Maroon leaf monkeys are medium-sized primates that belong to the Old World monkey family. Their fur color is reddish-maroon throughout the body and tail. The skin on their faces is grey to bluish-grey, and their lower lips are pale. Infants are creamy to buff in color.
Maroon leaf monkeys are found in Southeast Asia. They occur in the Danum Valley of Sabah within Northern Borneo. Red Leaf monkeys are endemic to the Borneo island which is part of Malaysia, Indonesia and Brunei. These monkeys live in the tropical rainforest and occasionally may visit native gardens in search of food.
Maroon leaf monkeys are arboreal and spend most of the time in trees rarely coming down to earth. They are social creatures and and live in groups that consist of 2-13 individuals. Each group is led by a dominant male. Maroon leaf monkeys are very territorial and chase away any intruders within their home range. Males produce a loud call to calim their territory and warn rivals away. These monkeys are active during the day and spend the majority of the time eating. During April, June, and August Maroon Leaf monkeys consume top soil of termite mounds. This way they obtain the minerals needed for a balance diet as the termite mound soil has high levels of calcium and magnesium.
Little is known about he mating system and reproductive behavior of Maroon leaf monkeys.
Main threats to Maroon leaf monkeys include hunting for meat and traditional “medicine” and habitat loss due to deforestation. Much of their habitat is lost because of expanding oil palm plantations.
The IUCN Red List and other sources don’t provide the number of the Maroon leaf monkey total population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.