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Pampas deer (''Ozotoceros bezoarticus'') live in the grasslands of South America at low elevations.〔Geist, Valerius. ''Deer of the world their evolution, behaviour, and ecology''. Mechanicsburg, Pa: Stackpole Books, 1998〕 They are known as or in Spanish and as in Portuguese. Their habitat includes water and hills, often with winter drought, and grass that is high enough to cover a standing deer.〔P., Walker, Ernest. ''Walker's Mammals of the world''. Baltimore: Johns Hopkins UP, 1991〕 Many of them live on the Pantanal wetlands, where there are ongoing conservation efforts, and other areas of annual flooding cycles. Human activity has changed much of the original landscape. They are known to live up to 12 years in the wild, longer if captive, but are threatened due to over-hunting and habitat loss. Many people are concerned over this loss, because a healthy deer population means a healthy grassland, and a healthy grassland is home to many species, some also threatened. Many North American birds migrate south to these areas, and if the Pampas deer habitat is lost, they are afraid these bird species will also decline. There are approximately 80,000 Pampas deer total, with the majority of them living in Brazil.〔''IUCN Mammal Red Data Book''. Gland, Switzerland: IUCN, 1982〕 ==Taxonomy and evolution== The Pampas deer are part of the New World deer, another term for all South American deer species. Fossil records indicate that New World deer traveled to South America from North America as part of the Great American Interchange around 2.5 million years ago, following the formation of the Isthmus of Panama. It is believed that they rapidly evolved into different species, with only a few surviving today. Due to the large continental glaciers and the high soil acidity in areas where there were no glaciers, a huge part of the fossil record has been destroyed, so there is no indication what the New World deer used to look like. Fossil records begin with clear differentiation and are close to what they currently look like. The Pampas deer evolved as plains dwellers. Their direct ancestor first appeared during the Pleistocene period (the Ice Age) during the Pampean Formation.〔''Grzimeks Animal Life Encyclopedia Mammals'' (Grzimek's Animal Life Encyclopedia). Vol. 15. Detroit: Gale Cengage, 2003〕 Scientists believe the deer evolved with no culling predators because when alarmed, they stamp their feet, have a particular trot and whistle, and deposit odor.〔 The Pampas deer share a similar gene pattern with another deer species called ''Blastocerus''. Unique to those two species, they have two fused chromosomes.〔 The Pampas deer have 3 subspecies: ''O. b. bezoarticus'' that live in eastern and central Brazil, south of the Amazon river into Uruguay. ''O. b. leucogaster'' that live in southwestern Brazil, to southeastern Bolivia, to Paraguay and into northern Argentina. ''O. b. celer'' from the southern part of Argentina. They are the most rare and are an endangered species.〔 Pampas deer are the most polymorphic mammals. This large genetic variation reflects the fact that there were millions at one time. Their current high nucleotide diversity shows that they had very large numbers even in just the recent past; so recent it is not reflected in their genes yet.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「pampas deer」の詳細全文を読む スポンサード リンク
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