Javan Rhinoceros

Rhinoceros sondaicus
Critically Endangered

ETYMOLOGY | TAXONOMY | RANGE | BEHAVIOR | DIET | REPRODUCTION | ECOSYSTEM | STATUS | IMAGES | FAUNAFACTS | VIDEO | SOURCES

The Javan rhinoceros is one of the five extant rhinoceros species. Although there were three subspecies recognized, two have now become extinct. This herbivorous rhino is the rarest and most endangered of rhinos with less than 70 remaining. None are currently kept in captivity and all are found in Ujung Kulon National Park.

 

PHYSICALITY

The Javan rhinoceros is an odd-toed terrestrial ungulate, and each of its feet ends in three hooved toes. As in other ungulates, the rhino’s teeth are lophodont, having transverse ridges on the grinding surfaces. The rhino also has a unique, prehensile, upper lip that functions as an aid for feasting on leaves. The lip is pointed to allow for food to be grasped and brought to the mouth. The rhino’s hairless skin is a dusky, hazy grey and contains tough folds that create an armor-like plating. Despite having smaller ears than other rhinoceroses, the Javan rhino has keen senses of smell and hearing, but is known for having poor eyesight.

The Javan rhino possesses a single horn on the top of its nose, the smallest horn of all rhinos. Like human fingernails, the horn is made up of keratin. The horns of male Javan rhinos can grow to a length of 25 centimeters (10 inches), but females have shorter, less prominent horns or may lack a horn entirely. There is little sexual dimorphism in the Javan rhinoceros aside from horn size.

The Javan rhino is smaller than most other rhinos and is only larger than the Sumatran rhinoceros (Dicerorhinus sumatrensis). It is the largest animal in Java and the second-largest animal in Indonesia after the Asian elephant (Elephas maximus). An average adult Javan rhino is approximately 11-12 feet in length with a height of 5-6 feet at the top of its shoulders. It is about the same size as the black rhinoceros (Diceros bicornis). A study to collect accurate measurements of the animals has never been conducted and is not a priority because of their extreme conservation status. No substantial size difference is seen between genders, but females may be slightly bigger. The rhinos in Vietnam appeared to be significantly smaller than those in Java, based on studies of photographic evidence and measurements of their footprints.

The Javan rhinoceros is very similar in appearance to the closely related Indian rhinoceros (Rhinoceros unicornis), but it is slightly smaller and has a much smaller head and looser, less apparent skin folds.

SHOULDER HEIGHT
1.2-1.8 m. / 4-6 ft.
BODY LENGTH
2-4 m. / 6.5-13 ft.
HEAD LENGTH
27-35 cm. / 10-14 in.
HORN LENGTH
25 cm. / 10 in.
BODY MASS
900-2,300 kg. / 1,980-5,070 lb.
SEXUAL DIMORPHISM
Larger Horned Males
Slightly Larger Females

ALTERNATE NAMES
Asian Lesser One-Horned Rhino
Javan Rhino
Sunda Rhino
GROUP
Crash, Stubborness
MALE
Bull
FEMALE
Cow
YOUNG
Calf
KINGDOM
PHYLUM
CLASS
ORDER
FAMILY
GENUS
SPECIES
Animalia
Chordata
Mammalia
Perissodactyla
Rhinocerotidae
Rhinoceros
Sondaicus
SUBSPECIES (3)
R. s. annamiticus (Vietnamese)
R. s. inermis (Lesser Indian)
R. s. sondaicus (Indonesian)
ETYMOLOGY

The Javan rhinoceros’ scientific name is Rhinoceros sondaicus and is one of only two species of rhinos in the Rhinoceros genus, the other being the Indian rhinoceros (Rhinoceros unicornis).

The genus name, Rhinoceros, comes from the ancient Greek word, rhino or rhis, meaning nose and ceros or ceras, meaning horn.

Sondaicus comes from Latin as icus indicates a locality. Sonda refers to the Sunda islands in Indoneisa and means Java.

The Javan rhinoceros is also known as the lesser one-horned rhinoceros, in contrast to the Indian rhinoceros being called the great one-horned rhinoceros. Both of these rhinos have a single horn, but the Javan’s is smaller than the Indian’s.

TAXONOMY

There are three recognized subspecies of the Javan rhinoceros, though two are now extinct.

The Lesser Indian Javan rhinoceros (R. s. inermis) subspecies formerly occurred in northeastern India, Bangladesh, and Myanmar, but is now extinct.

The Vietnamese Javan rhinoceros (R. s. annamiticus) subspecies formerly occurred in Vietnam, Laos, Cambodia, and eastern Thailand. Following the Vietnam war, the Vietnamese Javan rhinoceros was thought to be extinct as Agent Orange, land mines, and general warfare decimated the rhinoceros population, but in 1999, a population of 7-15 was discovered. The population was then restricted to the area in and around the Cat Loc part (Dong Nai province) of the Cat Tien National Park in Vietnam, but was officially declared extinct in 2011 after the last rhino was found dead in 2010. It had been shot and its horn had been removed.

The last remaining extant subspecies of the Javan rhinoceros, the Indonesian Javan rhinoceros (R. s. sondaicus), currently only occurs in one small isolated area, within Ujung Kulon National Park on the Ujung Kulon Peninsula, which forms the westernmost extremity of the island of Java in Indonesia. It has been restricted to this area since around the 1930s, but it formerly occurred from Thailand through Malaysia, to the islands of Java and Sumatra.

 

GEOGRAPHIC RANGE

 

 

REGION

The Javan rhinoceros historically roamed across a vast swathe of Asia from northeastern India through Bangladesh, Myanmar, Thailand, Laos, Cambodia, and Vietnam through peninsular Malaya to Sumatra and Java. It probably lived in southern China, as well. The species’ precise historical range is indeterminate, as early accounts failed to distinguish rhinos to specific level, due to partial sympatry with the other two Asian rhino species, the Indian rhinoceros (Rhinoceros unicornis) and Sumatran rhinoceros (Dicerorhinus sumatrensis). Over the past 150 years, beginning in the middle of the 19th century, the species was extirpated from most of its historical range and its population shrank dramatically.

The Lesser Indian Javan rhinoceros (R. s. inermis) subspecies formerly occurred in northeastern India, Bangladesh, and Myanmar, but is now extinct.

The Vietnamese Javan rhinoceros (R. s. annamiticus) subspecies formerly occurred in Vietnam, Laos, Cambodia, and eastern Thailand. It was once restricted to the area in and around the Cat Loc part (Dong Nai province) of the Cat Tien National Park in Vietnam, but is also now extinct.

The last remaining extant subspecies of the Javan rhinoceros, the Indonesian Javan rhinoceros (R. s. sondaicus), currently only occurs in one small isolated area, within Ujung Kulon National Park on the Ujung Kulon Peninsula, which forms the westernmost extremity of the island of Java in Indonesia. It has been restricted to this area since around the 1930s, but it formerly occurred from Thailand through Malaysia, to the islands of Java and Sumatra.

HABITAT

The Javan rhinoceros is a lowland species that typically occurs up to 600 meters, but has been recorded above 1,000 meters. It currently occurs in incredibly dense, low-lying tropical rainforest areas, especially in the vicinity of waters, as it prefers areas with abundant water and mud wallows.

Because of its rarity, little is known about the Javan rhino’s biology and preferred habitat, but it’s certainly not naturally restricted to dense tropical forest water. The species formerly occurred in more open mixed forest and grassland and on high mountains. Unfortunately, the habitat in which the last remaining population resides may not be optimal.

 

CO-HABITANTS

 

BEHAVIOR

The Javan rhinoceros is fairly solitary, except when pairs form for mating and when mothers tend their young. They especially prefer areas with abundant water and mud wallows and enjoy wading in waters for hours at a time, almost entirely submerged.

Javan rhinoceroses keep home ranges that extend between 3-20 square miles, with various groups having ranges the overlap one another. The home range size of females is probably no more than 500 ha, while males wander over larger areas, with likely limited dispersal distance.

 

DIET

Javan rhinoceroses appear to be more adaptable feeders than other rhino species. In the tropical rainforest, where the species now survives, it’s a pure, herbivorous browser, but it was possibly a mixed feeder and both browsed and grazed on leaves, young shoots, twigs, and fruit in other parts of its historic range.

The Javan rhinoceros is herbivorous and eats an estimated 50 kilograms, or 110 pounds, of food daily. It feasts on diverse plant species, especially their shoots, twigs, young foliage, and fallen fruit. Most of the plants favored by the species grow in sunny areas in forest clearings, shrubland, and other vegetation types with no large trees.

In order to reach its food, the Javan rhinoceros will knock down saplings and utilize its unique, prehensile upper lip that functions as an aid for feasting on leaves.

Like the Sumatran rhino (Dicerorhinus sumatrensis), the Javan rhinoceros needs salt in its diet. The salt licks that were once common in its historical range do not exist in Ujung Kulon National Park, where the rhinos currently exist, but the ungulates there have been observed drinking seawater, likely for the same nutritional need.

 

REPRODUCTION

The Javan rhinoceros’ mating season occurs roughly from July to November.

Because of its rarity, little is known about the Javan rhinoceros’ reproduction and mating system. The gestation period, inter-birth intervals, and sexual maturity is currently unknown and must be presumed based on information from closely related rhinoceros species, such as the Indian rhinoceros (Rhinoceros unicornis).

It is assumed that female Javan rhinoceroses become sexually mature between three-six years and males after six years, possibly as late as ten years old. It is also assumed that the gestation period is approximately 15-16 months.

The Javan rhinoceros has never been bred in captivity.

Mother Javan rhinoceroses are estimated to give birth to a single calf approximately every 2-3 years.

A young Javan rhino will be active shortly after birth and will be suckled by its mother for one to two years.

 

SEXUAL MATURITY
Females 3-6 Years
Males 6-10 Years
BREEDING SEASON
July-November
GESTATION
15-16 Months

 

 

ECOSYSTEM ROLES

The main cause of decline in the Javan rhinoceros is the excessive demand for rhino horn and other products for Chinese and allied medicine systems. Eastern Asian medicine views rhino horns as an important, if not essential part, of medicine. 60% of Eastern Asian doctors stock rhino horn, with Asian horns being preferred over their African counterparts. In this part of the world, one kilogram of rhino horn sells for approximately $60,000.

During colonial times, Javan rhinos were killed across their range by trophy hunters. More recently, they’ve been relentlessly poached, like other rhino species, for their horns and meat. Poaching ultimately wiped out the species in Vietnam and remains an ever-present threat to the last rhinos in Java. Javan rhinos face a constant threat from poachers, though evidence suggests that current poaching levels are under control.

 

PREDATORS

STATUS
LC NT VU EN CR EW EX

The Javan rhinoceros is the most endangered species of the rhinoceros family and probably the rarest large mammal in the world. It is rarely seen as there are approximately 46-67 individuals surviving. The rhino is listed as Critically Endangered on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species because there are less than 50 mature individuals and fewer than 250 mature individuals with no subpopulation greater than 50. The species was experiencing a continuing decline, but has recently begun increasing its numbers. For decades, Javan rhino population estimates have hovered around 40-50 animals, but the most recent camera trap data show that there are now between 63 and 67 animals. With such a small population of Javan rhinoceros left in the world, however, the prospects for the survival of the species are not good.

 

THREATS

The main cause of decline in the Javan rhinoceros is the excessive demand for rhino horn and other products for Chinese and allied medicine systems. Javan rhinos also face a constant threat from poachers, though evidence suggests that current poaching levels are under control. The Javan rhinoceros is also threatened by the invasive Arenga palm, which is having a devastating impact on the plants the rhino relies on for food.

Unfortunately, the last remaining population of Javan rhinoceroses that occurs within Ujung Kulon National Park may be limited to the effective carrying capacity of the area, around 50 animals. With so few animals, there is low genetic diversity and the likelihood of inbreeding is great, which could increase the likelihood of birth defects or disease. It is also not known how many of the rhinos are females; if there are few females left, their death could mean the end of the species.

Because all remaining Javan rhinoceroses are restricted to one small location, the population faces the threat of natural disasters. Should an environmental catastrophe, such as a forest fire, volcano, earthquake, or disease affect the population, dire consequences could result.

Lastly, although the land on which the Javan rhino lives is currently protected, there is pressure to use the land for agricultural purposes. Many people in the Javan rhinoceros’ homelands, especially in Vietnam, have cleared the lands for agricultural purposes. Surrounding forests are still under pressure from human activities and the Javan rhino has now lost most of its forest habitat over the last century due to habitat loss and degradation.

CONSERVATION

The Javan rhinoceros is legally protected in all range states and the species has been on CITES Appendix I since 1975. Ujung Kulon National Park, where the last remaining population of Javan rhinoceroses inhabit, is also currently protected.

The International Rhino Foundation (IRF) has funded a Rhino Protection Unit (RPU) in Ujung Kulon National Park in order to guard and protect the Javan rhinos from poaching.

In order to give the species a greater chance of long-term survival, authorities are now working with the World Wildlife Fund for Nature (WWF) and other organizations in order to study the feasibility of translocating and reintroducing rhinos from Ujung Kulon National Park to establish a second population in another suitable and secure habitat. This urgently-needed second population could ease the pressure on Ujung Kulon, offer breeding space for the Javan rhino, and provide the best possible hope for the species’ survival.

As early as 1962, WWF pioneered scientific research on the Javan rhinoceros. The organization is continuing to conduct important studies today, helping to reveal critical information on the rhino’s behavioral patterns, distribution, population size, sex ratio, and genetic diversity. There is also a need to survey parts of the Javan rhinos historical range for the very remote possibility that small remnant populations exist, especially in parts of Laos or Cambodia.

WWF supports anti-poaching patrols in Indonesia’s Ujung Kulon National Park with its Wildlife Crime Initiative. The organization recommends consumers don’t purchase rhinoceros horn products as the illegal trade in rhinoceros horn continues to pose one of the greatest threats to the Javan rhinoceros today.

WWF is also conducting studies to increase the availability of the rhino’s natural food supply by halting and reversing the invasion of Arenga palm.

Lastly, WWF is also supporting efforts to enhance the rhino’s existing habitat by reducing human encroachment and competition for food with banteng (Bos javanicus). It urges consumers to use and support sustainable wood, paper, and palm oil by purchasing certified sustainable products. FSC-certified forest products, retailers, traders, and manufacturers can help protect the Javan rhinoceros’ habitat and consumers can play their part by demanding certified products.

 

IMAGES

 

 

FAUNAFACTS
Javan Rhinoceros Javan Rhinoceros - The Javan rhinoceros' hairless skin is a dusky, hazy grey and contains tough folds that create an armor-like plating.
Javan Rhinoceros Javan Rhinoceros - The Javan rhinoceros' single horn is the smallest of all rhinos, growing to a length of 25cm (10in).
Javan Rhinoceros Javan Rhinoceros - The Javan rhinoceros population in Ujung Julon National Park has been increasing over the past 5 years and the feasibility of establishing a second population in another suitable, secure habitat is being considered.

 

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SOURCES

Foose, T. J., & van Strien, N. (Eds). (1997). Asian Rhinos. Status Survey and Conservation Action Plan. Gland, Switzerland: IUCN/SSC Asian Rhino Specialist Group.
Grubb, P. (2005). Artiodactyla. In: D. E. Wilson & D. M. Reeder (Eds.), Mammal Species of the World: A Taxonomic and Geographic Reference (3 ed.) (pp. 637-722). Baltimore, MD: Johns Hopkins University Press.
Hariyadi, A. R. S., Priambudi, A., Setiawan, R., Daryan, A. S., Yayus, Asep, & Purnama, H. (2011, January-June). Estimating the population structure of Javan rhinos (Rhinoceros sondaicus) in Ujung Kulon National Park using the markrecapture method based on video and camera trap identification. Pachyderm, 49, 90-99.
Hoogerwerf, A. (1970). Udjung Kulon: The Land of the Last Javan Rhinoceros. Leiden, The Netherlands: E. J. Brill.
Hutchins, M., & Kreger, M. D. (2006). Rhinoceros behaviour: Implications for captive management and conservation. International Zoo Yearbook, 40 (1), 150–173. doi:10.1111/j.1748-1090.2006.00150.x.
International Rhino Foundation (IRF). (2011). Javan Rhino. International Rhino Foundation.
Nowak, R. M. (1999). Walker’s Mammals of the World (6 ed., Vol. 2). Baltimore: MD: John Hopkins University Press.
Rookmaaker, L. C., Jones, M. L., Kloes, H. G., & Reynolds, R. J. (1998). The rhinoceros in captivity: A list of 2439 rhinoceroses kept from Roman times to 1994. The Hague, The Netherlands: SPB Academic Publishing bv.
Schenkel, R., Schenkel-Hulliger, L., & Ramono, W. S. (1978). Area management for the Javan rhinoceros (Rhinoceros sondaicus Desm.): A pilot study. The Malayan Nature Journal, 31, 253-275.
van Strien, N. J., Steinmetz, R., Manullang, B., Han Sectionov, K. H., Isnan, W., Rookmaaker, K., Sumardja, E., Khan, M. K. M. & Ellis, S. (2008). Rhinoceros sondaicus. The IUCN Red List of Threatened Species 2008: e.T19495A8925965. http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T19495A8925965.en.
Waters, M. (2000). “Rhinoceros sondaicus“. Animal Diversity Web.
Wilson, D. E. & Reeder, D. M. (2005). Mammal Species of the World: A Taxonomic and Geographic Reference (3 ed.). Baltimore, MD: Johns Hopkins University Press.

Wikipedia. (2019, March 26). Javan rhinoceros. Wikipedia: The Free Encyclopedia.
World Wide Fund For Nature (WWF). (2015). Javan Rhino. WWF.

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