page_title: Crab-eating macaque
section_title: Tool use
hierarchical_section_title: Crab-eating macaque / Behavior / Tool use
caption_attribution_description: English: Macaca fascicularis aurea stone tools. Each tool is accompanied by a photo of the tool in use by a macaque prior to its collection. Each tool is represented by a photograph (with 1 cm scale) and a 3D scan of the same face, displaying use-wear. Tool codes are: (a) Tik01; (b) Che01; (c) Amb02; (d) Orc01; (e) Sln01; (f) Amb03. Macaque photos by Michael D. Gumert, tool photos by Michael D. Gumert and Michael Haslam. doi:10.1371/journal.pone.0072872.g002
context_page_description: The crab-eating macaque, also known as the long-tailed macaque, is a cercopithecine primate native to Southeast Asia. It is referred to as the cynomolgus monkey in laboratories. It has a long history alongside humans; it has been alternately seen as an agricultural pest, sacred animal in some temples, and more recently, the subject of medical experiments.
  The crab-eating macaque lives in matrilineal social groups of up to eight individuals dominated by females. Male members leave the group when they reach puberty. It is an opportunistic omnivore and has been documented using tools to obtain food in Thailand and Myanmar. The crab-eating macaque is a known invasive species and a threat to biodiversity in several locations, including Hong Kong and western New Guinea. The significant overlap in macaque and human living space has resulted in greater habitat loss, synanthropic living, and inter- and intraspecies conflicts over resources.
context_section_description: In Thailand and Myanmar, crab-eating macaques use stone tools to open nuts, oysters and other bivalves, and various types of sea snails (nerites, muricids, trochids, etc.) along the Andaman sea coast and offshore islands.
  Another instance of tool use is washing and rubbing foods such as sweet potatoes, cassava roots, and papaya leaves before consumption. Crab-eating macaques either soak these foods in water or rub them through their hands as if to clean them. They also peel the sweet potatoes, using their incisors and canine teeth. Adolescents appear to acquire these behaviors by observational learning of older individuals.
caption: Stone tool usage by crab-eating macaques in Laem Son National Park in Thailand
exif: {}