Animal Behavior – DECISION STATS

According to the paper, “Payment for Sex in a Macaque Mating Market,” published in the December issue of Animal Behavior, males in a group of about 50 long-tailed macaques in Kalimantan Tengah, Indonesia, traded grooming services for sex with females; researchers, who studied the monkeys for some 20 months, found that males offered their payment up-front, as a kind of pre-sex ritual. It worked. After the females were groomed by male partners, female sexual activity more than doubled, from an average of 1.5 times an hour to 3.5 times. The study also showed that the number of minutes that males spent grooming hinged on the number of females available at the time: The better a male’s odds of getting lucky, the less nit-picking time the females received.