In a new paper we show experimentally that adult female cuckoo finches (at left in photo) in Zambia have evolved to resemble harmless and abundant bishop-birds (right), which should help them to slip past being attacked by host parents while they try to lay their egg. However, hosts are not fooled by this attempted deception, and defend themselves against parasitic cuckoo finches and harmless bishop-birds alike. To our knowledge this is the first time that such “wolf-in-sheep’s-clothing” plumage mimicry has been experimentally shown to exist in any adult bird. The paper is by Will Feeney, Jolyon Troscianko, Naomi Langmore and Claire Spottiswoode, and is available open access in Proceedings of the Royal Society of London B.
New paper on imperfect egg mimicry
Our paper “Combined measures of mimetic fidelity explain imperfect mimicry in a brood parasite-host system” has just been published in the journal Biology Letters. This study was led by Tanmay Dixit, and carried out together with Gary Choi, Salem al-Mosleh, Jess Lund, Jolyon Troscianko, Collins Moya, L Mahadevan, and Claire Spottiswoode, as part of a collaboration between our group and Prof. Mahadevan and his lab at Harvard University. Together we combined mathematical tools and field experiments in Zambia to quantify a key difference – “squiggle” markings – between the eggs of hosts (tawny-flanked prinias) and parasites (cuckoo finches). We showed that suboptimal behaviour on the part of prinias allows cuckoo finches to get by with an imperfect copy of prinia eggs.