The Cuckoos (Cuculidae) comprises 147 species belonging to five different subfamilies:
-Anis (Crotophaginae)
-Ground-Cuckoos & Roadrunners (Neomorphinae)
-Couas (Couinae)
-Coucals (Centropodinae)
-Cuckoos (Cuculinae)

The majority are arboreal, with a sizeable minority that are terrestrial. The family has a cosmopolitan distribution, with the majority of species being tropical. The temperate species are migratory. The cuckoos feed on insects, insect larvae and a variety of other animals, as well as fruit. Many species are brood parasites, laying their eggs in the nests of other species, but the majority of species raise their own young.

Cuckoos are often highly secretive and in many cases best known for their wide repertoire of calls. Calls are usually relatively simple, resembling whistles, flutes, or hiccups. The calls are used in order to demonstrate ownership of a territory and to attract a mate. Within a species the calls are remarkably consistent across the range, even in species with very large ranges. This suggests, along with the fact that many species are not raised by their true parents, that the calls of cuckoos are innate and not learnt.