Common eland

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Common eland
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Subfamily: Bovinae
Genus: Taurotragus
Species: T. oryx
Binomial name
Taurotragus oryx
(Pallas, 1766)
Synonyms
  • Tragelaphus oryx

The common eland (Taurotragus oryx), also known as the southern eland or eland antelope, is a savannah and plains antelope found in East and Southern Africa. It is a species of the family Bovidae and genus Taurotragus. It was first described by Peter Simon Pallas in 1766.[2] An adult male is 1.63 metres (5.3 ft) tall at the shoulder (females are 20 centimetres (7.9 in) shorter) and weighs an average of 500–600 kilograms (1,100–1,300 lb, 340–445 kilograms (750–980 lb) for females). It is the second largest antelope in Africa, slightly smaller than the Giant Eland.[2]

Mainly a herbivore, its diet is primarily made up of grasses and leaves.[2] Common elands form herds of up to 500 animals, but are not territorial. The common eland prefers habitats with a wide variety of flowering plants such as savannah, woodlands, open and montane grasslands, avoiding dense forests.[2] It uses various forms of communication, notably loud barks, visual and postural movements and (in males during mating season) the flehmen response to communicate and warn others about danger.[2] The common eland provides rich and nutritious milk[2] and leather, and has been domesticated in many areas.

It is native to Botswana, Burundi, Congo, Ethiopia, Kenya, Lesotho, Malawi, Mozambique, Namibia, Rwanda, South Africa, South Sudan, Swaziland, Tanzania, Uganda, Zambia and Zimbabwe but is no longer present in Burundi[3] and Angola.[4] The common eland's population is decreasing but is still considered of Least Concern by International Union for Conservation of Nature.[1]

Contents

[edit] Etymology

The scientific name of the common species is Taurotragus oryx, composed of three words: tauros, tragos and oryx. Tauros is Greek for a bull or bullock, meaning the same as the Latin taurus.[5] Tragos is Greek for a male goat, referring to the tuft of hair that grows in the ear and its resemblance to a goat's beard.[6] Oryx is Latin and Greek (generally orygos) for pickaxe, which focuses at the pointed horns of North African antelopes like common eland and scimitar-horned oryx.[7] The common name eland is Dutch for elk.[8]

[edit] Physical description

Common eland

Common elands are spiral-horned antelopes belonging to the Bovid tribe of Tragelaphini. They are sexually dimorphic, with females being smaller than the males.[9] Females weigh 300–600 kg (660–1,300 lb), measure 200–280 cm (79–110 in) from the snout to the base of the tail and stand 125–153 cm (49–60 in) at the shoulder. Bulls weigh 400–942 kg (880–2,080 lb),[10] are 240–345 cm (94–136 in) from the snout to the base of the tail and stand 150–183 cm (59–72 in) at the shoulder. The tail adds a further 50–90 cm (20–35 in).[2][11]

Their pelage differs from place to place. North African elands have distinctive markings, which fade away in South African elands.[12] Coats are generally smooth over most of the body except for a rough mane. Females have a tan coat, while males have a darker tan coat with a bluish-grey tinge; there may also be a series of white stripes vertically on the sides of bulls (mainly in parts of the Karoo in South Africa). As males age they tend to turn a greyer color. Males have dense fur on their foreheads and a large dewlap on their throats.[2]

Both sexes have horns with a steady spiral ridge (resembling that of the bushbuck). The horns are visible as small buds in newborns and grow rapidly during the first seven months.[13] The horns of males are thicker and shorter than those of females (43–66 centimetres (17–26 in) long versus 51–69 centimetres (20–27 in)), as well as having a tighter spiral. Horns are used by males during rutting season to wrestle and butt heads with rivals, while females will stab predators with their horns.[2] Both sexes also use them during feeding.[further explanation needed]

Common elands are the slowest antelope, with a peak speed of 40 kilometres (25 mi) per hour that tires them quickly, but can maintain a 22 kilometres (14 mi) per hour trot indefinitely. Elands are capable of jumping up to 2.5 metres (8 ft 2 in) from a standing start when startled[12] (up to 3 metres (9.8 ft) for young elands).[2] Life expectancy is generally between 15 and 20 years, with some living up to 25 years.[2]

Eland herds are accompanied by a loud clicking sound that has been subject to considerable speculation. It is believed that the weight of the animal causes the two halves of its hooves to splay apart, and the clicking is the result of the hoof snapping together when the animal raises its leg.[14] The sound carries some distance from a herd, and may be a form of communication.[15]

[edit] Taxonomy

Juvenile East African eland (Tragelaphus oryx pattersonianus).

The common eland was first described in 1766 by the German zoologist and botanist Peter Simon Pallas. It belongs to the order Artiodactyla, family Bovidae and subfamily Bovinae.[16] Common eland are sometimes considered part of the genus Tragelaphus on the basis of molecular phylogenetics, but are usually categorized as Taurotragus, along with the giant eland (T. derbianus).[2]

[edit] Subspecies

Three subspecies of common eland have been recognized, although their validity requires investigation.[1][2][3][9][13]

  • T. o. livingstonii (Sclater, 1864; Livingstone's eland): also called kaufmanni, niediecki, selousi, and triangularis. It is found in the Central Zambezian Miombo woodlands. Livingstone's eland has a brown pelt with up to twelve stripes.
  • T. o. oryx (Pallas, 1766; Cape eland): also called alces, barbatus, canna, oreas. It is found in south and southwest Africa. The fur is tawny, and adults lose their stripes.
  • T. o. pattersonianus (Lydekker, 1906; east African eland): also called billingae. It is found in east Africa, hence its name. Its coat can have up to 12 stripes.

[edit] Diseases and parasites

Common elands are resistant to trypanosomiasis, a bacterial infection that has the tsetse fly as a vector, and show few symptoms when infected by the Rhipicephalus-transmitted disease theileriosis. However infection by one strain of the disease-causing bacteria (Theileria taurotragi) can be lethal. Clostridium chauvoei can also be harmful. Elands are hosts to several kinds of ticks. Elands produce antibodies to Brucella bacteria, but none for Mycobacterium paratuberculosis or various types of pneumonia that are normally infectious in cows or antelopes.[2]

[edit] Genetics and evolution

Male elands have 31 and females 32 diploid chromosomes – the male (Y) chromosome has been translocated to the short arm of an autosome.[2] Both the X and Y replicate late.[further explanation needed] The chromosomes resemble those of the greater kudu (Tragelaphus strepsiceros)[17] and the male eland and female greater kudu can produce a viable male hybrid, though it is not known if it is sterile. An attempt at crossing an eland with a kudu in a zoo produced a sterile hybrid. Female elands can also act as surrogates for bongos.[2]

The Bovidae family ancestors of the common eland evolved approximately 20 million years ago in Africa, with fossils found throughout the continent (as well as some in France) and the best record appearing in sub-Saharan Africa. The first members of the Tragelaphini (the eland's tribe) appear 6 million years in the past during the late Miocene. An extinct ancestor of the common eland (Taurotragus arkelli) appears in the Pleistocene and the first T. oryx fossil appears in the Holocene.[2]

[edit] Ecology and behavior

Common elands resting in herds.

Common elands are nomadic and crepuscular, feeding in the morning and evening, resting in shade when hot and remaining in sunlight when cold. They are commonly found in herds of up to 500, with individual members remaining in the herd anywhere from several hours to several months. Juveniles and mothers tend to form larger herds, while males may separate into smaller groups or wander individually. During estrus, groups tend to form more regularly.[2] In southern Africa common elands will often associate with herds of zebras, roan antelopes and oryxes.[18]

Common elands communicate via gestures, vocalizations, scent cues and display behaviors. The flehmen response also occurs, primarily in males in response to contact with female urine or genitals. Females will urinate to both indicate fertility during the appropriate phase of their estrous cycle, as well as to indicate lack of fertility when harassed by males.[2] Eland bulls will bark and attempt to attract the attention of others by trotting back and forth until the entire herd feels, with the bulls in the rear.[18] Some of their main predators include lions, wild dogs, cheetahs and spotted hyenas, with juvenile elands being more vulnerable than adults.[2]

[edit] Habitat and distribution

Distribution of the common eland over the savannas and plains in eastern and southern Africa.

Common eland live on the open plains of southern Africa and along the foothills of the great southern African plateau. The species extends north into Ethiopia and most arid zones of Sudan, to the east into western Angola and Namibia, and now even into South Africa (Lydon). However, there is low density of elands in Africa due to poaching, human settlement etc. There are at least 3 elands/sq mi (1.2/km2).[19] The species has been reintroduced in Zimbabwe.

Elands prefer to live in semi-arid areas that contain many shrub-like bushes, and often inhabit grasslands, woodlands, sub-desert, bush and mountaintops of altitudes about 15,000 ft (4600 m).[20] Elands do, however, avoid forests, swamps, and deserts. The places inhabited by elands generally contain Acacia, Combretum, Commiphora, Diospyros, Grewia, Rhus and Ziziphus trees and shrubs, and some of these also serve as their food.

Elands can be found in many National Parks and reserves today, like Nairobi and Tsavo National Park, Masai Mara NR, Kenya; Serengeti, Ruaha, and Tarangire National Park, Ngorongoro Crater, Tanzania; Kagera National Park, Rwanda; Nyika National Park, Malawi; Luangwa Valley and Kafue National Park, Zambia; Hwange and Matobo National Park, Tuli Safari Area, Zimbabwe; Kruger National Park, Giant's Castle, Suikerbosrand NR, South Africa.[21]

They live on home ranges that can be 174–422 km2 for females and juveniles and 21–75 km2 for males, but in the dry season the home ranges reduce to 9–58 km2 and 1–39 km2 for females and males respectively. Sometimes the home ranges of males overlap when the females are in estrus, that is, the phase when the female is sexually receptive. Since food resources are not scarce and females roam frequently, males need not have a territory of their own.[citation needed]

[edit] Diet

Elands are mainly grazers.

Common elands are herbivores which browse during drier winter months but have also adapted to grazing during the rainy season when grasses are more common.[2] They require a high-protein diet of succulent leaves of flowering plants but will consume lower quality plant material if available including forbs, trees, shrubs, grasses, seeds and tubers.[2][15][19][20] Most of their water is obtained from their food, though they will drink water when available.[2] Elands will use their horns to break off branches they cannot reach with their mouths.[22]

[edit] Sociability and reproduction

Two male elands fighting over dominance, Knowsley Safari Park, 9 September 2009

Females are sexually mature at 15–36 months and males at 4–5 years. Mating may occur anytime after reaching sexual maturity, and is especially observed during the rainy season. In Zambia young are born in July and August, a distinct breeding season.[20] This is due to elands gathering to feed on lush green plains with plentiful grass, in which some males and females start mating with each other in separate groups. Males chase the females in order to know if they is in estrus by testing their urine. Usually a female chooses the most dominant and fittest male to mate with. Sometimes she runs away from males trying to mate, causing more attraction. This results in fights between males, in which their hard horns are used. It is 2–4 hours before a female allows a male to mount. Males usually keep close contact with females in the mating period.[19] The dominant male can mate with more than one female.[20] Females have a gestation period of 9 months, and give birth to only one calf each time.[23]

There are three different social groups. Firstly, there is the male group, the smallest one, living close to each other and sticking firmly to a particular food or water source. Male groups are always roaming and are not stable. Secondly, the female group is much larger in size and covers greater areas.[20] They travel around the plains full of grass in wet periods and during dry periods prefer bushy areas. In an experiment it was found that females have a complex linear hierarchy. It is often thought that it is the mother which determines a female's dominance. Thirdly there is the nursery group, which is naturally formed when females give birth to calves. In no more than 24 hours the mother and calf join this group. The calves start befriending each other and stay back in the nursery group while the mother returns to the female group. The calves leave the nursery group when they are at least 2 years old and join a male or female group according to their sex.[23]

[edit] Conservation

Common eland in a zoo in Kraków, Poland.

Currently, common elands are not endangered. They are conserved by the U.S. Endangered Species Act, and regulated in international trade by the Convention on International Trade in Endangered Species.[24] Using ground counts and aerial surveys, the International Union for Conservation of Nature (IUCN) calculates the population density of the common eland to be between 0.05 and 1 per square kilometre with a total population estimate of 136,000.[1] Populations are considered stable or increasing in the countries of Namibia, Botswana, Zimbabwe, South Africa, Malawi and possibly Tanzania. Population trends vary from increasing to decreasing within individual protected areas, and are generally increasing on private land and decreasing in other areas.[1]

The IUCN states that about half of the estimated total population occurs in protected areas and 30% on private land. Protected areas that support major populations include Omo (Ethiopia), Serengeti, Katavi, Ruaha and Selous-Kilombero (Tanzania), Kafue and North Luangwa (Zambia), Nyika (Malawi), Etosha (Namibia), Kgalagadi Transfrontier Park (Botswana/South Africa) and Ukhahlamba Drakensberg Park (South Africa). Most of these populations appear to be stable. Relatively large numbers of common eland now occur on private land, particularly in Namibia, Zimbabwe and South Africa, reflecting its value as a trophy animal. Common elands have also been widely domesticated in Zimbabwe, South Africa and Kenya, as well as in Russia, Ukraine, and England.[25][26]

The population is gradually decreasing due to habitat loss (caused by expanding human settlements) and poaching for its superior meat.[27] As they are docile and inactive most of the time they can easily be killed.[28] The species became extinct in Swaziland, but has been reintroduced.[3]

[edit] Uses

Coat of arms of Grootfontein, Namibia.

Common eland are sometimes farmed and/or hunted for their meat, and in some cases can be better utilized than cattle due to their being more suited to their natural habitat. This has led to some Southern African farmers switching from cattle to eland. Common elands are also pictured as supporters in the logo of the coat of arms of Grootfontein, Namibia.

[edit] Husbandry

Common elands have a mild temperament and have been successfully domesticated for meat and milk production in South Africa and Russia.[22] Their need for water is quite low (they produce urine with a high-urea content) but they require a substantial grazing area, salt licks and large amounts of supplementary foods like maize, sorghums, melons and beans which can be expensive. A female can produce up to 7 kilograms (15 lb) of milk per day that is richer in milkfat than cow milk. The pleasant-tasting milk has a butterfat content of 11-17% and can be stored for up to eight months if properly prepared (versus several days for cow milk).[2]

Housing common elands is difficult due to their ability to jump over fences as tall as 3 metres (9.8 ft) or simply break through using their substantial mass. Sometimes wild eland will break through enclosures to mix with domesticated ones. Common eland can reproduce in captivity, but calf survival is low and the young may need to be separated from their mothers to ensure health and adequate feeding.[2] Husbandry requires care as while eland are generally not aggressive, they startle easily and require large amounts of space.[9]

[edit] References

  1. ^ a b c d e IUCN SSC Antelope Specialist Group (2008). "Tragelaphus oryx". IUCN Red List of Threatened Species. Version 2011.1. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/22055. Retrieved 21 November 2011. 
  2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y Pappas, LA (2002). "Taurotragus oryx" (pdf). Mammalian Species 689: 1–5. http://www.science.smith.edu/msi/pdf/689_Taurotragus_oryx.pdf. 
  3. ^ a b c Wilson, DE; Reeder DM (2005). "Artiodactyla:Bovidae:Bovinae". Mammal Species of the World: A Taxonomic and Geographic Reference, Volume 1 (3rd ed.). Baltimore: Johns Hopkins University Press. pp. 696–7. ISBN 0-8018-8221-4. 
  4. ^ "Tragelaphus oryx-Geographic range of common eland.". Iucnredlist.org. http://www.iucnredlist.org/apps/redlist/details/22055/0. Retrieved 5 January 2011. 
  5. ^ "Taurus". Online Etymology Dictionary. http://www.etymonline.com/index.php?allowed_in_frame=0&search=Tauro&searchmode=none. 
  6. ^ "Tragos". Online Etymology Dictionary. http://www.etymonline.com/index.php?allowed_in_frame=0&search=tragos&searchmode=none. 
  7. ^ "Oryx". Online Etymology Dictionary. http://www.etymonline.com/index.php?allowed_in_frame=0&search=Taurotragus+oryx&searchmode=none. 
  8. ^ "Common Eland". Tititudorancea.com. 14 October 2010. http://www.tititudorancea.com/z/common_eland.htm. Retrieved 5 January 2011. 
  9. ^ a b c Harris, H (April 30, 2010). "Husbandry Guidelines For The Common Eland" (PDF). http://nswfmpa.org/Husbandry%20Manuals/Published%20Manuals/Mammalia/Common%20Eland.pdf. Retrieved 2012-04-14. 
  10. ^ Kingdon, J (1997). The Kingdon Field Guide to African Mammals. Princeton University Press. ISBN 069111692X. 
  11. ^ "Common Eland: Tragelaphus (Taurotragus) oryx". Library.thinkquest.org. http://library.thinkquest.org/16645/wildlife/common_eland.shtml. Retrieved 5 January 2011. 
  12. ^ a b Estes, RD (1999). "Bushbuck Tribe". The Safari Companion: A Guide to Watching African Mammals, Including Hoofed Mammals, Carnivores, and Primates. Chelsea Green Publishing. pp. 154. ISBN 0-9583223-3-3. 
  13. ^ a b Skinner, JD; Chimimba, CT (2005). "Ruminantia". The Mammals of the Southern African Subregion (3rd ed.). Cambridge: Cambridge University Press. pp. 637–9. ISBN 0-521-84418-5. 
  14. ^ Carnaby T (2008). Beat About the Bush: Mammals. Jacana Media. pp. 172. ISBN 978-1-77009-240-2. 
  15. ^ a b "Animal Bytes – Common Eland". Seaworld.org. http://www.seaworld.org/animal-info/animal-bytes/animalia/eumetazoa/coelomates/deuterostomes/chordata/craniata/mammalia/artiodactyla/common-eland.htm. Retrieved 2012-04-08. 
  16. ^ "Common eland: Taxonomy". Museumstuff.com. http://www.museumstuff.com/learn/topics/Common_eland::sub::Taxonomy. Retrieved 5 January 2011. 
  17. ^ Groves, CP; Grubb P (2011). "Artiodactyla". Ungulate Taxonomy. Maryland: Johns Hopkins University Press. pp. 142. ISBN 978-1-4214-0093-8. 
  18. ^ a b Burton, RM (2002). "Eland". International wildlife encyclopedia (3 ed.). New York: Marshall Cavendish. pp. 757-8. ISBN 0-7614-7266-5. 
  19. ^ a b c "The Living Africa: Wildlife – Bovid Family – Common Eland". Library.thinkquest.org. http://library.thinkquest.org/16645/wildlife/common_eland.shtml. Retrieved 2012-04-09. 
  20. ^ a b c d e "Taurotragus Oryx:Information". University of Michigan Museum of Zoology. Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Taurotragus_oryx.html. 
  21. ^ "Wild Animals of Africa-Common eland". Wackywildlifewonders.com. http://www.wackywildlifewonders.com/files/animals/eland.html. Retrieved 5 January 2011. 
  22. ^ a b Rafferty JP, ed. (2010). "Elands, Antelopes". Grazers (1st ed.). New York, NY: The Rosen Publishing Group. pp. 77–78. ISBN 978-1-61530-465-3. 
  23. ^ a b "Taurotragus oryx (Common eland)-Ontogeny and Reproduction". Ultimateungulate.com. http://www.ultimateungulate.com/Artiodactyla/Taurotragus_oryx.html. Retrieved 5 January 2011. 
  24. ^ "Common Eland". http://www.antelopetag.com/assets/docs/Antelope/Common_Eland.pdf. 
  25. ^ "Conservation status (least concern)". Iucnredlist.org. http://www.iucnredlist.org/apps/redlist/details/22055/0. Retrieved 5 January 2011. 
  26. ^ East, comp. by Rod; Group, the IUCN/SSC Antelope Specialist (1999). "Common Eland (Conservation status)" (PDF). African antelope database 1998. Gland, Switzerland: The IUCN Species Survival Commission. p. 139. ISBN 2-8317-0477-4. 
  27. ^ East, compiled by R. (1990). "Common Eland (Tragelaphus oryx)" (PDF). West and Central Africa.. Gland: IUCN. p. 131. ISBN 2-8317-0016-7. http://books.google.co.in/books?id=n22ER5vZqTkC&pg=PA131&dq=common+eland&hl=en&sa=X&ei=yMJqT7THDtDKrAf227WhAg&ved=0CFoQ6AEwBg#v=onepage&q=common%20eland&f=false. 
  28. ^ "Ecology and conservation of the eland". Seaworld.org. http://www.seaworld.org/animal-info/animal-bytes/animalia/eumetazoa/coelomates/deuterostomes/chordata/craniata/mammalia/artiodactyla/common-eland.htm#ec. Retrieved 5 January 2011. 

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