Long-tailed macaques practice good dental hygiene, researchers found when they followed a troupe around a coastal village on Great Nicobar Island in the eastern Indian Ocean, New Scientist reports.
The Nicobar long-tailed macaque (Macaca fascicularis umbrosus) is only found on three islands in the eastern Indian Ocean. One of them is Great Nicobar Island.
The monkeys 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.
After eating, adult and sub-adult 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. Some modify the threads before use, for instance by tearing them apart.
Nine of the 20 macaques were seen “flossing”. They did so after eating various foods in different habitats, says Kumara.
The Nicobar long-tailed macaques are the third monkeys seen flossing their teeth. Japanese macaques use their own fur, while Thailand’s long-tailed macaques use human hair.
Macaques adapt well to human-dominated landscapes, where they tend to manipulate objects more, says primatologist Michael Gumert at the Nanyang Technological University, Singapore. “They are the king of generalists… about as adaptable as we are.”
Tool use on its own doesn’t take much intelligence, says Gumert. “However, the modification of tools does show planning and foresight – something that someone who has ever observed macaques in any detail would never have doubted.”
For the full report go to newscientist.com