Jan. 17 - A group of female capuchin monkeys in northern Brazil have developed an unusual method of attracting male sexual partners when they're in heat; they throw rocks at them. Writing in November's online journal, PLOS ONE, researchers say the practice could mark the evolution of learned behaviour, peculiar to one specific group. Ben Gruber reports.
When certain female capuchin monkeys are in the mood for sex, they don't hold back. They identify a potential partner…and throw rocks at him. Over a period of two years, researchers studied two groups of monkeys from the same species in a forest in North Eastern Brazil. They observed that some of the females in one group had developed the technique of rock-throwing to attract a mate, whereas no such behaviour was observed in the other capuchin community. They say their observation indicate that throwing rocks for sex may have proven successful for at least one of the group's females, leading others to learn and copy the behaviour, usually with the alpha males of the group as the targets of their desire.. It's the first time such behaviour as been observed with capuchin groups in the wild. And the researchers, from the University of Sao Paulo say, say they'll continue to watch the animals to see how their rocky relationships evolve over time.