The name cuckoo is common to many parasitic bird species that rely upon others to raise their young.

African tawny-flanked prinias are the targets of cuckoo finches in southern Zambia.

Prinias' egg colours vary widely but by laying multiple eggs in a nest, cuckoo finches reduce the risk of rejection.

The results of the study undertaken by researchers from the University of Exeter and the University of Cambridge are published in the journalNature Communications.

"Many brood parasites [such as cuckoo finches] and hosts are locked in ongoing evolutionary arms races, with parasites evolving attack strategies to get their eggs accepted - such as egg mimicry - and hosts evolving defences - such as egg rejection," explained co-author Dr Martin Stevens from the University of Exeter.