Guide to Boreal Birds
The name "Rough-winged" refers to tiny hooklets on the outer vane (flat part of a feather) near the end of the shaft of the outer primary feathers. The function of these hooks, visible only under a magnifying glass and found also in an unrelated group of African swallows, is unknown. Unlike the Bank Swallow, Rough-wings do not usually dig their own nesting burrows but use ready-made nesting sites along streams. Thus they do not nest in large colonies like the Bank Swallow, although occasionally a few pairs may be found close together.
5-5 3/4" (13-15 cm). Pale brown above, white below, with dingy brown throat. Bank Swallow is similar, but smaller, and has white throat and brown breast band.
A low, unmusical br-r-ret, more drawn out than the call of the Bank Swallow and often doubled.
4-8 white eggs in a burrow or cavity; will utilize ready-made cavities in bridges, culverts, or other streamside masonry. Not highly colonial; often nests singly.
Riverbanks. Prefers drier sites than the Bank Swallow.
Breeds from southeastern Alaska and southern Canada southward throughout United States. Winters north to southern California, Gulf Coast, and southern Florida.