Giant cowbird looking for titbits, Pantanal, Brazil

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. The Giant Cowbird is one of the larger species of icterid. It is wholly black with long and pointed wings, a rather long and rounded tail, a stout black bill with broad and flattened frontal shield, and with the feathers of sides of neck developed into erectile lateral ruffs. ail about three-fourths as long as wing, rounded, rectrices with broad ends. Tarsus with anterior scutella distinct. Feathers of neck greatly developed laterally and posteriorly, forming a conspicuous ruff in males, less so in females, with bare or downy space immediately behind on sides of neck.

Male General color is black. Feathers of head, neck and body more or less broadly tipped uniformly with glossy violet, and back tending to bronzy; on underparts forming a sharply defined terminal band or margin to each feather — basal black conspicuously exposed and violet tips becoming narrower posteriorly and less distinct on rump than on under parts. The smaller wing coverts, tail coverts and thighs uniform black or with indistinct bluish violet margins. Larger wing coverts, remiges and rectrices faintly glossed with bluish. Alternate and basic plumages similar. Female Much duller than male. Black, with tips of feathers of head, neck and body indistinctly tipped with more glossy violaceous-black. Dies is Fruit (Ficus trigona and Coussapoa sp.), nectar (chiefly Combretum sp. and Quararibea sp.), and arthropods. One bird collected had been eating rice; stomach of young male had seeds.The conservation status of the Giant Cowbird is rated as of Least Concern.