IUCN Red List
Origin of IUCN Red List
historical usage of IUCN Red List
The classifications and defining criteria for the IUCN Red List have changed over the years to accommodate the ever-advancing means by which a conservation status is determined. As the knowledge and observation of species have improved, so has the analysis of such crucial information as geographic distribution, population fragmentation, and of course rate of decline. As of 2018, the IUCN Red List classifies species into these categories:
• extinct (EX) = having no living member remaining, either in the wild or in captivity.
• extinct in the wild (EW) = having members living only in captivity or as a naturalized population.
• critically endangered (CR) = having the highest risk of extinction among threatened species.
• endangered (EN) = threatened with extinction.
• vulnerable (VU) = likely to be classified endangered in the near future unless circumstances that threaten reproduction and survival improve.
• near threatened (NT) = inclined to be threatened with extinction but not yet qualified as vulnerable.
• conservation dependent (CD) = dependent on conservation practices to prevent its becoming threatened with extinction.
• least concern (LC) = assessed to be thriving, with a distribution or population status that is neither threatened nor near threatened.
• data deficient (DD) = lacking a properly assessed conservation status due to insufficient information.
• not evaluated (NE) = not having been studied and assessed for conservation status by the IUCN.
It is sometimes assumed that “threatened” is one of the Red List categories, but the term threatened species is used by the IUCN to include all species that are classified under these three categories: vulnerable , endangered , and critically endangered .
Because extensive research and verification are required before a species is classified as either extinct or extinct in the wild , there may be any number of critically endangered species that are in fact extinct or extinct in the wild. The IUCN’s avian authority, BirdLife International , has therefore recommended—and the IUCN has adopted—two subcategories under the critically endangered category:
• possibly extinct (PE) = so critically endangered that evidence of existence is profoundly limited and extremely difficult to verify.
• possibly extinct in the wild (PEW) = so critically endangered that evidence of existence outside of captivity or a naturalized population is profoundly limited and extremely difficult to verify.
Words nearby IUCN Red List
How to use IUCN Red List in a sentence
As this list shows, punishments typically run to a short-ish jail sentence and/or a moderately hefty fine.
Former Red Sox star Curt Schilling says his politics are keeping him out of Cooperstown.Conservative Curt Says His Politics, Not His Pitching, Kept Him Out of the Hall of Fame|Ben Jacobs|January 9, 2015|DAILY BEAST
Nor does the jet have the ability to capture high-definition video, utilize an infra-red pointer.
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There was deep brown flesh, and bronze flesh, and pallid white flesh, and flesh turned red from the hot sun.Powerful Congressman Writes About ‘Fleshy Breasts’|Asawin Suebsaeng|January 7, 2015|DAILY BEAST
Beginners must be warned against mistaking the edges of cells, or particles which have retained the red stain, for bacilli.A Manual of Clinical Diagnosis|James Campbell Todd
Under the internal pressure his whiskers stood on end and his face grew red.The Bondboy|George W. (George Washington) Ogden
“You appear to feel it so,” rejoined Mr. Pickwick, smiling at the clerk, who was literally red-hot.The Posthumous Papers of the Pickwick Club, v. 2(of 2)|Charles Dickens
Ripperda's eye fell upon the mantle,—it was discoloured a dark red in many places, he nodded his head, and the man withdrew.The Pastor's Fire-side Vol. 3 of 4|Jane Porter
C was a Captain, all covered with lace; D was a drunkard, and had a red face.