The chalky cliffs along the Hat Creek Canal (Shasta County CA) provide nesting sites for the violet-green swallow (see “Violet-green Swallow” 05-14-14) as well as northern rough-winged swallows (Stelgidopteryx serripennis). While photographing these two species I watched violet-greens and rough-wings tending nest cavities located next to each other.
The northern rough-winged swallow has a dull brown head and upper parts and is dirty white below with a pale brown throat. The tail is squared off in flight. This small swallow gets its common name from small hooks on the outer wing feathers. These “hooks”, whose function is unknown, can be felt if one runs their finger along the feather.
Wintering along the Gulf Coast of the United States and in Central America, northern rough-winged swallows are found throughout most of North America during the breeding season. Rough-winged swallows prefer open habitat close to water with nearby vertical surfaces (natural or man-made) containing burrows or cavities.
Northern rough-winged swallows do not nest in large colonies, rather a few pairs will breed in close proximity. The nests are usually placed in cavities dug by other birds, however they occasionally may dig their own cavity. Four to eight white eggs are incubated for 12 to 16 days before the helpless chicks hatch. After another 19 or 20 days the nestlings fledge. For a few days after they flegde and before they leave, the parents will feed their young.
Northern rough-winged swallows are aerial foragers whose diet consists of mainly insects.
John James Audubon collected a northern rough-winged swallow in 1819 in Louisiana.
Although they are not visible to the naked eye, the hooks on the outer wing feathers obviously impressed early taxonomists. The genus name, Stelgidopteryx, is from the Greek and means “scraper wing” while the species name, serripennis, means “saw feather” in Latin.