This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the northern rough-winged swallow.
Curved barbs along the outer edges of the male’s primary wing feathers give this bird both its common and scientific names. Saw-winged edges is an interesting adaptation with an unexplained purpose.
It can be difficult to pick out individual markings in a mass of flying, diving birds, but in perched swallows, the differences become apparent. Northern rough-winged swallows are small, long-bodied birds with a small head and bill. These swallows are brown above with a dusky-colored face and throat blending to a whitish belly. They lack the dark breast band of the brown bank swallow. Except during times of nest building and egg laying, they are generally quiet.
The rough-winged tends to fly lower, and with slower wing beats, than other swallow species. With a wide, gaping mouth, it often catches insects that are on or just emerging from the water’s surface and it even drinks on the wing.
In summer, these swallows are common across the United States and southern Canada in open areas, often near water, where they feast on flying insects. Most often, they build nests inside the abandoned burrows of squirrels, kingfishers or bank swallows in clay, sand or gravel banks near water. They will also nest in crevices of man-made structures.
Unlike the colony nesting bank swallows, northern rough-winged pairs nest alone or only in small groups. Like many birds that are aerial insectivores, these swallows have experienced population declines which may be attributed to increased pesticide use and a warming climate.
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