Rhinoceros sondaicusJavan rhinoceros

Geographic Range

The Javan rhino, Rhinoceros sondaicus, is also known as the lesser-one horned rhino. The historical range of the Javan rhino is believed to have included southeastern areas of Asia. In the past, the Javan rhino ranged from the highest northern parts of Burma and quite possibly extended to present-day eastern Vietnam. However, it is known that the Javan species also inhabited all areas of Sumatra. It was also found in the north and northeastern region of Thailand, extending into Cambodia. It is possible that the rhino's range included the southern Malaysian peninsula. The rhino once inhabited the majority of the Javan island.

Today, its only known location is in the Udjong Kulon Nature Reserve, located in the furthest southwestern areas of Java, where some 50 individuals remain. There is also a small (less than 10 individuals) population in the Cat Tien National Park in Viet Nam. (Barbour and Glover, 1932; Penny, 1988; Schenkel and Schenkel-Hulliger, 1969)

Habitat

Javan rhinos are most commonly found in tropical forests that are generally close to sea level. Rhinoceros sondaicus thrives in the lowland, grassy fields close to a water source where it typically spends most of the day wallowing.

This lowland species may be found at elevations up to 1000m, but it's much more common below 600m. (Enright, 2008; van Strein, et al., 2008)

  • Range elevation
    1000 (high) m
    3280.84 (high) ft
  • Average elevation
    600 m
    1968.50 ft

Physical Description

Rhinoceros sondaicus is also known as the lesser one-horned rhinoceros, as its horn is smaller than any of the other rhino species. Mature males have only one horn that is 25 cm long, while females lack a horn entirely. The horn has no attachment to the bone structures of the skull. The Javan rhino has a grey hide with multiple rigid folds that come together to form sectionalized creases.

Unlike Rhinoceros unicornis (Indian rhinoceros), the Javan rhino has a dorsal crease rather than one originating from the neck. The folds of the Javan rhino are present on the shoulder, the back, and the hind end. The horn shares the same color of the hide.

Rhinoceros sondaicus averages about 1.7m at the shoulder. Its length may vary between 2.0-4 m. Males and females have a similar average body mass. However, some measurements of heads indicate that females are larger. The body mass of both sexes can range from 1500-2000 kg.

Despite being virtually hairless, the Javan rhino does have sparse hairs around the nose and horn. The 70-cm tail has a patch of hair at the end.

As a forager, the rhino has developed an elongated upper lip that extends out and over the bottom lip. Is has large incisor teeth; however, no information on the description of the incisors has been published.

Much of the historical information about physical description on the rhino is questionable as it had been mistaken for the Sumatran rhinoceros, Dicerorhinus sumatrensis through the late 1800's. (Clauss, et al., 2003; Enright, 2008; Nowak, 1999)

  • Range mass
    1500 to 2000 kg
    3303.96 to 4405.29 lb
  • Range length
    2 to 4 m
    6.56 to 13.12 ft

Reproduction

Mating behavior in Rhinoceros sondaicus has only been observed on a few accounts, but it is thought to be polygynandrous. Male and female Javan rhinos fight and produce loud roars, presumably a type of courtship. One pairs had been observed tearing up vegetation together, followed by a pursuit of over 200m.

Other species of rhinos like the Indian rhino (Rhinoceros unicornis) have extensive ritualized behaviors prior to copulation, occasionally resulting in serious injury. (Groves and Leslie Jr., 2011)

Male rhinos will "whistle" to attract females in the area; typically the loudest whistle is associated with the most dominant male.

Javan rhinos breed year-round, producing one calf at a time. The calf is weaned within 1-2 years. The breeding interval is once every 4-5 years, due to a 16-month gestation period and a lengthy period of mother-calf interaction.

Rhinos of this species attain sexual maturity as early as 5-7 years of age for females, and 10 years of age in males.

Only anecdotal information is available regarding growth and rate of maturity. In one case, a fetus was noted to be 17cm and presumed to be halfway through gestation. In a second case, a young rhino, in which the age was not specified, was 130cm in length. It was fully grown by the age of 4 and had reached 170cm in length. (Barbour and Glover, 1932; Groves and Leslie Jr., 2011; Hariyadi, et al., 2011; van Strein, et al., 2008)

  • Breeding interval
    Once every 4-5 years
  • Breeding season
    year-round
  • Range number of offspring
    1 (high)
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    16 months
  • Average gestation period
    502 days
    AnAge
  • Range weaning age
    12 to 24 months
  • Average time to independence
    2 years
  • Range age at sexual or reproductive maturity (female)
    5 to 7 years
  • Average age at sexual or reproductive maturity (male)
    10 years

A cow will stay with the calf for up to two years post-partum. The calf feeds from the mother shortly after walking is achieved, which is 1-2 hours after birth. The bull has no parental investment beyond mating. (Barbour and Glover, 1932; Hariyadi, et al., 2011)

  • Parental Investment
  • female parental care
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Records on the longevity of Rhinoceros sondaicus do not exist. It is predicted that they could reach 30-40 years of age in the wild. A specific captive rhino lived to 21 years and died in 1907. The species is known for its lower lifespan when placed in captivity. A pair of rhinos kept at a London zoo only lived to 11 and 14. The expected lifespan in captivity is about 10-20 years. (Enright, 2008; Groves and Leslie Jr., 2011)

  • Range lifespan
    Status: captivity
    11 to 21 years
  • Typical lifespan
    Status: wild
    30 to 40 years
  • Typical lifespan
    Status: captivity
    10 to 20 years

Behavior

Rhinoceros sondaicus is generally solitary. The majority of is spent wallowing in order to keep its hide moisturized. Inhibition of wallowing may result in possible bacterial and disease issues.

Researcher Yahya found no difference in wallowing behavior between the sexes. While wallowing, the rhino will stand or sit. The Javan rhino will roll in the mud and rub its horn into the sediment, generally understood as an attempt to deepen the watering hole. The horn helps protect the rhino in dense brush areas. The rhino will also sleep while wallowing.

Javan rhinos will perform various bouts that are not seen to be used for communication. Rubbing their horn against a solid surface (like a tree), shaking their head, and moving their ears are typical gestures. The Javan rhino uses many aggressive behaviors, like attacking and/or charging a threat. The rhinos will also concentrate on a supposed threat and not move to indicate their refusal to step back and give up their ground. This aggressive behavior is generally seen in the bulls, accompanied by loud roaring.

There are some behaviors in the rhino solely categorized by interactions between a cow and her calf. If a threat arises, the cow will stand in between the threat and her calf in an offensive manner. In other instances, a cow was seen rushing toward her young when a supposed threat was detected. (Enright, 2008; Penny, 1988)

Home Range

Javan rhinos may travel up 20 km in a span of one day, browsing for suitable food items.

The predicted size of the home range for a female is a maximum of 500 ha or 5 square km. It's suspected that male home ranges are even larger. For example, a single male was recorded using an area of 100 square kilometers.

The Javan rhino does not defend a specific territory. Males will secrete a orange-red urine onto vegetation around the area they are occupying.

Population density is low in the Udjong Kulon Park at 0.30 rhinos per square kilometer. In this park, individuals move 0.4-3.8 km per day. Females overlap often while males rarely overlap, especially those that have made a clear defined trail. (Groves and Leslie Jr., 2011; Nowak, 1999; van Strein, et al., 2008)

Communication and Perception

Rhinoceros sondaicus does not have strong visual perception. Therefore, it predominately uses its sense of smell and hearing.

The Javan rhino communicates via chemical methods by spreading bodily secretions throughout the environment to display dominance or protection of territory. Such secretions include defecating on or nearby another Javan rhino's previous defacating site, most likely done more by dominant males. The Javan rhinos are also found to relieve their bowels in some form of water the majority of the time. It is also frequently done in wallows.

The Javan rhino is able to produce an array of sounds that have a distinct meaning. The various acoustics produced by the Javan rhino include a "neigh," a "bleat," a "shriek," "lip vibrations" and a "snort" (Groves and Leslie Jr., 2011). There are some accounts of loud growling that can be heard >600m away.

Generally solitary, it will interact while attracting mates by displays of fighting. The mother of a newborn will stay with its calf for over two years. (Groves and Leslie Jr., 2011; Hutchins and Kreger, 2006; Nowak, 1999; Penny, 1988)

Food Habits

Rhinoceros sondaicus is an herbivore, but does not eat grasses. While the Javan rhino can eat bamboo and some plants with sharp structures, this rhino will preferably consume softer vegetation such as some figs Ficus variegata and guest tree Kleinhovia variegata.

This rhino may resort to extreme methods to access food. Some have been seen bending taller plants to reach the desired food. There are some accounts of the rhinos saddling themselves on a tree's base and then working their way to the top until the tree is bent and the vegetation is accessible.

Low and tropical forested areas have a higher density of toxic plants and the Javan rhinoceros is able to ingest certain kinds of toxic plants in large quantities. (Nardelli, 2013; Penny, 1988)

  • Plant Foods
  • leaves
  • wood, bark, or stems
  • fruit

Predation

Aside human destruction of habitat and illegal poaching, there are no known predators of Javan rhinos. The now extinct Javan tiger (Panthera tigris sondaica) was capable of killing a stranded calf less than six months old. (Groves and Leslie Jr., 2011; Penny, 1988)

  • Known Predators
    • Javan tigers (Panthera tigris sondaica)
    • humans (Homo sapiens)

Ecosystem Roles

Due to the rarity of the Javan rhino, it is no longer sympatric with the banteng, Bos javanicus, as well as the Sumatran rhino Dicerorhinus sumatrensis. The Javan rhino was once competitive with these species. The Javan tiger, Panthera tigris, once preyed on the young of Javan rhinos.

Parasitic organisms have been detected in the feces of Rhinoceros sondaicus. Organisms in the Amblyomma (ticks) and Tabanus (roundworms) genera have been found in and on the Javan rhino.

Rhinoceros sondaicus will typically affect the environment by laying trails by stomping and breaking vegetation. (Groves and Leslie Jr., 2011; Penny, 1988)

Commensal/Parasitic Species

Economic Importance for Humans: Positive

The horn of the Javan rhino has been greatly sought after in many cultures. The horns of Asian rhino species are worth up to 10 times their African counterparts. The horns are used for medical purposes in Chinese remedies as a fever reducer. Other non-legitimate purposes include snake bite cures, Indian aphrodisiacs and a natural detector of poisonous substances. It is believed that the reaction occurring from poisonous substances is from the high concentration of calcium. However, no real medical values have ever been confirmed. (Groves and Leslie Jr., 2011)

Economic Importance for Humans: Negative

There are no negative effects by Rhinoceros sondaicus on human populations.

Conservation Status

The IUCN Redlist placed the Javan rhino as critically endangered in 2008. With only 60 individuals in the Ujong Kulon National Park, less than 10 in Viet Nam, and none in captivity, the Javan rhino faces extinction without the necessary conservation. This makes the Javan rhino the rarest rhino species, behind the Sumatran rhino, Dicerorhinus sumatrensis. The last captive Javan rhino died in 1907. None are kept in captivity due to the Javan rhino's diminished lifespan in zoo environs.

In the early 1800's extensive poaching and habitat loss began in most of the areas inhabited by Rhinoceros sondaicus. There are some biological influences that threaten this population, like a few seismic volcanoes in Java that could potentially wipe out the species in the event of an eruption.

The Asian Rhino Specialist Group has established a plan of action to increase the population. This plan includes relocating a few individuals to a new breeding area. However, natural reproduction has not been documented in the existing population in Viet Nam; it's been suggested that the remaining individuals (perhaps just 6) are either all the same sex or too old to breed.

More planning is needed before real actions are taken.

CITES lists the Javan rhino under appendix I. All species in this category are considered to be threatened with possible extinction. Import and export of any part of this species is generally not allowed. Commercial use of the species is forbidden.

The Federal Endangered Species List listed the Javan rhino as endangered before the Endangered Species Act was passed. The Federal Register recognizes that the species is endangered under the list of Endangered Foreign Species. However, Rhinoceros sondaicus does not actually appear on the Federal list. (Groves and Leslie Jr., 2011; Scriabine, 1982; van Strein, et al., 2008)

Contributors

Matt Crider (author), Radford University, Karen Powers (editor), Radford University, April Tingle (editor), Radford University, Emily Clark (editor), Radford University, Cari Mcgregor (editor), Radford University, Jacob Vaught (editor), Radford University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

Glossary

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

drug

a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

sexual ornamentation

one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.

solitary

lives alone

tactile

uses touch to communicate

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

vibrations

movements of a hard surface that are produced by animals as signals to others

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

Amin, R., K. Thomas, R. Emslie, T. Foose, N. Van Strein. 2006. An overview of the conservation status of and threats to rhinoceros species in the wild. International Zoo Yearbook, 40/1: 96-117.

Barbour, T., M. Glover. 1932. The lesser one-horned rhinoceros. Journal of Mammalogy, 13/2: 144-149.

Clauss, M., R. Frey, B. Keifer, M. Lechner-Doll, W. Loehlein, C. Polster, G. Rössner, W. Streich. 2003. The maximum attainable body size of herbivorous mammals: morphophysiological constraints on foregut, and adaptations of hindgut fermenters. Oecologia, 136/1: 14-27.

Enright, K. 2008. Rhinoceros. London, UK: Reaktion Books LTD.

Groves, C., D. Leslie Jr.. 2011. Rhinoceros sondaicus (Perissodactyla: Rhinocerotidae). Mammalian Species, 884/888: 190-208.

Hariyadi, A., A. Priambudi, R. Setiawan, D. Daryan, A. Yayus, H. Purnama. 2011. Estimating the population structure of Javan rhinos (Rhinoceros sondaicus) in Ujung Kulon National Park using the mark-recapture method based on video and camera trap identification. Pachyderm, 49: 90-99.

Hariyadi, A., R. Setiawan, A. Daryan, H. Purnama. 2010. Preliminary behaviour observations of the Javan rhinoceros (Rhinoceros sondaicus) based on video trap surveys in Ujung Kulon national park. Pachyderm, 47: 93-99.

Hermes, R., F. Göritz, W. Streich, T. Hildebrandt. 2007. Assisted reproduction in female rhinoceros and elephants – current status and future perspective. Reproduction in Domestic Animals, 42/1: 33-44.

Hutchins, M., M. Kreger. 2006. Rhinoceros behaviour: implications for captive management and conservation. International Zoo Yearbook, 40/1: 150-173.

Nardelli, F. 2013. The mega-folivorous mammals of the rainforest: Feeding ecology in nature and in a controlled environment: a contribution to their conservation. International Zoo News, 6/5: 323-339.

Nowak, R. 1999. Walker's Mammals of the World, 6th Edition: Volume 1. Baltimore, Maryland: Johns Hopkins University Press.

Palmieri, J., P. Ammaun, H. Ammaum. 1980. Parasites of the lesser one-horned rhinoceros (Rhinoceros sondaicus Desmarest). The Journal of Parasitology, 66/6: 1031.

Penny, M. 1988. Rhinos: Endangered Species. New York, NY: Facts on File Inc.

Raloff, J. 1999. Rarest of the rare: remote-camera images and dung-heap data give a portrait of Vietnam's rhinos. Science News, 156/1: 153-155.

Schenkel, R., L. Schenkel-Hulliger. 1969. The Javan Rhinoceros. Udjung Kulon Nature Reserve: Verlag für Recht und Gesellschaf.

Scriabine, R. 1982. IUCN and Indonesia: over 20 years of cooperation. The World's Protected Areas, 11/5: 318-320.

Taylor, L., T. Kaiser, C. Schwitzer, D. Müller, D. Codron, M. Clauss, E. Schulz. 2013. Detecting inter-cusp and inter-tooth wear patterns in rhinocerotids. PLoS ONE, 8/12: 1-12.

Willerslev, E., T. Gilbert, J. Binladen, I. Ho, P. Campos, A. Ratan, L. Tomsho, R. da Fonseca, A. Sher, T. Kuznetsova, M. Nowak-Kemp, T. Roth, W. Miller, S. Schuster. 2009. Analysis of complete mitochondrial genomes from extinct and extant rhinoceroses reveals lack of phylogenetic resolution. BMC Evolutionary Biology, 9/95: 1-11.

van Strein, ., R. Steinmetz, B. Manullang, K. Sectionv, K. Han, W. Isnan, K. Rookmaaker, E. Sumardja, M. Khan, S. Ellis. 2008. "Rhinoceros sondaicus" (On-line). Accessed March 03, 2015 at http://www.iucnredlist.org/details/full/19495/0.