Endangered
Crab-eating macaque
Macaca fascicularis
Crab-eating macaque, variously known by common names such as crab-eating macaque, long-tailed macaque, or cynomolgus monkey, is a macaque species native to Southeast Asia.
Appearance
Dorsal pelage is generally greyish or brownish with a white underbelly with black and white highlights around the crown and face. The face skin is brownish to pinkish except for the eyelids that are white. Adults are usually bearded on and around the face, except for around the snout and eyes.
The crab-eating macaque is sexually dimorphic, with males weighing between 4.7 and 8.3 kg (10 and 18 lb) and females weighing 2.5–5.7 kg (5.5–12.6 lb).
Range and habitat
The crab-eating macaque's native range encompasses most of mainland Southeast Asia, through the Malay Peninsula and Singapore, the Maritime Southeast Asia islands of Sumatra, Java, and Borneo, offshore islands, the islands of the Philippines, and the Nicobar Islands in the Bay of Bengal. This primate is a rare example of a terrestrial mammal that violates the Wallace line, being found out across the Lesser Sunda Islands. It lives in a wide variety of habitats, among them primary lowland rainforests, disturbed and secondary rainforests, shrubland, and riverine and coastal forests of nipa palm and mangrove.
M. F. Umbrosa is likely of important biological significance and has been recommended as a candidate for protection in the Nicobar Islands, where its small, native population has been seriously fragmented.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet
Dusky leaf monkeys, crab-eating macaques and white-thighed surilis form tolerant foraging associations, with juveniles playing together. Crab-eating macaques are omnivorous frugivores and eat fruits, leaves, flowers, shoots, roots, invertebrates, and small animals in variable quantities.
Males that emigrate with a partner are more successful than those that leave alone. It lives in matrilineal groups ranging from 10 to 85 individuals, with groups exhibiting female philopatry and males emigrating from natal group at puberty.
In crisis
Due to these threats, the crab-eating macaque was listed as Endangered on the IUCN Red List in 2022. Researchers have been raising alarms about crab-eating macaque population decline at least since 1986. Many authors cite a 40% decline in the entire crab-eating macaque population between 1980 and 2006.
This comes from a population estimate of 5 million in the 1980s-90s. Population estimate of 3 million in 2006. Using a noninvasive probability model to estimate the maximum population abundance, it was estimated that the current population of crab-eating macaques is 1 million, that reflects a continuous decline in the population – 80% reduction over 35 years.
CITES lists this taxon on Appendix II. Confirm the current appendix on the CITES checklist.
Crab-eating macaque is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Crab-eating macaque, Wikidata item Q301676. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
