Long tailed macaques are found in Southeast Asia and their habitats are in which they have been found are primary forests, disturbed and secondary forests, and riverside and coastal forests.
The body fur of long-tailed macaques tends to be grey-brown to reddish brown with body length is 40 to 47 cm. The tail is grayish-brown with 50 to 60 cm length. The average weight for males is 4.8 to 7 kg and 3 to 4 kg for females. This species has the highest degree of arboreality (live in tree) of all macaque species. Long-tailed macaques are omnivores, but still 96% of the feeding time per day is spent eating fruit based on ripeness or color.
In Sumatra, each social group of these monkeys contains an average of 5 males and 9 females. Within groups, a strict linear dominance hierarchy develops among males and determined by age, size, and fighting skills.
Long-tailed macaques are unique because of their ability to show learned or cultural behavior. This was observed in the preparation of food by long-tailed macaques. On one occasion, an adult female dipped a piece of fruit into a river and then she consumed it. It was proposed that perhaps the female was cleaning sand off the fruit. The controversy of what cultural behavior means is still being researched.
Long-tailed macaques, along with other species of macaques, have benefited humans through their use as research models. They are also important members of ecosystems and may serve as a basis for ecotourism ventures.
Conservation Status for long-tailed macaques are IUCN Red List Lower Risk - Near Threatened and CITES Appendix II. Long-tailed macaques receive some protection and food in temples in Bali. In Malaysia, long-tailed macaques are legally protected, and they are fed and protected in urban forests and parks. In Thailand, long-tailed macaques receive protection in temple ruins and if they hunted, captured, or kept in captivity, it is only under license and the export of this species is regulated by a quota system. This may increase the chances of their survival in these reserves.
But hunting is still a problem. In Thailand and Borneo, they are hunted for food and killed because it is a pest to agriculture. The fact that these macaques destroy crops has prevented some governments from making serious conservation efforts.