Maroon leaf monkeys (Presbytis rubicunda) are endemic to the island of Borneo in Southeast Asia. Their habitat is dense dipterocarp evergreen forest.

Borneo has a healthy tropical rainforest. It also contains shallow swampy areas made up of acidic, decomposed plant matter. These swampy areas have seasonal bouts of dry weather; during the wet season the rivers rise around two meters. Maroon leaf monkeys are arboreal primates and spend most of their time in the canopy. They have a large home ranges and low population densities compared to other primates. This is believed to be because they rely on specific trees which are rare and widely dispersed.

Orange-naped Red or Maroon Langur (Presbytis rubicunda ignita) Kinabatangan River area Sabah Malaysian Borneo

Orange-backed Red or Maroon Langur (Presbytis rubicunda chrysea) Danum Valley Resort area