Macaca fascicularis

Macaca fascicularis, variously known by common names such as crab-eating macaque, long-tailed macaque, or cynomolgus monkey, is a macaque species native to Southeast Asia. As a synanthropic species, the crab-eating macaque thrives near human settlements and in secondary forests. The crab-eating macaque has developed a variety of cultural perceptions, from being smart and adaptive, to being sacred, to even being pests in some cases. The crab-eating macaque is omnivorous and frugivorous. It lives in matrilineal groups ranging from 10 to 85 individuals, with groups exhibiting female philopatry and males emigrating from natal group at puberty. The crab-eating macaque is the only old-world monkey known to use stone tools in their daily foraging, and it engages in a robbing and bartering behavior in some tourist locations. The crab-eating macaque is the most traded primate species and also the most popular species used in scientific research. Due to these threats, the crab-eating macaque was listed as Endangered on the IUCN Red List in 2022.