Helicopter parenting, it seems, is not a uniquely human trait. Female bonobos interfere with their sons’ love lives in order to get grandchildren, a new study has found, even dragging their sons to fertile females.
Scientists observed bonobos in the Democratic Republic of the Congo – the only country where these great apes are found in the wild.
The bonobo mums engaged in a variety of behaviours to increase their chances of having grandchildren, including protecting their sons’ mating attempts from interfering rivals, intervening in the rivals’ mating attempts, and bringing the sons to ovulating females.
The overbearing mums were successful – their tactics made it three times more likely that their sons would have children.
- Chimpanzee gestures ape features of human language
- Monkeys with human brain genes: has it crossed an ethical line?
“This is the first time that we can show the impact of the mother’s presence on a very important male fitness trait, which is their fertility,” said Dr Martin Surbeck, a primatologist at the Max Planck Institute for Evolutionary Anthropology who led the study. “We were surprised to see that the mothers have such a strong, direct influence on the number of grandchildren they get.”
Uniquely among the great apes, bonobos live in what some primatologists believe is a matriarchal society, with males deriving their status from the status of their mum.
Like a VIP pass to high society, the bonobo mums were seen using their status to give their sons access to popular spots in the community, helping the males to achieve better status and better mating opportunities.
Why the mums are so keen to have grandchildren is not fully understood, but Surbeck and his team think that the behaviour could have evolved as a way for bonobos to propagate their genes, albeit indirectly.
“These females have found a way to increase their reproductive success without having more offspring themselves,” said Surbeck.
James is staff writer at BBC Science Focus magazine. He especially enjoys writing about wellbeing and psychology.