Modern ornithology defines the cuckoos (Cuculidae) as a family of around 130 species which are found almost everywhere except at the two poles--their song can be heard all over Africa, Asia, Europe and the Americas.
近代的鳥類學裡，被分類在所謂杜鵑科（cuckoo）的鳥，多達一百三十種左右，除了兩極不見杜鵑，亞、歐、美、非洲，可以說處處聞啼鳥。