Sumatran Rhinoceros
Encyclopedia
The Sumatran Rhinoceros (Dicerorhinus sumatrensis) is a member of the family Rhinocerotidae and one of five extant rhinoceros
es. It is the only extant species of the genus
Dicerorhinus. It is the smallest rhinoceros, although is still a large mammal. This rhino stands 112–145 cm (3.7–4.8 ft) high at the shoulder, with a head-and-body length of 2.36–3.17 m (7.7–10.4 ft) and a tail of 35–70 cm (13.8–27.6 in). The weight is reported to range from 500 to 1000 kg (1,102.3 to 2,204.6 lb), averaging 700–800 kg (1,543.2–1,763.7 lb), although there is a single record of a 2000 kg (4,409.2 lb) specimen. Like the African species, it has two horns; the larger is the nasal horn, typically 15–25 cm (5.9–9.8 in), while the other horn is typically a stub. A coat of reddish-brown hair covers most of the Sumatran Rhino's body.
Members of the species once inhabited rainforests, swamp
s and cloud forest
s in India
, Bhutan
, Bangladesh
, Myanmar
, Laos
, Thailand
, Malaysia, Indonesia
, and China
. In historical times they lived in southwest China, particularly in Sichuan
. They are now critically endangered
, with only six substantial populations in the wild: four on Sumatra
, one on Borneo
, and one in the Malay Peninsula
. Their numbers are difficult to determine because they are solitary animals that are widely scattered across their range, but they are estimated to number fewer than 275. The decline in the number of Sumatran Rhinoceros is attributed primarily to poaching for their horns, which are highly valued in traditional Chinese medicine
, fetching as much as US$30,000 per kilogram on the black market
.
The Sumatran Rhino is a mostly solitary animal except for courtship and child-rearing. It is the most vocal rhino species and also communicates through marking soil
with its feet, twisting saplings into patterns, and leaving excrement. The species is much better studied than the similarly reclusive Javan Rhinoceros
, in part because of a program that brought 40 Sumatran Rhinos into captivity with the goal of preserving the species. The program was considered a disaster even by its initiator; most of the rhinos died and no offspring were produced for nearly 20 years, representing an even worse population decline than in the wild.
, in 1793. Drawings of the animal, and a written description, were sent to the naturalist
Joseph Banks
, then president of the Royal Society of London, who published a paper on the specimen that year. It was not until 1814, however, that the species was given a scientific name, by Johann Fischer von Waldheim
, a German
scientist
and curator
of the State Darwin Museum in Moscow
, Russia
.
The scientific name Dicerorhinus sumatrensis comes from the Greek
terms , , and ' onMouseout='HidePop("53938")' href="/topics/Nose">nose
"). Sumatrensis signifies "of Sumatra
", the Indonesia
n island where the rhinos were first discovered. Carolus Linnaeus
originally classified all rhinos in the genus
Rhinoceros; therefore the species was originally identified as Rhinoceros sumatrensis. Joshua Brookes
considered the Sumatran Rhinoceros, with its two horns, a distinct genus from the one-horned Rhinoceros, and gave it the name Didermocerus in 1828. Constantin Wilhelm Lambert Gloger
proposed the name Dicerorhinus in 1841. In 1868, John Edward Gray
proposed the name Ceratorhinus. Normally the oldest name would be used, but a 1977 ruling by the International Commission on Zoological Nomenclature
established the proper genus name as Dicerorhinus.
There are three subspecies
:
D. s. sumatrensis, known as the Western Sumatran Rhinoceros, has only 170-230 rhinos remaining, mostly in the national parks of Bukit Barisan Selatan
and Gunung Leuser
in Sumatra. Around 75 may also live in Peninsular Malaysia
. The main threats against this subspecies are habitat loss and illegal poaching
. There is a slight genetic
difference between the Western and Eastern Sumatran Rhinos. The rhinos in Peninsular Malaysia were once known as D. s. niger, but were later recognized to be similar to the rhinos on western Sumatra.
D. s. harrissoni, known as the Eastern Sumatran Rhinoceros or Bornean Rhinoceros, were once common throughout Borneo
; now only about 50 individuals are estimated to survive. The known population on Borneo lives in Sabah
. There are unconfirmed reports of animals surviving in Sarawak
and Kalimantan
. This subspecies is named after Tom Harrisson
, who worked extensively with Bornean zoology and anthropology in the 1960s. The Bornean subspecies is markedly smaller than the other two.
D. s. lasiotis, known as the Northern Sumatran Rhinoceros, once roamed in India
and Bangladesh
but has been declared extinct in these countries. Unconfirmed reports suggest that there may be a small population still surviving in Burma, but the political situation in the country has prevented verification. The name lasiotis is derived from the Greek for "hairy-ears". Later studies showed that their ear-hair was not longer than other Sumatran Rhinos, but D. s. lasiotis remained a subspecies because it was significantly larger than the other subspecies.
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 Sumatran Rhinoceros is considered the least derived
of the extant species as it shares more traits with its Miocene ancestors. Paleontological evidence in the fossil record dates the genus Dicerorhinus to the Early Miocene, 23–16 million years ago. Many fossils have been classified as members of Dicerorhinus, but there are no other recent species in the genus. Molecular dating suggests a split of Dicerorhinus from the four other extant species as far back as 25.9 ± 1.9 million years. Three hypotheses have been proposed for the relationship between the Sumatran Rhinoceros and the other living species. One hypothesis suggests that the Sumatran Rhinoceros is closely related to the Black and White Rhinos in Africa, evidenced by the species having two horns, instead of one. Other taxonomists regard the Sumatran Rhinoceros as a sister taxon
of the Indian and Javan Rhinoceros because their ranges overlap so closely. A third hypothesis, based on more recent analyses, however, suggests that the two African rhinos, the two Asian rhinos and the Sumatran Rhinoceros represent three essentially separate lineages that split around 25.9 million years ago, and it may therefore be unclear which group diverged first.
Because of morphological similarities, the Sumatran Rhinoceros is believed to be closely related to the extinct Woolly Rhinoceros
(Coelodonta antiquitatis). The Woolly Rhinoceros, so named for the coat of hair it shares with the Sumatran Rhinoceros, first appeared in China and by the Upper Pleistocene ranged across the Eurasian continent from Korea
to Spain
. The Woolly Rhinoceros survived the last Ice Age
, but like the Woolly Mammoth
, most or all became extinct around 10,000 years ago. Although some morphological studies questioned the relationship, recent molecular analysis has supported the two species as sister taxa.
. The Sumatran Rhino lives an estimated 30–45 years in the wild, while the record time in captivity is a female D. lasiotis who lived for 32 years and 8 months before dying in the London Zoo in 1900.
Two thick folds of skin encircle the body behind the front legs and before the hind legs. The rhino has a smaller fold of skin around its neck. The skin itself is thin, 10–16 mm (0.393700787401575–0.62992125984252 in), and in the wild the rhino appears to have no subcutaneous fat. Hair can range from dense (the most dense hair in young calves) to scarce and is usually a reddish brown. In the wild this hair is hard to observe because the rhinos are often covered in mud. In captivity, however, the hair grows out and becomes much shaggier, likely because of less abrasion from walking through vegetation. The rhino has a patch of long hair around the ears and a thick clump of hair at the end of the tail. Like all rhinos, they have very poor vision. The Sumatran Rhinoceros is fast and agile; it climbs mountains easily and comfortably traverses steep slopes and riverbanks.
, swamps and cloud forest
s. It inhabits hilly areas close to water, particularly steep upper valleys with a lot of undergrowth. The Sumatran Rhinoceros once inhabited a continuous range as far north as Burma, eastern India
and Bangladesh
. Unconfirmed reports also placed the Sumatran Rhino in Cambodia
, Laos
and Vietnam
. All known living animals occur in Peninsular Malaysia
, the island of Sumatra
and Sabah
, Borneo
. Some conservationists hope that Sumatran Rhinos may still survive in Burma, though it is considered unlikely. Political turmoil in Burma has prevented any assessment or study of possible survivors. The last reports of stray animals from Indian limits were in 1990s.
The Sumatran Rhino is widely scattered across its range, much more so than the other Asian rhinos, which has made it difficult for conservationists to protect members of the species effectively. Only six areas are known to contain communities of more than a handful of Sumatran Rhinoceros: Bukit Barisan Selatan National Park
, Gunung Leuser National Park
, Kerinci Seblat National Park
, and Way Kambas National Park
on Sumatra; Taman Negara National Park
in Peninsular Malaysia; and the Tabin Wildlife Reserve
in Sabah
, Malaysia on the island of Borneo.
Genetic analysis of Sumatran Rhino populations has identified three distinct genetic lineages. The channel between Sumatra and Malaysia
was not as significant a barrier for the rhinos as the Barisan Mountains
along the length of Sumatra, for rhinos in eastern Sumatra and Peninsular Malaysia are more closely related than the rhinos on the other side of the mountains in western Sumatra. In fact the eastern Sumatra and Malaysia rhinos show so little genetic variance that the populations were likely not separate during the Pleistocene
, when sea levels were much lower and Sumatra formed part of the mainland. Both populations of Sumatra and Malaysia, however, are close enough genetically that interbreeding would not be problematic. The rhinos of Borneo are sufficiently distinct that conservation geneticists
have advised against crossing their lineages with the other populations. Conservation geneticists have recently begun to study the diversity of the gene pool within these populations by identifying microsatellite loci. The results of initial testing found levels of variability within Sumatran Rhino populations comparable to those in the population of the less endangered African rhinos, but the genetic diversity of Sumatran Rhinos is an area of continuing study.
The rhino spends a large part of its day in wallows. When mud holes are unavailable, the rhino will deepen puddles with its feet and horns. The wallowing behaviour helps the rhino maintain its body temperature and protect its skin from ectoparasites and other insects. Captive specimens of Sumatran Rhinoceros, deprived of adequate wallowing, have quickly developed broken and inflamed skins, suppurations, eye problems, inflamed nails, hair loss and have eventually died. One 20-month study of wallowing behavior found that the Sumatran Rhinoceros will visit no more than three wallows at any given time. After 2–12 weeks using a particular wallow, the rhino will abandon it. Typically, the rhino will wallow around midday for 2–3 hours at a time before venturing out for food. Although in zoos the Sumatran Rhino has been observed wallowing less than 45 minutes a day, the study of wild animals found 80–300 minutes (an average of 166 minutes) per day spent in wallows.
There has been little opportunity to study epidemiology
in the Sumatran Rhinoceros. Tick
s and gyrostigma
were reported to cause deaths in captive animals in the 19th century. The rhino is also known to be vulnerable to the blood disease surra
which can be spread by horse-flies
carrying parasitic trypanosome
s; in 2004, all five rhinos at the Sumatran Rhinoceros Conservation Centre died over an 18-day period after becoming infected by the disease. The Sumatran Rhino has no known predators other than humans. Tiger
s and wild dog
s may be capable of killing a calf, but calves stay close to their mothers, and the frequency of such killings is unknown. Although the rhino's range overlaps with elephants
and tapirs
, the species do not appear to compete for food or habitat. Elephants (Elephas maximus) and Sumatran Rhinos are even known to share trails, and many smaller species such as deer, boar and wild dogs will use the trails that the rhinos and elephants create.
The Sumatran Rhino maintains trails across its range. The trails fall into two types. Main trails will be used by generations of rhinos to travel between important areas in the rhino's range, such as between salt lick
s, or in corridors
through inhospitable terrain that separates ranges. In feeding areas the rhinos will make smaller trails, still covered by vegetation, to areas containing food the rhino eats. Sumatran Rhino trails have been found that cross rivers deeper than 1.5 meters (5 ft) and about 50 meters (165 ft) across. The currents of these rivers are known to be strong, but the rhino is a strong swimmer. A relative absence of wallows near rivers in the range of the Sumatran Rhinoceros indicates that they may occasionally bathe in rivers in lieu of wallowing.
Most feeding occurs just before nightfall and in the morning. The Sumatran Rhino is a browser, with a diet of young saplings, leaves, fruits, twigs and shoots. The rhinos usually consume up to 50 kg (110 lb) of food a day. Primarily by measuring dung samples, researchers have identified more than 100 food species consumed by the Sumatran Rhinoceros. The largest portion of the diet is tree saplings with a trunk diameter of 1–6 cm (0.4-2.4 inches). The rhinoceros typically pushes these saplings over with its body, walking over the sapling without stepping on it, to eat the leaves. Many of the plant species the rhino consumes exist in only small portions, which indicates that the rhino is frequently changing its diet and feeding in different locations. Among the most common plants the rhino eats are many species from the Euphorbiaceae
, Rubiaceae
and Melastomataceae
families. The most common species the rhino consumes is Eugenia
.
The vegetal diet of the Sumatran Rhinoceros is high in fiber
and only moderate in protein
. Salt licks are very important to the nutrition of the rhino. These licks can be small hot springs, seepages of salty water or mud-volcanoes
. The salt licks also serve an important social purpose for the rhinos—males visit the licks to pick up the scent of females in oestrus. Some Sumatran Rhinos, however, live in areas where salt licks are not readily available, or the rhinos have not been observed using the licks. These rhinos may get their necessary mineral requirements by consuming plants that are rich in minerals.
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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 is the only extant species of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Dicerorhinus. It is the smallest rhinoceros, although is still a large mammal. This rhino stands 112–145 cm (3.7–4.8 ft) high at the shoulder, with a head-and-body length of 2.36–3.17 m (7.7–10.4 ft) and a tail of 35–70 cm (13.8–27.6 in). The weight is reported to range from 500 to 1000 kg (1,102.3 to 2,204.6 lb), averaging 700–800 kg (1,543.2–1,763.7 lb), although there is a single record of a 2000 kg (4,409.2 lb) specimen. Like the African species, it has two horns; the larger is the nasal horn, typically 15–25 cm (5.9–9.8 in), while the other horn is typically a stub. A coat of reddish-brown hair covers most of the Sumatran Rhino's body.
Members of the species once inhabited rainforests, swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
s and cloud forest
Cloud forest
A cloud forest, also called a fog forest, is a generally tropical or subtropical evergreen montane moist forest characterized by a persistent, frequent or seasonal low-level cloud cover, usually at the canopy level. Cloud forests often exhibit an abundance of mosses covering the ground and...
s in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, Bhutan
Bhutan
Bhutan , officially the Kingdom of Bhutan, is a landlocked state in South Asia, located at the eastern end of the Himalayas and bordered to the south, east and west by the Republic of India and to the north by the People's Republic of China...
, Bangladesh
Bangladesh
Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
, 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....
, 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...
, 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...
, Malaysia, 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...
, and China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. In historical times they lived in southwest China, particularly in Sichuan
Sichuan
' , known formerly in the West by its postal map spellings of Szechwan or Szechuan is a province in Southwest China with its capital in Chengdu...
. They are now 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 six substantial populations in the wild: four on 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...
, one on 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 one in the Malay Peninsula
Peninsular Malaysia
Peninsular Malaysia , also known as West Malaysia , is the part of Malaysia which lies on the Malay Peninsula. Its area is . It shares a land border with Thailand in the north. To the south is the island of Singapore. Across the Strait of Malacca to the west lies the island of Sumatra...
. Their numbers are difficult to determine because they are solitary animals that are widely scattered across their range, but they are estimated to number fewer than 275. The decline in the number of Sumatran Rhinoceros is attributed primarily to poaching 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 US$30,000 per kilogram on the black market
Underground economy
A black market or underground economy is a market in goods or services which operates outside the formal one supported by established state power. Typically the totality of such activity is referred to with the definite article as a complement to the official economies, by market for such goods and...
.
The Sumatran Rhino is a mostly solitary animal except for courtship and child-rearing. It is the most vocal rhino species and also communicates through marking soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
with its feet, twisting saplings into patterns, and leaving excrement. The species is much better studied than the similarly reclusive Javan Rhinoceros
Javan Rhinoceros
The Javan Rhinoceros or Lesser One-horned Rhinoceros is a member of the family Rhinocerotidae and one of five extant rhinoceroses...
, in part because of a program that brought 40 Sumatran Rhinos into captivity with the goal of preserving the species. The program was considered a disaster even by its initiator; most of the rhinos died and no offspring were produced for nearly 20 years, representing an even worse population decline than in the wild.
Taxonomy and naming
The first documented Sumatran Rhinoceros was shot 16 kilometres (9.9 mi) outside Fort Marlborough, near the west coast of SumatraSumatra
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...
, in 1793. Drawings of the animal, and a written description, were sent to the naturalist
Naturalist
Naturalist may refer to:* Practitioner of natural history* Conservationist* Advocate of naturalism * Naturalist , autobiography-See also:* The American Naturalist, periodical* Naturalism...
Joseph Banks
Joseph Banks
Sir Joseph Banks, 1st Baronet, GCB, PRS was an English naturalist, botanist and patron of the natural sciences. He took part in Captain James Cook's first great voyage . Banks is credited with the introduction to the Western world of eucalyptus, acacia, mimosa and the genus named after him,...
, then president of the Royal Society of London, who published a paper on the specimen that year. It was not until 1814, however, that the species was given a scientific name, by Johann Fischer von Waldheim
Johann Fischer von Waldheim
Johann Gotthelf Fischer von Waldheim was a German anatomist, entomologist and paleontologist....
, a German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
scientist
Scientist
A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word...
and curator
Curator
A curator is a manager or overseer. Traditionally, a curator or keeper of a cultural heritage institution is a content specialist responsible for an institution's collections and involved with the interpretation of heritage material...
of the State Darwin Museum in Moscow
Moscow
Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
.
The scientific name Dicerorhinus sumatrensis comes from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
terms , , and ' onMouseout='HidePop("53938")' href="/topics/Nose">nose
Nose
Anatomically, a nose is a protuberance in vertebrates that houses the nostrils, or nares, which admit and expel air for respiration in conjunction with the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passes through the pharynx, shared with the...
"). Sumatrensis signifies "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...
", the 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...
n island where the rhinos were first discovered. Carolus Linnaeus
Carolus Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
originally classified all rhinos in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Rhinoceros; therefore the species was originally identified as Rhinoceros sumatrensis. Joshua Brookes
Joshua Brookes
'Joshua Brookes was a British anatomist and naturalist.He studied under John Hunter in London. He became a teacher of anatomy in London, and the founder of the Brookesian Museum of Comparative Anatomy.This private museum is described in his 1830 catalogue Museum Brookesianum Embracing an Almost...
considered the Sumatran Rhinoceros, with its two horns, a distinct genus from the one-horned Rhinoceros, and gave it the name Didermocerus in 1828. Constantin Wilhelm Lambert Gloger
Constantin Wilhelm Lambert Gloger
Constantin Wilhelm Lambert Gloger was a German zoologist and ornithologist.Gloger was the first person to recognise the structural differences between swallows and swifts, and also the first to put up artificial bat boxes.He was the originator of Gloger's rule, which states that dark pigments...
proposed the name Dicerorhinus in 1841. In 1868, John Edward Gray
John Edward Gray
John Edward Gray, FRS was a British zoologist. He was the elder brother of George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray ....
proposed the name Ceratorhinus. Normally the oldest name would be used, but a 1977 ruling by the International Commission on Zoological Nomenclature
International Commission on Zoological Nomenclature
The International Commission on Zoological Nomenclature is an organization dedicated to "achieving stability and sense in the scientific naming of animals". Founded in 1895, it currently comprises 28 members from 20 countries, mainly practicing zoological taxonomists...
established the proper genus name as Dicerorhinus.
There are three subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
:
D. s. sumatrensis, known as the Western Sumatran Rhinoceros, has only 170-230 rhinos remaining, mostly in the national parks of Bukit Barisan Selatan
Bukit Barisan Selatan National Park
Bukit Barisan Selatan National Park is a national park in Sumatra, Indonesia. The park has a total area of 3,568 km², and spans three provinces: Lampung, Bengkulu, and South Sumatra...
and Gunung Leuser
Gunung Leuser National Park
Gunung Leuser National Park is a national park covering 7,927 km² in northern Sumatra, Indonesia, straddling the border of North Sumatra and Aceh provinces. The national park, named after Mount Leuser , protects a wide range of ecosystems. An orangutan sanctuary of Bukit Lawang is located inside...
in Sumatra. Around 75 may also live in Peninsular Malaysia
Peninsular Malaysia
Peninsular Malaysia , also known as West Malaysia , is the part of Malaysia which lies on the Malay Peninsula. Its area is . It shares a land border with Thailand in the north. To the south is the island of Singapore. Across the Strait of Malacca to the west lies the island of Sumatra...
. The main threats against this subspecies are habitat loss and illegal poaching
Poaching
Poaching is the illegal taking of wild plants or animals contrary to local and international conservation and wildlife management laws. Violations of hunting laws and regulations are normally punishable by law and, collectively, such violations are known as poaching.It may be illegal and in...
. There is a slight genetic
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
difference between the Western and Eastern Sumatran Rhinos. The rhinos in Peninsular Malaysia were once known as D. s. niger, but were later recognized to be similar to the rhinos on western Sumatra.
D. s. harrissoni, known as the Eastern Sumatran Rhinoceros or Bornean Rhinoceros, were once common throughout 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....
; now only about 50 individuals are estimated to survive. The known population on Borneo lives in Sabah
Sabah
Sabah is one of 13 member states of Malaysia. It is located on the northern portion of the island of Borneo. It is the second largest state in the country after Sarawak, which it borders on its southwest. It also shares a border with the province of East Kalimantan of Indonesia in the south...
. There are unconfirmed reports of animals surviving in Sarawak
Sarawak
Sarawak is one of two Malaysian states on the island of Borneo. Known as Bumi Kenyalang , Sarawak is situated on the north-west of the island. It is the largest state in Malaysia followed by Sabah, the second largest state located to the North- East.The administrative capital is Kuching, which...
and Kalimantan
Kalimantan
In English, the term Kalimantan refers to the Indonesian portion of the island of Borneo, while in Indonesian, the term "Kalimantan" refers to the whole island of Borneo....
. This subspecies is named after Tom Harrisson
Tom Harrisson
Major Tom Harnett Harrisson DSO OBE was a British polymath. In the course of his life he was an ornithologist, explorer, journalist, broadcaster, soldier, guerrilla, ethnologist, museum curator, archaeologist, documentarian, film-maker, conservationist, and writer...
, who worked extensively with Bornean zoology and anthropology in the 1960s. The Bornean subspecies is markedly smaller than the other two.
D. s. lasiotis, known as the Northern Sumatran Rhinoceros, once roamed in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
and Bangladesh
Bangladesh
Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
but has been declared extinct in these countries. Unconfirmed reports suggest that there may be a small population still surviving in Burma, but the political situation in the country has prevented verification. The name lasiotis is derived from the Greek for "hairy-ears". Later studies showed that their ear-hair was not longer than other Sumatran Rhinos, but D. s. lasiotis remained a subspecies because it was significantly larger than the other subspecies.
Evolution
Ancestral rhinoceroses first diverged from other perissodactyls in the Early Eocene. Mitochondrial DNAMitochondrial DNA
Mitochondrial DNA is the DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, adenosine triphosphate...
comparison suggests that the ancestors of modern rhinos split from the ancestors of Equidae
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 Sumatran Rhinoceros is considered the least derived
Derived
In phylogenetics, a derived trait is a trait that is present in an organism, but was absent in the last common ancestor of the group being considered. This may also refer to structures that are not present in an organism, but were present in its ancestors, i.e. traits that have undergone secondary...
of the extant species as it shares more traits with its Miocene ancestors. Paleontological evidence in the fossil record dates the genus Dicerorhinus to the Early Miocene, 23–16 million years ago. Many fossils have been classified as members of Dicerorhinus, but there are no other recent species in the genus. Molecular dating suggests a split of Dicerorhinus from the four other extant species as far back as 25.9 ± 1.9 million years. Three hypotheses have been proposed for the relationship between the Sumatran Rhinoceros and the other living species. One hypothesis suggests that the Sumatran Rhinoceros is closely related to the Black and White Rhinos in Africa, evidenced by the species having two horns, instead of one. Other taxonomists regard the Sumatran Rhinoceros as a sister taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
of the Indian and Javan Rhinoceros because their ranges overlap so closely. A third hypothesis, based on more recent analyses, however, suggests that the two African rhinos, the two Asian rhinos and the Sumatran Rhinoceros represent three essentially separate lineages that split around 25.9 million years ago, and it may therefore be unclear which group diverged first.
Because of morphological similarities, the Sumatran Rhinoceros is believed to be closely related to the extinct Woolly Rhinoceros
Woolly Rhinoceros
The woolly rhinoceros is an extinct species of rhinoceros that was common throughout Europe and Asia during the Pleistocene epoch and survived the last glacial period. The genus name Coelodonta means "cavity tooth"...
(Coelodonta antiquitatis). The Woolly Rhinoceros, so named for the coat of hair it shares with the Sumatran Rhinoceros, first appeared in China and by the Upper Pleistocene ranged across the Eurasian continent from Korea
Korea
Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...
to Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
. The Woolly Rhinoceros survived the last Ice Age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
, but like the Woolly Mammoth
Woolly mammoth
The woolly mammoth , also called the tundra mammoth, is a species of mammoth. This animal is known from bones and frozen carcasses from northern North America and northern Eurasia with the best preserved carcasses in Siberia...
, most or all became extinct around 10,000 years ago. Although some morphological studies questioned the relationship, recent molecular analysis has supported the two species as sister taxa.
Description
A mature Sumatran Rhino stands about 120–145 cm (3.9–4.8 ft) high at the shoulder, has a body length of around 250 centimetres (8.2 ft) and weighs 500–800 kg (1,102.3–1,763.7 lb), though the largest individuals in zoos have been known to weigh as much as 1000 kilograms (2,204.6 lb). Like the African species, it has two horns. The larger is the nasal horn, typically only 15–25 cm (5.9–9.8 in), though the longest recorded specimen was much longer at 81 centimetres (31.9 in). The posterior horn is much smaller, usually less than 10 centimetres (3.9 in) long, and often little more than a knob. The larger nasal horn is also known as the anterior horn; the smaller posterior horn as the frontal horn. The horns are dark gray or black in color. The males have larger horns than the females, though the species is not otherwise sexually dimorphicSexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
. The Sumatran Rhino lives an estimated 30–45 years in the wild, while the record time in captivity is a female D. lasiotis who lived for 32 years and 8 months before dying in the London Zoo in 1900.
Two thick folds of skin encircle the body behind the front legs and before the hind legs. The rhino has a smaller fold of skin around its neck. The skin itself is thin, 10–16 mm (0.393700787401575–0.62992125984252 in), and in the wild the rhino appears to have no subcutaneous fat. Hair can range from dense (the most dense hair in young calves) to scarce and is usually a reddish brown. In the wild this hair is hard to observe because the rhinos are often covered in mud. In captivity, however, the hair grows out and becomes much shaggier, likely because of less abrasion from walking through vegetation. The rhino has a patch of long hair around the ears and a thick clump of hair at the end of the tail. Like all rhinos, they have very poor vision. The Sumatran Rhinoceros is fast and agile; it climbs mountains easily and comfortably traverses steep slopes and riverbanks.
Distribution and habitat
The Sumatran Rhinoceros lives in both lowland and highland secondary rainforestRainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
, swamps and cloud forest
Cloud forest
A cloud forest, also called a fog forest, is a generally tropical or subtropical evergreen montane moist forest characterized by a persistent, frequent or seasonal low-level cloud cover, usually at the canopy level. Cloud forests often exhibit an abundance of mosses covering the ground and...
s. It inhabits hilly areas close to water, particularly steep upper valleys with a lot of undergrowth. The Sumatran Rhinoceros once inhabited a continuous range as far north as Burma, eastern India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
and Bangladesh
Bangladesh
Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
. Unconfirmed reports also placed the Sumatran Rhino 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...
, 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...
and 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 –...
. All known living animals occur in Peninsular Malaysia
Peninsular Malaysia
Peninsular Malaysia , also known as West Malaysia , is the part of Malaysia which lies on the Malay Peninsula. Its area is . It shares a land border with Thailand in the north. To the south is the island of Singapore. Across the Strait of Malacca to the west lies the island of Sumatra...
, 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...
and Sabah
Sabah
Sabah is one of 13 member states of Malaysia. It is located on the northern portion of the island of Borneo. It is the second largest state in the country after Sarawak, which it borders on its southwest. It also shares a border with the province of East Kalimantan of Indonesia in the south...
, 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....
. Some conservationists hope that Sumatran Rhinos may still survive in Burma, though it is considered unlikely. Political turmoil in Burma has prevented any assessment or study of possible survivors. The last reports of stray animals from Indian limits were in 1990s.
The Sumatran Rhino is widely scattered across its range, much more so than the other Asian rhinos, which has made it difficult for conservationists to protect members of the species effectively. Only six areas are known to contain communities of more than a handful of Sumatran Rhinoceros: Bukit Barisan Selatan National Park
Bukit Barisan Selatan National Park
Bukit Barisan Selatan National Park is a national park in Sumatra, Indonesia. The park has a total area of 3,568 km², and spans three provinces: Lampung, Bengkulu, and South Sumatra...
, Gunung Leuser National Park
Gunung Leuser National Park
Gunung Leuser National Park is a national park covering 7,927 km² in northern Sumatra, Indonesia, straddling the border of North Sumatra and Aceh provinces. The national park, named after Mount Leuser , protects a wide range of ecosystems. An orangutan sanctuary of Bukit Lawang is located inside...
, Kerinci Seblat National Park
Kerinci Seblat National Park
Kerinci Seblat National Park is the largest national park in Sumatra Indonesia. It has a total area of 13,791 km2, and spans four provinces: West Sumatra, Jambi, Bengkulu and South Sumatra....
, and Way Kambas National Park
Way Kambas National Park
Way Kambas National Park is a national park covering 1,300 square kilometres in Lampung province, southern Sumatra, Indonesia.It consists of swamp forest and lowland rain forest, mostly of secondary growth as result of extensive logging in the 1960s and 1970s...
on Sumatra; Taman Negara National Park
Taman Negara National Park
Taman Negara was established in Malaysia in 1938/1939 as the King George V National Park. It was renamed to Taman Negara after independence, which literally means "national park" in Malay...
in Peninsular Malaysia; and the Tabin Wildlife Reserve
Tabin Wildlife Reserve
Tabin Wildlife Refuge is a nature preserve in Sabah, eastern Malaysia, on the island of Borneo. It was created in 1984 to preserve Sabah’s disappearing wild animals...
in Sabah
Sabah
Sabah is one of 13 member states of Malaysia. It is located on the northern portion of the island of Borneo. It is the second largest state in the country after Sarawak, which it borders on its southwest. It also shares a border with the province of East Kalimantan of Indonesia in the south...
, Malaysia on the island of Borneo.
Strait of Malacca
The Strait of Malacca is a narrow, stretch of water between the Malay Peninsula and the Indonesian island of Sumatra. It is named after the Malacca Sultanate that ruled over the archipelago between 1414 to 1511.-Extent:...
was not as significant a barrier for the rhinos as the Barisan Mountains
Barisan Mountains
The Bukit Barisan or the Barisan Mountains are a mountain range on the western side of Sumatra, Indonesia, covering nearly 1,700 km from the north to the south of the island. The Bukit Barisan range consists primarily of volcanoes shrouded in dense jungle cover, including Sumatran tropical pine...
along the length of Sumatra, for rhinos in eastern Sumatra and Peninsular Malaysia are more closely related than the rhinos on the other side of the mountains in western Sumatra. In fact the eastern Sumatra and Malaysia rhinos show so little genetic variance that the populations were likely not separate during the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
, when sea levels were much lower and Sumatra formed part of the mainland. Both populations of Sumatra and Malaysia, however, are close enough genetically that interbreeding would not be problematic. The rhinos of Borneo are sufficiently distinct that conservation geneticists
Conservation genetics
Conservation genetics is an interdisciplinary science that aims to apply genetic methods to the conservation and restoration of biodiversity. Researchers involved in conservation genetics come from a variety of fields including population genetics, molecular ecology, biology, evolutionary biology,...
have advised against crossing their lineages with the other populations. Conservation geneticists have recently begun to study the diversity of the gene pool within these populations by identifying microsatellite loci. The results of initial testing found levels of variability within Sumatran Rhino populations comparable to those in the population of the less endangered African rhinos, but the genetic diversity of Sumatran Rhinos is an area of continuing study.
Behaviour
Sumatran Rhinoceroses are solitary creatures except for pairing before mating and during child rearing. Individuals have home ranges: bulls have territories as large as 50 square kilometre whereas females' ranges are 10 square kilometre. The ranges of females appear to be spaced apart; male ranges often overlap. There is no evidence that Sumatran Rhinos defend their territory through fighting. Marking their territory is done by scraping soil with their feet, bending saplings into distinctive patterns, and leaving excrement. The Sumatran Rhino is usually most active when eating, at dawn, and just after dusk. During the day the rhino wallows in mud baths to cool down and rest. In the rainy season they move to higher elevations; in the cooler months they return to lower areas in their range.The rhino spends a large part of its day in wallows. When mud holes are unavailable, the rhino will deepen puddles with its feet and horns. The wallowing behaviour helps the rhino maintain its body temperature and protect its skin from ectoparasites and other insects. Captive specimens of Sumatran Rhinoceros, deprived of adequate wallowing, have quickly developed broken and inflamed skins, suppurations, eye problems, inflamed nails, hair loss and have eventually died. One 20-month study of wallowing behavior found that the Sumatran Rhinoceros will visit no more than three wallows at any given time. After 2–12 weeks using a particular wallow, the rhino will abandon it. Typically, the rhino will wallow around midday for 2–3 hours at a time before venturing out for food. Although in zoos the Sumatran Rhino has been observed wallowing less than 45 minutes a day, the study of wild animals found 80–300 minutes (an average of 166 minutes) per day spent in wallows.
There has been little opportunity to study epidemiology
Epidemiology
Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...
in the Sumatran Rhinoceros. Tick
Tick
Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...
s and gyrostigma
Gyrostigma
Gyrostigma is a genus of botfly which parasitize rhinoceroses. The best-known species is Gyrostigma rhinocerontis, the rhinoceros stomach botfly, which develops in the stomach lining of the Black Rhinoceros and White Rhinoceros of Africa, and the adult of which is the largest fly known in...
were reported to cause deaths in captive animals in the 19th century. The rhino is also known to be vulnerable to the blood disease surra
Surra
Surra is a disease of vertebrate animals. The disease is caused by protozoan trypanosomes, specifically Trypanosoma evansi, of several species which infect the blood of the vertebrate host, causing fever, weakness, and lethargy which lead to weight loss and anemia...
which can be spread by horse-flies
Horse-fly
Insects in the order Diptera, family Tabanidae, are commonly called horse flies. Often considered pests for the bites that many inflict, they are among the world's largest true flies. They are known to be extremely noisy during flight. They are also important pollinators of flowers, especially in...
carrying parasitic trypanosome
Trypanosoma
Trypanosoma is a genus of kinetoplastids , a monophyletic group of unicellular parasitic flagellate protozoa. The name is derived from the Greek trypano and soma because of their corkscrew-like motion. All trypanosomes are heteroxenous and are transmitted via a vector...
s; in 2004, all five rhinos at the Sumatran Rhinoceros Conservation Centre died over an 18-day period after becoming infected by the disease. The Sumatran Rhino has no known predators other than humans. Tiger
Tiger
The tiger is the largest cat species, reaching a total body length of up to and weighing up to . Their most recognizable feature is a pattern of dark vertical stripes on reddish-orange fur with lighter underparts...
s and wild dog
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
s may be capable of killing a calf, but calves stay close to their mothers, and the frequency of such killings is unknown. Although the rhino's range overlaps with elephants
Asian Elephant
The Asian or Asiatic elephant is the only living species of the genus Elephas and distributed in Southeast Asia from India in the west to Borneo in the east. Three subspecies are recognized — Elephas maximus maximus from Sri Lanka, the Indian elephant or E. m. indicus from mainland Asia, and E. m....
and tapirs
Malayan Tapir
The Malayan Tapir , also called the Asian Tapir, is the largest of the four species of tapir and the only one native to Asia. The scientific name refers to the East Indies, the species' natural habitat...
, the species do not appear to compete for food or habitat. Elephants (Elephas maximus) and Sumatran Rhinos are even known to share trails, and many smaller species such as deer, boar and wild dogs will use the trails that the rhinos and elephants create.
The Sumatran Rhino maintains trails across its range. The trails fall into two types. Main trails will be used by generations of rhinos to travel between important areas in the rhino's range, such as between salt lick
Salt lick
A mineral lick is a natural mineral deposit where animals in nutrient-poor ecosystems can obtain essential mineral nutrients...
s, or in corridors
Wildlife corridor
A wildlife corridor or green corridor is an area of habitat connecting wildlife populations separated by human activities . This allows an exchange of individuals between populations, which may help prevent the negative effects of inbreeding and reduced genetic diversity that often occur within...
through inhospitable terrain that separates ranges. In feeding areas the rhinos will make smaller trails, still covered by vegetation, to areas containing food the rhino eats. Sumatran Rhino trails have been found that cross rivers deeper than 1.5 meters (5 ft) and about 50 meters (165 ft) across. The currents of these rivers are known to be strong, but the rhino is a strong swimmer. A relative absence of wallows near rivers in the range of the Sumatran Rhinoceros indicates that they may occasionally bathe in rivers in lieu of wallowing.
Diet
 |
|
 |
 |
| The Sumatran Rhino eats a wide range of plants such as: (clockwise from top left), Mallotus Mallotus (plant) Mallotus is a genus of the spurge family Euphorbiaceae. 2 species are found in tropical Africa and Madagascar. About 140 species are found in East and Southeast Asia and from Indomalaysia to New Caledonia and Fiji, northern and eastern Australia... , mangosteen Mangosteen The purple mangosteen , colloquially known simply as mangosteen, is a tropical evergreen tree believed to have originated in the Sunda Islands and the Moluccas of Indonesia. The tree grows from 7 to 25 m tall... s, Ardisia Ardisia Ardisia is a genus of flowering plants in the family Myrsinaceae , native to warm temperate to tropical regions of the Americas, Asia, and Australasia... , and Eugenia Eugenia Eugenia is a genus of flowering plants in the myrtle family Myrtaceae. It has a worldwide, although highly uneven, distribution in tropical and subtropical regions. The bulk of the approximately 1,000 species occur in the New World tropics, especially in the northern Andes, the Caribbean, and the... . |
|
Most feeding occurs just before nightfall and in the morning. The Sumatran Rhino is a browser, with a diet of young saplings, leaves, fruits, twigs and shoots. The rhinos usually consume up to 50 kg (110 lb) of food a day. Primarily by measuring dung samples, researchers have identified more than 100 food species consumed by the Sumatran Rhinoceros. The largest portion of the diet is tree saplings with a trunk diameter of 1–6 cm (0.4-2.4 inches). The rhinoceros typically pushes these saplings over with its body, walking over the sapling without stepping on it, to eat the leaves. Many of the plant species the rhino consumes exist in only small portions, which indicates that the rhino is frequently changing its diet and feeding in different locations. Among the most common plants the rhino eats are many species from the Euphorbiaceae
Euphorbiaceae
Euphorbiaceae, the Spurge family are a large family of flowering plants with 300 genera and around 7,500 species. Most are herbs, but some, especially in the tropics, are also shrubs or trees. Some are succulent and resemble cacti....
, Rubiaceae
Rubiaceae
The Rubiaceae is a family of flowering plants, variously called the coffee family, madder family, or bedstraw family. The group contains many commonly known plants, including the economically important coffee , quinine , and gambier , and the horticulturally valuable madder , west indian jasmine ,...
and Melastomataceae
Melastomataceae
right|thumb|200px|Characteristic venation of many melastomesThe family Melastomataceae is a taxon of dicotyledonous flowering plants found mostly in the tropics comprising some 200 genera and 4500 species...
families. The most common species the rhino consumes is Eugenia
Eugenia
Eugenia is a genus of flowering plants in the myrtle family Myrtaceae. It has a worldwide, although highly uneven, distribution in tropical and subtropical regions. The bulk of the approximately 1,000 species occur in the New World tropics, especially in the northern Andes, the Caribbean, and the...
.
The vegetal diet of the Sumatran Rhinoceros is high in fiber
Dietary fiber
Dietary fiber, dietary fibre, or sometimes roughage is the indigestible portion of plant foods having two main components:* soluble fiber that is readily fermented in the colon into gases and physiologically active byproducts, and* insoluble fiber that is metabolically inert, absorbing water as it...
and only moderate in protein
Protein in nutrition
Proteins are polymer chains made of amino acids linked together by peptide bonds. Proteins and carbohydrates contain 4 kcal per gram as opposed to lipids which contain 9 kcal per gram....
. Salt licks are very important to the nutrition of the rhino. These licks can be small hot springs, seepages of salty water or mud-volcanoes
Mudpot
A mudpot, mud pool or paint pot is a sort of hot spring or fumarole consisting of a pool of usually bubbling mud. The mud is generally of white to greyish color, but is sometimes stained with reddish or pink spots from iron compounds...
. The salt licks also serve an important social purpose for the rhinos—males visit the licks to pick up the scent of females in oestrus. Some Sumatran Rhinos, however, live in areas where salt licks are not readily available, or the rhinos have not been observed using the licks. These rhinos may get their necessary mineral requirements by consuming plants that are rich in minerals.
Communication
vocalizations (.wav files)|-
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- [ftp://ftp.aip.org/epaps/acoust_res_lett/E-ARLOFJ-4-005303/MM.1.wav Eep]
- [ftp://ftp.aip.org/epaps/acoust_res_lett/E-ARLOFJ-4-005303/MM.2.wav Whale]
- [ftp://ftp.aip.org/epaps/acoust_res_lett/E-ARLOFJ-4-005303/MM.3.wav Whistle-blow]
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The Sumatran Rhinoceros is the most vocal of the rhinoceros species. Observations of the species in zoos show the animal almost constantly vocalizing and it is known to do so in the wild as well. The rhino makes three distinct noises: eeps, whales, and whistle-blows. The eep, a short, one-second-long yelp, is the most common sound. The whale, named for its similarity to vocalizations of the Humpback Whale
Humpback Whale
The humpback whale is a species of baleen whale. One of the larger rorqual species, adults range in length from and weigh approximately . The humpback has a distinctive body shape, with unusually long pectoral fins and a knobbly head. It is an acrobatic animal, often breaching and slapping the...
(see: Whale song
Whale song
Whale sounds are the sounds made by whales and which are used for different kinds of communication.The word "song" is used to describe the pattern of regular and predictable sounds made by some species of whales, notably the Humpback Whale...
), is the most song-like vocalization and the second most common. The whale varies in pitch and lasts from 4–7 seconds. The whistle-blow is named because it consists of a two-second-long whistling noise and a burst of air in immediate succession. The whistle-blow is the loudest of the vocalizations, loud enough to make the iron bars in the zoo enclosure where the rhinos were studied vibrate. The purpose of the vocalizations is unknown, though they are theorized to convey danger, sexual readiness, and location, as do other ungulate vocalizations. The whistle-blow could be heard at a great distance even in the dense brush in which the Sumatran Rhino lives. A vocalization of similar volume from elephants has been shown to carry 9.8 km (6.1 mi) and thus the whistle-blow may carry as far. The Sumatran Rhinoceros will sometimes twist saplings that they do not eat. This twisting behavior is believed to be used as a form of communication, frequently indicating a junction in a trail.
Reproduction
Females become sexually mature at the age of 6–7 years, while males become sexually mature at about 10 years old. The gestation periodGestation period
For mammals the gestation period is the time in which a fetus develops, beginning with fertilization and ending at birth. The duration of this period varies between species.-Duration:...
is around 15–16 months. The calf, which typically weighs 40–60 kg (88–132 lb), is weaned after about 15 months and stays with the mother for the first 2–3 years of its life. In the wild, the birth interval for this species is estimated to be 4–5 years; its natural child-rearing behavior is unstudied.
The reproductive habits of the Sumatran Rhinoceros have been studied in captivity. Sexual relationships begin with a courtship period characterized by increased vocalization, tail raising, urination
Urination
Urination, also known as micturition, voiding, peeing, weeing, pissing, and more rarely, emiction, is the ejection of urine from the urinary bladder through the urethra to the outside of the body. In healthy humans the process of urination is under voluntary control...
and increased physical contact, with both male and female using their snouts to bump the other in the head and genitals. The pattern of courtship is most similar to that of 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...
. Young Sumatran Rhino males are often too aggressive with females, sometimes injuring and even killing them during the courtship. In the wild, the female could run away from an overly aggressive male, but in their smaller captive enclosures they cannot; this inability to escape aggressive males may partly contribute to the low success rate of captive breeding programs.
The period of oestrus itself, when the female is receptive to the male, lasts about 24 hours, and observations have placed its recurrence between 21–25 days. Rhinos in the Cincinnati Zoo have been observed copulating for 30–50 minutes, similar in length to other rhinos; observations at the Sumatran Rhinoceros Conservation Centre in Malaysia have shown a briefer copulation cycle. As the Cincinnati Zoo has had successful pregnancies, and other rhinos also have lengthy copulatory periods, a lengthy rut may be the natural behavior. Though researchers observed successful conceptions, all these pregnancies ended in failure for a variety of reasons until the first successful captive birth in 2001; studies of these failures at the Cincinnati Zoo discovered that the Sumatran Rhino's ovulation is induced by mating and that it had unpredictable progesterone
Progesterone
Progesterone also known as P4 is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy and embryogenesis of humans and other species...
levels. Breeding success was finally achieved in 2001, 2004 and 2007 by providing a pregnant rhino with supplementary progestin
Progestin
A progestin is a synthetic progestogen that has progestinic effects similar to progesterone. The two most common uses of progestins are for hormonal contraception , and to prevent endometrial hyperplasia from unopposed estrogen in hormone replacement therapy...
.
Conservation
Sumatran Rhinoceroses were once quite numerous throughout Southeast AsiaSoutheast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
. It is now estimated that fewer than 275 individuals remain. The species is classed as 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:...
primarily due to illegal poaching. Until the early 1990s, the population decline was estimated at more than 50% per decade, and the small scattered populations now face high risks of 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...
. Most remaining habitat is in relatively inaccessible mountainous areas of 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...
.
Poaching of Sumatran Rhinoceros is a cause for concern, as the price of its horn has been estimated as high as $30,000 per kilogram. This species has been over-hunted for many centuries, leading to the current greatly reduced – and still declining – population. The rhinos are difficult to observe and hunt directly (one field researcher spent seven weeks in a treehide near a salt lick without ever observing a rhino directly), so poachers make use of spear traps and pit traps. In the 1970s, uses of the rhinoceros's body parts among the local people of Sumatra were documented, such as the use of rhino horns in amulet
Amulet
An amulet, similar to a talisman , is any object intended to bring good luck or protection to its owner.Potential amulets include gems, especially engraved gems, statues, coins, drawings, pendants, rings, plants and animals; even words said in certain occasions—for example: vade retro satana—, to...
s and a folk-belief that the horns offer some protection against poison. Dried rhinoceros meat was used as medicine for diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
, leprosy
Leprosy
Leprosy or Hansen's disease is a chronic disease caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Named after physician Gerhard Armauer Hansen, leprosy is primarily a granulomatous disease of the peripheral nerves and mucosa of the upper respiratory tract; skin lesions...
and tuberculosis
Tuberculosis
Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
. "Rhino-oil," a concoction made from leaving a rhino's skull in coconut oil
Coconut oil
Coconut oil is an edible oil extracted from the kernel or meat of matured coconuts harvested from the coconut palm . Throughout the tropical world, it has provided the primary source of fat in the diets of millions of people for generations. It has various applications in food, medicine, and industry...
for several weeks, may be used to treat skin diseases. The extent of use and belief in these practices is not known. It was once believed that rhinoceros horn was widely used as an aphrodisiac
Aphrodisiac
An aphrodisiac is a substance that increases sexual desire. The name comes from Aphrodite, the Greek goddess of sexuality and love. Throughout history, many foods, drinks, and behaviors have had a reputation for making sex more attainable and/or pleasurable...
; in fact 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...
never used it for this purpose. Nevertheless, hunting in this species has primarily been driven by a demand for rhino horns with supposedly medicinal properties.
The rainforests of Indonesia and Malaysia, which the Sumatran Rhino inhabits, are also targets for legal and illegal logging because of the desirability of their hardwoods. Rare woods like merbau, meranti and semaram
Gutta-percha
Gutta-percha is a genus of tropical trees native to Southeast Asia and northern Australasia, from Taiwan south to the Malay Peninsula and east to the Solomon Islands. The same term is used to refer to an inelastic natural latex produced from the sap of these trees, particularly from the species...
are valuable on the international markets, fetching as much as $1,800 per m3 ($1,375 per cu yd). Enforcement of illegal-logging laws is difficult because humans live within or near many of the same forests as the rhino. The 2004 Indian Ocean earthquake
2004 Indian Ocean earthquake
The 2004 Indian Ocean earthquake was an undersea megathrust earthquake that occurred at 00:58:53 UTC on Sunday, December 26, 2004, with an epicentre off the west coast of Sumatra, Indonesia. The quake itself is known by the scientific community as the Sumatra-Andaman earthquake...
has been used to justify new logging. Although the hardwoods in the rainforests of the Sumatran Rhino are destined for international markets and not widely used in domestic construction, the number of logging permits for these woods has increased dramatically because of the tsunami. However, while it has been suggested that this species is highly sensible to habitat disturbance, it appears this is of little importance compared to hunting, as it can withstand more or less any forest condition.
In captivity
Though rare, Sumatran Rhinoceroses have occasionally been exhibited in zoos for nearly a century and a half. The London ZooLondon Zoo
London Zoo is the world's oldest scientific zoo. It was opened in London on 27 April 1828, and was originally intended to be used as a collection for scientific study. It was eventually opened to the public in 1847...
acquired two Sumatran Rhinoceros in 1872. One of these, a female named Begum, was captured in Chittagong
Chittagong
Chittagong ) is a city in southeastern Bangladesh and the capital of an eponymous district and division. Built on the banks of the Karnaphuli River, the city is home to Bangladesh's busiest seaport and has a population of over 4.5 million, making it the second largest city in the country.A trading...
in 1868 and survived at the London Zoo until 1900, the record lifetime in captivity for a Sumatran Rhino. Begum was also the type of the extinct sub-species D. s. lasiotis. At the time of their acquisition, Philip Sclater
Philip Sclater
Philip Lutley Sclater was an English lawyer and zoologist. In zoology, he was an expert ornithologist, and identified the main zoogeographic regions of the world...
, the secretary of the Zoological Society of London
Zoological Society of London
The Zoological Society of London is a charity devoted to the worldwide conservation of animals and their habitats...
, claimed that the first Sumatran Rhinoceros in zoos had been in the collection of the Zoological Garden of Hamburg
Zoological Garden of Hamburg
The Zoological Garden of Hamburg was a zoo in Hamburg, Germany that operated from 1863 until 1930. Its aquarium, which opened in 1864, was among the first in the world.- Founding :...
since 1868. Before the extinction of the subspecies Dicerorhinus sumatrensis lasiotis, at least seven specimens were held in zoos and circuses. Sumatran Rhinos, however, did not thrive outside their native habitats. A rhino in the Calcutta Zoo successfully gave birth in 1889, but for the entire 20th century not one Sumatran Rhino was born in a zoo. In 1972, the only Sumatran Rhino remaining in captivity died at the Copenhagen Zoo.
Despite the species' persistent lack of reproductive success, in the early 1980s some conservation organizations began a captive breeding program for the Sumatran Rhinoceros. Between 1984 and 1996 this ex situ conservation program transported 40 Sumatran Rhinos from their native habitat to zoos and reserves across the world. While hopes were initially high, and much research was conducted on the captive specimens, by the late 1990s not a single rhino had been born in the program, and most of its proponents agreed the program had been a failure. In 1997, the IUCN's Asian Rhino specialist group, which once endorsed the program, declared that it had failed "even maintaining the species within acceptable limits of mortality," noting that, in addition to the lack of births, 20 of the captured rhinos had died. In 2004, a surra
Surra
Surra is a disease of vertebrate animals. The disease is caused by protozoan trypanosomes, specifically Trypanosoma evansi, of several species which infect the blood of the vertebrate host, causing fever, weakness, and lethargy which lead to weight loss and anemia...
outbreak at the Sumatran Rhinoceros Conservation Centre killed all the captive rhinos in Peninsular Malaysia, reducing the population of captive rhinos to eight.
Seven of these captive rhinos were sent to the United States (the other was kept in Southeast Asia), but by 1997, their numbers had dwindled to three: a female in the Los Angeles Zoo
Los Angeles Zoo
The Los Angeles Zoo , is a zoo founded in 1966 and located in Los Angeles, California. The City of Los Angeles owns the entire zoo, its land and facilities, and the animals...
, a male in the Cincinnati Zoo, and a female in the Bronx Zoo
Bronx Zoo
The Bronx Zoo is located in the Bronx borough of New York City, within Bronx Park. It is the largest metropolitan zoo in the United States, comprising of park lands and naturalistic habitats, through which the Bronx River flows....
. In a final effort, the three rhinos were united in Cincinnati. After years of failed attempts, the female from Los Angeles, Emi, became pregnant for the sixth time, with the zoo's male Ipuh. All five of her previous pregnancies ended in failure. But researchers at the zoo had learned from previous failures, and, with the aid of special hormone treatments, Emi gave birth to a healthy male calf named Andalas (an Indonesian
Indonesian language
Indonesian is the official language of Indonesia. Indonesian is a normative form of the Riau Islands dialect of Malay, an Austronesian language which has been used as a lingua franca in the Indonesian archipelago for centuries....
literary word for "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...
") in September 2001. Andalas's birth was the first successful captive birth of a Sumatran Rhino in 112 years. A female calf, named Suci (Indonesian for "pure"), followed on July 30, 2004. On April 29, 2007, Emi gave birth a third time, to her second male calf, named Harapan (Indonesian for "hope") or Harry. In 2007, Andalas, who had been living at the Los Angeles Zoo
Los Angeles Zoo
The Los Angeles Zoo , is a zoo founded in 1966 and located in Los Angeles, California. The City of Los Angeles owns the entire zoo, its land and facilities, and the animals...
, was returned to 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...
to take part in breeding programs with healthy females.
Despite the recent successes in Cincinnati, the captive breeding program has remained controversial. Proponents argue that zoos have aided the conservation effort by studying the reproductive habits, raising public awareness and education about the rhinos, and helping raise financial resources for conservation efforts in Sumatra. Opponents of the captive breeding program argue that losses are too great; the program too expensive; removing rhinos from their habitat, even temporarily, alters their ecological role; and captive populations cannot match the rate of recovery seen in well-protected native habitats.
Cultural depictions
Aside from those few individuals kept in zoos and pictured in books, the Sumatran Rhinoceros has remained little known, overshadowed by the more common Indian, Black and White rhinos. Recently, however, video footage of the Sumatran Rhinoceros in its native habitat and in breeding centers has been featured in several nature documentaries. Extensive footage can be found in an Asia Geographic documentary The Littlest Rhino. Natural History New ZealandNatural History New Zealand
NHNZ is a New Zealand-based factual television production company that creates around 60 hours of television programming each year in the genres of nature, history, science, adventure and people....
showed footage of a Sumatran rhino, shot by freelance Indonesian-based cameraman Alain Compost, in the 2001 documentary The Forgotten Rhino, which featured mainly Javan and Indian rhinos.
Though documented by droppings and tracks, pictures of the Bornean Rhinoceros were first taken and widely distributed by modern conservationists in April 2006 when camera traps photographed a healthy adult in the jungles of Sabah in Malaysian Borneo. On April 24, 2007 it was announced that cameras had captured the first ever video footage of a wild Bornean Rhino. The night-time footage showed the rhino eating, peering through jungle foliage, and sniffing the film equipment. The World Wildlife Fund which took the video has used it in efforts to convince local governments to turn the area into a rhino conservation zone. Monitoring has continued; fifty new cameras have been set up and in February 2010 what appeared to be a pregnant rhino was filmed.
A number of folk tales about the Sumatran Rhino were collected by colonial naturalists and hunters from the mid 19th century to early 20th century. In Burma, the belief was once widespread that the Sumatran Rhino ate fire. Tales described the fire-eating rhino following smoke to its source, especially camp-fires, and then attacking the camp. There was also a Burmese belief that the best time to hunt was every July when the Sumatran Rhinos would congregate beneath the full moon. In Malaya it was said that the rhino's horn was hollow and could be used as a sort of hose for breathing air and squirting water. In Malaya and Sumatra it was once believed that the rhino shed its horn every year and buried it under the ground. In Borneo, the rhino was said to have a strange carnivorous practice: after defecating in a stream it would turn around and eat fish that had been stupefied by the excrement.
External links
- Sumatran Rhino Info & Sumatran Rhino Pictures on the Rhino Resource Center
- Sumatran Rhino at 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...
. - Information on the Sumatran Rhino from the International Rhino Foundation
- Asian Rhino Foundation
- Rhino iCam at the Cincinnati Zoo
- Rhino and Forest Fund
- Borneo Rhino Alliance