Nav: Home

Bonobo moms play an active role in helping their sons find a mate

May 20, 2019

Many social animals share child-rearing duties, but research publishing May 20 in the journal Current Biology finds that bonobo moms go the extra step and actually take action to ensure their sons will become fathers. From physically preventing other males from mating to bringing their sons in close proximity to ovulating females, bonobo moms bring new meaning to the notion of being overbearing - but in so doing, they increase their sons' chance of fatherhood three-fold.

"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," says Martin Surbeck, a primatologist at the Max Planck Institute for Evolutionary Anthropology. "We were surprised to see that the mothers have such a strong, direct influence on the number of grandchildren they get."

Surbeck and his colleagues observed wild populations of bonobos in the Democratic Republic of Congo, as well as wild populations of chimpanzees in Côte d'Ivoire, Tanzania, and Uganda. They found that while both bonobo and chimpanzee mothers would advocate for their sons in male-on-male conflicts, bonobo moms went the extra mile to aid their sons' copulation efforts. This involved protecting their sons' mating attempts from other males, intervening in other male's mating attempts, and intentionally bringing their sons around fertile females.

The bonobo mothers were also able to use their rank in the bonobo's matriarchal society to give their sons access to popular spots within social groups in the community and help them achieve higher status--and therefore, better mating opportunities. The authors note that these interactions were rare in chimpanzee societies likely because males hold dominant positions over females, making the actions of chimp mothers less influential than those of bonobo mothers.

Interestingly, bonobo moms did not extend similar help to their daughters, nor were there any observations of daughters receiving assistance in rearing their offspring. "In bonobo social systems, the daughters disperse from the native community and the sons stay," Surbeck says. "And for the few daughters that stay in the community, which we don't have many examples of, we don't see them receiving any help from their mothers."

Moving forward, Surbeck and his team would like to better understand the benefits these behaviors confer on bonobo mothers. Currently, they think that it allows for an indirect continuation of their genes. "These females have found a way to increase their reproductive success without having more offspring themselves," he says, noting that the prolongation of the post-reproductive human female lifespan, as well as the early age at which human women can no longer bear children, may have evolved from this indirect method of continuing their genetic line.

Surbeck acknowledges that gathering data on post-reproductive lifespans of females in chimp and bonobo communities will require a long-term, collaborative study, similar to this one. "Without the help and participation from all of the field sites where data were collected, these important interactions could have been overlooked," he says. "Now as the director of a bonobo field site, I'm looking forward to further exploring this topic."
-end-
The authors acknowledge support from the Max Planck Society, the National Geographic Society, and the Wenner-Gren Foundation. They also acknowledge partial support by SNF.

Current Biology, Surbeck, M.: "Males with a mother living in their group have higher paternity success in bonobos but not in chimpanzees" http://www.cell.com/current-biology/fulltext/S0960-9822(19)30338-0

Current Biology (@CurrentBiology), published by Cell Press, is a bimonthly journal that features papers across all areas of biology. Current Biology strives to foster communication across fields of biology, both by publishing important findings of general interest and through highly accessible front matter for non-specialists. Visit: http://www.cell.com/current-biology. To receive Cell Press media alerts, contact press@cell.com.

Cell Press

Related Mothers Articles:

Older mothers are better mothers
New research shows that older mothers are less likely to punish and scold their children while raising them, and that the children have fewer behavioral, social and emotional difficulties.
Mothers and infants connect through song
Research from UM Frost School of Music provides insight into the importance of song for infants and mothers.
For chimps, mothers matter 
A group of researchers has shown, for the first time, that chimpanzees learn certain grooming behaviors from their mothers.
Older first-time mothers are also more likely to live longer
The average age of a woman giving birth for the first time has risen dramatically in the United States over the past 40 years, driven by factors like education or career.
Shy wild boars are sometimes better mothers
The personality of wild boar mothers can affect the wellbeing of their young.
The cell copying machine: How daughters look like their mothers
Tiny structures in our cells, called centrioles, control both cell division and motility.
Children of older mothers do better
The benefits associated with being born in a later year outweigh the biological risks associated with being born to an older mother.
Mothers with postnatal depression reluctant to have more than two children
Mothers who have postnatal depression are unlikely to have more than two children according to research carried out by evolutionary anthropologists the University of Kent and published by Evolution, Medicine and Public Health.
Generous mothers are nagged less
For the first time, scientists have identified specific genetic variations in offspring that lead to preferential maternal treatment, which in turn improves offspring fitness.
Mothers should be cautious when discussing weight with daughters
How should a concerned mother discuss issues of diet and weight with her daughter?

Related Mothers Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...