Monkeys are adaptable creatures, and none more so that those living on remote islands in the eastern Indian Ocean. Using an array of tools to get food, it turns out that they also take good care of their teeth, even going so far as to floss them with feathers.
New research is shedding light on the impressive array of tool use shown by troops of Nicobar long-tailed macaques, a subspecies confined to just three islands in the Andaman and Nicobar archipelago off the eastern coast of Myanmar. It seems these isolated primates have come up with a whole repertoire of ingenious ways to get more food, and also to improve on the lot they’ve already got.
Publishing their results in the journal Primates, researchers have recorded the varied ways in which the monkeys survive on the islands. They macaques have become particularly good at collecting coconuts, climbing trees and twisting the drupes before nipping the stalk with their teeth. If the coconut is young enough, they’ll remove the husk with their teeth, but if it is more mature, they have taken to pounding the food on rocks and concrete in order to get to the tasty flesh and water inside.
But sometimes the food you already have is not quite edible, and the monkeys have this covered too. For toxic cashew nuts, the macaques rub the surface with whatever is lying around, be it dry leaves, plastic, or trash from humans. They have also been found to brush food that is covered in sand, while others were observed using puddles to clean fruit.
To round things off, the primates were found to have surprisingly good dental hygiene. After chowing down on a meal, the monkeys would use a variety of fibers to floss their teeth. By holding the fibers between their teeth and pulling on them, using whatever they had to hand such as a bird's feather, a piece of coconut husk, or a piece of nylon, they were able to do a seemingly good job at cleaning their gnashers. The monkeys were even found to modify the fiber if it was too thick.
This is not the first time that populations of our primate cousins have been discovered keeping their teeth in good nick. Japanese macaques have been seen using their own fur to floss, while a group of long-tailed macaques living near a Buddhist shrine in Thailand has been found (somewhat creepily) to use human hair to floss, with mothers even teaching their offspring the perfect technique.
None of these behaviors are necessarily unique to the Nicobar long-tailed macaques, though one does stand out, in which the monkeys purposefully shake plants and bushes to disturb insects that they then catch and gobble down.
[H/T: New Scientist]