É. Geoffroy, 1812
The proboscis monkey eats mainly fruit and leaves. It also eats flowers, seeds and insects to a lesser extent. At least 55 different plant species are eaten. Young leaves are preferred over mature leaves and unripe fruits are preferred over ripe fruit. Being a seasonal eater, the proboscis monkey eats mostly fruit from January to May and mostly leaves from June to December. Groups usually sleep in adjacent trees. Monkeys tend to sleep near rivers, if they are nearby. Proboscis monkeys will start the day foraging and then rest further inland. Proboscis monkeys' daily activities consist of resting, traveling, feeding and keeping vigilant.
The male proboscis monkey is known for its very unique, large floppy nose. Females have a smaller pointed nose. Another fact is that a baby proboscis, with its dark blue face and black furs, looks very different from its parents. As it gets older, its fur changes to the orange color of its parents.
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- Yeager CP (1992). "Proboscis monkey (Nasalis larvatus) social organization: group structure". Am J Primatol. 20 (2): 95–106.