In Sarawak you will find them in Bako National Park.
Proboscis monkeys live in-groups of five to fifteen with an adult male as their leader.
This monkeys feed on leaves, shoots and fruits found in the jungle. Figures show that there are only about 1000 proboscis monkeys left in Sarawak now. There were 6000 in the late 1970s. There are about another 4000 in other parts of Borneo. Unlike the orangutans, proboscis monkeys can't be kept in zoos or in a wildlife sanctuary as they die after a while.