Even in the ape world, it pays to have dashing good looks. Researchers have found that the “Brad Pitt” of bonobos in one ape community they studied has managed to woo the majority of the females, and as such fathered most of the infants.
Published in Current Biology, the work found that even though bonobos in general live in a fair and equal society, this does not hold for who becomes the daddy. Surprisingly, the researchers discovered that a single particularly good-looking male within a community found in the Democratic Republic of Congo has sired 60 percent of all infants born over a 12-year period.
“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,” explained the Max Planck Institute for Evolutionary Anthropology’s Martin Surbeck.
Despite their slightly outdated leading man reference, the researchers have made a fascinating find. Bonobos are commonly known as the most peaceable of the great apes. While their chimpanzee cousins across the Congo engage in vicious warfare, with males beating, tearing, and ripping each other to death, bonobos are found to be a whole lot more relaxed.
Because of this intense competition between males within chimpanzee communities, it has been thought that chimps would display far more skewed reproduction as a single male dominates as many females as possible. But it turns out that in spite of the more equitable society of the bonobos, which made researchers think that the paternity of infants would similarly be more diverse, the reproductive skew within bonobos is greater than is seen within chimps.
They think that what may actually be at play here is the increase in sexual freedom of the females of the bonobos. A recent study found that within primates, females may not have as much freedom in choice as previously thought as males use violence to coerce them into sex, but with bonobos this may not be the case. Rather than the expansive female choice allowing more males to father offspring, it seems that the opposite has occurred.
“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,” co-author Kevin Langergraber said. “Perhaps they choose high-ranking males.”
For reasons that are still unclear, it seems that multiple females within the single group have chosen the same male with whom to mate. More work will need to be done to clarify whether or not this is common practice within bonobo societies, or if this particular group just happens to be an anomaly.