Macaca fascicularis, commonly known as the long-tailed macaque or crab-eating macaque, is a highly adaptable primate found in Southeast Asia. They are known for their long tails, social behavior, and ability to thrive in diverse habitats including forests and urban areas. These macaques are omnivorous and often seen near water, showcasing their swimming abilities.

Macaca fascicularis, also known as the long-tailed macaque or crab-eating macaque, is native to Southeast Asia. Its geographical distribution includes countries such as Thailand, Malaysia, Indonesia, the Philippines, Vietnam, Cambodia, Laos, Myanmar, and parts of southern China. The species is also found on numerous islands within this range, including Sumatra, Borneo, and the Java Islands.

The long-tailed macaque typically inhabits tropical and subtropical forests. It is highly adaptable and can also be found in coastal mangroves, swamps, and riverine forests. The species is often observed near human settlements, exploiting cultivated areas and urban environments. The climate in its habitat is generally hot and humid, with a distinct wet and dry season.

Macaca fascicularis is primarily arboreal but is also known to forage on the ground. It is omnivorous, feeding on a varied diet that includes fruits, seeds, leaves, and small animals. The species plays a role in seed dispersal due to its feeding habits. The long-tailed macaque is highly social, living in large multi-male, multi-female groups, and exhibits complex social structures and behaviors.