JP/18/GIBBON

JP/18/GIBBON

Conservation a priority for endangered Javan gibbon

Jarot Arisona
Contributor/Depok

The Javan, or silvery, gibbon (Hylobates moloch) is one of the
world's rarest primates.

This lesser ape occurs nowhere but on Java, more precisely, in
the western and central part of the island. It is confined to
floristically rich patches of relatively undisturbed lowland to
lower mountain rain forest of less than 1,600 meters in altitude.

During the last decade, the Javan gibbon population has
declined rapidly throughout its range, mainly due to the loss of
tropical forest habitat. According to Whitten and others (1999),
Java has lost close to 90 percent of its tropical forest, leaving
less than 19,828 square kilometers of forest, mostly mountain
areas.

Furthermore, the economic crisis since 1997 and
misinterpretation of the meaning of reform prompted people to
clear many of the remaining forests for agriculture, causing more
deforestation.

A study on the Javan gibbon population and distribution was
carried out by the Indonesian Foundation for the Advancement of
Biological Sciences (IFABS) and Center for Biodiversity &
Conservation Studies, University of Indonesia (CBCS-UI), during
2002 and 2003.

The study surveyed 25 forest sites from Ujung Kulon National
Park in West Java to the easternmost known distribution of the
gibbon, namely the Dieng Plateau in Central Java. New localities
for the Javan gibbon, especially in Central Java have been added,
namely the Kendeng Mountains (Sekesod, Sokokembang, and Karang
Gondang), Mount Jaran (Pandanarum village), and Mount
Rendet/Mount Sulaeman (Sigugur village).

All the localities are located in protected forests, which
have a lesser degree of protection than nature reserves or
national parks. On the other hand, gibbons may have vanished from
five localities (Lengkong, Mt. Porang, Mt. Kencana, Bojongpicung,
and Pasir Susuru) where they had previously been reported.

The total number of gibbons estimated by this study to still
exist ranges between 4,000 and 4,800 individuals. The populations
are divided up into sub-populations, with mostly small numbers of
individuals living in fragmented, small patches of forest.

Furthermore, the study listed seven locations at which the
gibbon population has apparently fallen below 10 individuals,
namely, in forest patches on Mt. Papandayan, Mt. Limbung-Halimun,
Mt. Jaran, Mt. Rendet/Mt. Sulaeman, Mt. Slamet, Watukumpul, and
Lewuweng Sancang.

Under these conditions of small and isolated populations,
local extinction can result. Meanwhile, the total extent of
the forest patches available to the gibbons is estimated to be
only 1,144 sq. km.

The field study records that the gibbons are under threat from
multiple direct and indirect threats, the most intense of which
originate from forest clearance and agriculture. Meanwhile,
geographically speaking, the most extensive source of threats
comes from game hunting and land clearance.

This study strongly recommends in-situ gibbon conservation
measures by exploring the prospects for establishing new reserves
in Central Java as a priority, including in a forest patch of
about 9,000 hectares on Mt. Kendeng, Dieng Plateau.

The development and recognition of community conservation
areas is recommended, which would ensure long term community
engagement toward increased local commitment and protection.

Furthermore, detailed studies and monitoring are needed in 15
most important gibbon sites, including: Mt. Jayanti, Mt. Salak,
Telaga Warna, Mt. Malang, Mt. Sanggabuana, Mt. Simpang, Mt. Tilu,
Mt. Limbung-Halimun, Mt. Kendeng (Dieng Plateau), Mt. Slamet, Mt.
Wayang, Mt. Jaran, Mt. Watukumpul, and Mt. Pembarisan.

The study also supports the call for protected corridors, for
instance, between Salak and the Halimun mountains. Overall,
responding to the relatively high incidence of trading in
gibbons, law enforcement needs to involve the prosecution of the
middlemen and the people behind the illegal wildlife trade, with
maximum sentencing employed as a deterrent

The writer is a researcher at the Indonesian Foundation for the
Advancement of Biological Sciences (IFABS) and Center for
Biodiversity & Conservation Studies, University of Indonesia
(CBCS-UI).