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The conservation status of a group of organisms (for instance, a species) indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation status: not simply the number of individuals remaining, but the overall increase or decrease in the population over time, breeding success rates, and known threats. The IUCN Red List of Threatened Species is the best known worldwide conservation status listing and ranking system. Species are classified by the IUCN Red List into nine groups set through criteria such as rate of decline, population size, area of geographic distribution, and degree of population and distribution fragmentation.〔(Categories and Criteria ) The IUCN Red List of Threatened Species. Retrieved 18 September 2015.〕〔IUCN. (2012) (''IUCN Red List Categories and Criteria: Version 3.1'' ) Second edition. Gland, Switzerland and Cambridge, UK. ISBN 9782831714356.〕 Also included are species that have gone extinct since 500 AD. When discussing the IUCN Red List, the official term "threatened" is a grouping of three categories: critically endangered, endangered, and vulnerable. * Extinct (EX) – No known individuals remaining * Extinct in the wild (EW) – Known only to survive in captivity, or as a naturalized population outside its historic range * Critically endangered (CR) – Extremely high risk of extinction in the wild * Endangered (EN) – High risk of extinction in the wild * Vulnerable (VU) – High risk of endangerment in the wild * Near threatened (NT) – Likely to become endangered in the near future * Least concern (LC) – Lowest risk; does not qualify for a higher risk category. Widespread and abundant taxa are included in this category. * Data deficient (DD) – Not enough data to make an assessment of its risk of extinction * Not evaluated (NE) – Has not yet been evaluated against the criteria. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) aims to ensure that international trade in specimens of wild animals and plants does not threaten their survival. Many countries require CITES permits when importing plants and animals listed on CITES. ==Multi-country systems== In the European Union (EU), the EU Wildlife Trade Regulation〔(【引用サイトリンク】title=EU Wildlife Trade Regulation )〕 is legislation to provide for the implementation of CITES within the EU, and additional measures. NatureServe conservation status focuses on Latin America, USA, Canada, and the Caribbean. It has been developed by scientists from NatureServe, The Nature Conservancy, and the network of natural heritage programs and data centers. It is increasingly integrated with the IUCN Red List system. Its categories for species include: ''presumed extinct'' (GX), ''possibly extinct'' (GH), ''critically imperiled'' (G1), ''imperiled'' (G2), ''vulnerable'' (G3), ''apparently secure'' (G4), and ''secure'' (G5). The system also allows ambiguous or uncertain ranks including ''inexact numeric ranks'' (e.g. G2?), and ''range ranks'' (e.g. G2G3) for when the exact rank is uncertain. NatureServe adds a qualifier for ''captive or cultivated only'' (C), which has a similar meaning to the IUCN Red List ''extinct in the wild'' (EW) status. The Red Data Book of the Russian Federation is used within the Russian Federation, also accepted in parts of Africa. 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「Conservation status」の詳細全文を読む スポンサード リンク
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