(Part of the) common name of many members of the family Cuculidae (order Cuculiformes) and in the plural the general name for the family (± 127 species). Used without qualification for Cuculus canorus of which the name is derived from its familiar call. Other common names used for members of the family include 'anis', 'guiras', 'roadrunners', 'couas' and 'coucals'. The subfamily Cuculinae contains the typical cuckoos with its well-known parasitic breeding habits (which is not shown by the other members). Members of the family range in size from 16 cm (size of a House Sparrow) to 70 cm (size of a Raven) and have often a somewhat elongated body with a neck of moderate length. The tail is often graduated (broadest in the middle and with a V-shaped ending) and of at least medium length but it may be very long. The legs are short, except in ground-living species with zygodactyl feet (2 opposable toes. They have stout and slightly decurved (sometimes heavy) bills of moderate length. The plumage has a rather loose appearance and often a coloured ring of bare skin round the eye is present. Cuckoos (in a broad sense) are solitary (except one genus) and mainly arboreal birds, a few species are terrestrial. They are largely insectivorous, but molluscs, small vertebrates and fruits are also eaten. The typical parasitic cuckoos are restricted to the Old World, but widely represented therein. The Cuckoo Cuculus canorus breeds throughout the Palaearctic Region, migrating to Africa and southern Asia. The 'breeding-' or 'nest parasitism' of typical cuckoos means that the eggs are laid in the nest of another species, which then tends and rears the parasite's young. To be successful, this required some adaptations of the parasitic birds, notably a reduction in the size of the eggs and the length of the incubation period, but also the evolution of egg mimicry in colour and pattern to minimise rejection or desertion by the host parents. Adaptations of the young ('s habits) were also often necessary, like throwing out nest-mates or mimicking juvenile plumages, to ensure (sufficient) feeding and rear.

Alternative forms for cuckoos : Clamator, cuckoo, Cuculus.