The third largest island’s most iconic wildlife – from atop the rainforest canopies to the mighty waterways.

If you’ve gone to Borneo for an adventure trip, chances are, you’ve heard of the Big Five.
Especially if you’ve paid a visit to Sukau Rainforest Lodge, deep within the exotic Lower
Kinabatangan district of Sabah, Borneo!

The Bornean Orangutan, the Bornean Pygmy Elephant, the Proboscis Monkey, the Estuarine Crocodile and the Rhinoceros Hornbill – all five can be found at the lush Kinabatangan forests and waterways that surround the Rainforest Lodge.

These five faunae are the most iconic in the island for their exotic and unique characteristics, as well as their rarity. Unfortunately, most of the animals in this list are under a grave threat as they are categorised as endangered or critically endangered species. Various factors such as deforestation and loss of habitat have contributed to their decline – and though there are ongoing efforts to secure their future, such as ecologically ethical tours that fund their rehabilitation projects here in Borneo, there is always a risk that these majestic creatures’ time on Earth may be limited.

While you’re here, let’s learn about some fascinating facts about the Bornean Big Five!

Bornean Orangutan

Orangutan by Kurt Douglas

With their matted orange fur and status as the largest primates and canopy dwellers, the Orangutan is arguably the most iconic wildlife on this island! Previously classified as a sub-species of the critically endangered Sumatran Orangutan, the Bornean Orangutan was eventually recognised as a separate, unique species in the late 90’s.

Known as one of the most intelligent animals and the closest to humans after the African great apes, Orangutans share approximately 97% DNA with us. These human-like apes have completely adapted to their arboreal or tree-dwelling lifestyle, possessing arms which are one and a half times longer than their legs and large grasping hands and feet that let them traverse across the forest canopy with ease.

The Bornean Orangutan is a semi-solitary creature. Typically, adult males live alone, while females are tagged along by their young for some time before the latter grows old enough to live their own independent lives. Occasionally, Orangutans have been observed to gather in large numbers – this usually occurs during fruiting season, where multiple individuals can be seen feasting on the delicious fruits of the same tree.

Bornean Orangutan population has been dwindling by more than 50% over the past 60 years due to their habitat being heavily reduced and destroyed. This fiery-red-haired ape’s future remains uncertain. An estimated 11,000 orangutans are left in Lower Kinabatangan, Sukau, which is one of the last few bastions of hope for the species.

Bornean Pygmy Elephant

Borneo pygmy elephant by Kurt Douglas

The biggest of the Big Five who, interestingly enough, also happen to be the smallest elephant subspecies in the world! They can be found roaming in scattered populations around restricted areas in the northern and southern part of Borneo. Only recently discovered as a subspecies, they are genetically different from their mainland cousins and have distinctive characteristics, both physically and behaviourally.

Like other elephant species, Bornean Elephants move in large herds of 30-50 individuals or more and are typically led by a female matriarch. Young males that reach maturity will leave these herds, either moving in small bands or alone, and will only be close to the main herd during mating periods.

The Kinabatangan River is one of the best places to see pygmy elephants in Borneo. They can occasionally be seen along the riverside in the late afternoon, feeding and drinking along the banks as well as bathing in the cool waters to get some reprieve from the warm tropical sun. If luck is on your side, you may see a herd of these small (relatively speaking!) elephants swim across the river in a straight-line formation while moving through their home range – a rare and beautiful event to witness!

Today, the biggest threats for this species come from both habitat loss due to deforestation and increasingly worse human-elephant conflict. Due to their shrinking habitat, pygmy elephants have been forced to live closer and closer to human settlements and plantations, resulting in occasional violence. Protected areas such as the Lower Kinabatangan region remains one of the few places they can live in relative safety and isolation.

Proboscis Monkey

Proboscis monkey by Kurt Douglas

Regarded as one the most peculiar primates due to their strikingly large noses, Proboscis Monkeys are an endemic species found in wild only in the jungles of Borneo – and nowhere else in the world.

Lounging on branches and swinging across the forest canopy, these long-nosed monkeys are most commonly found in lowland forest habitats, including several types of coastal, riparian, and swamp forests, and can often be found in the surrounding trees of the Kinabatangan River. In the late afternoon, they can be typically be found gathered on trees along the riverside, spending their time foraging for food and choosing the perfect spot for their evening bed.

For ages, we have been fascinated with these creatures, particularly for their almost human-like characteristics and the distinctively large protruding noses of the adult males. Proboscis Monkeys are larger than life creatures that are worth seeing and appreciating in person, not just for its unique features, but also for the sad fact that as of today, less than 6,000 of their species can be found inhabiting along the coastal areas of Sabah – faring shockingly worse than their distant cousins, the Bornean Orangutans.

Rhinoceros Hornbill

Rhinoceros hornbill by Kurt Douglas

Hornbills are regarded as a symbol of love due to their monogamous lifestyle – they are one of the few animal species who live in pairs almost their entire lives! The male and female are seemingly inseparable, spending most of their time on treetops, feeding and nesting. At first glance, the male and female Rhinoceros Hornbills look nearly identical. The key to identifying them lies in the eyes: the male has a distinct orange or red irises, while the female has white irises.

All Bornean hornbills are cavity nesters. When it’s time to nest, they find a natural tree hole or hollow, where the female is sealed inside the cavity for a number of days with only a small opening at the entrance, allowing the male to deliver meals for both the female and their young.

Once the nesting period ends, and the young are finally ready to fly, the female will break the seal, allowing her and the young to re-join the male. The young will gradually separate from their parents to find his or her own partner, embarking on their own beautiful life story.

Estuarine Crocodile or Saltwater Crocodile

Estuarine crocodile by Kurt Douglas

These large reptilians inhabit a vast area of the Kinabatangan River, including the upper and lower regions as well as the adjacent coastline. Known for its ferocious reputation as one of the top predators in the animal kingdom, this reptile is undoubtedly a prolific carnivore.

A highly territorial species, they can usually be seen resting or basking on riverbanks at daytime, and are active throughout most of the night, which is when they do their hunting. Their list of prey depends on the size of the individual, from aquatic creatures like fish, to large land mammals such as deer and wild boar, and even humans! They command the respect of the locals, who know not to thread into the waters.

The name itself is misleading. This species can actually adapt to almost any aquatic habitat, including the sea, brackish water, and freshwater habitats.

Borneo is blessed with an incredibly rich biodiversity. Passionate globetrotters and wildlife
enthusiasts from all over the world flock to this island, expecting to catch a glimpse of some
of Earth’s most beautiful and magnificent creatures. Whenever you visit Borneo, be sure to
put the Big Five in your list – they are simply not to be missed!