458 
BIRDS OF NEW MEXICO 
That the Swallows return to the same general region to nest is 
suggested by some banding experiments made by Dayton Stoner. 
Only one bird was re-taken in the burrow from which it was banded, 
but one was recovered about fifty yards away, where it had a family 
of young in the nest (1928, p. 45). 
In one of the colonies of Bank Swallows studied by Mr. Stoner, 
“in practically all the burrows examined, the outer one-third to one- 
quarter was somewhat lower than the terminal two-thirds or three- 
fourths.” The slight ascent had the advantage of preventing slanting 
rain from washing in too far, and flying enemies like hawks from easily 
seeing the young while waiting near the mouth of the burrow for food. 
During migration, at Mesilla Park, Professor Merrill wrote, “This 
small traveler arrives about the same time the other swallows do, 
flocks with them, though they are not quite as numerous perhaps, and 
departs with them” (MS). 
Like other swallows the Banks migrate in great flocks, collecting 
in roosts at night. In North Dakota during an August migration, I 
was fortunate enough to be on their route. A flock gathered at the 
Sweetwater Lakes, increasing day by day till it was between nine 
hundred and a thousand strong. Then at sundown, from the tele¬ 
phone wires on which the birds had collected, long sections would 
suddenly drop from the wires and flying high over the wheat fields to 
the lake pitch down into the tules, where they could find safe harbor 
for the night. After this great flock had gone on to the south, a smaller 
flock of perhaps three hundred appeared on the wires, but toward 
night, instead of flying to the lake, they flew up into the sky, to my 
amazement rising higher and higher till they actually went out of 
sight in the sky—a winged host translated (1920, pp. 23-25). It 
was an experience of a lifetime. 
Additional Literature.—Seton, E. T., Bird-Lore, XXII, 334-335, 1920 (sun 
baths, etc.).— Stoner, D., Auk, XLII, 86-94, 1925; XLTII, 198-213, 1926 (colonies, 
nests, and banding). 
ROUGH-WINGED SWALLOW: Stelgidopteryx serripennis (Audubon) 
Description. — Length: 5-5.7 inches, wing 4-4.7, tail 2-2.3. Bill small, tail 
short, slightly emarginate, outer web of outer primary saw-toothed in male, roughened 
in female. Adults: Upperparts plain grayish brown, darker on head, wings, and tail; 
anterior underparts pale grayish brown , posterior underparts white. Young injuvenal 
plumage: Similar to adults but more or less washed with rusty, wings with broad 
cinnamon tips and margins; throat and breast almost cinnamon. 
Comparisons. —The only adult New Mexico swallows with brown backs, the 
Rough-winged and the Bank, are easily distinguished—the Rough-winged, by its 
plain brownish underparts, the Bank by its white underparts crossed by a brown 
chest band. “The adult Rough-winged somewhat resembles a young Tree Swallow 
in general coloration but is duskier below, especially on the breast" (Chapman). 
(See p. 456). 
