Species of Borneo

Portrait of a young Orang-utan (<i>Pongo pygmaeus</i>). / ©: WWF / Alain COMPOST
Portrait of a young Orang-utan (Pongo pygmaeus).
Orangutan (Pongo pygmaeus)
These elusive, tree-dwelling primates are the only great ape in all of Asia and exist only on the islands of Borneo and Sumatra, in neighboring Indonesia. They spend much of their time searching for fruit, using their long arms and legs to move from tree to tree.

Each night, orangutans build a nest of leaves and sticks high above the ground, often with "roofs" to provide shelter from the rain. The orangutan's dependence on trees for food and shelter, along with a slow breeding rate, makes the orangutan vulnerable to human intrusions such as deforestation. The orangutans of Borneo were declared a completely separate species from the Sumatran orangutans in 2000.

Macaques (Macaca spp.)
Macaques spend most of their time in trees, foraging for fruits and small animals to eat. These creatures can be a nuisance to farmers, causing damage to cropland that was once rainforest. Primates are a critical component of the ecosystems within the Heart of Borneo.
Rhinoceros hornbill (<i>Buceros rhinoceros</i>). / ©: WWF / Alain COMPOST
Rhinoceros hornbill (Buceros rhinoceros).
Rhinoceros hornbill (Buceros rhinoceros)
Named for the large horn-like casque on top of their colorful beaks, these birds build their nests in the cavities of large trees. With the female securely inside, the nesting hole is sealed off with a layer of mud except for a small opening through which the male feeds his mate and their offspring. 

Bornean gibbon (Hylobates muelleri)
These tree-dwelling lesser apes move throughout the forest using their long arms, swinging from branch to branch. With strong arms and hands, gibbons are extremely agile, able to change directions in the blink of an eye. At dawn, pairs of gibbons display their vocal talents with a chorus of duets.

Sumatran rhinoceros (<i>Dicerorhinus sumatrensis</i>). / ©: WWF / Michel TERRETTAZ
Sumatran rhinoceros (Dicerorhinus sumatrensis).
Sumatran rhino (Dicerorhinus sumatrensis)
These three-toed, hairy rhinos are the smallest rhinoceros species in the world. When they aren't looking for leafy branches to eat, these shy, shaggy creatures cool off in mud wallows or in the shade. Their horns - which are made up of the same substance as fingernails (the protein keratin) - have made them the target of the traditional Asian medicines trade. Poachers stalk these rare creatures for their horns even though there is no scientific evidence of their medicinal properties and shrinking habitat remains a significant threat.

Bornean yellow muntjac (Muntiacus atherodes)
Bornean yellow muntjacs occur only on the island of Borneo and are primarily diurnal. Previously classified as a subspecies of the Bornean red muntjac (Muntiacus muntjak), they finally received formal species status in 1982. Bornean yellow muntjacs make a noise that sounds like a barking dog, a common characteristic among muntjac species. These small animals reach a height just over 1.7 feet (50 cm) at the shoulder and are found mainly in moist forests. Their diet includes herbs, grasses, fruits and seeds.

Borneo bearded pig (<i>Sus barbatus</i>). / ©: WWF / Alain COMPOST
Borneo bearded pig (Sus barbatus).
Bearded pig (Sus barbatus)
This species of pig gets its name from the long, light-colored whiskers that grow on its lower jaw. The pigs use their long snouts to dig for insects and roots to eat. Bearded pigs are also known to follow groups of macaques around the forest, scavenging for fruits that are left behind. These animals adapt well to cleared areas of land, but can become a nuisance to farmers as they feed on their crops.

Banteng (Bos javanicus)
These large, nocturnal bovines can be seen munching on grass and low vegetation in forest clearings, although they are quite shy, often seeking shelter deep within the forest. Little is known about the banteng's behavior, since very few studies have been done. Deforestation and human settlement continue to threaten these endangered animals.
Sun bear (<i>Helarctos malayanus</i>). / ©: WWF / Terry DOMICO
Sun bear (Helarctos malayanus).
© WWF / Terry DOMICO
Sun bear (Helarctos malayanus)
Although the sun bear is the smallest species of bear in the world, it is said to be one of the fiercest animals in the Asian jungle. Barking loudly upon attack, the sun bear uses its long claws and powerful jaws to drive off any threat. Sun bears are omnivorous, eating anything from insects to small animals. They are also fond of honey - they use their long claws to tear apart trees to get at beehives.

Flying fox (Pteropus vampyrus)
The large flying fox is the biggest of the 90 bat species on the island of Borneo. With a wingspan of more than four feet, this fruit-eater takes flight each evening in search of food. The flying fox is important to many trees, pollinating flowers and distributing seeds throughout the rainforest.
Clouded leopard (<i>Neofelis nebulosa</i>). / ©: WWF / Gerald S. CUBITT
Clouded leopard (Neofelis nebulosa).
© WWF / Gerald S. CUBITT
Clouded leopard (Neofelis nebulosa)
The clouded leopard is the largest cat species on the island of Borneo. These top predators help keep the population of prey species (such as deer, wild pigs and monkeys) in check, ensuring balance in the rainforest ecosystem. The presence of these carnivores is a sign of a healthy forest. Unfortunately, habitat loss and over-hunting have made these cats vulnerable to extinction.
Female Sambar (<i>Cervus unicolor</i>) deer in tall grass. / ©: WWF / A. Christy WILLIAMS
Female Sambar (Cervus unicolor) deer in tall grass.
© WWF / A. Christy WILLIAMS
Sambar deer (Cervus unicolor)
The sambar deer is the largest deer in southern Asia, weighing up to 770 pounds (350 kg). They feed on a multitude of plants and fruits including some that are poisonous to other animals. These deer have adapted to poisons found in their diet thanks to organisms in their digestive tracts that break down the toxins.
Dipterocarp trees (family Dipterocarpaceae)
In Borneo, there is a tremendous diversity of dipterocarp trees with more than 260 different species recorded on the island so far. Dipterocarp means "two-winged fruit" and refers to the fruit that most of these trees produce. When mature, these fruits use their "wings" to ride the winds for distribution across the forest. These trees can reach heights of up to 130 feet and provide habitat for a variety of wildlife, from orangutans to several species of orchid.

Lady’s slipper orchid (Paphiopedilum spp.)
Of the approximately 2,500 species of orchid that are found in Borneo, 12 are types of lady’s slipper. These orchids are found growing on the forest floor, on trees (epiphytes), or even on rocks (lithophytes). These flowers are prized by collectors for their beauty and are regulated in international trade.

Durian tree (Duriospp .)
The durian is one of many fruit trees in these rainforests that are important to both people and wildlife. In fact, the durian fruit is considered the "king of fruits" in many parts of Asia. These trees depend on primates, bats and other mammals to distribute their seeds throughout the rainforest. These animals eat the custard-like interior of these spiky fruits and pass the seeds through their gut.

Rafflesia (Rafflesia spp.)
Lacking its own stem and roots, this parasitic flower can only bloom using the stem and roots of a host plant. Its faint odor - that some liken to rotting flesh - attracts insects that come to pollinate this unusual flower. The blossom can reach a diameter of more than three feet (1 m), making it the largest flower in the world.

Large Dipterocarpaceae tree, a popular timber species. / ©: WWF / Sylvia Jane YORATH
Large Dipterocarpaceae tree, a popular timber species.
© WWF / Sylvia Jane YORATH
Rafflesia pricei just opened to full flower. / ©: WWF / Gerald S. CUBITT
Rafflesia pricei just opened to full flower.
© WWF / Gerald S. CUBITT

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