News
“Save North Sumatra’s Last Wilderness”
The Batang Toru Landscape, with a total area of around 150,000 ha, is located in the North Tapanuli, Central Tapanuli, South Tapanuli Districts of North Sumatra Province. Of this area, nearly 142,000 ha are primary forests. The intact Batang Toru landscape has amazing biodiversity and deserves greater public attention. In addition, the Batang Toru landscape also supports the lives of more than 130,000 people who enjoy the benefits of the environmental services it provides.
Fascinating Flora and Fauna
The Batang Toru ecosystem serves as a habitat for many protected and endangered wildlife species such as the Sumatran tiger (Panthera tigris sumatrae), sun bear (Helarctos malayanus), tapir (Tapirus indicus), serow (Capricornis sumatraensis) and various other charismatic species, including Ivory Hornbills (Rhinoplax vigil) and the Argus pheasant (Argusianus argus). Interesting plants include the tallest and largest flowers in the world, namely various types of Amorphophallus spp. and rafflesia (Rafflesia cf. micropylora-gadutensis). These steep mountain habitats have yielded many new species of orchids and several other interesting flora such as parasitic plants from the Balanophoraceae family, and new species of the saprophyticThismia genus.
The Tapanuli Orangutan: Pongo tapanuliensis
In November 2017 the names ‘Tapanuli’ and ‘Batang Toru’ suddenly became world famous! The orangutans in Tapanuli were previously considered the southernmost orangutan population of the Sumatran Orangutan, Pongo abelii. However, based on in-depth research by a group of Indonesian and international researchers in the fields of genetics, morphology, ecology and behaviour, orangutans in Batang Toru were found to be genetically closer to the Bornean Orangutan, Pongo pygmaeus, so they had to be declared a separate species, namely the Tapanuli Orangutan (Pongo tapanuliensis).
Its distribution is very limited, and its small population (<800 individuals) makes the Tapanuli Orangutan the rarest and most endangered species of great ape in the world. It has already been designated as Critically Endangered (the highest threat category before “Extinct” on the IUCN Red Data List, highlighting just how endangered it is. Also, because it is only found in North Sumatra Province, the Tapanuli Orangutan is the only great ape species in the world that is endemic to one Province (Sumatran Orangutans are endemic to Indonesia but two Provinces)!
Unfortunately, this rare orangutan only found in the Batang Toru Landscape has already been fragmented into 3 populations, with only the west block population (500 to 600 individuals) deemed viable in the long term (assuming no further disturbance or loss of habitat). The populations in the east block (160 individuals) and in the Sibual-buali Nature Reserve (less than 30 individuals left) will become extinct due to inbreeding if they cannot be reconnected to the population in the west block.
The extremely slow breeding rate of Tapanuli Orangutans makes them highly vulnerable to extinction: females have their first child at the age of 15 years, with a typical interbirth period around 8 or 9 years.