Common Cuckoo

A bird better known for its call than its looks

The common cuckoo is a slim, long-tailed bird with grey upperparts and a barred underside that can remind people of a small hawk. It is much easier to hear than to see. In spring, males perch in the open and call for hours, and the sound is so familiar that in many European countries it is treated as a sign that the season has changed.

What the call means

The two-note song belongs to the male and works as a territorial and advertising call. Females do not sing it; they make a rapid, bubbling trill instead. Just before and during the breeding season a male may call at a steady rhythm, and the second note often drops in pitch. Listeners who record the call at different times of year will notice that the pace becomes more hurried and the notes can break into a stuttering “cu-cu-cuck” as the season goes on.

A parasitic way of life

The cuckoo is a brood parasite. Females lay a single egg in the nest of a smaller host such as a reed warbler or meadow pipit, and the young cuckoo evicts the host’s own eggs after hatching. Different female cuckoos specialise on different host species and lay eggs that match the host’s in colour. Numbers have declined in parts of Europe, which researchers link to falling insect numbers and changes along their long migration routes.

Further reading: How Birds Learn Their Songs — Nature's Music Lessons

Conservation status follows the IUCN Red List as we understand it at the time of writing. Assessments are revised regularly, so please check the IUCN Red List for the current listing.