Cercopithecidae
Primates
Mammalia
about 165 days
1 per litter
Present in numerous zoological centers and research centers.
It feeds on fruits, leaves, seeds, insects, small vertebrates and, occasionally, crabs and other aquatic animals.
In the wild: Up to 30 years. In captivity: Up to 39 years
The crab-eating macaque (Macaca fascicularis) is a medium-sized primate belonging to the Cercopithecidae family. It is characterized by its grayish or brown fur and a long, non-prehensile tail that exceeds the length of its body. Its face is elongated, with a hairless face and expressive eyes. It exhibits marked sexual dimorphism, with males being significantly larger than females. It inhabits a variety of environments, from tropical forests to urban areas, showing remarkable adaptability to different habitats. Its omnivorous diet includes fruits, leaves, seeds, insects, and small vertebrates, and it is known for its ability to exploit food resources in anthropogenic environments. This adaptability has allowed it to expand its range and survive in areas with high human presence.
The crab-eating macaque is a diurnal and highly social species that lives in matrilineal groups composed of multiple females and their offspring, along with a few adult males. Males typically migrate from their natal group upon reaching sexual maturity. These groups feature an established social hierarchy, with complex interactions that include grooming, play, and vocalizations to maintain group cohesion. It is known for its opportunistic behavior, exploiting food resources in urban and agricultural areas, which often leads to conflicts with humans. Furthermore, it has been observed using simple tools, such as using stones to open shells or hard fruits, demonstrating a remarkable level of intelligence among non-human primates.
The crab-eating macaque is currently classified as Endangered on the IUCN Red List due to a significant population decline in recent decades. The main threats include the loss and fragmentation of its natural habitat, capture for the pet trade, and its extensive use in biomedical research. Furthermore, its adaptability to urban environments has led to frequent conflicts with humans, resulting in persecution and hunting in some regions. Although it is listed on CITES Appendix II, which regulates its international trade, stricter implementation of these regulations is required to ensure its conservation. Captive breeding programs and in situ conservation efforts are essential for the long-term survival of this species.
The common name “crab-eating macaque” comes from observations in coastal areas of Southeast Asia where it has been recorded capturing and consuming small crabs, although this behavior is sporadic.
It is one of the few non-human primate species that uses tools: some individuals have been observed using stones to open shellfish, nuts, or conch shells.
It is the most widely distributed primate in Asia, inhabiting areas from coastal zones to jungles and dense urban areas.
Their ability to adapt to the human environment has generated situations of "synanthropy," that is, close coexistence with human settlements.
In Bali and other parts of Indonesia, it is frequently found in Hindu temples, such as the famous “Monkey Forest,” where it actively interacts with tourists.
It has a longer tail than other macaque species, which gives it excellent balance when moving between branches.
It exhibits a complex social hierarchy with submissive behaviors, coalitions between females, and rank shifts.
It is common to see mothers carrying their young clinging to their abdomen, even swimming.
It is one of the best swimming primates, capable of crossing rivers and canals using coordinated strokes.
It can emit more than 20 different types of vocalizations to warn of danger, maintain group cohesion, or show emotions.
Sometimes he washes his food before eating it, a behavior also observed in some Japanese macaques.
It has been the subject of numerous ethological studies, especially in relation to cooperation, deception and problem solving.
“Stealing and bartering” behavior has been documented among tourists: they take items such as glasses or hats and return them in exchange for food.
In urban settings, they have learned to turn on faucets, open doors, or manipulate plastic bags to obtain food.
In some cultures it is considered a symbol of fertility and wisdom, while in others it is seen as a plague.
It has scent glands on the chest and perineal region, used to mark territory or reproductive status.
The longevity and resilience of this species have made it a key animal model in biomedicine since the mid-20th century.
There are more than 10 recognized subspecies, with morphological variations depending on the region, including M. f. fascicularis (the most common).
In rural areas of Thailand, cases of cooperation between individuals to obtain fruit from tall trees in turns have been reported.
In cognitive studies, they have been shown to recognize their reflection in the mirror after training, which is rare in non-hominoid primates.
