Javan Rhinoceros
Encyclopedia
The Javan Rhinoceros or Lesser One-horned Rhinoceros (Rhinoceros sondaicus) is a member of the family Rhinocerotidae and one of five extant rhinoceros
es. It belongs to the same genus as the Indian Rhinoceros
, and has similar mosaicked skin which resembles armor, but at 3.1–3.2 m (10–10.5 feet) in length and 1.4–1.7 m (4.6–5.8 ft) in height, it is smaller. (In fact, it is closer in size to the Black Rhinoceros
of the genus Diceros.) Its horn is usually less than 25 cm (10 inches), smaller than those of the other rhino species.
Once the most widespread of Asian rhinoceroses, the Javan Rhinoceros ranged from the islands of Java
and Sumatra
, throughout Southeast Asia, and into India and China. The species is critically endangered
, with only one known population in the wild, and no individuals in captivity. It is possibly the rarest large mammal on earth, with a population of as few as 40 in Ujung Kulon National Park
on Java
in Indonesia
. A second population in Cat Tien National Park
in Vietnam
was confirmed as extinct in 2011. The decline of the Javan Rhinoceros is attributed to poaching, primarily for their horns, which are highly valued in traditional Chinese medicine
, fetching as much as $30,000 per kilogram on the black market. Loss of habitat, especially as the result of wars, such as the Vietnam War
, in Southeast Asia, has also contributed to the species's decline and hindered recovery. The remaining range is within one nationally protected area, but the rhinos are still at risk from poachers, disease and loss of genetic diversity leading to inbreeding depression
.
The Javan Rhino can live approximately 30–45 years in the wild. It historically inhabited lowland rain forest, wet grasslands and large floodplains. The Javan Rhino is mostly solitary, except for courtship and child-rearing, though groups may occasionally congregate near wallows and salt licks. Aside from humans, adults have no predators in their range. The Javan Rhino usually avoids humans, but will attack when it feels threatened. Scientists and conservationists rarely study the animals directly due to their extreme rarity and the danger of interfering with such an endangered species. Researchers rely on camera trap
s and fecal samples to gauge health and behavior. Consequently, the Javan Rhino is the least studied of all rhino species. Two adult rhinos with their calves were filmed in a motion-triggered video released on February 28, 2011 by WWF
and Indonesia's National Park Authority, which proved that it is still breeding in the wild.
s from outside of its region took place in 1787 when two animals were shot in Java. The skulls were sent to the renowned Dutch naturalist Petrus Camper
, who died in 1789 before he was able to publish his discovery that the rhinos of Java were a distinct species. Another Javan Rhinoceros was shot on the island of Sumatra
by Alfred Duvaucel
who sent the specimen to his stepfather Georges Cuvier
, a famous French scientist. Cuvier recognized the animal as a distinct species in 1822, and in the same year it was identified by Anselme Gaëtan Desmarest
as Rhinoceros sondaicus. It was the last species of rhinoceros to be identified. Desmarest initially identified the rhino as being from Sumatra, but later amended this to say his specimen was from Java.
The genus name Rhinoceros, which also includes the Indian Rhinoceros, is derived from Greek
: rhino meaning nose, and ceros meaning horn; sondaicus is derived from sunda
, the biogeographical
region that comprises islands of Sumatra, Java, Borneo
, and surrounding smaller islands. The Javan Rhino is also known as the Lesser One-Horned Rhinoceros (in contrast with the Greater One-Horned Rhinoceros, another name for the Indian Rhino).
There are three distinct subspecies, of which only one is still extant:
Ancestral rhinoceroses first diverged from other Perissodactyls in the Early Eocene. Mitochondrial DNA comparison suggests that the ancestors of modern rhinos split from the ancestors of Equidae
around 50 million years ago. The extant family, the Rhinocerotidae, first appeared in the Late Eocene in Eurasia
, and the ancestors of the extant rhino species dispersed from Asia beginning in the Miocene
.
The Indian and Javan Rhinoceros, the only members of the genus Rhinoceros
, first appear in the fossil record in Asia around 1.6 million–3.3 million years ago. Molecular estimates, however, suggest the species may have diverged much earlier, around 11.7 million years ago. Although belonging to the type genus
, the Indian and Javan Rhinoceros are not believed to be closely related to other rhino species. Different studies have hypothesized that they may be closely related to the extinct Gaindetherium or Punjabitherium. A detailed cladistic
analysis of the Rhinocerotidae placed Rhinoceros and the extinct Punjabitherium in a clade with Dicerorhinus, the Sumatran Rhino. Other studies have suggested the Sumatran Rhinoceros is more closely related to the two African species. The Sumatran Rhino may have diverged from the other Asian rhinos as far back as 15 million years ago.
. The body length of the Javan Rhino (including its head) can be up to 3 to 4 m (9.8 to 13.1 ft), and it can reach a height of 1.4–1.7 m (4.6–5.8 ft). Adults are variously reported to weigh between 900 and 2,300 kg (2,000 and 5,100 lb), although because they are endangered, a study to collect accurate measurements of the animals has never been conducted and is not a priority. There is not a substantial size difference 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.
Like its Indian cousin, the Javan Rhinoceros has a single horn (the other extant species have two horns). Its horn is the smallest of all extant rhinos, usually less than 20 cm (7.9 inches) with the longest recorded only 27 cm (10½ in). The Javan Rhinoceros does not appear to often use its horn for fighting, but instead uses it to scrape mud away in wallows, to pull down plants for eating, and to open paths through thick vegetation. Similar to the other browsing species of rhino (the Black, Sumatran and Indian Rhinoceroses), the Javan Rhino has long, pointed, upper lips which help in grabbing food. Its lower incisor
s are long and sharp; when the Javan Rhino fights it uses these teeth. Behind the incisors, two rows of six low-crowned molars
are used for chewing coarse plants. Like all rhinos, the Javan Rhino smells and hears well but has very poor vision. They are estimated to live for 30 to 45 years.
Its hairless, splotchy gray or gray-brown skin falls in folds to the shoulder, back and rump. The skin has a natural mosaic pattern which lends the rhino an armored appearance. The neck folds of the Javan Rhinoceros are smaller than those of the Indian Rhinoceros, but still form a saddle shape over the shoulder. Because of the risks of interfering with such an endangered species, however, the Javan Rhinoceros is primarily studied through fecal sampling and camera traps. They are rarely encountered, observed or measured directly.
Even the most optimistic estimate suggests there are fewer than 100 Javan Rhinos in the wild. They are considered possibly the most endangered of all large mammals. The Javan Rhinoceros is known to survive in only one place, the Ujung Kulon National Park
on the western tip of Java.
The animal was once widespread from Assam
and Bengal
(where their range would have overlapped with both the Sumatran and Indian Rhino) eastward to Myanmar
, Thailand
, Cambodia
, Laos
, Vietnam
, and southwards to the Malay Peninsula
and the islands of Sumatra
, Java
and possibly Borneo
. The Javan Rhino primarily inhabits dense lowland rain forests, tall grass and reed beds that are plentiful with rivers, large floodplains, or wet areas with many mud wallows. Although it historically preferred low-lying areas, the subspecies in Vietnam has been pushed onto much higher ground (up to 2,000 m or 6,561 ft), probably because of human encroachment and poaching.
The range of the Javan Rhinoceros has been shrinking for at least 3,000 years. Starting around 1000 BC, the northern range of the rhinoceros extended into China, but began moving southward at roughly 0.5 km (0.310686368324903 mi) per year, as human settlements increased in the region. It likely became locally extinct in India in the first decade of the 20th century. The Javan Rhino was hunted to extinction on the Malaysian peninsula by 1932. By the end of the Vietnam War
, the Vietnamese Rhinoceros was believed extinct across all of mainland Asia. Local hunters and woodcutters in Cambodia
claim to have seen Javan Rhinos in the Cardamom Mountains
, but surveys of the area have failed to find any evidence of them. In the late 1980s a small population was found in the Cat Tien area of Vietnam. However, the last individual was shot in 2010.. A population may have existed on the island of Borneo
as well, though these specimens could have been the Sumatran Rhinoceros, a small population of which still lives there.
Males mark their territory with dung piles and by urine spraying. Scrapes made by the feet in the ground and twisted saplings also seem to be used for communication. Members of other rhino species have a peculiar habit of defecating in massive rhino dung piles and then scraping their back feet in the dung. The Sumatran and Javan Rhinoceros, while defecating in piles, do not engage in the scraping. This adaptation in behavior is thought to be ecological; in the wet forests of Java and Sumatra, the method may not be useful for spreading odors.
The Javan Rhino is much less vocal than the Sumatran; very few Javan Rhino vocalizations have ever been recorded. Adult Javan Rhinos have no known predators other than humans. The species, particularly in Vietnam, is skittish and retreats into dense forests whenever humans are near. Though a valuable trait from a survival standpoint, it has made the rhinos difficult to study. Nevertheless, when humans approach too closely, the Javan Rhino becomes aggressive and will attack, stabbing with the incisors of its lower jaw while thrusting upward with its head. Its comparatively anti-social behavior may be a recent adaptation to population stresses; historical evidence suggests that, like other rhinos, the species was once more gregarious.
Loss of habitat because of agriculture has also contributed to its decline, though this is no longer as significant a factor because the rhinoceros only lives in one nationally protected park. Deteriorating habitats have hindered the recovery of rhino populations that fell victim to poaching. Even with all the conservation efforts, the prospects for the Javan Rhinoceros's survival are grim. Because the population is restricted to one small area, they are very susceptible to disease and the problems of inbreeding. Conservation geneticists estimate that a population of 100 rhinos would be needed to preserve the genetic diversity of this conservation reliant species
.
peninsula was devastated by the eruption of Krakatoa
in 1883. The Javan Rhinoceros recolonized the peninsula after the explosion, but humans never returned in large numbers, thus creating a haven. In 1931, as the Javan Rhinoceros was on the brink of extinction in Sumatra, the government of the Dutch Indies declared the rhino a legally protected species, which it has remained ever since. In 1967 when a census was first conducted of the rhinos in Ujung Kulon, only 25 animals were recorded. By 1980 that population had doubled, and has remained steady at about 50 ever since. Although the rhinos in Ujung Kulon have no natural predators, they have to compete for scarce resources with wild cattle which may keep the rhino's numbers below the peninsula's carrying capacity
. Ujung Kulon is managed by the Indonesian Ministry of Forestry. Evidence of at least four baby rhinos was discovered in 2006, the most ever documented for the species.
In March 2011, hidden-camera video was published showing adults and juveniles, indicating recent matings and breeding.
. The tactics used in the combat wrought havoc on the ecosystems of the region: use of napalm
, extensive defoliation from Agent Orange
, aerial bombing and use of landmines. The war also flooded the area with inexpensive weapons. After the war, many poor villagers, who previously relied on methods like pit traps, now had deadly weapons at their disposal, enabling them to become efficient poachers.
In 1988 the assumption of the subspecies extinction was challenged when a hunter shot an adult female, proving the species had somehow survived the war. In 1989, scientists surveyed Vietnam's southern forests to search for evidence of other survivors. Fresh rhinoceros tracks belonging to at least 15 rhinos were found along the Dong Nai River
. Largely because of the rhinoceros, the region they inhabited became part of the Cat Tien National Park in 1992.
By early 2000s, their population was feared to have declined past the point of recovery in Vietnam, with some conservationists estimating that as few as 3–8 rhinos, and possibly no males, survived. Conservationists debated whether or not the Vietnamese Rhinoceros had any chance of survival, with some arguing that rhinos from Indonesia should be introduced in an attempt to save the population, with others arguing that the population could recover.
Genetic analysis of dung samples collected in Cat Tien National Park in a survey from October 2009 to March 2010 showed that only a single individual Javan Rhinoceros remained in the park. In early May 2010, the body of a Javan rhinos was found in the Park. The animal had been shot and its horn removed by poachers. In October 2011 the International Rhino Foundation confirmed that the Javan Rhinoceros was extinct in Vietnam, leaving only the rhinos in Ujung Kulon.
The Javan Rhinoceros never fared well in captivity. The oldest lived to be 20, about half the age the rhinos will reach in the wild. The last captive Javan Rhino died at the Adelaide Zoo
in Australia
in 1907 where the species was so little known that it had been exhibited as an Indian Rhinoceros. Because a lengthy and expensive program in the 1980s and 1990s to breed the Sumatran Rhinoceros
(Dicerorhinus sumatrensis) in zoos failed badly, attempts to preserve the Javan species in zoos are unlikely.
Rhinoceros
Rhinoceros , also known as rhino, is a group of five extant species of odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia....
es. It belongs to the same genus as the Indian Rhinoceros
Indian Rhinoceros
The Indian Rhinoceros is also called Greater One-horned Rhinoceros and Asian One-horned Rhinoceros and belongs to the Rhinocerotidae family...
, and has similar mosaicked skin which resembles armor, but at 3.1–3.2 m (10–10.5 feet) in length and 1.4–1.7 m (4.6–5.8 ft) in height, it is smaller. (In fact, it is closer in size to the Black Rhinoceros
Black Rhinoceros
The Black Rhinoceros or Hook-lipped Rhinoceros , is a species of rhinoceros, native to the eastern and central areas of Africa including Kenya, Tanzania, Cameroon, South Africa, Namibia, Zimbabwe, and Angola...
of the genus Diceros.) Its horn is usually less than 25 cm (10 inches), smaller than those of the other rhino species.
Once the most widespread of Asian rhinoceroses, the Javan Rhinoceros ranged from the islands of Java
Java
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
and Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
, throughout Southeast Asia, and into India and China. The species is critically endangered
Critically endangered
Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...
, with only one known population in the wild, and no individuals in captivity. It is possibly the rarest large mammal on earth, with a population of as few as 40 in Ujung Kulon National Park
Ujung Kulon National Park
Ujung Kulon National Park is located at the western-most tip of Java, Banten, Indonesia. It includes the volcanic island group of Krakatoa and other islands including Panaitan, Handeuleum and Peucang on the Sunda Strait.-Geography:...
on Java
Java
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
in Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
. A second population in Cat Tien National Park
Cat Tien National Park
Cát Tiên National Park is an important national park located in the south of Vietnam, approximately 150 km north of Ho Chi Minh City. It has an area of about 720 km² and protects one of the largest areas of lowland tropical rainforests left in Vietnam.-History:Cát Tiên national park was...
in Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
was confirmed as extinct in 2011. The decline of the Javan Rhinoceros is attributed to poaching, primarily for their horns, which are highly valued in traditional Chinese medicine
Traditional Chinese medicine
Traditional Chinese Medicine refers to a broad range of medicine practices sharing common theoretical concepts which have been developed in China and are based on a tradition of more than 2,000 years, including various forms of herbal medicine, acupuncture, massage , exercise , and dietary therapy...
, fetching as much as $30,000 per kilogram on the black market. Loss of habitat, especially as the result of wars, such as the Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
, in Southeast Asia, has also contributed to the species's decline and hindered recovery. The remaining range is within one nationally protected area, but the rhinos are still at risk from poachers, disease and loss of genetic diversity leading to inbreeding depression
Inbreeding depression
Inbreeding depression is the reduced fitness in a given population as a result of breeding of related individuals. It is often the result of a population bottleneck...
.
The Javan Rhino can live approximately 30–45 years in the wild. It historically inhabited lowland rain forest, wet grasslands and large floodplains. The Javan Rhino is mostly solitary, except for courtship and child-rearing, though groups may occasionally congregate near wallows and salt licks. Aside from humans, adults have no predators in their range. The Javan Rhino usually avoids humans, but will attack when it feels threatened. Scientists and conservationists rarely study the animals directly due to their extreme rarity and the danger of interfering with such an endangered species. Researchers rely on camera trap
Camera trap
A camera trap is a remotely activated camera that is equipped with a motion sensor or an infrared sensor, or uses a light beam as a trigger. Camera trapping is a method for capturing wild animals on film when researchers are not present, and has been used in ecological research for decades...
s and fecal samples to gauge health and behavior. Consequently, the Javan Rhino is the least studied of all rhino species. Two adult rhinos with their calves were filmed in a motion-triggered video released on February 28, 2011 by WWF
World Wide Fund for Nature
The World Wide Fund for Nature is an international non-governmental organization working on issues regarding the conservation, research and restoration of the environment, formerly named the World Wildlife Fund, which remains its official name in Canada and the United States...
and Indonesia's National Park Authority, which proved that it is still breeding in the wild.
Taxonomy and naming
The first studies of the Javan Rhinoceros by naturalistNaturalist
Naturalist may refer to:* Practitioner of natural history* Conservationist* Advocate of naturalism * Naturalist , autobiography-See also:* The American Naturalist, periodical* Naturalism...
s from outside of its region took place in 1787 when two animals were shot in Java. The skulls were sent to the renowned Dutch naturalist Petrus Camper
Petrus Camper
Peter, Pieter, or usually Petrus Camper was a Dutch physician, anatomist, physiologist, midwife, zoologist, anthropologist, paleontologist and a naturalist. He studied the orangutan, the rhinoceros, the skull of a whale...
, who died in 1789 before he was able to publish his discovery that the rhinos of Java were a distinct species. Another Javan Rhinoceros was shot on the island of Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
by Alfred Duvaucel
Alfred Duvaucel
Alfred Duvaucel was a French naturalist and explorer. He was the stepson of Georges Cuvier.- Journeys in South and Southeast Asia :...
who sent the specimen to his stepfather Georges Cuvier
Georges Cuvier
Georges Chrétien Léopold Dagobert Cuvier or Jean Léopold Nicolas Frédéric Cuvier , known as Georges Cuvier, was a French naturalist and zoologist...
, a famous French scientist. Cuvier recognized the animal as a distinct species in 1822, and in the same year it was identified by Anselme Gaëtan Desmarest
Anselme Gaëtan Desmarest
Anselme Gaëtan Desmarest was a French zoologist and author. He was the son of Nicolas Desmarest and father of Anselme Sébastien Léon Desmarest...
as Rhinoceros sondaicus. It was the last species of rhinoceros to be identified. Desmarest initially identified the rhino as being from Sumatra, but later amended this to say his specimen was from Java.
The genus name Rhinoceros, which also includes the Indian Rhinoceros, is derived from Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
: rhino meaning nose, and ceros meaning horn; sondaicus is derived from sunda
Sundaland
Sundaland is a biogeographical region of Southeastern Asia which encompasses the areas of the Asian continental shelf that was exposed during the last ice age. It included the Malay Peninsula on the Asian mainland, as well as the large islands of Borneo, Java, and Sumatra and their surrounding...
, the biogeographical
Biogeography
Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...
region that comprises islands of Sumatra, Java, Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
, and surrounding smaller islands. The Javan Rhino is also known as the Lesser One-Horned Rhinoceros (in contrast with the Greater One-Horned Rhinoceros, another name for the Indian Rhino).
There are three distinct subspecies, of which only one is still extant:
- Rhinoceros sondaicus sondaicus, the type subspecies, known as the Indonesian Javan Rhinoceros, once lived on Java and Sumatra. The population is now confined to as few as 40 animals in the wild, Ujung Kulon National ParkUjung Kulon National ParkUjung Kulon National Park is located at the western-most tip of Java, Banten, Indonesia. It includes the volcanic island group of Krakatoa and other islands including Panaitan, Handeuleum and Peucang on the Sunda Strait.-Geography:...
on the western tip of the island of JavaJavaJava is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
. One researcher has suggested that the Javan Rhino on Sumatra belonged to a distinct subspecies, R.s. floweri, but this is not widely accepted. - Rhinoceros sondaicus annamiticus, known as the Vietnamese Javan Rhinoceros or Vietnamese Rhinoceros, once lived across Vietnam, CambodiaCambodiaCambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...
, LaosLaosLaos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...
and into ThailandThailandThailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
and Malaysia. Annamiticus is derived from the Annamite Mountain RangeAnnamite RangeThe Annamite Range or the Annamese Mountains is a mountain range of eastern Indochina, which extends approximately through Laos, Vietnam, and a small area in northeast Cambodia. It is known in Vietnamese as Dãy Trường Sơn, in Lao as Xai Phou Luang , and in French as the Chaîne Annamitique...
in Southeast Asia, part of this subspecies's range. In 2006, a single population, estimated at fewer than 12 remaining rhinos, lived in an area of lowland forest in the Cat Tien National ParkCat Tien National ParkCát Tiên National Park is an important national park located in the south of Vietnam, approximately 150 km north of Ho Chi Minh City. It has an area of about 720 km² and protects one of the largest areas of lowland tropical rainforests left in Vietnam.-History:Cát Tiên national park was...
in VietnamVietnamVietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
. Genetic analysis suggested that the this subspecies and the Indonesian Javan Rhinoceros last shared a common ancestor between 300,000 and 2 million years ago. The last individual of this population was shot by a poacher in 2010. - Rhinoceros sondaicus inermis, known as the Indian Javan Rhinoceros, once ranged from BengalBengalBengal is a historical and geographical region in the northeast region of the Indian Subcontinent at the apex of the Bay of Bengal. Today, it is mainly divided between the sovereign land of People's Republic of Bangladesh and the Indian state of West Bengal, although some regions of the previous...
to Burma, but is presumed to have gone extinct before 1925. Inermis means unarmed, as the most distinctive characteristic of this sub-species is the small horns in males, and evident lack of horns in females. The original specimen of this species was a hornless female. The political situation in Burma has prevented assessment of the species in that country, but its survival is considered unlikely.
Evolution
Equidae
Equidae is the taxonomic family of horses and related animals, including the extant horses, donkeys, and zebras, and many other species known only from fossils. All extant species are in the genus Equus...
around 50 million years ago. The extant family, the Rhinocerotidae, first appeared in the Late Eocene in Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
, and the ancestors of the extant rhino species dispersed from Asia beginning in the Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
.
The Indian and Javan Rhinoceros, the only members of the genus Rhinoceros
Rhinoceros (genus)
The members of the genus Rhinoceros are the one-horned rhinoceroses. The word "rhinoceros" is of Greek origin; "rhino" meaning "nose", and "ceros" meaning "horn". The genus contains two species, the Indian Rhinoceros and the Javan Rhinoceros...
, first appear in the fossil record in Asia around 1.6 million–3.3 million years ago. Molecular estimates, however, suggest the species may have diverged much earlier, around 11.7 million years ago. Although belonging to the type genus
Type genus
In biological classification, a type genus is a representative genus, as with regard to a biological family. The term and concept is used much more often and much more formally in zoology than it is in botany, and the definition is dependent on the nomenclatural Code that applies:* In zoological...
, the Indian and Javan Rhinoceros are not believed to be closely related to other rhino species. Different studies have hypothesized that they may be closely related to the extinct Gaindetherium or Punjabitherium. A detailed cladistic
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
analysis of the Rhinocerotidae placed Rhinoceros and the extinct Punjabitherium in a clade with Dicerorhinus, the Sumatran Rhino. Other studies have suggested the Sumatran Rhinoceros is more closely related to the two African species. The Sumatran Rhino may have diverged from the other Asian rhinos as far back as 15 million years ago.
Description
The Javan Rhino is smaller than its cousin, the Indian Rhinoceros, and is close in size to the Black RhinocerosBlack Rhinoceros
The Black Rhinoceros or Hook-lipped Rhinoceros , is a species of rhinoceros, native to the eastern and central areas of Africa including Kenya, Tanzania, Cameroon, South Africa, Namibia, Zimbabwe, and Angola...
. The body length of the Javan Rhino (including its head) can be up to 3 to 4 m (9.8 to 13.1 ft), and it can reach a height of 1.4–1.7 m (4.6–5.8 ft). Adults are variously reported to weigh between 900 and 2,300 kg (2,000 and 5,100 lb), although because they are endangered, a study to collect accurate measurements of the animals has never been conducted and is not a priority. There is not a substantial size difference 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.
Like its Indian cousin, the Javan Rhinoceros has a single horn (the other extant species have two horns). Its horn is the smallest of all extant rhinos, usually less than 20 cm (7.9 inches) with the longest recorded only 27 cm (10½ in). The Javan Rhinoceros does not appear to often use its horn for fighting, but instead uses it to scrape mud away in wallows, to pull down plants for eating, and to open paths through thick vegetation. Similar to the other browsing species of rhino (the Black, Sumatran and Indian Rhinoceroses), the Javan Rhino has long, pointed, upper lips which help in grabbing food. Its lower incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
s are long and sharp; when the Javan Rhino fights it uses these teeth. Behind the incisors, two rows of six low-crowned molars
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
are used for chewing coarse plants. Like all rhinos, the Javan Rhino smells and hears well but has very poor vision. They are estimated to live for 30 to 45 years.
Its hairless, splotchy gray or gray-brown skin falls in folds to the shoulder, back and rump. The skin has a natural mosaic pattern which lends the rhino an armored appearance. The neck folds of the Javan Rhinoceros are smaller than those of the Indian Rhinoceros, but still form a saddle shape over the shoulder. Because of the risks of interfering with such an endangered species, however, the Javan Rhinoceros is primarily studied through fecal sampling and camera traps. They are rarely encountered, observed or measured directly.
Distribution and habitat
Ujung Kulon National Park
Ujung Kulon National Park is located at the western-most tip of Java, Banten, Indonesia. It includes the volcanic island group of Krakatoa and other islands including Panaitan, Handeuleum and Peucang on the Sunda Strait.-Geography:...
on the western tip of Java.
The animal was once widespread from Assam
Assam
Assam , also, rarely, Assam Valley and formerly the Assam Province , is a northeastern state of India and is one of the most culturally and geographically distinct regions of the country...
and Bengal
Bengal
Bengal is a historical and geographical region in the northeast region of the Indian Subcontinent at the apex of the Bay of Bengal. Today, it is mainly divided between the sovereign land of People's Republic of Bangladesh and the Indian state of West Bengal, although some regions of the previous...
(where their range would have overlapped with both the Sumatran and Indian Rhino) eastward to Myanmar
Myanmar
Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
, Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
, Cambodia
Cambodia
Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...
, Laos
Laos
Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...
, Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
, and southwards to the Malay Peninsula
Malay Peninsula
The Malay Peninsula or Thai-Malay Peninsula is a peninsula in Southeast Asia. The land mass runs approximately north-south and, at its terminus, is the southern-most point of the Asian mainland...
and the islands of Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
, Java
Java
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
and possibly Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
. The Javan Rhino primarily inhabits dense lowland rain forests, tall grass and reed beds that are plentiful with rivers, large floodplains, or wet areas with many mud wallows. Although it historically preferred low-lying areas, the subspecies in Vietnam has been pushed onto much higher ground (up to 2,000 m or 6,561 ft), probably because of human encroachment and poaching.
The range of the Javan Rhinoceros has been shrinking for at least 3,000 years. Starting around 1000 BC, the northern range of the rhinoceros extended into China, but began moving southward at roughly 0.5 km (0.310686368324903 mi) per year, as human settlements increased in the region. It likely became locally extinct in India in the first decade of the 20th century. The Javan Rhino was hunted to extinction on the Malaysian peninsula by 1932. By the end of the Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
, the Vietnamese Rhinoceros was believed extinct across all of mainland Asia. Local hunters and woodcutters in Cambodia
Cambodia
Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...
claim to have seen Javan Rhinos in the Cardamom Mountains
Cardamom Mountains
The Krâvanh Mountains, literally the "Cardamom Mountains" , is a mountain range in the south west of Cambodia, jutting into southeastern Thailand.-Location and description:...
, but surveys of the area have failed to find any evidence of them. In the late 1980s a small population was found in the Cat Tien area of Vietnam. However, the last individual was shot in 2010.. A population may have existed on the island of Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
as well, though these specimens could have been the Sumatran Rhinoceros, a small population of which still lives there.
Behavior
The Javan Rhinoceros is a solitary animal with the exception of breeding pairs and mothers with calves. They will sometimes congregate in small groups at salt licks and mud wallows. Wallowing in mud is a common behavior for all rhinos; the activity allows them to maintain a cool body temperature and helps prevent disease and parasite infestation. The Javan Rhinoceros does not generally dig its own mud wallows, preferring to use other animals' wallows or naturally occurring pits, which it will use its horn to enlarge. Salt licks are also very important because of the essential nutrients the rhino receives from the salt. Male home ranges are larger at 12–20 km² (5–8 miles²) compared to the female, which are around 3–14 km² (1–5 mi²). Male territories overlap each other less than those of the female. It is not known if there are territorial fights.Males mark their territory with dung piles and by urine spraying. Scrapes made by the feet in the ground and twisted saplings also seem to be used for communication. Members of other rhino species have a peculiar habit of defecating in massive rhino dung piles and then scraping their back feet in the dung. The Sumatran and Javan Rhinoceros, while defecating in piles, do not engage in the scraping. This adaptation in behavior is thought to be ecological; in the wet forests of Java and Sumatra, the method may not be useful for spreading odors.
The Javan Rhino is much less vocal than the Sumatran; very few Javan Rhino vocalizations have ever been recorded. Adult Javan Rhinos have no known predators other than humans. The species, particularly in Vietnam, is skittish and retreats into dense forests whenever humans are near. Though a valuable trait from a survival standpoint, it has made the rhinos difficult to study. Nevertheless, when humans approach too closely, the Javan Rhino becomes aggressive and will attack, stabbing with the incisors of its lower jaw while thrusting upward with its head. Its comparatively anti-social behavior may be a recent adaptation to population stresses; historical evidence suggests that, like other rhinos, the species was once more gregarious.
Diet
The Javan Rhinoceros is herbivorous and eats 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. The rhino knocks down saplings to reach its food and grabs it with its prehensile upper lip. It is the most adaptable feeder of all the rhino species. Currently it is a pure browser but probably once both browsed and grazed in its historical range. The rhino eats an estimated 50 kg (110 lb) of food daily. Like the Sumatran Rhino, it needs salt in its diet. The salt licks common in its historical range do not exist in Ujung Kulon, but the rhinos there have been observed drinking seawater, likely for the same nutritional need.Conservation
The main factor in the continued decline of the Javan Rhinoceros population has been poaching for horns, a problem that affects all rhino species. The horns have been a traded commodity in China for over 2,000 years where they are believed to have healing properties in Traditional Chinese Medicine. Historically, its hide was used to make armor for Chinese soldiers and some local tribes in Vietnam believed the hide can be used to make an antidote for snake venom. Because the rhinoceros's range encompasses many areas of poverty, it has been difficult to convince local people not to kill a seemingly useless animal which could be sold for a large sum of money. When the Convention on International Trade in Endangered Species of Wild Fauna and Flora first went into effect in 1975, the Javan Rhinoceros was placed under complete Appendix 1 protection: all international trade in the Javan Rhinoceros and products derived from it is illegal. Surveys of the rhinoceros horn black market have determined that Asian rhinoceros horn fetches a price as high as $30,000 per kilogram, three times the value of African rhinoceros horn.Loss of habitat because of agriculture has also contributed to its decline, though this is no longer as significant a factor because the rhinoceros only lives in one nationally protected park. Deteriorating habitats have hindered the recovery of rhino populations that fell victim to poaching. Even with all the conservation efforts, the prospects for the Javan Rhinoceros's survival are grim. Because the population is restricted to one small area, they are very susceptible to disease and the problems of inbreeding. Conservation geneticists estimate that a population of 100 rhinos would be needed to preserve the genetic diversity of this conservation reliant species
Conservation reliant species
Conservation reliant species are endangered or threatened animal or plant species that require continuing species specific wildlife management intervention such as predator control, habitat management and parasite control to survive even when self-sustaining population recovery goals are...
.
Ujung Kulon
The Ujung KulonUjung Kulon National Park
Ujung Kulon National Park is located at the western-most tip of Java, Banten, Indonesia. It includes the volcanic island group of Krakatoa and other islands including Panaitan, Handeuleum and Peucang on the Sunda Strait.-Geography:...
peninsula was devastated by the eruption of Krakatoa
Krakatoa
Krakatoa is a volcanic island made of a'a lava in the Sunda Strait between the islands of Java and Sumatra in Indonesia. The name is used for the island group, the main island , and the volcano as a whole. The island exploded in 1883, killing approximately 40,000 people, although some estimates...
in 1883. The Javan Rhinoceros recolonized the peninsula after the explosion, but humans never returned in large numbers, thus creating a haven. In 1931, as the Javan Rhinoceros was on the brink of extinction in Sumatra, the government of the Dutch Indies declared the rhino a legally protected species, which it has remained ever since. In 1967 when a census was first conducted of the rhinos in Ujung Kulon, only 25 animals were recorded. By 1980 that population had doubled, and has remained steady at about 50 ever since. Although the rhinos in Ujung Kulon have no natural predators, they have to compete for scarce resources with wild cattle which may keep the rhino's numbers below the peninsula's carrying capacity
Carrying capacity
The carrying capacity of a biological species in an environment is the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment...
. Ujung Kulon is managed by the Indonesian Ministry of Forestry. Evidence of at least four baby rhinos was discovered in 2006, the most ever documented for the species.
In March 2011, hidden-camera video was published showing adults and juveniles, indicating recent matings and breeding.
Cat Tien
Once widespread in Southeast Asia, the Javan Rhinoceros was presumed extinct in Vietnam in the mid-1970s, at the end of the Vietnam WarVietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
. The tactics used in the combat wrought havoc on the ecosystems of the region: use of napalm
Napalm
Napalm is a thickening/gelling agent generally mixed with gasoline or a similar fuel for use in an incendiary device, primarily as an anti-personnel weapon...
, extensive defoliation from Agent Orange
Agent Orange
Agent Orange is the code name for one of the herbicides and defoliants used by the U.S. military as part of its herbicidal warfare program, Operation Ranch Hand, during the Vietnam War from 1961 to 1971. Vietnam estimates 400,000 people were killed or maimed, and 500,000 children born with birth...
, aerial bombing and use of landmines. The war also flooded the area with inexpensive weapons. After the war, many poor villagers, who previously relied on methods like pit traps, now had deadly weapons at their disposal, enabling them to become efficient poachers.
In 1988 the assumption of the subspecies extinction was challenged when a hunter shot an adult female, proving the species had somehow survived the war. In 1989, scientists surveyed Vietnam's southern forests to search for evidence of other survivors. Fresh rhinoceros tracks belonging to at least 15 rhinos were found along the Dong Nai River
Dong Nai River
Đồng Nai is a river in Vietnam that originates in the Central Highlands of the southern portion of the country. It is approximately 586 km in length.-External links:*, from the UNDP*...
. Largely because of the rhinoceros, the region they inhabited became part of the Cat Tien National Park in 1992.
By early 2000s, their population was feared to have declined past the point of recovery in Vietnam, with some conservationists estimating that as few as 3–8 rhinos, and possibly no males, survived. Conservationists debated whether or not the Vietnamese Rhinoceros had any chance of survival, with some arguing that rhinos from Indonesia should be introduced in an attempt to save the population, with others arguing that the population could recover.
Genetic analysis of dung samples collected in Cat Tien National Park in a survey from October 2009 to March 2010 showed that only a single individual Javan Rhinoceros remained in the park. In early May 2010, the body of a Javan rhinos was found in the Park. The animal had been shot and its horn removed by poachers. In October 2011 the International Rhino Foundation confirmed that the Javan Rhinoceros was extinct in Vietnam, leaving only the rhinos in Ujung Kulon.
In captivity
A Javan Rhinoceros has not been exhibited in zoos in a century. In the 19th century, at least four rhinos were exhibited in Adelaide, Calcutta and London. A total of at least 22 Javan Rhinos have been documented as having been kept in captivity, and it is possible that the number is greater as the species was sometimes confused with the Indian Rhinoceros.The Javan Rhinoceros never fared well in captivity. The oldest lived to be 20, about half the age the rhinos will reach in the wild. The last captive Javan Rhino died at the Adelaide Zoo
Adelaide Zoo
Adelaide Zoo is Australia's second oldest zoo, and the only major metropolitan zoo in Australia to be owned and operated on a non-profit basis. It is located in the parklands just north of the city centre of Adelaide, South Australia. It is a full institutional member of the Zoo and Aquarium...
in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
in 1907 where the species was so little known that it had been exhibited as an Indian Rhinoceros. Because a lengthy and expensive program in the 1980s and 1990s to breed the Sumatran Rhinoceros
Sumatran Rhinoceros
The Sumatran Rhinoceros is a member of the family Rhinocerotidae and one of five extant rhinoceroses. It is the only extant species of the genus Dicerorhinus. It is the smallest rhinoceros, although is still a large mammal. This rhino stands high at the shoulder, with a head-and-body length of ...
(Dicerorhinus sumatrensis) in zoos failed badly, attempts to preserve the Javan species in zoos are unlikely.
External links
- Javan Rhino Info & Javan Rhino Pictures on the Rhino Resource Center
- International Rhino FoundationInternational Rhino FoundationThe International Rhino Foundation is a Yulee, Florida-based charity focused on the conservation of the five species of rhinoceros: the White Rhinoceros and Black Rhinoceros in Africa; the Indian Rhinoceros, Javan Rhinoceros and Sumatran Rhinoceros in Asia....
dedicated to the conservation of rhinos: Javan Rhino - ARKiveARKiveARKive is a global initiative with the mission of "promoting the conservation of the world's threatened species, through the power of wildlife imagery", which it does by locating and gathering films, photographs and audio recordings of the world's species into a centralised digital archive. Its...
- images and movies of the Javan Rhinoceros (Rhinoceros sondaicus) - UNEP & WCMC species sheet on the Javan Rhinoceros.