The sex life of treefrogs: how females build better nests by mating with multiple partners

African grey foam-nest treefrogs (Chiromantis xerampelina) are common across the savannahs and dry forests of south-eastern Africa. Despite their unremarkable outward appearance, these small animals display some of the most intriguing reproductive behaviours known to science. Most notably, the females are highly polyandrous, constructing elaborate foam nests and mating with many different male partners in a breeding season. Until the 1990s, evolutionary biologists thought that polyandry was…