Northern rough-winged swallow

The northern rough-winged swallow (Stelgidopteryx serripennis) is a small, migratory swallow. It is very similar to the southern rough-winged swallow, Stelgidopteryx ruficollis.

Adults are 13–15 cm (5.1–5.9 in) in length, brown above with white underparts, a small bill, and a forked tail. Their throat is white with a brownish-grey wash, and below the throat are white underparts. The adults have a wingspan of 27–30 cm (11–12 in) and a weight of 10–18 g (0.35–0.63 oz). The males' undertail coverts are longer and broader than those 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 those of the males. Juveniles can be distinguished from adults by their reddish-brown wing-bars.

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.

The call of this swallow is described as a short, harsh zeep. It has also been described as a rough, low bzzt. It is often doubled. This call is similar to the call of the bank swallow.