Brood parasitic birds lay their eggs in the nests of others, sparing themselves the expense of rearing their own young. The resulting coevolutionary arms race includes sophisticated defenses by ...

She then swallows one of the eggs that’s been laid there and lays one of her own—a behavior known as brood parasitism ... observed the birds’ behavior in 2014 in Amsterdam, where she ...

The common brown-headed cowbird is the most widespread brood parasite in North America ... almost finchlike. Foraging birds are commonly seen on the ground with the tail cocked.

The Brown-headed cowbird is one of two cowbird species in North America. Both species are brood parasites - they lay their eggs in the nests of other birds. Brown-headed cowbirds are native to ...