Host species of brood-parasitic birds can evolve features such as spots, squiggles and colours on their eggs that act like ‘signatures’ that are difficult for parasites to forge, helping hosts to detect and reject imposter eggs. In this new paper, we show that hosts of cuckoo finches and diederik cuckoos in Zambia have optimised this defence by arranging signature traits in unpredictable combinations. Thus, egg signatures are individually distinctive and hard for parasites to mimic, helping hosts distinguish parasitic eggs from their own. The paper arose from MPhil research by Eleanor Caves (co-authored by Martin Stevens, Edwin Iversen and Claire Spottiswoode) and the data were all obtained from Major John Colebrook-Robjent‘s wonderful egg collection. It is available open access in Proceedings of the Royal Society of London B.
During this year’s British Science Week, we’ve been engaging with local school children in Cambridgeshire. Mairenn Attwood led interactive talks at the Thomas Clarkson Academy in Wisbech, a school partnered with ‘Teach First’ (a charity aimed at reducing educational inequality).