Cuckoos are dove-sized birds with ash-grey upperparts and dark-barred white bellies. They are very hard to spot; if you do manage to see one, it will probably appear just as a dark, streamlined shape flying quite fast across fields, often between areas of woodland. They are much easier to hear, however: a male Cuckoo sings ‘cuck-oo, cuck-oo’ to announce his presence, sounding just like a Cuckoo-clock!
Cuckoos have been declining in Ireland, and they are less common now than they were a few decades ago.
Cuckoos are found in all types of terrain, in woodland and in open country right up to mountain slopes. The most interesting thing about the Cuckoo is that it does not make its own nest: the female lays her eggs in the nest of other birds. Young Cuckoos hatch before their foster parents' own eggs, and once the Cuckoo chick has hatched it pushes out the rest of the eggs.
What do they eat?
Insects – mostly caterpillars and beetles. The Cuckoo does not specialize in particular species of prey, but catches the insects which are most numerous in its local area, and therefore easiest to find and catch.
Instead of building their own nest, Cuckoos use the nests of ‘host’ birds, such as Dunnocks and Meadow Pipits. When a female Cuckoo finds a suitable nest, and the other birds aren’t looking, she removes one of their eggs and lays her own egg in its place. Sometimes these nests are built by birds that are much smaller than the Cuckoo chick. The ‘parent’ birds must work even harder to feed their giant baby, mistaking it for their own.
Cuckoos which nest in Europe spend the winter in Africa, usually on savannas. Some birds from the western part of Asia also winter in Europe, others in Asia, up to New Guinea in the Pacific.
The population of Cuckoos in Europe
In Europe the population of Cuckoos is quite large and stable, although the size of the Western European population has dropped in recent times, most notably in France.