Science Questions

Do other species cuckold like cuckoos? Helen Scales

We posed this question to Rebecca Kilner from the University of Cambridge...

It’s not just confined to the birds and that’s because universally across the animal kingdom providing child care is costly.  So, that means there’s a tremendous incentive for individuals to steal childcare from other individuals.  We know that that happens in fish - for example, there’s a cat fish that steals parental care from fish that brood their eggs and fry in their mouth.  So, it takes care to get its host to swallow its fertilized egg and then the cat fish develops within the mouth of the host fish and it eats all the other eggs and fry in there and grows spikes so that the host doesn’t swallow it and then, finally, is spat out when it’s completed development.

There are also some equally horrible insects that steal parental care from ant colonies. Say for example, the cuckoo butterfly, is so named because it induces ants to pick up its caterpillar and carry it back to their colony where they treat it like a giant member of their own colony and they carefully nurture it for between 11 months and 2 years until it’s grown large enough to pupate and then it becomes the adult butterfly.  So yes, it’s widespread in the animal kingdom.

September 2009