Cuckoo

Cuckoo is a common name for a group of birds in the family Cuculidae. The best-known member is the common cuckoo (Cuculus canorus), a migratory bird of Europe and Asia famous for its distinctive vocalization and for the brood parasitism practiced by many of its relatives.

Description and range vary among species. Most cuckoos are medium-sized, with slender bodies, long tails, and patterned plumage that blends with their habitat. They occur in a broad range of environments, including forests, woodlands, scrub, and savannas, from tropical to temperate regions.

A defining trait of many cuckoos is brood parasitism. Female cuckoos lay eggs in the nests of other bird species; the host incubates the egg and raises the chick, often at the expense of its own young. In many cases the cuckoo chick ejects or otherwise suppresses host eggs or nestlings. Host birds sometimes recognize and reject foreign eggs, which has driven an ongoing evolutionary arms race.

Diet is mostly insects such as caterpillars, but some species eat fruit, seeds, or small vertebrates. Cuckoos are generally elusive, and many species are migratory, with breeding populations in temperate regions and wintering grounds in the tropics.

Taxonomically, the cuckoos belong to family Cuculidae and include several genera, such as Cuculus, Clamator, Chrysococcyx, and Coccyzus. While brood parasitism characterizes many Old World cuckoo species, several New World species build their own nests. Most species face no immediate conservation concern, though habitat loss and climate change threaten some populations.