Brood-parasitic birds lay eggs that mimic those of other species, to trick hosts into incubating their egg and raising their chick. Hosts often fight back by evolving egg colours and patterns that look different from those of their parasites, making an impostor easier to spot. In this study, we tested whether natural selection also drives hosts to evolve eggs that look different from those of other hosts, to avoid being susceptible to their neighbour’s specialist parasites when several host species live side by side. Using data from Major John Colebrook-Robjent‘s wonderful egg collection, we find evidence for this in the hosts of African brood-parasitic birds, which have evolved astonishingly diverse eggs. Read more in the full paper is published in Proceedings of the Royal Society of London B, by Eleanor Caves (former MPhil student), Martin Stevens and Claire Spottiswoode; see also a news article about this research in The Economist.
In a new paper published in Evolution, Dr Gabriel Jamie along with Silky Hamama, Collins Moya and Prof. Claire Spottiswoode from the African Cuckoos team and collaborators from University of Puerto Rico (Steven Van Belleghem), Princeton University (Dr Cassie Stoddard and Dr Ben Hogan) and University of Cambridge (Professor Rebecca Kilner) provide evidence of host-specific mimicry in the indigobirds and whydahs of Africa. Building on the pioneering work of Robert Payne and Jürgen Nicolai, they provide quantitative evidence that nestling Vidua finches mimic the patterns, colours and begging calls of their host’s nestling, and qualitative evidence of mimicry of host movements.