The grayish baywing, formerly known as the bay-winged cowbird, is a species of bird in the family Icteridae. It is currently placed in 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, The isolated population in north-eastern Brazil is usually now considered a separate species, the pale baywing. The greyish baywing has been recorded as a vagrant in Chile.
Region
Southern South America
Typical Environment
Occurs across northern and central Argentina, Uruguay, Paraguay, eastern Bolivia, and southern to central Brazil, with occasional vagrants to Chile. It favors open country such as pampas grasslands, Chaco scrub, savanna edges, and agricultural mosaics with scattered trees. Common around ranches, towns, and roadsides, especially where thorny shrubs or small trees provide nesting sites. It avoids dense, continuous forest and very humid interiors but readily uses edges and clearings.
Altitude Range
Sea level to 2000 m
Climate Zone
Temperate
Ease of Keeping
Beginner friendly: 2/5
Formerly called the bay-winged cowbird, this species is not a brood parasite; instead it is a cooperative breeder with helpers assisting the nesting pair. It is a frequent host of the screaming cowbird, which lays its eggs in baywing nests. Adaptable and often found near ranches and farmland, it thrives in open and semi-open landscapes. A closely related population in northeastern Brazil is now treated as a separate species, the pale baywing.
Temperament
social and active
Flight Pattern
short rapid wingbeats with low, undulating flights
Social Behavior
Usually found in pairs or family groups, often forming small loose flocks outside the breeding season. It is a cooperative breeder: helpers, often offspring from previous broods, assist in feeding nestlings. Cup nests are placed in thorny bushes or low trees, and the species is frequently parasitized by the screaming cowbird.
Migratory Pattern
Resident
Song Description
Song is a series of mellow, whistled phrases mixed with soft trills and chatters. Calls include clear contact whistles and harsh scolds when alarmed. Vocalizations are carried from exposed perches and within low shrubs.
