European Cuckoo at Reed Warbler's nest

European Cuckoo removing Reed Warbler's egg

European Cuckoo laying her own egg

European Cuckoo's egg in a Reed Warbler's nest

European Cuckoos' eggs (center)
and eggs of their hosts (top and bottom)

Newly hatched European Cuckoo ejecting a Reed Warbler's egg

Young European Cuckoo fed by Reed Warbler

Whydahs and indigo birds (Viduinae)
and their firefinch (Estrildinae) hosts

Firefinch feeding a young indigo bird and its own young

Mouth markings of nestling estrildine finches (left)
and their viduine brood parasites (right)

... extraordinary photos of European Cuckoos by Ian Wylie (The Cuckoo)