Rhinoceros
- For other uses, see Rhinoceros (disambiguation).
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 Black Rhinoceros, Diceros bicornis
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Ceratotherium |
The rhinoceros (IPA: [ɹɑɪˈnɒsəɹəs], or rhino) is any of five surviving species of odd-toed ungulates in the family Rhinocerotidae. Two species are native to Africa and three to southern Asia. Four of the five species are either endangered or critically endangered.
The word "rhinoceros" is derived from the Greek words rhino, meaning nose, and keras, meaning horn; hence "horn-nosed". The plural can be either rhinoceros, rhinoceri, or rhinoceroses, though the standard form is rhinoceri.
The family is characterized by large size (one of the few remaining megafauna, animals whose average adult weight exceed 100 pounds (44 kg), surviving today) with all of the species capable of reaching one ton or more in weight; herbivorous diet; and a thick protective skin, 1.5-5 cm thick, formed from layers of collagen positioned in a lattice structure; relatively small brains for mammals this size (400-600g); and its horn. The rhino is prized for its horn. Not a true horn, it is made of thickly matted hair that grows from the skull without skeletal support. Rhinoceros also have acute hearing and sense of smell, but poor eyesight over any distance. Most rhinoceros live to be about 50 years old or more. The collective noun for a group of rhinoceros is "crash".
Rhinos have an elongate skull, which is elevated posteriorly. They have a small braincase, and the nasal bones project forward freely and may extend beyond and above the premaxillae. The surface of the nasals where the horns sit is roughened. There is a strongly developed occipital crest. Rhinos have 24-34 teeth, mostly premolars and molars for grinding (dental formula 1-2/0-1, 0/1-1, 3-4/3-4, 3/3). The canines and incisors are vestigial except for the lower incisors in Asian rhinos, which are developed into powerful slashing tusks.
The African and the Asian rhino have some distinct, differing characteristics, for example, it has been found that African rhinos are more aggressive than Asian rhinos. African rhinos fight with their horns, using them to impale and throw their adversaries, while the Asian rhino, fights with their bottom teeth, using them in a slashing motion. Their feeding habits vary too, African rhinos feed low to the ground, whereas the Asian rhino browses on leaves that are higher up. Both African varieties have two horns in tandem while the Asian types have a single horn.
However, the 2 have a lot in common also, both African and Asian Rhinos are more active in the evening, night and early morning spending the hot day time resting in the shade. Both groups are herbivores and feed primarily on grass or branches, depending on the species, some may eat more grass than branches. Both African and Asian rhinos sleep in both standing and laying positions and both enjoy wallowing in muddy pools and sandy riverbeds.
White rhinoceros
The White Rhinoceros or Square-lipped rhinoceros (Ceratotherium simum) is one of the five species of rhinoceros that still exist and is one of the few megafauna species left. Behind the elephant, it is probably the most massive remaining land animal in the world, along with the Indian Rhinoceros which is of comparable size. It is well known for its wide mouth used for grazing and for being the most social of all rhino species. The White Rhino is the most common of all rhinos and consists of two subspecies, with the northern subspecies being rarer than the southern. The northern subspecies may have as few as 50 remaining world wide.
The name White Rhino originated in South Africa where the Afrikaans language developed from the Dutch language. The Afrikaans word "wyd" (derived from the Dutch word "wijd"), which means "wide", referred to the width of the Rhinoceros mouth. Early English settlers in South Africa misinterpreted the "wyd" for "white". So the rhino with the wide mouth ended up being called the White Rhino and the other one, with the narrow pointed mouth, was called the Black Rhinoceros. The wide mouth was adapted to cropping large swaths of grass, while the narrow mouth was adapted to eating leaves on bushes. A White Rhino's skin colour is quite similar to that of the Black Rhino. An alternative common name for the white rhinoceros, more accurate but rarely used, is the square-lipped rhinoceros. The White Rhinoceros' genus, Ceratotherium, appropriately means "horned beast".
Unlike the other species of rhinoceros, the White Rhino is a more social animal, forming groups rather than being solitary. A typical group consists of mother and offspring, but larger groups, including several subadults as well as one or more adult females, are also formed. Subadults almost always form groups with one or more subadults of similar age, of the same or opposite sex, or with an adult female lacking a calf. Adult males are solitary, except when accompanying females.
Reproduction of the White Rhinoceros
Although calves can be born throughout the year, there is a peak in the number of cows in heat during the rainy season in Hluhluwe-Umfolozi (the oldest wild safari park in Africa) and in turn there is a correspondence of births in late summer. The gestation period of the rhino is 16 months and the calf is born weighing 145lb (65kg). Usually the cow comes into heat while suckling a calf and once the new calf is born the older one, having been weaned, is driven away.
Conservation Status of the White Rhinoceros
By 2000 more than 10,000 white rhinos were existing in the wild, however due to the value of their horns and how easy it is to hunt them down this number is dwindling and the white rhino's population is decreasing, it has been listed as Near Threatened by IUCN.
Black rhinoceros
The Black Rhinoceros, Diceros bicornis also colloquially Black Rhino is a mammal in the order Perissodactyla, native to the eastern and central areas of Africa including Kenya, Tanzania, Cameroon, South Africa, Namibia and Zimbabwe. Although the Rhino is referred to as a "Black" creature, it is actually more of a grey-white color in appearance.
The name of the species was chosen to distinguish it from the White Rhinoceros (Ceratotherium simum). This is very misleading, as those two species are not really distinguishable by colour. The word "White" in name "White Rhinoceros" deriving from the Afrikaans word for "wide" rather than the color white.
Unlike the white rhino, the black rhino is a solitary animal rarely forming groups. A female and her offspring are the usual group, whereas, males are mostly solitary except when courting a female. When male adult black rhinos meet they often perform a complex ceremony involving stiff-legged scraping, imposing postures, and short charges sometimes accompanied by screaming groans. The male rhinos, or bulls, also mark their territory, they do so by dragging, their legs, urine spraying surrounding bushes and creating dung heaps.
Reproduction of the Black Rhinoceros
Similar to the white rhinoceros, black rhinoceros cows go into heat during the African wet season and therefore give birth to their calves in late summer. Gestation lasts for 15 months and the calf is born weighing 9-11lbs (20-25kg). Calves leave their mother when her next offspring are born and often form groups with other calves their age.
Conservation Status of the Black Rhinoceros
The World Conservation Union (IUCN) announced on 7 July 2006 that one of the four subspecies, the West African Black Rhinoceros (Diceros bicornis longipes), has been tentatively declared as extinct (Times Online, 2006).
Sumatran rhinoceros
The Sumatran rhinoceros, Dicerorhinus sumatrensis is the smallest extant rhinoceros species, as well as the one with the most fur. Due to habitat loss and poaching, its numbers have declined and it is one of the world's rarest mammals. The Sumatran Rhinoceros is the last surviving species in the same group as the extinct Woolly Rhinoceros.
The Sumatran rhinoceros' thick fur not only helps it survive in the high altitudes of Sumatra and Borneo but it allows a very thick coat of mud to stick to the rhino and prevent insect bites and thorns.
Formerly, the Sumatran rhinoceros extended in a continuous distribution as far north as Myanmar and eastern India but poaching has made it extinct in Thailand and Vietnam, whilst it has not been seen in Cambodia, Laos or Myanmar for many years. Now, they are mainly found only in Sumatra and Borneo.
Reproduction of the Sumatran Rhinoceros
The mating of the Sumatran rhino is very aggressive. Gestation lasts 475 days, the calf's weight at birth is 14lb (33kg). At 16-17 months of age the calf is ready to leave his mother, she will move back to the non-breeding range and the calf will stay close to the salt lick ( a naturally occurring salt deposit that animals lick to obtain minerals they need).
Conservation Status of the Sumatran Rhinoceros
Poaching and encroachment remain a large threat to the Sumatran rhinos and they are currently listed as Critically Endangered by the IUCN.
One-horned rhinoceroses
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 (Rhinoceros unicornis) and the Javan Rhinoceros (Rhinoceros sondaicus). The Javan Rhinoceros is one of the most endangered large mammals in the world with only 60 indiviuals surviving, in only two known locations: Java (Indonesia) and Vietnam. The one-horned rhinoceros is a solitary animal, however they tend to congregate in bathing pools and feeding areas. The one-horned rhino males are aggressive and are known to challenge another male for dominance. Submissive males may share the home range of a dominant male but, unlike the dominant male, they do not squirt-urinate and run away if challenged. Indian Rhinos, or One-Horned rhinos are highly vocal animals and produce a variety of sounds.
Reproduction of the One-horned Rhinoceros
The female one-horned rhino ensures she chooses the strongest bull as a mate but making a series of rhythmical whistling sounds and running extremely fast, the bull that can catch her will usually be the strongest bull in the area. Gestation lasts and the birth weight of the calf is 140-150lbs (65-70kg). The calf continues to live and nurse with the mother until 2 years of age and will be driven off 1-2 weeks before the birth of the next calf.
Conservation Status of the One-Horned Rhinoceros
The one-horned rhino is listed as Endangered by the IUCN. The surviving population totaled at about 2,400. But it seems to be improving as the rhinos have been moved to establish new populations in new parks in Nepal and India.
Rhinoceros horns
The most obvious distinguishing characteristic of the rhinos is a large horn above the nose. Rhinoceros horns, unlike those of other horned mammals, consist of keratin, fibrous structural protiens, only and lacks a bony core, such as bovine horns,however it has been discovered by scientists at Ohio University that the rhinoceros horn actually contains calcium and melanin deposits, they believe that the calcium is what gives it the core it's hardness and the melanin protects it from the sun. Rhinoceros horns are used in traditional Asian medicine, and for dagger handles in Yemen and Oman.
One repeated fallacy is that rhinoceros horn in powdered form is used as an aphrodisiac in Traditional Chinese Medicine. It is, in fact, prescribed for life-threatening fevers and convulsions and has been clinically shown to have fever-reducing properties (Bensky, Clavey, Stoger and Gamble, 2004). This misunderstanding has interfered with discussions with TCM practitioners in order to reduce its use since the TCM doctors see it as a life-saving medicine of last resort after cheaper substitutes like water buffalo horn are exhausted. An extensive review of rhinoceros horn in TCM materia medicas shows no aphrodisiac use and the source of the fallacy is not clear unless it was a supposition based on the form that was picked up at a time when sources were more difficult to find in English (Parry-Jones and Vincent, 1998), China has signed the CITES treaty however. To prevent poaching, in certain areas rhinoceroses have been tranquilized and their horns removed.
Legend
There are a number of legends about rhinoceroses stamping out fire. The story seems to have been common in Malaysia, India, and Burma. This type of rhinoceros even had a special name in Malay, badak api, where badak means rhinoceros and api means fire. The animal would come when a fire is lit in the forest and stamp it out. Whether or not there is any truth to this has not yet been proven, as there has been no documented sighting of this phenomenon in recent history. This lack of evidence may stem from the fact that rhinoceros sightings overall in Southeast Asia have become very rare, largely due to widespread poaching of the critically endangered animal. This legend is featured prominently in the movie The Gods Must Be Crazy as well as on an episode of The Simpsons.
In James and the Giant Peach by Roald Dahl, James' parents are eaten up by a rhinoceros which escaped from the London Zoo even though rhinoceros are, in fact, herbivores. Albrecht Dürer created a famous woodcut of a rhinoceros in 1515, without ever seeing the animal depicted. As a result, Dürer's Rhinoceros is rather inaccurate.
Ancient Chinese practices cite rhinoceros horns as a medicinal remedy for intractable fevers, though there is no modern medical evidence supporting this, causaly or correlatively
Classification
Several rhinoceros species became extinct within geologically recent times, notably the Giant Unicorn and the Woolly Rhinoceros in Eurasia; the extent to which climate change or human predation was responsible is debated. Current evidence indicates that they probably had survived many climate changes before modern man arrived.
Rhinoceros-like animals first appeared in the Eocene as rather slender animals, and by the late Miocene there were many species. Most were large. One, Indricotherium, may have weighed about 20 tons and (so far as is known) was the largest terrestrial mammal that ever lived. Rhinos in North America became locally extinct during the Pliocene, and in northern Asia, and Europe during the Pleistocene.
The five living species fall into three categories. The critically endangered Sumatran Rhinoceros is the only surviving representative of the most primitive group, the Dicerorhinini, which emerged in the Miocene (about 20 million years ago)(Rabinowitz1995). The extinct Woolly Rhinoceros of northern Europe and Asia was also a member of this tribe. There are two living Rhinocerotini species, the endangered Indian Rhinoceros and the critically endangered Javan Rhinoceros, which diverged from one another about 10 million years ago. The two African species, the White Rhinoceros and the Black Rhinoceros, diverged during the early Pliocene (about 5 million years ago) but the Dicerotini group to which they belong originated in the middle Miocene, about 14 million years ago. The main difference between black and white rhinos is the shape of their lips. White rhinos have broad flat lips for grazing and black rhinos have long pointed lips for eating foliage. The name White Rhinoceros was actually a mistake for wijd (wide) because of their square lips. White Rhinoceros are divided into Northern and Southern subspecies.
A subspecific hybrid white rhino (Ceratotherium s. simum × C. s. cottoni) was bred at the Dvurkralv Zoo (Zoological Garden Dvur Kralove nad Labem) in the Czech Republic in 1977.
Interspecific hybridisation of Black and White Rhinoceros has also been confirmed [citation needed].
- Family Rhinocerotidae
- Subfamily Rhinocerotinae
- Tribe Aceratheriini
- Aceratherium (extinct)
- Acerorhinus (extinct)
- Alicornops (extinct)
- Aphelops (extinct)
- Chilotheridium (extinct)
- Chilotherium (extinct)
- Dromoceratherium (extinct)
- Floridaceras (extinct)
- Hoploaceratherium (extinct)
- Mesaceratherium (extinct)
- Peraceras (extinct)
- Plesiaceratherium (extinct)
- Proaceratherium (extinct)
- Sinorhinus (extinct)
- Subchilotherium (extinct)
- Tribe Teleoceratini
- Aprotodon (extinct)
- Brachydiceratherium (extinct)
- Brachypodella (extinct)
- Brachypotherium (extinct)
- Diaceratherium (extinct)
- Prosantorhinus (extinct)
- Shennongtherium (extinct)
- Teleoceras (extinct)
- Tribe Rhinocerotini
- Gaindatherium (extinct)
- Rhinoceros - Indian & Javan Rhinoceros
- Tribe Dicerorhinini
- Coelodonta - Woolly Rhinoceros (extinct)
- Dicerorhinus - Sumatran Rhinoceros
- Dihoplus (extinct)
- Lartetotherium (extinct)
- Stephanorhinus (extinct)
- Tribe Ceratotheriini
- Ceratotherium - White Rhinoceros
- Tribe Dicerotini
- Diceros - Black Rhinoceros
- Paradiceros (extinct)
- Tribe Aceratheriini
- Subfamily Elasmotheriinae
- Gulfoceras (extinct)
- Tribe Diceratheriini
- Diceratherium (extinct)
- Subhyracodon (extinct)
- Tribe Elasmotheriini
- Bugtirhinus (extinct)
- Caementodon (extinct)
- Elasmotherium - Giant Unicorn (extinct)
- Hispanotherium (extinct)
- Huaqingtherium (extinct)
- Iranotherium (extinct)
- Kenyatherium (extinct)
- Menoceras (extinct)
- Ougandatherium (extinct)
- Parelasmotherium (extinct)
- Procoelodonta (extinct)
- Sinotherium (extinct)
- Subfamily Rhinocerotinae
ReferencesISBN links support NWE through referral fees
- Forster, Lisa. 1998. "Scientists Crack Rhino Horn". Research News, Ohio University. Retrieved July 26, 2008.
- Chapman, Jan. 1999. The Art of Rhinoceros Horn Carving in China. Christies Books, London. ISBN 0-903432-57-9.
- Laufer, Berthold. 1914. "History of the Rhinoceros." In: Chinese Clay Figures, Part I: Prolegomena on the History of Defence Armor. Field Museum of Natural History, Chicago, pp. 73-173.
- Rhinoceros skin and horn characteristics (pdf file)
- Bensky, Dan, Clavey, Steven, Stoger, Erich and Gamble Andrew. (2004). Chinese Herbal Medicine: Materia Medica, Third Edition.
- [1]]Can we tame wild medicine? To save a rare species, Western conservationists may have to make their peace with traditional Chinese medicine. Rob Parry-Jones and Amanda Vincent New Scientist vol 157 issue 2115 - 03 January 98
- Robinson, Terry J. and V. Trifonov, I. Espie, E.H. Harley (01 2005). Interspecific hybridization in rhinoceroses: Confirmation of a Black × White rhinoceros hybrid by karyotype, fluorescence in situ hybridization (FISH) and microsatellite analysis. Conservation Genetics 6 (1): 141-145. Digital object identifier (DOI): 10.1007/s10592-004-7750-9.
- Ballenger, L. and P. Myers. 2001. "Rhinocerotidae" (On-line). Animal Diversity Web. Retrieved July 11, 2007.
- The Gale Group, Inc. 2005. White Rhinoceros. Grzimek's Animal Life Encyclopedia. Retrieved July 18, 2007.
- The Gale Group, Inc. 2005. Black Rhinoceros. Grzimek's Animal Life Encyclopedia. Retrieved July 18, 2007.
- The Gale Group, Inc. 2005. Sumatran Rhinoceros. Grzimek's Animal Life Encyclopedia. Retrieved July 23rd, 2007.
External links
- Rhinoceros Information
- International Rhino Foundation
- The Ol Pejeta Conservancy, Kenya
- SOS Rhino
- Save The Rhino
- Rhinoceros entry on World Wide Fund for Nature website.
- Rhino photographs and information
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