Orangutans live in two places : Borneo and Sumatra . In 2004 , we thought there were only 6,600 Sumatran Pongo pygmaeus ( Pongo abelii ) left in the wilderness , but this calendar week , investigator conducting nest sight on the Indonesian island report a new dumbfounding idea : 14,613 Sumatran orangs in 2015 .
Unfortunately , this higher idea does n’t contemplate an factual step-up in the population – rather , it ’s due to a more wide - ranging study exertion that get hold orangs in places that were n’t previously canvassed . And despite this apparent double , the critically endangered apes are still gravely threatened by forest loss and poaching , according to a newScience Advancesstudy .
When an international team led bySerge Wichof Liverpool John Moores University conducted line - transect nest surveys that covered the intact stove of Sumatran orangutans , they encounter 3,166 orangutan nest on 259 line transects with a total distance of 305.8 kilometre ( 190 international mile ) . Based on multi - model prediction of orangutan density over their current grasp of 17,797 square kilometers ( 6871.5 straight mile ) , that ’s adequate to 14,613 individuals – about 8,000 more animals than previous estimates .
Orangutan densities are mellow in peat - swamp forests and lowland forest on mineral soil . They were find living higher than 1,500 meters ( 4,900 feet ) above ocean level – height previously regard alfresco of their scope – and in area west of the Toba Lake that were n’t surveyed before . Additionally , Pongo pygmaeus were also find more widely pass out in logged forests . Their range used to be enormously underestimated at 6,946 square kilometers ( 2681.9 straight Roman mile ) .
woods loss in the Leuser Ecosystem , the principal fastness of the Sumatran orangutan . Serge Wich
The team then developed a serial of model to investigate the impact of nine different land - cover change scenario . And despite this double of population estimates , Sumatran orangutan numbers are expected to decline under all of the scenario they modeled because of next deforestation . As many as 4,500 individuals could vanish by 2030 .
woods red is occurring in both protect and unprotected wood in their range . Peat - swampland forests are being converted into oil palm Plantation , while timberland on mineral soil are being used for other agricultural use of goods and services like rubber and candlenut woodlet . Meanwhile , poaching is mostly confined to an region south of the specie ’ reach , but orangutans are also being capture or killed when they venture into farming land or area that were late disafforest .
