The common cuckoo is known for its deceitful nesting behaviour — by laying eggs in the nests of other bird species, it fools host parents into rearing cuckoo chicks alongside their own. While common cuckoos mimic their host’s eggs, new research has revealed that a group of parasitic finch species in Africa have evolved to mimic their host’s chicks — and with astonishing accuracy. The study is published in the journal Evolution.
Working in the savannahs of Zambia, a team of international researchers collected images, sounds and videos over four years to reveal a striking and highly specialised form of mimicry. They focused on a group of finches occurring across much of Africa called the indigobirds and whydahs, of the genus Vidua.
Like cuckoos, the 19 different species within this group of finches forego their parental duties and instead lay their eggs in the nests of other birds. Each