Charcoal diet

scientists working on the east African island of Zanzibar have observed that the red colobus monkey ( Procolobus Kirkii ) has added charcoal to its diet, apparently to help it overcome the chemical defences of the plants it eats. The monkeys can now tolerate a wider range of plants and, as a result, their population has soared.

Thomas Struhsaker of Duke University in Durham, North Carolina says that the primates have developed a taste for charcoal, eating up to five grams a day. Struhsaker says that the monkeys get charcoal from burned tree and palm stumps in fields, out of abandoned kilns and even steal it from villagers' hearths.

Some human cultures eat charcoal because it absorbs toxins in their diets. But charcoal eating has never been seen among other primates. Struhsaker adds that the charcoal has made new food sources available to the monkeys -- leaves of the Indian almond ( Terminalia catappa ) and mango ( Mangifera indica ) trees, which contain potent toxic defence chemicals. This has caused an explosion in the colobus population to more than 700 per square kilometre.