The Bay-winged Cowbird (Agelaioides badius), also known as the Baywing, is a species of bird in the Icteridae family. It is monotypic within the genus Agelaioides, but has traditionally been placed in the genus Molothrus. It is found in the northern half of Argentina, Bolivia, Uruguay, Paraguay and southern and central Brazil, with an isolated population in north-eastern Brazil. The latter population is sometimes considered a separate species, the Pale Cowbird or Pale Baywing (Agelaioides fringillarius). The Bay-winged Cowbird has been recorded as a vagrant in Chile.

Description and behavior A. b. fringillarius.

It has a total length of approximately 18 cm (7 in). It is overall ashy-brown with contrasting black lores and rufous wings. The taxon fringillarius has more black in the face and is overall more rufescent (less ashy).

It is social and commonly seen in small groups. Unlike the "true" cowbirds in the genus Molothrus, this species is not a brood parasite. In contrast, the Screaming Cowbird is a brood parasite of the Bay-winged Cowbird, and while adult Screaming Cowbirds are overall blackish, juvenile Screaming Cowbirds closely resemble Bay-winged Cowbirds.

Habitat and status

It is found in a wide range of semi-open habitats, including scrub and light woodland. The north-eastern taxon fringillarius is primarily found in Caatinga and Cerrado. It is generally fairly common, and consequently considered to be of least concern by BirdLife International and IUCN.