against the sides of its nesting tunnel 
Ornithology of Calif., Vol. I., Land Birds, p. no. 
530 
