Honeyguides and other brood parasitic birds are famous for tricking host parents by laying eggs that mimic their own. Honeyguide eggs mimic host eggs in size yet, surprisingly, bee-eater hosts are undiscriminating and readily accept mismatched eggs. This study shows that honeyguide egg size adaptation has probably rather evolved to trick other honeyguides, not host parents: honeyguides selectively puncture any mismatched egg already present in the nest when they lay their own, lest it be the offspring of another honeyguide female and brutally kill their own chick when it hatches.
Read the full paper in Biology Letters [Open Access], or Ed Yong’s excellent article about the study. Here are some other nice articles and podcasts online covering this study: The Behaviour, Ecology & Evolution Podcast | Take Part blog | Earth Times.
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.