Noun
The cow blackbird (Molothrus ater), an American starling. Like the European cuckoo, it builds no nest, but lays its eggs in the nests of other birds; -- so called because frequently associated with cattle.
Source: Webster's dictionaryOne study found that 9% of nests had brown-headed cowbird eggs in them. citation American goldfinches make very poor hosts for brood parasites, with studies showing low hatching rates of brown-headed cowbird eggs and no fledging success. Source: Internet
Nest of an eastern phoebe that has been parasitised by a brown-headed cowbird Incubation, which optimises temperature for chick development, usually begins after the last egg has been laid. Source: Internet