Yes, proboscis monkeys are endemic to Borneo, and Sabah remains one of the most reliable places on the island to see them. Your best options are a river cruise along the Kinabatangan or Klias, or a visit to the Labuk Bay Proboscis Monkey Sanctuary near Sandakan. This is an endangered species, so the sightings that matter most are the ones arranged through low-impact, licensed operators.
TL;DR:
- Safest sightings occur in protected sites like Labuk Bay Sanctuary, Kinabatangan River, and Klias River, where monkeys are habituated and less stressed by humans.
- Habitat fragmentation from infrastructure projects and agricultural expansion significantly reduces suitable, connected forest corridors for proboscis monkeys.
- Responsible operators focus on small group sizes, trained guides, and strict quiet rules to minimize disturbance and support conservation efforts.
- Sabah’s conservation plan prioritizes habitat restoration, community involvement, and ongoing population monitoring to ensure the species’ long-term survival.
Table of Contents
- What does a proboscis monkey Sabah sighting actually look like?
- How many proboscis monkeys are left in Sabah, and where?
- Where can you see proboscis monkeys in Sabah?
- Why are proboscis monkeys endangered, and what is Sabah doing about it?
- How do you choose a responsible operator?
- What role do proboscis monkeys play in Sabah’s mangrove ecosystem?
- What is being done to protect proboscis monkeys in Sabah?
- What has research revealed about Sabah’s proboscis monkeys?
- Borneo Dream: recommended ethical wildlife excursions in Sabah
- Sources
- FAQ
What does a proboscis monkey Sabah sighting actually look like?
You will spot males before you spot females, mostly because of that unmistakable, bulbous nose. It grows throughout a male’s life and acts as an amplifier for his honking alarm calls, which carry across water and mangrove canopy far better than a plain call would. Females and juveniles have smaller, upturned noses that look almost pixie-like by comparison, one of the clearest examples of sexual dimorphism among Asian primates.
The other giveaway is the belly. Proboscis monkeys carry a rounded, pot-bellied silhouette because their gut hosts specialised bacteria that ferment tough leaves and unripe fruit, a bit like a cow’s rumen. That gut chemistry shapes their whole diet: young leaves, shoots, and unripe seeds dominate, and mature fruit is largely avoided because the sugars can disrupt the fermentation process. Watch for reddish-brown fur on the back contrasting against pale grey or cream limbs and a whitish tail, often held out for balance as they leap between branches.
Socially, proboscis monkeys live in two main configurations: harem groups of one adult male with several females and their young, and all-male bachelor groups that the dominant males exclude from breeding units. Group sizes commonly run from around ten to twenty animals, though several groups sometimes converge at a favoured riverside sleeping tree in the evening, creating the sort of dense, noisy gathering that makes for a memorable cruise. They are almost exclusively arboreal, rarely touching the ground, which is exactly why boats moving quietly along a riverbank at dawn or dusk, when the animals move to feed or settle for the night, give you the best possible sightings.
How many proboscis monkeys are left in Sabah, and where?
Sabah’s proboscis monkey population clusters along a handful of coastal and riverine strongholds: the Lower Kinabatangan floodplain, the Segama and Sugut river systems, mangroves around Sandakan, the Klias Peninsula, and pockets near Semporna and Tawau Bay. Outside these corridors, sightings thin out fast.
A comprehensive 2005 survey put the statewide minimum population at roughly 5,907 individuals, a figure still widely cited today because more recent work has focused on smaller regions rather than repeating a full state census. That more recent work is not encouraging. Targeted surveys across northwestern Sabah recorded proboscis monkeys at only 7 of 18 wetland sites visited, with small, isolated groups rather than the healthy troops the 2005 numbers might suggest. Of the habitat judged potentially suitable in that region, less than half currently sits inside a protected area.
The gap between “suitable habitat” and “protected habitat” is the real story here. Field research from the same northwestern surveys points out that forest cover alone does not guarantee a viable population. Connectivity between patches, and legal protection status, matter more than raw area. Aquaculture ponds carved into mangroves, oil palm expansion, and infrastructure projects including sections of the Pan Borneo Highway have all fragmented river corridors the species depends on. For travellers, this fragmentation has a practical consequence: sightings in heavily disturbed stretches of river can be patchy and unpredictable, which is one more reason established, well-managed sites tend to deliver more consistent results.
Where can you see proboscis monkeys in Sabah?
Three destinations account for most confirmed proboscis monkey Sabah sightings, and each suits a slightly different kind of trip.
Labuk Bay Proboscis Monkey Sanctuary, roughly forty minutes from Sandakan, began life as a mangrove remnant deliberately left standing inside an oil palm estate. It now supports around 150 habituated monkeys visible from two observation platforms, and because these groups are used to human presence, your odds of a close, well-lit sighting are high. Feeding sessions run four times daily, at 9:30, 11:30, 2:30, and 4:30, and on-site lodging means you can catch both the morning and afternoon sessions without a long drive in between.
The Kinabatangan River, Sabah’s longest, offers a wilder experience. Lodge-based cruises head out at dawn and again in late afternoon, when proboscis monkeys move down to riverside trees to feed or bed down for the night. Staying overnight near the river rather than day-tripping in gives you two extra cruise windows and a real shot at orangutans, hornbills, and elephants alongside the monkeys.
The Klias River, on the Klias Peninsula, is the classic day trip from Kota Kinabalu, typically paired with an evening firefly cruise once the light fades. It suits travellers based in Kota Kinabalu who cannot spare an overnight stay in Kinabatangan.
- Best sighting window: early morning or late afternoon, when the monkeys are most active near the water
- Travel time: roughly 1.5 to 2 hours from Kota Kinabalu to Klias; around 5 to 6 hours, or a short flight to Sandakan, for Kinabatangan and Labuk Bay
- What to bring: a light rain jacket, binoculars, and a camera with a decent zoom, since boats keep a respectful distance from the banks
Pro Tip: Bring a telephoto lens or a phone clip-on zoom rather than relying on cropping later. River light shifts fast at dawn and dusk, and a proboscis monkey silhouetted against a bright sky loses all its colour in a straight crop.
For a deeper look at what else shares the water with these monkeys, our guide to wildlife on the Kinabatangan River covers the species mix you can realistically expect.
Why are proboscis monkeys endangered, and what is Sabah doing about it?
The proboscis monkey is listed as Endangered and sits on CITES Appendix I, the strictest tier of international trade protection, reflecting a population in ongoing decline across Borneo. Habitat loss is the driver behind almost every threat assessment: mangrove clearance for aquaculture, oil palm conversion, and infrastructure development have all chipped away at the riverine corridors these monkeys need.
Sabah’s response is the Proboscis Monkey Action Plan for Sabah (2019 to 2028), often shortened to PMAP. It sets out five core priorities: halting further habitat loss, restoring connectivity between fragmented forest patches, strengthening law enforcement against encroachment, running regular population monitoring, and building public awareness of the species’ legal protection under Sabah law.
That last point matters for anyone planning a visit. With only 43% of suitable northwestern habitat currently inside a protected area, tourism revenue channelled through well-managed sites can genuinely support PMAP’s goals, funding ranger patrols, habitat monitoring, and community incentives to leave riverside forest standing. Poorly run tours that pressure boat drivers to chase animals or encourage crowding do the opposite, stressing already vulnerable groups.
How do you choose a responsible operator?
A few checks separate a genuinely low-impact trip from one that adds to the pressure these monkeys already face.
- Group size and boat capacity. Small boats carrying a handful of guests can approach quietly and reverse away without startling a group; large, crowded vessels rarely manage this.
- Licensed, trained guides. A guide who knows local troop locations and river conditions will read animal behaviour and back off before a monkey shows stress signals.
- Clear rules on distance and noise. Ask whether the operator briefs guests on staying quiet, skipping flash photography, and not calling out to get an animal’s attention.
- Evidence of local benefit. Operators that employ community boat drivers and guides, or contribute to habitat restoration, put tourism income closer to where PMAP’s conservation goals actually need it.
On the water, keep voices low, stay seated, and let the guide position the boat rather than asking to get closer. Bring a lifejacket (most licensed operators supply one but check before boarding), sun protection, and a strong insect repellent for the mangrove stretches. At sanctuary sites like Labuk Bay, remember that feeding habituates monkeys to people, which makes for a superb photograph but is a different kind of encounter to a wild river sighting, worth knowing before you compare the two experiences. For more on travelling lightly around wildlife generally, this piece on mindful nature travel is a useful companion read.
Pro Tip: If a boat driver starts revving the engine to get you closer for a photo, ask him to hold position instead. The best shots come from patience, not proximity, and a monkey that bolts upriver ruins the sighting for the next boat too.
What role do proboscis monkeys play in Sabah’s mangrove ecosystem?
Proboscis monkeys are a quiet engine of forest regeneration along Sabah’s riverbanks. As they move through mangrove and riparian canopy feeding on young leaves, shoots, and unripe seeds, they disperse seeds across distances a falling seed could never travel alone, helping regenerate forest along the very corridors the species itself depends on for survival.
Their fermenting gut plays a specific role here too. Because the bacteria in a proboscis monkey’s stomach break down tough plant matter that many other animals cannot digest, the species can exploit food sources, mangrove leaves in particular, that would otherwise go largely untouched by other primates. That makes them one of the few large mammals genuinely adapted to a mangrove diet, rather than simply tolerating the habitat.
They also matter as a food source and an indicator species. Predators such as clouded leopards and large raptors take juveniles opportunistically, tying proboscis monkey numbers into the wider predator-prey balance of Sabah’s riverine forest. Because the species is so sensitive to habitat quality and connectivity, researchers increasingly treat proboscis monkey presence or absence as a rough proxy for the health of an entire mangrove or riverine system. A stretch of river that has lost its monkeys has usually lost a good deal else besides, from hornbill nesting trees to fish nursery habitat in the root systems below.
What is being done to protect proboscis monkeys in Sabah?
Beyond the state-level Proboscis Monkey Action Plan, conservation on the ground in Sabah increasingly runs through partnerships between government agencies, NGOs, and the communities living along key river systems. Habitat restoration projects along fragmented stretches of the Kinabatangan and Klias focus on replanting riparian corridors and protecting the specific mangrove feeding trees these monkeys rely on, work that only pays off with sustained, multi-year commitment rather than one-off tree planting drives.
Community involvement has become a central plank of that effort, and for good reason. Villagers along river corridors who once had few economic alternatives to logging or converting mangrove for aquaculture now have a direct financial stake in keeping proboscis monkey habitat intact, through boat driving, guiding, and homestay income tied to wildlife tourism. Operators that fund or actively participate in habitat restoration measurably improve outcomes for the species, because riparian corridor recovery is precisely what closes the gap between fragmented pockets of forest and the connected habitat proboscis monkeys need long term.
Monitoring programs, many building on the survey methods used in the northwestern Sabah fieldwork, continue to track group locations, sizes, and habitat occupancy year on year. That data feeds directly back into PMAP’s enforcement and connectivity priorities, giving the state a clearer picture of where intervention is most urgent, and giving responsible tour operators a stake in reporting sightings and unusual habitat pressures back to the researchers tracking them.
What has research revealed about Sabah’s proboscis monkeys?
Much of what is known about proboscis monkey numbers in Sabah traces back to a landmark 2005 survey that produced the widely cited minimum estimate of roughly 5,907 individuals statewide, a figure that has anchored population discussions for two decades. That survey established the coastal and riverine stronghold map still used today, from the Lower Kinabatangan through to Sandakan’s mangroves and the Klias Peninsula.
The more recent 2025 fieldwork in northwestern Sabah marks a significant shift in how researchers assess the species. Rather than repeating a broad state census, that study surveyed eighteen individual wetland sites and found proboscis monkeys present at only seven, a far more granular, and more concerning, picture than a single statewide number can convey.
Alongside these population studies, behavioural and physiological research, including long-term work on arboreal habits and gut fermentation, has clarified why proboscis monkeys are so habitat-specific in the first place. Their dependence on young mangrove leaves and limited tolerance for disturbed ground explains why fragmentation hits this species harder than more adaptable primates. Researchers increasingly argue that future surveys need to track connectivity between sites, not just presence or absence at each one, if Sabah is to understand whether its population is stabilising or still sliding.
Borneo Dream: recommended ethical wildlife excursions in Sabah
A licensed, experienced operator offers reliable routes to proboscis monkey sightings, organising Kinabatangan wildlife excursions, lodge-based multi-day stays, and combined proboscis-monkey-and-firefly evenings on the Klias, all built around the small-group, low-impact approach this guide has described.
We are a RAID Dive Centre rather than a PADI operation, and that same emphasis on properly trained, safety-first guiding carries across everything we run, wildlife trips included. Clients booking through us get guides who know exactly where troops are likely to be at dawn and dusk, rather than a boat that motors up and down hoping for luck.
If a multi-day Kinabatangan stay or a Klias river and firefly evening fits your Sabah itinerary, take a look at our Kinabatangan River wildlife adventure page, check dates, and get in touch to request a bespoke itinerary built around your travel dates.
Sources
- Status and Conservation of Proboscis Monkeys (Nasalis larvatus) in Sabah, East Malaysia
- Population and Habitat of Proboscis Monkeys (Nasalis larvatus) in Northwest Sabah, Borneo, Malaysia
- Proboscis Monkey Action Plan for Sabah (2019–2028)
FAQ
Is the proboscis monkey found in Borneo?
Yes, the proboscis monkey is endemic to Borneo, found only on the island across parts of Malaysia, Indonesia, and Brunei, with Sabah home to several of the most accessible populations.
Are male proboscis monkeys always erect?
No. Male proboscis monkeys sometimes display an erection as part of dominance signalling within a group, but this is occasional behaviour rather than a constant physical state, and it is not the reason for their distinctive nose, which is used mainly to amplify vocal calls.
What are the big five animals in Borneo?
Borneo’s “big five” typically refers to the orangutan, proboscis monkey, Bornean pygmy elephant, rhinoceros hornbill, and clouded leopard, all species you have a realistic chance of encountering on a Kinabatangan river cruise.
What types of monkeys live in Borneo?
Borneo hosts several primate species alongside the proboscis monkey, including the long-tailed macaque, pig-tailed macaque, and silvered langur, plus great apes such as the Bornean orangutan.
Where is the best place to see proboscis monkeys in Sabah?
The Kinabatangan River, the Klias River, and Labuk Bay Proboscis Monkey Sanctuary near Sandakan are Sabah’s three most reliable sites, each suited to a different style of trip, from wild river cruises to closer sanctuary viewing.