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.
Dr Gabriel Jamie has just returned from a successful couple of months of fieldwork in Zambia as part of his Leverhulme Early Career Research Fellowship. For this research, Dr Jamie is exploring the evolution of polymorphisms across diverse avian family Cisticolidae which exhibit some of the most complex and diverse eggs of any group of birds in the world.