Science Fair Project Encyclopedia
The conservation status of a species is an indicator of the likelihood of that species continuing to survive. Many factors are taken into account when assessing the conservation status of a species: not simply the number remaining, but the overall increase or decrease in the population over time, breeding success rates, known threats, and so on.
The best-known worldwide conservation status listing is the IUCN Red List, but many more specialised lists exist.
- Secure (SE): no immediate threat to the survival of the species. Examples: Human, Cat, Dog, Llama.
- Lower Risk (LR): of conservation concern, facing some risk of extinction in the medium to longer term. Divided into three subcategories, cd (conservation dependent), where cessation of current conservation measures could result in its becoming classified at a higher risk level, nt (near threatened), close to qualifying for listing as Vulnerable but not fully meeting those criteria, and lc (least concern), where threats exist but are not currently serious. Examples: Bigcone Douglas-fir (LRnt), Coast Redwood (LRcd), Leopard (LRlc).
- Vulnerable (VU): faces a high risk of extinction in the medium-term. Examples: Ring-tailed Lemur, Great White Shark.
- Endangered (EN): faces a very high risk of extinction in the near future. Examples: Blue Whale, Desert Bighorn Sheep.
- Critical or critically endangered (CR): faces an extremely high risk of extinction in the immediate future. Examples: Slender-billed Curlew, Spanish Lynx.
- Extinct in the Wild (EW): captive individuals survive, but there is no free-living, natural population. Examples: Przewalski's Horse (in preliminary recovery), Black-footed Ferret (undergoing reintroduction).
- Extinct (EX): the last remaining member of the species had died, or is presumed to have died beyond reasonable doubt, within recent history. IUCN sets a date of 1500 for modern extinctions. Examples: Thylacine, Dodo, Moa, Huia.
- Data Deficient (DD): a taxon is listed as Data deficient when there is inadequate information to make an assessment of its risk category, either through lack of knowledge of population size, threats to it, or to taxonomic uncertainty of the validity of the taxon. Examples: Scottish Crossbill (taxonomic uncertainty with respect to Parrot Crossbill), Yunnan Cypress (lack of knowledge of wild population size).
- Prehistoric: someplace between Extinct and Fossil: the species went extinct before 1500, but some specimens exist in a non-fossilized state. This is of particular use in human evolution, as molecular analysis of the specimens can be compared against that of other modern and prehistoric specimens.
- Fossil: not a conservation status as much as an indication that the species is only known from the fossil records.
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