In Kubang Badak river we can be spotted long-tailed macaque, which also known as crab-eating macaques. Long-tailed macaques are ecologically diverse and in Malaysia we can see a group of them in coastal lowland forests and the swamp forests. Within groups, a strict linear dominance hierarchy lead by one alpha male followed by the beta male, and females breeding. This hierarchy is determined by such factors as age, size and fighting skills. The juvenile is the lowest in the hierarchy and they need to search and submission the food to the upper of the hierarchy.