“Sometimes a man may be as ugly as a monkey, and a monkey may have something very human about it; indeed, it is quite customary to call monkeys humanity’s caricatures. Of none this can be said with such truth as of the Borneo proboscis-monkey” – Eric Mjöberg, Forest Life and Adventures in the Malay Archipelago
The proboscis or long-nosed monkey (Nasalis lavartus) is endemic to the jungles of Borneo, living close to rivers, tidal swamps and mangroves. It never ventures too far away from water and is rarely seen far inland – it might therefore not come as a surprise that they are proficient swimmers with evolved webbed feet and hands in order to outpace saltwater crocodiles. However, the species is highly arboreal and instead of swimming most prefer to cross water by impressive leaps – often followed by rather comical flat landings on their distinctive pot-belly.
Proboscis monkeys are sexually dimorphic with males that have giant noses dwarfing those of the females and often hanging lower than their mouth. This fleshy appendage doesn’t give the proboscis a better sense of smell than other monkeys: it instead provides them with an organ that amplifies their vocal powers – handy when warning other group members of imminent danger and impressive for the many females that live in their harem.