THE ROUGH-WINGED SWALLOW. 281 
social twittering and gyrating. The wonder is that the rapidly moving parts 
of this aerial kaleidoscope never collide, and that the cases of turning up at 
the wrong number are either so few or so amicably adjusted. The nesting 
season is, however, beset with dangers. Weasels and their ilk sometimes 
find entrance to their burrows: and they are also an easy prey to untaught 
small boys; while the undermining of the river or the lapping waves some- 
times precipitate an entire colony—at least its real and personal property— 
to destruction. As an instance of the last, I remember once coming upon a 
large colony on the Lake Erie shore. Recent rains, added to the basal en- 
croachment of the waves, had dislodged an extensive layer from the face of 
the nesting bluff, to a depth of two or three feet. The catastrophe had evi- 
dently taken place only a day or two before, and egg-shells and nesting ma- 
terials were freely mingled through the fallen clay ; yet the foolish birds had 
gone right to work again upon the same treacherous site, and in the colony 
of, say, five hundred birds, a hundred nests were already under Way. 
Bank Swallows are perhaps the least musical of their kind—unless we 
except the Rough-winged species, which is naturally associated with them. 
They have, however, a characteristic twitter, an unmelodious sound, like the 
rubbing together of two pebbles. An odd effect is produced when the excited 
birds are describing remonstrant parabolas at an intruder’s head. The height- 
ened pitch in the notes of the rapidly approaching bird followed instantly by 
the lower tone of full retreat, is enough to startle a slumbering conscience in 
one who meditates mischief against a Swallow’s home. 
No. 124. 
ROUGH-WINGED SWALLOW. 
ee OW Noe 617, Stelgidopteryx serripennis (Aud.). 
Description —Adult: Warm brownish gtay or snuft-brown, including 
throat and breast; thence passing insensibly below to white of under tail-coverts ; 
wings fuscous. Young birds exhibit some Tusty edging of the feathers above, 
especially on the wings, and lack the peculiar, recurved hooks on the edge of the 
outer primary. Size a little larger than the last. Length 5.00-5.75 (127.-146.1) ; 
Wing 4.30 (109.2) ; tail 1.85 (47.) ; bill from nostril .21 (5.3). 
Recognition Marks.—Medium Swallow size; throat not white; warmish 
brown coloration, and brownish suffusion below fading to white on belly. It is 
easy to distinguish between this and the preceding species if a little care is taken 
to note the general pattern of under parts. 
