Western Java Mountain Forests | WWF

Western Java Mountain Forests

Nipa palm (Nypa fruticans), Java, Indonesia.
© WWF / Sylvia Jane YORATH

About the Area

The Western Java Mountain Forests harbour a diversity of habitats, which in turn gives way to a rich variety of flora and fauna, with many endemic species. Endemism is highest for mammals, but is also significant for birds.

With many mountains and with a rainfall amounting to 3 m (10 ft) per annum in some places, the Java island has, as might be expected, an abundance of springs and running streams, and these make possible a very perfect system of irrigation which has converted it into 'a vast garden’.

Nearly all of the original forest has been cleared to make way for Java's dense and expanding population. Nonetheless, rain forests and river habitats remain in a few parks and contribute to the region's great biodiversity.

6,200 sq. km (2,400 sq. miles)

Habitat type:
Tropical and Subtropical Moist Broadleaf Forests

Geographic Location:
Java, a large island in Indonesia

Conservation Status:
Local Species
These forests contain many species now virtually extinct elsewhere in Java, including trees such as Elaeocarpus macrocerus, Alstonia spathulata, Wild mango (Mangifera gedebe), Stemonurus secundiflora, and a huge sedge (Thoracostachyrum sumatrana).

Besides the globally threatened surili leaf monkey (Presbytis comata), the endemic Javan gibbon (Hylobates moloch) lives here too.

Characteristic of the bird fauna are species such as the endemic Javan tesia (Tesia superciliaris), green spectacled pigeon (Treron oxyura), and the Sunda thrush (Zoothera andromedae).

Featured Species

The surili leaf monkey (Presbytis comata) is a small, slim built primate. Its fur at the top is brown, grey or black and at the lower surface whitish, sometimes also orange, with some species having fur designs at the head or at the hips. Its German name, meaning ‘capped langur’, comes from the hair on its head, which forms a tuft. It ranges in adult length from 40 to 60 cm (with a 50 to 85 cm long tail) and a weight of 5 to 8 kg.

A diurnal forest dweller, it spends nearly all its life in the trees. It lives predominantly in groups of 6 to 8 animals consisting of a male, several females, and their young. More recently it has been observed in monogamous pairings (particularly the Mentawai Langur), although this might be a reaction to the decrease of their habitat. The groups are hierarchically developed, with intergroup communication that is both vocal and postural.

The surilis' diet consists of leaves, fruits, and seeds. Its life expectancy is estimated at 20 years.

Read more:
Only 5% of the original habitat remains in this ecoregion, as it is located on the most densely populated island in Indonesia. Erosion and burning pose serious threats to the fragments that remain.
WWF’s work
Ujung Kulon National Park contains a unique remnant of lowland Javan rainforest separated from inhabited areas by a volcano and narrow isthmus.

WWF first began supporting conservation work in Ujung Kulon in 1964, by providing equipment to Indonesian park authorities and funding scientific research. In 1967, an estimated 21-28 Javan rhinos lived in Ujung Kulon, but anti-poaching patrols and habitat protection allowed the population to grow to 45-54 animals by 1976. Anti-poaching patrols, supported by WWF, the International Rhino Foundation and other conservation partners, have helped Ujung Kulon's rhino population recover and these patrols continue to safeguard them today.

WWF is also using fecal DNA analysis and camera traps to gain a better understanding of the rhino's current population structure. WWF will also continue to assess habitat and rhino food availability in Ujung Kulon, as well as the feasibility of translocating rhinos to establish a new population elsewhere, once a suitable and secure site for a new population is identified.

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