African elephant: Difference between revisions
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{{Taxobox |
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| name = African elephants<ref name=MSW3/> |
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| image = Serengeti_Elefantenbulle.jpg |
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| image_caption = Loxodonta africana (male) |
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| regnum = [[Animal]]ia |
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| phylum = [[Chordate|Chordata]] |
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| classis = [[Mammal]]ia |
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| ordo = [[Proboscidea]] |
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| familia = [[Elephantidae]] |
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| genus = '''''Loxodonta''''' |
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| genus_authority = Anonymous, 1827 |
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| subdivision_ranks = [[Species]] |
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| subdivision = |
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''[[Loxodonta adaurora|L. adaurora]]'' [[Extinction|†]]<br> |
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:ssp. ''L. a. adaurora'' [[Extinction|†]] |
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:ssp. ''L. a. kararae'' [[Extinction|†]] |
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''[[African Bush Elephant|L. africana]]''<br> |
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''[[Loxodonta atlantica|L. atlantica]]'' [[Extinction|†]] <br> |
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:ssp. ''L. a. angammensis'' [[Extinction|†]] |
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:ssp. ''L. a. atlantica'' [[Extinction|†]] |
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''[[African Forest Elephant|L. cyclotis]]''<br> |
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''[[Loxodonta exaptata|L. exaptata]]'' [[Extinction|†]] |
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| range_map=African Elephant distribution map.svg |
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| range_map_caption=Distribution of ''Loxodonta africana'' (2007) |
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}} |
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'''African elephants''' are the species of [[elephant]]s in the [[genus]] '''''Loxodonta''''' (Greek for 'oblique-sided tooth'<ref name=Fossils>{{Cite book | last = Kalb | first = Jon E. | coauthors = Assefa Mebrate | title = Fossil Elephantoids from the Hominid-Bearing Awash Group, Middle Awash Valley, Afar Depression, Ethiopia | publisher = The American Philosophical Society | year = 1993 | location = Independence Square, Philadelphia | pages = 52–59 | url = http://books.google.com/books?id=AOzn0vdaDgUC&lpg=PA53&ots=OCPoM5tSar&dq=Loxodonta%20adaurora&pg=PA59#v=onepage&q=Loxodonta%20adaurora&f=false | isbn = 0-87169-831-5 }}</ref>), one of the two existing genera in [[Elephantidae]]. Although it is commonly believed that the genus was named by [[Georges Cuvier]] in 1825, Cuvier spelled it ''Loxodonte''. An anonymous author romanized the spelling to ''Loxodonta'' and the [[International Code of Zoological Nomenclature|ICZN]] recognizes this as the proper authority.<ref name=MSW3>{{MSW3 Proboscidea | id = 11500008 | page = 91 | heading = Genus ''Loxodonta''}}</ref> |
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[[Fossil]] members of ''Loxodonta'' have only been found in [[Africa]], where they developed in the middle [[Pliocene]]. |
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== Size == |
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African elephants are bigger than [[Asian elephant]]s. Males stand {{convert|3.2|-|4.0|m|ft|abbr=on}} tall at the shoulder and weigh {{convert|4700|-|6048|kg|lb|abbr=on}}, while females stand {{convert|2.2|-|2.6|m|ft|abbr=on}} tall and weigh {{convert|2160|-|3232|kg|lb|abbr=on}}.<ref>{{cite journal | title = Loxodonta africana | journal = Mammalian Species | date = 6 Jan 1978 | author = Barry Laurson & Marc Bekoff | volume = 92 | pages = 1–8| url = http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/pdf/i0076-3519-092-01-0001.pdf | format = PDF | accessdate = 2010-08-05}}</ref> |
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==Teeth== |
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[[File:Etosha elefant.jpg|thumb|left|A male African bush elephant in [[Namibia]]]] |
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Elephants have four molars; each weighs about {{convert|5|kg|lb|abbr=on}} and measures about {{convert|30|cm|in|abbr=on}} long. As the front pair wears down and drops out in pieces, the back pair shifts forward, and two new molars emerge in the back of the mouth. Elephants replace their teeth six times. At about 40 to 60 years of age, the elephant no longer has teeth and will likely die of starvation, a common cause of death. |
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Their tusks are teeth; the second set of incisors become the tusks. They are used for digging for roots and stripping the bark off trees for food, for fighting each other during mating season, and for defending themselves against predators. The tusks weigh from {{convert|23|-|45|kg|lb|abbr=on}} and can be from {{convert|1.5|-|2.4|m|ft|sigfig=1|abbr=on}} long. Unlike Asian elephants, both male and female African elephants have tusks.<ref><http://www.denverzoo.org/animals/asianElephant.asp></ref> The [[Tooth enamel|enamel plates]] of the [[molars]] are fewer in number than in Asian elephants.<ref name="Domestic">{{cite book | author = Clutton-Brock, Juliet| title = A Natural History of Domesticated Mammals | year = 1987 | isbn = 0521346975 | page = 208}}</ref> |
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== Species == |
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*[[African bush elephant]] (''Loxodonta africana'').<ref name=MSW3/> |
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*[[African forest elephant]] (''Loxodonta cyclotis'').<ref name=MSW3/> |
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*''[[Loxodonta adaurora]]'', [[extinct]], presumed antecedent of the modern African elephants.<ref name=Fossils/> |
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*''[[Loxodonta atlantica]]'', [[extinct]].<ref name=Fossils/> |
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*''[[Loxodonta exaptata]]'', [[extinct]].<ref name=Fossils/> |
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Bush and forest elephants were formerly considered [[subspecies]]<ref name=estes>{{cite book | last = Estes | first = Richard D. | title = The Safari Companion | page = 223 | publisher = Chelsea Green Publishing Company | year = 1999 | isbn = 1890132446 }}</ref> of the same species ''Loxodonta africana''. As described in the entry for the forest elephant in the third edition of ''[[Mammal Species of the World]]'' (MSW3),<ref name=cyclotis>{{MSW3 Proboscidea | id = 11500010 | page = 91 | heading = ''Loxodonta cyclotis''}}</ref> there is now evidence they should be considered as separate species, but also some recent evidence to the contrary, and the question remains undecided at present. |
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[[File:Serengeti_Elefantenherde2.jpg|thumb|left|Females usually live in smaller or larger herds, here ''Loxodonta africana'' in [[Tanzania]]]] |
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Much of the evidence cited in MSW3 is morphological. The African forest elephant has a longer and narrower mandible, rounder ears, a different number of toenails, straighter and downward tusks, and considerably smaller size. With regard to the number of toenails: the African bush elephant normally has four toenails on the front foot and three on the hind feet, the African forest elephant normally has five toenails on the front foot and four on the hind foot (like the Asian elephant), but hybrids between the two species commonly occur. |
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MSW3 lists the two forms as full species<ref name=MSW3/> and does not list any subspecies in its entry for ''Loxodonta africana''.<ref name=africana>{{MSW3 Proboscidea | id = 11500009 | page = 91 | heading = ''Loxodonta africana''}}</ref> However, this approach is not taken by the [[United Nations Environment Programme]]'s [[World Conservation Monitoring Centre]] nor by the [[International Union for Conservation of Nature]] (IUCN), both of which list ''L.cyclotis'' as a synonym (not even a subspecies) of ''L.africana''.<ref name=wcmc>[http://www.unep-wcmc.org/isdb/Taxonomy/tax-species-result.cfm?displaylanguage=ENG&Genus=%25Loxodonta%25&source=animals&speciesNo=71831&Country=&tabname=names UNEP-WCMC database entry for ''Loxodonta cyclotis'']</ref><ref name=iucn>{{IUCN2010|assessors=Blanc, J.|year=2008|version=2010.1|id=12392|title=Loxodonta africana|downloaded=10 June 2010}}</ref> |
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A consequence of the IUCN taking this view is that the [[IUCN Red List]] makes no independent assessment of the conservation status of the two forms of African elephant. It merely assesses the two forms taken together as a unit as [[Vulnerable species|vulnerable]].<ref name=iucn/> |
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==Conservation== |
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[[Image:Ivory trade.jpg|thumb|upright|Men with African elephant tusks, [[Dar es Salaam]], c. 1900]] |
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Poaching significantly reduced the population of ''Loxodonta'' in certain regions during the 20th century. An example of this poaching pressure is in the eastern region of Chad—elephant herds there were substantial as recently as 1970, with an estimated population of 400,000; however, by 2006 the number had dwindled to about 10,000. The African elephant nominally has governmental protection, but [[poaching]] is still a serious issue.<ref>{{cite web | title = 100 Slaughtered Elephants Found in Africa | url = http://www.livescience.com/animalworld/060830_chad_elephants.html | author = Goudarzi, Sara | date = 2006-08-30 | accessdate = 2006-08-31 | work = [http://LiveScience.com/ LiveScience.com]}}</ref> |
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Human encroachment into or adjacent to natural areas where bush elephants occur has led to recent research into methods of safely driving groups of elephants away from humans, including the discovery that playback of the recorded sounds of angry [[Western honey bee|honey bees]] is remarkably effective at prompting elephants to flee an area.<ref>Lucy E. King, Iain Douglas-Hamilton, Fritz Vollrath (2007) African elephants run from the sound of disturbed bees. ''Current Biology'' 17: R832-R833</ref> Some elephant communities have grown so large, in Africa, that some communities have resorted to culling large numbers to help sustain the ecosystem.<ref>{{cite web|last=Wilson |first=Sam |url=http://news.bbc.co.uk/1/hi/world/africa/4392800.stm |title=Africa | Elephant explosion triggers cull row |publisher=BBC News |date=2005-11-06 |accessdate=2009-11-22}}</ref> |
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==See also== |
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[[Ivory trade]] |
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==References== |
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{{Reflist}} |
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==External links== |
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{{commons}} |
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*[http://elephant.elehost.com/About_Elephants/about_elephants.htm Elephant Information Repository] - An in-depth resource on elephants |
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*[http://faculty.jsd.claremont.edu/dmcfarlane/MtElgon/index.htm "Elephant caves" of Mt Elgon National Park] |
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*[http://elephantvoices.org/ ElephantVoices] - Resource on elephant vocal communications |
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*[http://elephanttrust.org/ Amboseli Trust for Elephants] - Interactive web site |
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*David Quammen: " Family ties - The elephants of Samburu" [[National Geographic Magazine]] September 2008 [http://ngm.nationalgeographic.com/2008/09/samburu-elephants/quammen-text link] |
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{{Proboscidea}} |
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{{DEFAULTSORT:African Elephant}} |
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[[Category:Elephants]] |
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[[Category:EDGE Species]] |
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[[Category:National symbols of the Central African Republic]] |
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[[Category:National symbols of the Republic of the Congo]] |
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[[Category:National symbols of Côte d'Ivoire]] |
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[[Category:National symbols of Guinea]] |
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[[Category:National symbols of Swaziland]] |
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[[bs:Afrički slon]] |
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[[ca:Elefant africà]] |
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[[es:Loxodonta]] |
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[[fr:Éléphant d’Afrique]] |
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[[fy:Afrikaanske Oaljefanten]] |
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[[ko:아프리카코끼리속]] |
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[[hi:अफ़्रीकी हाथी]] |
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[[id:Gajah afrika]] |
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[[it:Loxodonta]] |
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[[he:פיל אפריקני]] |
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[[nl:Afrikaanse olifanten]] |
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[[ja:アフリカゾウ属]] |
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[[no:Afrikanske elefanter]] |
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[[pt:Elefante-africano]] |
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[[ru:Африканские слоны]] |
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[[stq:Loxodonta]] |
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[[sl:Afriški slon]] |
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[[fi:Afrikannorsut]] |
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[[sv:Afrikansk elefant]] |
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[[tl:Loxodonta]] |
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[[ta:ஆப்பிரிக்க யானை]] |
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[[zh-yue:非洲象]] |
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[[zh:非洲象]] |
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Revision as of 20:21, 23 September 2010
hi elephant