Monkeys living on an island have learned to use a startling variety of tools and techniques to obtain the juicy innards of different foods – and to floss their teeth afterwards.
The Nicobar long-tailed macaque is only found on three islands in the eastern Indian Ocean. One of them is Great Nicobar Island. Many of the macaques’ favoured foods are thorny, slimy, hairy or mucky. To get rid of these inedible coatings, the macaques either wash the foods in puddles or wrap them in leaves and rub them clean.
The macaques eat coconuts too, plucking them from the tree by twisting them around or using their teeth to cut them off. If it is tender, the macaques de-husk the coconut using their teeth. (As someone who’s tried husking a coconut at home, it takes some knife skills 🙂 but these monkeys do it with their teeth!)
After eating, macaques clean their teeth – they were seen holding a fine fibre between their teeth and pulling at it. The macaques used a range of materials as dental floss: a tree needle, a bird feather, a blade of grass, a coconut fibre, a nylon thread and a metal wire. (I wondered if the need to floss comes from all that coconut husk getting stuck in the teeth, but no). They did so after eating various foods in different habitats, the researchers told me.
If you enjoyed this excerpt, read the rest of the story published in New Scientist here.
Photo (thumbnail) credit: UNESCO/Zoological Survey of India