The First New Great Ape Species Discovered In 90 Years
A new orangutan species (photo credit: Maxime Aliaga) has become the first great ape species discovered in over 90 years, but the sad reality is that it’s already the world’s most endangered ape.
The entire populations of fewer than 800 individuals, all live in the Batang Toru forest in Tapanuli, northern Sumatra – an area of just 1,000km2. Until now, the scientific community had recognised seven extant species of great apes: Sumatran orangutans, Bornean orangutans, eastern gorillas, western gorillas, chimpanzees, bonobos and humans. Now an eight species exists.
Scientists have know about this new species of orangutan, now called Pongo tapanuliensis, since 1997 and, although research had suggested a difference in behaviour and genetics between this group and other orangutan species, they didn’t have enough evidence to say for certain that these differences supported the classification of a new species.
This all changed in November 2013, when scientists were given access to the body of an adult male who had died from wounds sustained by local villagers. The death of this orangutan, although obviously terrible for the survival of the species, gave the researchers study material (in the form of bone and teeth) that allowed them to conclusively identify them as a separate species.
The skull was compared to the skull of 33 other male orangutans, which found the skull of the Batang Toru male to be considerably smaller than that of individuals of the other two species. They also observed the behaviours of living Batang Toru orangutans, finding that the long booming calls of the males differ from those of the other two species.
One of the most obvious external characteristic differences between the species is their difference in fur. The new species has a more cinnamon-coloured coat than the Bornean orangutan, and a much frizzier texture than the Sumatran orangutans. Also, Batang Toru orangutans were found to have more facial hair than the other species - dominant males have more prominent moustaches, and the females often sport a beard!
Using genome analysis, they discovered that this new species had split from the Bornean orangutan population 3.4 million years ago in northern Sumatra. Then, no more than 700,000 years ago, the Bornean and Sumatran orangutans diverged into separate species. One reason why the researches were so shocked to discover such a distinct population of this new species is that there are Sumatran orangutans found just 100km away!
The outlook for the Batang Toru orangutan population is not looking good. Current threats to their survival include illegal road construction, human-orangutan conflict (usually over crops), and the illegal trade of the animals. Perhaps the most serious current threat though, is the proposed development of a hydroelectric dam on Sumatra that could have an impact on up to 8% of the Batang Toru population.
It is therefore vital that conservations measures are put into place quickly, if we are to ensure the long-term survival of this beautiful new great ape species!