Fan-tailed Cuckoo

Cacomantis flabelliformis

Fan-tailed Cuckoos arrive in southern South Australia to breed in late Winter. Photo: John Spiers

Around the world the call of the cuckoo heralds the arrival of spring, but it is often not the same type of cuckoo. In South Australia of the nine species of cuckoo recorded and the one you are most likely to hear is the Fan-tailed Cuckoo, whose loud descending trills resound through the woodlands in early spring. When you hear them, look up into the canopy. Unlike the rest of the year the bird is often prominent at this time when the males wants to be seen and heard by prospective mates.

Cuckoos are obligate nest parasites, meaning they have lost all ability to raise their own young. For host parents they favour small birds with a domed nest such as scrubwrens, fairy wrens, thornbills and heathwrens. They will also parasitise small birds with open cup-shaped nests – robins, honeyeaters, whistlers and fantails. Males sometimes distract the host while the female lays her eggs in the host’s nest. She has a short window of opportunity to do so, between the time when the unfortunate hosts lay their eggs and they hatch. Cuckoo eggs develop quickly and when hatched the cuckoo nestling ejects the host’s eggs or host hatchlings leaving it in sole possession of the nest. The hosts will often detect the eggs of a cuckoo, and either abandon the nests or else build a new nest over it. Curiously, however, once the egg hatches and they are presented with a nestling to feed the parenting instinct takes over. They will then feed it as if it was their own, even it grows to several times their size and looks nothing like their own young. Even birds other than the hosts have been observed feeding young cuckoos. The host loses out twice. Their own young are destroyed and they lose an entire season feeding the stranger, at great expense to themselves.

Cuckoos feed on insects (particularly caterpillars), centipedes and spiders, catching them by foraging in foliage, or by hawking. Only the nominate sub-species C. f. flabelliformis is found in South Australia. Look for them in forests and woodlands throughout the state.


Look for a bird a bit similar in size to a starling with a pale front, a dark-grey back, a long stripey tail and a yellow eye-ring (females are paler below with faint stripes along the sides).

Where to find it

The Fan-tailed Cuckoo is mainly migratory in South Australia. They may be found throughout the year but most move to the tropics of Northern Australia, New Guinea and nearby islands in about February, returning to breed from July to February, but mainly in in the spring months; September and October.