The Proboscis monkey is named after its elongated nose. It is endemic to the Southeast Asian island of Borneo.
Inhabiting mainly coastal areas, particularly mangrove swamps, they are arboreal and herbivorous.
They swim well, crossing rivers when required.
Males are significantly larger than females and twice the weight at some 20kg for adult males.
Males also have a larger, more pendulous nose, to amplify their calls to attract mates or deter rivals.
Groups comprise mainly an adult alpha male with females and offspring. Some males without a
family may form bachelor groups and some are solitary.
The only species in their genus, they are endangered by habitat loss from deforestation
to plant oil palm or logging. They are also hunted for consumption and traditional medicine.