The Javan Rhinoceros, Rhinoceros sondaicus or Sunda rhinoceros, and the lesser one-horned rhinoceros, is one of only five species of rhinoceros still in existence. With a length and height of 3.1-3.2 m (10-10 ft) and 1.4-1.7 m (4.6-5.6 ft), respectively, it is smaller than its Indian rhinoceros cousin (and more closely related to the black rhinoceros of the genus Diceros) than the Indian Rhinoceros itself.
Its horn is typically smaller than the horns of other rhinoceros species, measuring less than 25 centimeters (9.8 inches) in length. Bulls only get horns during puberty, and female cows never do.
Javan Rhinoceros Distribution
The Javan rhinoceros, or Rhinoceros sondaicus, is sometimes known as the lesser one-horned rhino. It is theorized that the Javan rhino’s original range spanned parts of southeastern Asia. The historical range of the Javan rhino probably included what is now eastern Vietnam, starting in the very northern regions of Burma.
Although the Javan species was first discovered in Java, it is now known to have spread throughout all of Sumatra. Also, it was discovered in the far north and northeast of Thailand, even reaching Cambodia. The southern part of the Malaysian peninsula may have been within the rhino’s natural habitat. There was a time when rhinos roamed all of Java.
The remaining 50 or so individuals are all found in the Udjong Kulon Nature Reserve in the most remote southwestern regions of Java. Cat Tien National Park in Vietnam is home to a much smaller population (less than 10 individuals).
Habitat: Where Do Javan Rhinoceros Live
As a result, the best places to spot a Javan rhino are in lowland tropical forests. The lowland grassy plains near a water supply are ideal habitats for Rhinoceros sondaicus, which spends most of its day wallowing.
Although these lowland species have been spotted at altitudes of up to 1000 meters, you’re considerably more likely to come across them below 600 meters.
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Appearance: How Do Javan Rhinoceros Look Like?
The horn of the Rhinoceros sondaicus is the smallest of any rhinoceros species, hence the alternative name “lesser one-horned rhinoceros.” Males have one horn that grows to be around 25 centimeters long at maturity, while females have none. The horn is not connected to any of the skull’s underlying bones. The grey hide of a Javan rhino features several hard folds that join to produce creases that are divided into sections.
The neck is not the source of the dorsal wrinkle seen on the Javan rhino, in contrast to the Indian rhinoceros, Rhinoceros unicornis. The Javan rhinoceros has folds on its shoulders, back, and tail. There is a close match between the horn and the skin.
The typical height of a male Rhinoceros sondaicus is 1.7 meters. Its length could be anywhere from 2.0 to 4 meters. Both sexes tend to be around the same size. The female head is larger, according to some measurements. Anyone of either sex can have a body weight of anywhere from 1500 to 2000 kilograms.
The Javan rhino is nearly hairless but for a few tufts of hair on its horn and snout. A tuft of hair can be found at the very tip of the 70 cm tail. An extended upper lip that hangs over the lower lip serves the rhino’s foraging needs. Its huge incisor teeth have never been described in print.
Until the late 1800s, the Sumatran rhinoceros, Dicerorhinus sumatrensis, was commonly thought to be the true rhino. Hence most of what is known about the true rhino’s physical description is shaky at best.
Javan Rhinoceros Reproduction
Few stories exist of Rhinoceros sondaicus mating habits. However, it is likely polygynandrous. The loud roars and violent clashes between male and female Javan rhinos are likely a form of courting. One couple was seen tearing up bushes together before taking off in chase over 200 meters away.
The Indian rhino (Rhinoceros unicornis) and other species of rhinoceros engage in elaborate ritualized actions before copulating, which can cause serious harm. For mating purposes, male rhinos will “whistle,” with the loudest calls coming from the alpha males.
The Javan rhinoceros is a perennial breeder that gives birth to a single calf each year. The calf is old enough to be weaned in between one and two years. Due to the long mother-calf bonding period and the 16-month gestation period, the breeding cycle is every 4-5 years.
Sexual maturity in females of this species of rhino occurs as early as 5–7 years of age, whereas, in males, it takes until they are 10 years old.
We lack any hard data on development or maturation, only anecdotal evidence. The size of a 17cm fetus suggests that its mother is about halfway through her pregnancy. Again, the age of the second rhino was not given, but its length was reported to be 130cm. By the time it was four years old, it had grown to its maximum of 170 cm in length.
Even after giving birth, a cow may choose to remain with her calf for up to two years. Feeding from the mother begins immediately after the calf is able to walk, usually within the first couple of hours of life. Besides mating, the bull has no interest in raising its young.
The lifespan of the Rhinoceros sondaicus is unknown. Experts estimate that they might live for another 30–40 years in the wild. The life of one particular captive rhino ended in 1907 after it had survived for 21 years. A captive Javan Rhinoceros population of this species has been shown to die off more quickly than wild populations. The zoo in London lost a pair of rhinos at the ages of 11 and 14. In captivity, a life span of 10–20 years is typical.
Javan Rhinoceros Behavior
Typically, Rhinoceros sondaicus will be found by itself. The animal spends most of its time wallowing to maintain a supple hide. Possible bacterial and illness complications could arise if wallowing is discouraged.
According to Yahya’s research, neither males nor females were shown to behave differently when allowed to wallow. The rhino can stand or sit when wallowing. Attempting to make the watering hole deeper, Javan rhinos will roll around in the mud and rub their horns against the silt. In highly brushy environments, the rhino’s horn serves as a useful weapon. While wallowing, the rhino will fall asleep as well.
Javan rhinoceros perform different bouts, but they are not thought to represent a means of communication. They most frequently use motions that include rubbing their horn against a stationary object (such as a tree), shaking their head, and adjusting their ears.
The Javan rhino is known to engage in a wide variety of aggressive behaviors, including attacking and/or charging at potential dangers. Similarly, when confronted by an imagined danger, rhinos will fixate on it and stay still, a stance that conveys a firm determination to retreat. In most cases, bulls will act aggressively and yell at one another.
Some rhino habits can only be understood by looking at how a mother interacts with her young. Cows are known to have an aggressive stance when protecting their calves from danger. Another common sighting involves a mother cow protecting her calves from apparent danger.
How Does Javan Rhinoceros Communicate
The optical capabilities of the Rhinoceros sondaicus are limited. As a result, it relies heavily on its hearing and sense of smell.
The Javan rhino spreads its body fluids over its environment as a means of chemical communication, usually to assert dominance or defend territory. Dominant males are more likely to engage in behavior that results in such secretions, which includes defecating on or near a place previously used by another Javan rhino. Like many other animals, Javan rhinos are often observed defecating in water. Wallows are another common location for this activity.
The Javan rhino can communicate using a variety of noises, each with its own meaning. The Javan rhino is capable of producing a wide range of sounds, including a “neigh,” “bleat,” “shriek,” “lip vibrations,” and “snort” (Groves and Leslie Jr., 2011). Growling has been reported to be heard from around 600 meters away.
Although it prefers to spend its time alone, this species has been observed interacting with others during courting. A mother will nurse her calf for more than two years.
Although it is a herbivore, Rhinoceros sondaicus does not consume grass. While the Javan rhino can eat bamboo and other plants with sharp structures, it prefers to munch on softer flora, such as figs Ficus variegata and guest tree Kleinhovia variegata.
In its desperation for sustenance, this rhino may resort to extreme measures. Some have even been witnessed leaning over lower plants in order to get to the higher ones where the food is. Some reports suggest that the rhinos saddle up at the tree’s trunk and work their way up until the tree is leaned over and the foliage can be reached.
The Javan rhinoceros can swallow huge quantities of certain toxic plants, which are more common in low and tropical wooded environments.
The Javan rhinoceros was listed as severely endangered by the IUCN in 2008. Only about 60 Javan rhinos are left in the wild (all in Ujong Kulon National Park), fewer than 10 in Viet Nam, and none in captivity if the species isn’t protected.
Given its extreme rarity, the Javan rhino is second only to the Sumatran rhino, Dicerorhinus sumatrensis, among rhinoceros species. In 1907, a zoo’s last Javan rhinoceros died of natural causes. The short lifetime of the Javan rhino in zoo conditions has led to its extinction in captivity.
Poaching of Rhinoceros sondaicus and the destruction of its habitat both began in earnest in the early 1800s, and both have only worsened since. Several seismic volcanoes in Java pose a hazard to this population since an eruption could result in species extinction.
In order to boost the number of Asian rhinos, the Asian Rhino Specialist Group has developed a strategy. The proposal calls for moving some of the population to a different breeding location. However, there is no evidence of natural reproduction in the current population in Viet Nam, and it has been hypothesized that the few remaining individuals (possibly only 6) are either of the same sex or too old to reproduce.
FAQs: Javan Rhinoceros
How Many Javan Rhino Are Left?
Approximately 67 Javan rhinos are thought to still exist today, making this species one of the most endangered rhinos on Earth. They can only be found in Ujung Kulon National Park, located on the southwestern tip of the Indonesian island of Java.
What Eats The Javan Rhino?
Both humans and wild cats are potential threats to Javan Rhinoceroses.
What Is Special About The Javan Rhino?
The horns of adult male Javan rhinos are the shortest of the five surviving species, with an average length of less than a foot. The critically endangered Javan rhinoceros is only found in Indonesia’s isolated Ujung Kulon National Park.
What Animal Eats A Rhino?
Africa’s lions and Asia’s tigers have the worst reputations as rhino predators, with both specializing in eating young animals. African rhino calf mortality is primarily attributable to poachers, but other predators like leopards, hyenas, wild dogs, and Nile crocodiles have also been implicated. However, humans are the greatest threat to rhinos.
Do Javan Rhinos Live Together?
The only exceptions to this rule are breeding pairs and moms with young, but even then, the Javan rhinoceros is primarily a lonely animal. Salt licks and mud wallows are popular places for them to gather in small groups.
Parvaiz Yousuf is a senior SEO writer and editor with an experience of over 6 years, who also doubles up as a researcher. With an MSc zoology degree under his belt and possessing complete Search Engine Optimization (SEO) knowledge, he works as a science journalist for a US-based website and Asian Scientist (A Singapore-based magazine). He also works as Director of Wetland Research Centre, Wildlife Conservation Fund YPJK since 2018. Besides, he has several publications to his name on cancer biology and biochemistry in some reputed journals such as Nature & International Journal of Molecular Sciences, & magazines such as Science Reporter, BUCEROS BNHS, and has an abiding interest in ornithology. He also worked as a Research Associate for JK Policy Institute.