The second orangutan species lives on the Malaysian island of Borneo. It is therefore very important that these results are not interpreted as indicating that Sumatran orangutan numbers have increased, nor that their range has expanded.
Around 14,600 of the great apes are thought to exist now, compared to earlier estimates of just 6,600, surviving on the island of Sumatra.
One of the study’s authors, Serge Wich from Liverpool John Moores University, says it was a thrill to find out that the Sumatran orangutan population is quite higher than documented before. This prompted headlines claiming that orangutans, a critically endangered species, were on the rebound in Sumatra. Still, the apes are far from being out of the woods, as scientists believe that the continued threat of poaching and habitat loss could keep compromising their numbers.
Yet it appears that the actual population of this endangered species is estimated to be about 14,600 based on new transect surveys and a better funding allowing researchers to explore new areas.
It is also essential to take note how other species aside from orangutans may be affected by deforestation, as disruptions to species within the range may also create an issue on the long-term survival of orangutans.
Ecologists say the rise is not due to population growth but because some apes were missed in past surveys.
New numbers shows that the Sumatra orangutan population has doubled since the last census. Apart from this, the orangutans that were found to be nesting in logged locations and in areas to the west of Toba Lake were not included in previous studies.
The number of Sumatran orangutans living in the wild is double what it was previously thought to be.
Dr Hjalmar Kuehl of the Max Planck Institute for Evolutionary Anthropology, added: ‘The Sumatran orangutans are the first ape taxon for which estimates of population size have changed considerably when taking a closer look, and they are likely not the last.
With the numerous development projects planned for Sumatra, the habitats of the orangutans could be severely reduced over the coming years, said Wich.
Wich thinks environmentalists need to continue working together with the Indonesian government and other parties to ensure that the population of these animals doesn’t drop in future.
Wich also mentioned that deforestation has not forced the animals into these areas, but the fact has certainly made the habitats more populated. Sumatran orangutans are critically endangered.
Deforestation is the biggest enemy of orangs and according to the several future deforestation scenarios that researchers considered as many as 4,500 individuals of these species could be dead by 2030 if the deforestation is actually carried out.
The team has urged that all developmental planning be accompanied by appropriate environmental impact assessments conforming with legislation. There’s still a lot of work to be done if they wish to “turn the tide for the Sumatran orangutans“.
“Given the rapid development in field and analytical methods, we will likely see upwards or downwards corrections of the estimated population sizes for several of the other 12 ape taxa in the years to come”. Having a clearer image of the situation will “guide the improved protection of great apes”. Fortunately, orangutans habitually build sleeping nest at night which can be found long after the animal has moved on.