Let's stick together

Female solidarity makes for a more peaceful society

source: Kate Roach
New Scientist vol 211, no 2830, September 17 2011 starts p53, 4 pages long

Bonobos have a common ancestor with chimps, but their societies are very different They are relatively peaceful, and egalitarian. Chimps are dominated by males who wage war and kill infants. Amy Cobden, from Atlanta's Emory University, sees bonobo society as influenced by plentiful food, while chimps compete with gorillas on their territory. Chimps split up to seek food, where gorillas leave scarce food on the ground. Chimps are more peaceful where there are no gorillas. Bonobos also split up, though males tend to forage alone, whereas females are more likely to diverge from chimp groups. Female bonobos influence the group more, and are together for longer. They are also in oestrus for longer, with a similar conception rate to chimps. This means that males are less able to monopolise attractive females. There are also more males, so group size increases.