What is the conservation status of the Proboscis Monkey?

The Proboscis Monkey is listed as Endangered on the IUCN Red List. Facing a very high risk of extinction in the wild.

Where is the Proboscis Monkey found?

The Proboscis Monkey is found in Malaysia, Indonesia, Brunei.

Proboscis Monkey (Nasalis larvatus) — Conservation Status & How to Help

About the Proboscis Monkey

The proboscis monkey (Nasalis larvatus) is a large, reddish-brown colobine primate found exclusively on the island of Borneo, living in riverine and coastal forests including mangroves, swamp forests, and lowland dipterocarp forest. Males are notably larger than females and carry a pendulous, fleshy nose that can exceed 10 centimeters in length, which amplifies their vocalizations and plays a role in mate attraction. They are highly social, typically moving through the forest canopy in harem groups led by a single adult male, and they are strong swimmers, capable of crossing rivers with a distinctive upright stroke.

Proboscis monkeys are specialized folivores, relying heavily on leaves, seeds, and unripe fruit, and their complex, multi-chambered stomachs support fermentation of plant material in a way that mirrors ruminant digestion. This dietary specialization ties them closely to intact, structurally diverse forest, making them highly sensitive to habitat degradation. The IUCN Red List classifies the species as Endangered, with the primary drivers of decline being deforestation for oil palm agriculture, logging, and coastal development, compounded by hunting pressure in some parts of their range.

Things worth knowing

Male proboscis monkeys can weigh up to 24 kilograms, making them one of the largest primates in Asia.
Their elongated nose is unique among primates and is thought to function as a resonating chamber that makes the male's honking calls louder and more attractive to females.
Proboscis monkeys have partially webbed feet, an adaptation that supports their frequent river crossings and readiness to swim to escape predators.
They are strict hindgut and foregut fermenters and cannot digest ripe, sugary fruit safely, as it can cause fatal bloating in their specialized stomachs.
Groups typically follow predictable travel routes between sleeping trees along riverbanks and inland feeding sites, making them particularly vulnerable to linear habitat fragmentation.
The IUCN Red List estimates the species has experienced a population decline of more than 50 percent over the past 36 to 40 years, driven primarily by habitat loss.

Proboscis Monkey

Things worth knowing

0 organizations protect the Proboscis Monkey