July 10 (UPI) -- Despite their reputation as friendly pacifists, bonobos don't necessarily spread the love around when it comes to reproduction. New research suggests just a few males father most of the offspring in bonobos communities.
Bonobos are known for their lack of aggression and peaceful relations, especially between the sexes. Males and females often form strong friendships. Scientists have hypothesized such relationships yield a more democratic distribution of reproductive success.
However, when scientists tested the paternity of 24 bonobos born between 2002 to 2013 in a community living in the Democratic Republic of the Congo, they found the most sexually successful male fathered 60 percent of the subsequent generation.
When it comes to fathering offspring, bonobo society appears to be more hierarchical than chimpanzee communities.
Scientists aren't entirely sure what accounts for the skew, but they've made some educated guesses.
Bonobos are much more communal and spend more time together as a group than do chimpanzees. This leaves lower-ranking males with fewer opportunities to sneak off for alone time with females.
The freedom given to female choice in bonobo societies may be the most important factor, however. Female bonobos may simply choose the most attractive option, with multiple females mating with the same dominant male.
"Unlike chimpanzees, where all adult males outrank all adult females, and even the lowest-ranking males can coerce females into mating, there appears to be a greater role for female choice in bonobos," Kevin Langergraber, a researcher at Arizona State University's School of Human Evolution and Social Change, said in a news release. "Perhaps they choose high-ranking males."
"The funny thing under such a scenario would be that most of the females would have the same preference for Camillo, the alpha male and 'Brad Pitt' of the bonobos at our research site," said Martin Surbeck, researcher with the Max Planck Institute for Evolutionary Anthropology in Germany.
In their study, published this week in the journal Current Biology, scientists acknowledged their research focused on just a single group of bonobos. More research is needed to confirm the same reproductive pattern among other bonobos communities.