As its common name indicates, the Giant Cowbird is a large cowbird. Indeed the Giant Cowbird dwarfs any other species of Molothrus, and at first glance may seem to have little in common with other cowbirds. Like other species of Molothrus, however, the Giant Cowbird is a brood parasite, and lays its eggs in the nest of other large-bodied birds, principally oropendolas (Psarocolius, perhaps other genera as well) and caciques (Cacicus). The male Giant Cowbird has a conspicuous ruff of feathers around the neck; this ruff may contribute to the Giant Cowbird's peculiar small-headed appearance. This species has a wide geographic range; it's distribution may be spreading higher into the Andes following deforestation, but it also may have been extirpated from some areas after the host species disappeared following the loss of their forest habitat.