Newly Confirmed Species of Endangered Sumatra Orangutan Already Faces Extinction Threat

Pam Wright
Published: November 8, 2017

Deep in the highland forests of Batang Toru in western Sumatra, a newly confirmed species of orangutan, considered the most endangered big apes in the world, is facing extinction.

Last week, scientists released a paper in Current Biology announcing the new species. According to the paper, DNA analysis confirmed Tapanuli orangutans (Pongo tapanuliensis) were a different species from two other living orangutan species, the Bornean (Pongo pygmaeus) and Sumatran (Pongo abelii). First reported in the 1930s, the Tapanuli orangutans have smaller heads, flatter faces and frizzier hair than their primate cousins.

Determining the apes were indeed a new species of orangutans took decades to confirm.

“I discovered the population south of Lake Toba in 1997, but it has taken us 20 years to get the genetic and morphological data together that shows how distinct the species is,” Erik Meijaard, a conservation scientist affiliated with Australian National University and an author of the paper, told the Bend Bulletin.

Today, the tiny band of orangutans is considered the most endangered of the big apes, the authors of the paper said, with numbers hovering around 800. They live in smaller family groupings on protected lands in an area no larger than 425 square miles in the Sumatra highlands.

Scientists say an isolated and tiny population of orangutans on the Indonesian island of Sumatra with frizzier hair and smaller heads are a new species of great ape.
(James Askew/Sumatran Orangutan Conservation Programme via AP)

Already endangered, scientists fear further development of the orangutans' habitat for agricultural, logging and mining endeavors, along with a proposed 520-megawatt hydroelectric dam on the Batan Toru river, could kill off the big apes, according to Mongabay.

Researchers say the proposed and controversial dam would flood part of the orangutans' habitat, bring more humans to the area and split the population apart, creating more inbreeding and eventual extinction.

Development has already separated a group of 17 orangutans from the larger population, Mongabay reported.

“These 17 orangutans could go extinct as time goes by,” Ian Singleton, director of the Sumatran Orangutan Conservation Program (SOCP) and co-author of the Current Biology paper, told Mongabay. “There should be more than 250 orangutans [in a single population] for them to stand a chance to survive in the long run. Less than that, they could go extinct.”


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