dimarts, 21 de maig del 2019

Pushy bonobo mothers help sons find sexual partners, scientists find by Ian Sample


Pushy bonobo mothers help sons find sexual partners, scientists find
High-ranking mothers lead sons to groups of females and keep guard while they mate

Ian Sample Science editor                 Mon 20 May 2019 16.00 BST

Their mothers are so keen for them to father children that they usher them in front of promising partners, shield them from violent competitors and dash the chances of other males by charging them while they are at it.

For a bonobo mother, it is all part of the parenting day, and analysis finds the hard work pays off. Males of the species that live with their mothers are three times more likely to father offspring than those whose mothers are absent.

Martin Surbeck, a primatologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, said: “We wanted to see if the mothers’ behaviour changes the odds of their sons’ success, and it does. The mothers have a strong influence on the number of grandchildren they get.”

Bonobo mothers seize every opportunity to give their sons a leg-up. In bonobo society, the lower ranks tend to be gender balanced, but females dominate the top ranks. Many mothers have social clout and chaperone their sons to huddles with fertile females, ensuring them better chances to mate. “The mothers tend to be a social passport for their sons,” said Surbeck.

But in the free-for-all that underpins bonobo sex, vigilance is the watchword. When their sons are finally copulating, bonobo mothers keep a wary eye on nearby males. Should any make a move to rush the busy couple – a tactic that is well-known – she can bound in and block the attack.

Such dirty tricks abound. When mothers spot other males on the job, they have been known to detach the hapless apes with a well-timed charge. On rare occasions, the mothers literally drag unrelated males off their sexual partners. “Once I saw a mother pulling a male away by the leg,” said Surbeck. “It doesn’t necessarily increase their son’s mating success, but it shows that they really get involved in the whole business.”

To assess the impact of mothers’ interventions, Surbeck and his colleagues observed several wild bonobo populations in the Democratic Republic of the Congo and wild chimpanzees in Tanzania, Uganda and Ivory Coast. Mothers from both species, which share the title of our closest living relative, helped their sons in fights, but only the bonobos boosted their sons’ mating success. In chimpanzee society, males are dominant, so the mothers have less influence.

(…)

Surbeck suspects bonobo mothers have hit on a winning strategy. In going the extra mile to get their sons mating, the mothers get to spread their genes without having to have more children themselves.


Courtesy of Guardian News & Media Ltd.
Bonobo image from www.publicdomainpictures.net CC0 Public domain


Vocabulary for Spanish readers:

Pushy
Dominante
Keen for
Estar interesado en
Usher
Conducir, dirigir
Shield
Proteger. Escudo, protección
Dash
Arruinar
Hard work pays off
El trabajo duro da sus frutos
Odds
Posibilidades
Leg-up
Dar una ventaja. Ayudar
Clout
Influencia
Chaperone
Acompañante, carabina.
Huddles
Acurrucarse, aproximarse, juntarse
Underpins
Apuntalar, sustentar
Watchword
Lema. En otros contextos santo y seña.
Wary eye
Mirada cautelosa, vigilante.
A move to rush
Un movimiento para molestar, para apresurar
Bound
Verbo bound: Moverse rápidamente mediante saltos o zancadas.
Spot
Ver, observar
Detach
Separar
Hapless
Desafortunados
Stack
Apilar. Posicionarse a favor de.
Hang around
Pulular, andar por la zona.

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