Some parents get overly involved in their kids’ personal lives, but bonobo mothers take this tendency to the extreme. They fix up their adult sons with a female of their choosing, and they even keep other males from getting near their future daughter-in-law. The behavior may seem overbearing, but it boosts the odds they’ll be surrounded by grandkids. That’s according to a study in the journal Current Biology. [Martin Surbeck et al., Males with a mother living in their group have higher paternity success in bonobos but not chimpanzees]
Researchers studying wild bonobos in the Congo noticed that some females behaved a bit like males—fighting over fertile females and fending off some of the males who come a-courtin’. That observation struck primatologist Martin Surbeck as odd.
“So I just wondered, hey what is it actually of their business, no? Most of the mammals it’s just a male business, this competition over the access to females.”
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To get to the bottom of this unusual activity, Surbeck, who is currently at the Max Planck Institute for Evolutionary Anthropology, got DNA samples from the players in this melodrama.
“And so it became more apparent when we did the paternity analysis and it turned out these females were mothers of some males. And in this female-dominated society of bonobos the mother acts kind of like a social passport, allowing their sons to be more central in the group and therefore having more opportunities to interact with other females.”
And after the moms introduce their sons to the most desirable ladies, they make sure the couple won’t be interrupted. As a result:
“We found that males have about three times higher likelihood to sire offspring while their mom was still alive in the community.”
In contrast, mothers of the closely related chimpanzees don’t chaperone their sons. In fact, male chimps are less likely to sire offspring when their moms are around. Seems that chimps prefer privacy for their monkey business.
—Karen Hopkin
(The above text is a transcript of this podcast)
