One on the left looking back the other looking to the right while swinging their tails, Dusky Leaf Monkey Trachypithecus obscurus, Thailand

trachypithecus obscurus spectacled leaf monkey dusky leaf monkey langur spectacled langur trachypithecus lutung primates monkeys simiiformes primate wildlife sanctuary long tail mammals foraging cercopithecidae habitat malaysia apes fruiting tree wildlife arboreal kaeng krachan mammalia animals branches jungle climbing habitat loss canopy endangered rainforest thailand myanmar endangered species mongkeys haplorhini trees folivorous nature leaves forest national parks natural morning green howling