Birdsong field guide
Giant Cowbird
Molothrus oryzivorus
The Giant Cowbird is a large, specialized brood parasite of the icterid family, known for targeting the nests of colonial oropendolas and caciques.
What it sounds like
A series of harsh, liquid gurgles and sharp 'check' notes, along with a thin, rising whistle.
Reference call, compare with what you heard
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Field notes
- It is the largest species of cowbird, with males displaying a prominent inflatable neck ruff during courtship.
- Unlike many brood parasites, its chicks may benefit the host by consuming botfly larvae that would otherwise harm host nestlings.
- Host colonies often show variable tolerance to its presence depending on the local density of parasitic botflies.
- Adult eye color is typically red or white, while juveniles possess dark eyes and a pale-colored bill.
- The species does not build its own nest, instead laying one or two eggs in the hanging, pouch-like nests of its hosts.
Habitat
Forest edges, clearings, and open woodlands, typically near host colonies in canopy trees.
Range
Tropical Americas, ranging from southern Mexico to northern Argentina and Uruguay.
Similar & commonly confused birds
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