Javan Rhinoceros

## Description

The Javan rhinoceros is amongst the world’s rarest big mammals. It is prehistoric-looking, is a dusky gray color, and has a single horn. Its hairless skin has several loose folds, which look like armor plating. Every Javan rhino lives in Indonesia’s Ujung Kulon National Park, which makes this species even more under threat of extinction. However, the numbers have been slowly increasing over the last five years and the establishment of a second population may soon mean that the species will have much-needed extra capacity. If the rhinos in Java are lost, the species will be extinct.

## Distribution

Javan rhinos live only in the Ujung Kulon National Park in the very western part of Java. They inhabit dense, lowland rain forests, grasslands, and reed beds with abundant rivers, large floodplains, or wet areas with many mud wallows.

## Behavior

There are still big gaps in information about Javan rhinos, as they are very difficult to study, and very little is known regarding their social behavior. They are solitary animals, except for breeding pairs and mothers with young. Their range extends from 3 to 20 sq m, and various groups have ranges that overlap each other. Javan rhinos sometimes gather in groups at salt-licks and wallows, the latter allowing them to maintain a cool body temperature and helping to prevent parasite infection and disease. Javan rhinos generally do not dig mud wallows themselves, preferring to use those of other animals or naturally occurring pits, enlarging them with their horn. They are much less vocal compared to related species, and very few vocalizations from Javan rhinos have been recorded.

## Diet

Javan rhinos are herbivores (folivores, frugivores). They mostly eat by browsing consuming leaves, twigs, young shoots, and fallen fruit.

## Reproduction

Javan rhinos live in very dense jungles and they have never been bred in captivity, so very little information is to hand with regard to their mating system. Pairs form for mating, which might mean that Javan rhinos are polygynous. The mating season is roughly from July through to November. Gestation is for 16 months, and births occur every four to five years. A single rhinoceros is born at one time. A young rhino is active soon after birth. It will be nursed by its mother for up to one to two years. Females reach maturity when they are three to four years old, and males after six years.

## Population

### Threats

The huge decline in Javan rhinoceros numbers has been mostly attributed to being hunted for its horn and other body parts to be used for traditional Chinese medicine. Habitat loss from logging and development has had a big impact on the species, and it has also suffered from disease and natural disasters, either of which could destroy an entire population.

### Number

According to the IUCN Red List resource, the total population size of the Javan rhino is 68 individuals. All of them live in Ujung Kulon National Park on the western tip of Java. Currently, this species is classified as Critically Endangered (CR) on the IUCN Red List and its numbers today are stable.

## Fun Facts

Ancient people thought that the rhino horn held magical properties, like purifying water or detecting poisons in drinks. The latter may actually be true. Due to the horn’s composition, some think that strongly alkaline poisons can produce a chemical reaction in a cup made from a rhino horn.

The structure of a rhino’s mouth means that it cannot easily graze like other animals, but instead has to tear up clumps of long grasses to eat.

The oxpecker bird is welcomed as a passenger for the rhino, due to its picking parasitic ticks from the rhino’s skin. Furthermore, these birds warn of the approach of humans by screeching loudly.

A rhino has been seen wallowing while six turtles climbed over her body, picking out ticks.

Needing to drink once every day, a rhino remains within 5km of water. If conditions are very dry, it can dig with its forefeet for water.

Some rhinos have had their horns removed to render them worthless to poachers.