Proboscis Monkey

Unmistakable and endemic to Borneo. Males carry a large pendulous nose thought to amplify their honking alarm calls and signal dominance to rivals; females have smaller, upturned noses. Both sexes have a notable pot belly, housing a specialised chambered stomach that ferments the leaves and unripe fruit that make up most of their diet.

Strictly tied to riverine, mangrove and swamp forest, rarely straying far from water — they are strong swimmers with partially webbed feet and will readily leap from overhanging branches into rivers to escape predators or cross channels. Kinabatangan and Trusan Sugut offer the most reliable river-based sightings, especially at dawn and dusk when troops gather at the water's edge.

Endangered, with numbers declining across most of their range due to loss of riverine and coastal forest.