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World Will Completely Miss 2010 Biodiversity Target
Species classified by the International Union for Conservation of Nature (IUCN) as "threatened" increased by 2.1 percent in 2009, as 365 species were added to the organization's Red List of Threatened Species.1 Only 2 species were removed from the list.2 Since 1996, a total of 47,677 species of animals, plants, fungi, and protists (a group that includes protozoans and most algae) have been evaluated by the IUCN, and 17,291 of these are now considered threatened—a full 36 percent.3 (See Table 1.)
All species evaluated by IUCN are given a threat rating based on a standardized set of data that includes population size and structure and geographic range.4 Evaluated species for which data exist are divided into seven groups: least concern, near threatened, vulnerable, endangered, critically endangered, extinct in the wild, and extinct. Species in the three middle categories—vulnerable, endangered, and critically endangered—are collectively referred to as threatened. Species for which data are not available are not included in the seven groups, even if many of them are thought to be threatened.5
A complete evaluation of the world’s 1.7 million known species—not to mention the 3–50 million species that have yet to be discovered—is extremely far off, but some species families have been completely described and evaluated, including birds, mammals, and amphibians.6 Below the family level, reef-forming corals, conifers, cycads (palm-like plants), freshwater crabs, groupers, and most recently sturgeon have also been evaluated.7 Currently, 30 percent of amphibians, 21 percent of mammals, and 12 percent of bird species are listed as threatened with extinction.8 Of all groups evaluated, cycads and sturgeon have the highest proportion of threatened species, at 52 and 85 percent respectively.9 (See Figure 1.)
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