The Nantu Forest is one of the last pristine sanctuaries in Sulawesi, providing a crucial refuge for many known endemic species like the babirusa and anoa. It also harbors countless undiscovered species within its untouched ecosystem, making it an invaluable site for both conservation and scientific discovery.

The Babirusa

Babyrousa celebensis


Vulnerable

The Pig-Deer


The Babirusa, known as pig-deer – “babi rusa” in Indonesian, is one of the most iconic species native to Sulawesi. These fascinating animals have intrigued humans since prehistoric times due to their unusual and ancient-looking appearance. One of the most striking features of the male babirusa is its upward-curving canine tusks, which grow through the flesh of the snout, giving them a distinctive and almost mythical look.

The babirusa inhabits dense forests and riverine areas, feeding on fruits, leaves, and small invertebrates. Their presence in the Nantu Forest contributes to the ecological balance, playing a role in seed dispersal. Babirusas are shy and elusive, often hidden deep within the forest, making them a rare sight but a key component of Sulawesi’s wildlife.

A Special Place for the Babirusa


Deep within the lush Nantu Forest lies a unique volcanic salt lick, a natural mineral-rich hotspot that has become a favored gathering place for the elusive Babirusa. They are drawn to the salt lick, where they can replenish essential nutrients from the soil. This special site could possibly be the best place in the world to observe Babirusa in their natural habitat.

Photo: Maxime Aubert, Griffith University, Australia

Babirusa Depictions in Sulawesi Caves


In the limestone caves of Sulawesi, Indonesia, ancient rock art dating back around 40000 years depicts striking images of the babirusa, alongside stenciled outlines of human hands. These paintings are considered the world’s oldest known figurative art, representing the earliest examples of humans depicting real-world animals in symbolic form. The detailed portrayal of the babirusa, combined with the haunting hand stencils, reflects the deep connection between early humans and their environment, making these artworks a profound window into prehistoric life and creativity.

Lowland Anoa

Bubalus depressicornis


Endangered

Mountain Anoa

Bubalus quarlesi


Endangered

The Unique Anoa


The mountain anoa (Bubalus quarlesi) and the lowland anoa (Bubalus depressicornis) are two endangered species of wild buffalo native to Indonesia’s rainforests. Resembling miniature water buffaloes, these animals weigh between 150 and 300 kg (330–660 lb). Unlike most cattle, anoas live alone or in pairs, only forming groups when females are ready to give birth. Anoas are found on the islands of Sulawesi and Buton, where they thrive in dense, undisturbed forests far from human activity. Unfortunately, human encroachment is rapidly shrinking these vital habitats.

Population Decline and Threats


Anoa populations have been in steady decline since the 1960s, with fewer than 5,000 of each species remaining. The primary threats are poaching for their meat, hides, and horns, as well as habitat loss due to logging and settlement expansion. These activities not only shrink their living spaces but also fragment populations, threatening genetic diversity and long-term survival.

The survival of the anoa is closely tied to the protection of the Nantu Forest, one of the last strongholds of their natural habitat. Along with stronger enforcement against poaching, preserving the Nantu Forest is crucial for ensuring the long-term survival of these endangered species and maintaining the ecological balance of Sulawesi.

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Babirusa and Anoa Wildlife Trader Detained by Project PatrolConfiscated Babirusa and Anoa Meat

Vulnerable and Facing Multiple Threats


Heck’s macaque is a primate species endemic to the northern arm of Sulawesi, Indonesia, specifically within the Nantu Forest. It is one of seven macaque species found on the island. Despite their importance, little is known about their behavior and lifestyle, and with their habitat rapidly decreasing, opportunities to study them in the wild are dwindling.

Like other macaques, Heck’s macaques likely live in social groups governed by strict hierarchies, with individuals adapting their behavior according to their rank. However, much of what we understand about them comes from studying other Sulawesi macaques and general macaque behavior.

The IUCN lists Heck’s macaque as Vulnerable due to threats such as habitat loss and forest fragmentation, which increase the risk of genetic bottlenecks in isolated populations. Even protected forests like Nantu face growing threats from human activities, including illegal gold mining and expanding settlements. Additionally, despite the legal protection of these macaques, hunting for their meat remains common, with macaques often seen in local markets.

Red-Knobbed hornbill

Rhyticeros cassidix


The Red-Knobbed Hornbill (Rhyticeros cassidix), native to the forests of Sulawesi, Indonesia, is a striking bird with vibrant plumage and a prominent red casque. Classified as Vulnerable by the IUCN, it faces growing threats from deforestation and habitat loss as its forest home continues to shrink.

 

Jatna's tarsier

Tarsius supriatnai


Jatna’s tarsier , recently discovered in the forests of Sulawesi, Indonesia, is a tiny primate known for its large eyes and nocturnal habits. Classified as Vulnerable by the IUCN, this species is at risk due to ongoing habitat loss and deforestation within its very limited range, which includes the critical Nantu Forest.

 

Sulawesi dwarf hornbill

Rhabdotorrhinus exarhatus


The Sulawesi dwarf hornbill , endemic to the lush forests of Sulawesi, is distinguished by its striking white and black plumage and a prominent, curved bill with a bright yellow patch. Classified as Vulnerable by the IUCN, the Sulawesi dwarf hornbill is threatened by habitat loss. The species relies on mature forest ecosystems for feeding and nesting, and the Nantu Forest is an ideal sanctuary.

 

Red-Knobbed Hornbill

Rhyticeros cassidix


Vulnerable

The Red-Knobbed Hornbill (Rhyticeros cassidix), native to the forests of Sulawesi, Indonesia, is a striking bird with vibrant plumage and a prominent red casque. Classified as Vulnerable by the IUCN, it faces growing threats from deforestation and habitat loss as its forest home continues to shrink.

 

Jatna's Tarsier

Tarsius supriatnai


Vulnerable

Jatna’s tarsier , recently discovered in the forests of Sulawesi, Indonesia, is a tiny primate known for its large eyes and nocturnal habits. Classified as Vulnerable by the IUCN, this species is at risk due to ongoing habitat loss and deforestation within its very limited range, which includes the critical Nantu Forest.

 

Sulawesi Dwarf Hornbill

Rhabdotorrhinus exarhatus


Vulnerable

The Sulawesi dwarf hornbill , endemic to the lush forests of Sulawesi, is distinguished by its striking white and black plumage and a prominent, curved bill with a bright yellow patch. Classified as Vulnerable by the IUCN, the Sulawesi dwarf hornbill is threatened by habitat loss. The species relies on mature forest ecosystems for feeding and nesting, and the Nantu Forest is an ideal sanctuary.