The European cuckoo is a medium-sized bird known for its distinctive call and unique breeding behavior. It has a grayish-brown body with a long tail and pointed wings. The male is particularly recognized for its loud, repetitive "cu-coo" song, which is often heard in spring and summer. One of the most interesting aspects of the European cuckoo is its brood parasitism. Instead of building its own nest, the female lays her eggs in the nests of other bird species, such as warblers or sparrows. The host birds then raise the cuckoo chick, often at the expense of their own offspring.