The most common North American bird that is a "nest parasite" -- lays eggs in other birds' nest -- is the brown-headed cowbird, a robin-sized songbird.
Cowbirds developed this adaptation in order to keep up with migrating herds of buffalo (cows) over the Great Plains. Creating a nest and raising a brood take a lot of time and energy, so the cowbird enlisted the unwitting aid of other bird parents to to this for them.
The cowbird lays its eggs in the host bird's nest and throws out existing eggs. The cobirds hatch first and are bigger that the host's chicks. But the host cannot disinguish between the cowbird chick and its own, so feeds the invader. The juvenile cowbird also kills the host's chicks sometimes.
In some areas, cowbird-eradication efforts are under way because of nest parasitism's effect on declining species of other birds.
Cowbirds developed this adaptation in order to keep up with migrating herds of buffalo (cows) over the Great Plains. Creating a nest and raising a brood take a lot of time and energy, so the cowbird enlisted the unwitting aid of other bird parents to to this for them.
The cowbird lays its eggs in the host bird's nest and throws out existing eggs. The cobirds hatch first and are bigger that the host's chicks. But the host cannot disinguish between the cowbird chick and its own, so feeds the invader. The juvenile cowbird also kills the host's chicks sometimes.
In some areas, cowbird-eradication efforts are under way because of nest parasitism's effect on declining species of other birds.