The Javan Rhinoceros was once common in Java, Sumatra, the Malay Peninsula and on the Asian continent. The last Javan Rhino outside Java was killed in Vietnam in 2010. The only Javan Rhinos alive in the world today live in the Udjung Kulon National Park on the western tip of Java next to the Sunda Straits which divide Java from Sumatra. The population in Udjung Kulon has recently been estimated at 65 individuals which are breeding successfully.
The prehistoric remains of hunted Javan Rhinoceros have been discovered in two places in Borneo, (1) in the Niah Caves of N. Sarawak and (2) in the Madai Caves of E. Sabah. These discoveries indicate that Javan Rhinoceros were once common in Borneo and died out due to hunting by humans, probably in the last 200-300 years.
Borneo’s plants including it’s figs evolved in a rain forest habitat where at least two species of rhinos were very common and due to their size and habits would have had a major influence on forest ecology. For example rhinos love eating fig leaves and it may be the case that strangling figs in Section Conosycea evolved a hemi-epiphytic habit to avoid predation by rhinos of saplings at ground level.
It would also seem likely that the 13 species (12 endemic) of Bornean figs in Section Eriosycea with hairy leaves and fig fruits with sharp hairs (both internally and externally) evolved to target rhinos for dispersal. See Ficus aurata and rhino dispersal
Summary: Diet of the Javan Rhinoceros at Udjung Kulon
- Javan Rhinos are browsers, feeding on a very wide variety of common secondary forest shrubs and saplings, eating both the leaves and the twigs.
- If the rhino cannot access the leaves of small trees they push the tree over and then browse the twigs and leaves. Rhinos were able to break stems up to 12 cm diameter.
- Ficus leaves and twigs are a popular part of the diet including Ficus benjamina, Ficus variegata, Ficus callosa, Ficus fistulosa and Ficus septica.
- Ficus septica is very common at Udjung Kulon and is the third most preferred plant in the rhino’s diet after Glochidion zeylanicum and Desmodium umbellatum.
- Note that in Sabah at BORA (Tabin) the captive Sumatran Rhinos refuse to eat Ficus septica even though it is very common.
6. Another favoured food plant is Dendrocnide (Larportea) stimulans a member of the nettle family (Urticaceae) with a very nasty sting causing a severe rash on human skin.
7. The Javan Rhino is a disperser of Arenga palm seeds. Important Note: there has been a dispute at Udjung Kulon about the increased population of Arenga palms which it is claimed are displacing the secondary shrubs e.g. Ficus preferred by rhinos. In Borneo Arenga palm seeds are dispersed by palm civets and the growing bud (ubud) is predated by elephants. It is possible that the Arenga palms are actually being spread by the Javan Rhinos and the fruit may be an important part of their diet. It would be premature to remove the Arenga palms without a full ecological study.