Though Isabukuru’s fondness for infants was especially striking, such behaviors are fairly common among the mountain gorillas of Rwanda’s Volcanoes National Park, the same group that Dian Fossey studied. The males, whether silverbacks or subordinates, will cuddle infants, play with them, welcome them into their nests, and just plain hang out with them. “I often describe it as babysitting,” says Rosenbaum. [...]
Many mountain gorilla groups include several adult males; some have as many as nine. The silverback might sire the majority of infants, but subordinates reproduce too. So when Rosenbaum first noticed males babysitting infants, she naturally figured that they must be looking after their own babies. She was wrong. “They really don’t seem to have any preference for their own offspring,” she says. [...]
It’s possible that the males who have already sired the most offspring are also more likely to pay attention to infants—but Rosenbaum thinks that this explanation can’t be the whole story. After all, some of the males in the study were very young, and had barely started fathering their own babies. And yet, their attentiveness to other infants predicted their future reproductive success.
The more likely explanation is that females are preferentially mating with the males who engage most with the group’s infants. They might be attracted to personality traits that, coincidentally, make males more likely to babysit. Or—and this is perhaps the most interesting possibility—it could be that the babysitting is attractive in itself. By mating with males who are most attentive to infants, female gorillas give their own offspring a better chance in life.
No comments:
Post a Comment