Cuckoos

Cuckoos are a diverse group of birds in the family Cuculidae, order Cuculiformes. The family contains roughly 60 to 70 species across several genera, found in woodlands and open habitats in Africa, Asia, Europe, the Americas, and Oceania. They range from small, slender species to larger, long-tailed forms, and most are adept at climbing and moving through vegetation while foraging for insects, fruit, and small vertebrates.

Many cuckoo species are brood parasites: females lay eggs in the nests of other bird species, leaving the host to incubate the eggs and raise the young. In obligate parasitism, no cuckoo nest is built; the chick often evicts host eggs or nestlings and begs aggressively for food from the foster parents. Some cuckoo eggs resemble the host eggs in color and pattern, aiding deception. The host species and the likelihood of parasitism vary by region.

Not all cuckoos are parasites. Several groups within Cuculidae, including the anis of the Americas (Crotophaga) and related lineages, raise their own young or practice cooperative breeding rather than parasitism.

Distribution and behavior: Temperate cuckoos such as the common cuckoo (Cuculus canorus) are migratory, breeding in Europe and Asia and wintering in Africa or the tropics. Others are resident or altitudinal migrants depending on climate.

Conservation: Most species are of least concern, but several island-endemic or forest-dependent cuckoos face threats from habitat loss and fragmentation. The cuckoo's ecological role as brood parasite has shaped the evolution of host defenses and host-parasite dynamics.