Monkeys Keep Their Food Clean, Sort Of

We all have our standards. For humans, it's the five-second rule. For macaques, it's "think twice before eating food off a pile of poop." The monkeys have several ways of keeping their food (sort of) clean. And the most fastidious macaques, it seems, are rewarded with fewer parasites. On the Japanese island of Koshima, scientists have been studying Japanese macaques (Macaca fuscata) for nearly seven decades. The tiny, forested island is overrun with the monkeys, which live there naturally and sometimes move between the island and the nearby mainland. Back in the 1950s, researchers started feeding the island macaques treats of sweet potatoes and wheat, so they could study the animals more easily. In recent decades, researchers have cut back on the snacks as much as possible without hurting the population. Now they feed the macaques two or three times a week, at a dedicated sandy beach. Although the Koshima ...