Long-tailed macaques on an island in southern Thailand use stone and shell tools to crack open seafood, researchers have found.
About 80% of them use 17 different action patterns, according to a study in the journal PLOS ONE by Amanda Tan from Nanyang Technological University, Singapore, and colleagues.
Most commonly, the macaques used one-handed hammering with the points of smaller tools to crack open rock oysters which require precision striking.
They also use one or two handed hammering with the faces and edges of larger tools to crack unattached shellfish .
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