Northern Rough-winged Swallow in Delaware City.

The Northern Rough-winged Swallow (Stelgidopteryx serripennis) is a small, migratory swallow.

Northern Rough-winged Swallow in Delaware City.

Adults are 5.1–5.9 inches in length, brown above with white underparts, a small bill, and a forked tail. Their throat is a white with a brownish-grey wash, and below the throat are its white underparts. The males’ under tail coverts are longer and broader than that of the females. The males also have hooked barbs on the outer web of their outer primary wings. The barbs on the females are shorter and straighter than that of the males. Juveniles can be distinguished from adults by their reddish-brown wing-bars.

Northern Rough-winged Swallow in Delaware City.

They are similar in appearance to the Bank Swallow but have a dusky throat and breast. They are closely related and very similar to the Southern Rough-winged Swallow, Stelgidopteryx ruficollis, but that species has a more contrasting rump, and the ranges do not quite overlap. [Wikipedia]

Northern Rough-winged Swallow in Delaware City.

A plain brown bird, the Northern Rough-winged Swallow, is fairly common across the United States in summer. The species derives its name from the outer wing feathers, which have small hooks or points on their leading edges. [All About Birds]

Northern Rough-winged Swallow in Pennsylvania.

Northern Rough-winged Swallow [All About Birds]

• The barbs on the primary feathers of the male Northern Rough-winged Swallow are distinctly hooked; those of the female are smaller and straighter. Running a finger from base to tip along the barbed wing edge yields a sensation similar to that of touching a rough file.
• The function of the rough wing edge of the Northern Rough-winged Swallow is not known.
• The Greek genus name of the Northern Rough-winged Swallow, Stelgidopteryx, means “scraper wing;” the Latin species name, serripennis, means “saw feather.”
• The oldest recorded Northern Rough-winged Swallow was a male, and at least 5 years, 11 months old when he was recaptured and rereleased in California.

Northern Rough-winged Swallow in Delaware City.

Northern Rough-winged Swallow in Pennsylvania.