Syofiardi Bachyul Jb, Padang – Five primate endemic species in Mentawai Islands regency, West Sumatra, are threatened with extinction, a researcher says.
A primate researcher from Padang's Andalas University Biological School, Rizaldi, said the five primate species were under serious threat due to further pressure on their habitat.
"They have lost their homes and habitat. Previously, they faced a serious threat from illegal logging, but now it's from traditional farms and modern plantations, as well as poaching with poisoned arrows, air rifles and poisoned darts. They are also traded outside the area as well as facing threats from logging through forest concessions," Rizaldi told The Jakarta Post on Thursday.
In 2008, the International Union for the Conservation of Nature (IUCN) listed the simakobu and Pagai bokoi primates as critically endangered, the bilou and joja as endangered and the Siberut bokoi as vulnerable.
Rizaldi expressed concern that stakeholders in the Mentawai Islands were not committed to resolving the situation.
He cited that the Mentawai regency administration and Mentawai Islands Regency Council (DPRD) had further urged Siberut National Park to relinquish land to make way for roads, public facilities and public activities within the park by changing the zonation, which could benefit the traditional community.
According to Rizaldi, the road that bisects the forested area will sacrifice trees and isolate the primates.
Bilou, or dwarf gibbons, for example, are not used to walking on the ground. Instead they move from one location to another by leaping through the trees.
"Should the trans-Mentawai highway be built, it would cause them to be segmented and their population would drop," said Rizaldi.
He added that there had yet to be a comprehensive study on the population of the five primate species. The species' classification was only carried out in 2014.
"The government should now think of a way to strengthen Siberut National Park as the last bastion for the primates and other endemic flora and fauna, besides establishing other conservation areas on the Pagai and Sipora islands," said Rizaldi.
Siberut National Park Region I section head Junaidi said the five primate species were at risk of being illegally traded by outsiders and poaching by the local community.
"Traditional hunting for the sake of customary rituals by the Mentawai tribe is still very limited and can still be tolerated. We are very concerned about the illegal trade due to the many gateways that require extra supervision in Siberut," Junaidi told the Post on Thursday.
The bilou is the primate most often traded as gifts and reared as pets due to its tiny form.
While there is yet to be data on the population of the five primate species on the Mentawai and Siberut islands, a joint survey conducted by the Siberut National Park and the West Sumatra Muhammadiyah University's Forestry School in 2014 in six locations in Siberut showed the bilou population at 1,934, simakobu at 4,045, joja at 1,832 and bokoi at 1,831.
"We will resume the survey in the same location after Idul Fitri to study the population growth," said Junaidi.
A senior researcher at the Forest Research Center of the Environment and Forestry Ministry, M. Bismark, who conducted a survey on the primates in 2009, said the serious threat faced by the primates was the presence of large-scale oil palm plantations on Siberut.
"The best move is to issue a moratorium on logging and restore the ecosystem until balanced biodiversity is achieved," said Bismark.