Primate species on verge of extinction

Primate species on verge of extinction

Syofiardi Bachyul Jb, The Jakarta Post/Padang

The population of the four primate species endemic to Mentawai
Islands, West Sumatra, has dropped drastically due to excessive
logging in the area. They are the bilou or dwarf gibbon
(Hylobates klosil), simakobu or pig-tailed monkey (Simias
concolor), bokkoi or Mentawai macaque (Macaca pagencis) and joja
or Mentawai monkey (Presbytis potenziani).

Based on data collected by the World Wide Fund for Nature
(WWF) in 1980 on Siberut island -- one of the four largest
islands and home to the four primates -- the total population of
bilou was 36,000, joja 46,000, simakobu 19,000 and bokkoi 39,000.

However, over the period of 18 years, their population
drastically dropped. Based on data recorded at the Biodiversity
and Conservation Study Center (PSBK), Mathematics and Natural
Sciences (FMIPA) department of the University of Indonesia in
1998, the bilou population stood at 8,300, joja 2,200, simakobu
1,600 and bokkoi 1,300.

There is no data on the population of the four primate species
on the island since then. But, according to head of the Siberut
National Park Bureau, Tri Prasetyo, the total population of the
primates, which could be found only on the Mentawai Islands, had
definitely dropped due to rampant logging by Natural Forest
Concession (HPHA) and Timber Utilization (IPK) permit holders.
"We plan to take inventories of the population of the primates
endemic to Siberut Island next year," said Tri recently.

They live in forested areas on four of the bigger islands on
the Mentawai Islands namely, Siberut, Sipora, Pagai Utara and
Pagai Selatan islands.

However, large-scale forest exploitation by HPHA and IPK
permit holders on the three other islands since 1969, has caused
their habitat to shrink and their populations to drastically
drop.

Based on research by DJ Whittaker from the Department of
Anthropology at the New York City University this year, the
population ratio of the four species of endemic primates in
Sipora was only 4.48 per animal per square kilometer (sq km),
while on Pagai Utara and Pagai Selatan the ratio was 6.8 per
individual animal per sq km.

According to him, the barren forests on the three islands have
had an immediate impact on the conservation of the arboreal
primates.

It is estimated that there are no more than 100 animals of
each species on each island and they too are on the verge of
extinction because there is little protected forest left.

Siberut island which measures 403,000 hectares, is one of the
islands in the Mentawai island chain still covered by vast
natural forests where the four species live. However, forest
exploitation is on the rise there due to the unrestrained
issuance of HPHA and IPK permits by the local authorities.

The Andalas Madani Cooperatives (KAM), affiliated to the
Andalas University in Padang, obtained a concession area of
49,650 hectares in 2001. The Ministry of Forestry is now
processing the forest concession permit for PT Salaki Summa
Sejahtera which is allotted 49,440 hectares.

Besides that, seven companies and cooperatives holding permits
issued by the Mentawai regent are operating 6,700 hectares of the
forest.

These areas border the Siberut National Park which measures
190,500 hectares.

"These logging activities will have an influence on the
decline of the primate populations there due to the decreasing
room for their movement," said Tri.

Tri was convinced that logging activities had caused a
decrease in the population of the four endemic primate species.
One of the causes was that they would be severely depressed, run
off and then die. Moreover, they not only survive in the national
park, but also in forest concession area which forms the whole
ecosystem.

They are not only threatened by large scale logging but also
by the Mentawai people's habit of hunting and eating the flesh of
the bilou, joja, simakobu and bokkoi. However, they do this in a
traditional way by using poisoned blow darts.

The four islands in Mentawai, including Siberut, are recorded
as islands with the densest primate population in the world,
followed by Taiwan with one primate species, Sulawesi with seven
species, Sumatra with one species, Madagaskar with 19 species and
Kalimantan with four primate species.