Cowbirds are birds belonging to the genus Molothrus in the family Icteridae. They are of New World origin and are obligate brood parasites, laying their eggs in the nests of other species.
The genus was introduced by English naturalist William Swainson in 1832 with the brown-headed cowbird (Molothrus ater) as the type species. The genus name combines the Ancient Greek mōlos, meaning "struggle" or "battle", with thrōskō, meaning "to sire" or "to impregnate". The English name "cowbird", first recorded in 1839, refers to this species often being seen near cattle.
Species
The genus contains six species:
Genus Molothrus – Swainson, 1832 – six species
Common name
Scientific name and subspecies
Range
Size and ecology
IUCN status and estimated population
Screaming cowbird
Molothrus rufoaxillaris Cassin, 1866
Northeast and central Argentina, southeast Bolivia, central Brazil and throughout Paraguay and Uruguay
Size:
Two subspecies
M. o. impacifus (Peters, JL, 1929)
M. o. oryzivorus (Gmelin, JF, 1788)
Southern Mexico south to northern Argentina, and on Trinidad and Tobago
Size:
Habitat:
Diet:
LC
Shiny cowbird Male
Female
Molothrus bonariensis (Gmelin, JF, 1789)
Seven subspecies
M. b. minimus Dalmas, 1900
M. b. cabanisii Cassin, 1866
M. b. venezuelensis Stone, 1891
M. b. aequatorialis Chapman, 1915
M. b. occidentalis Berlepsch & Stolzmann, 1892
M. b. riparius Griscom & Greenway, 1937
M. b. bonariensis (Gmelin, JF, 1789)
South America, the Caribbean, and Florida
Size:
