Portal:Extinct and endangered species

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The extinct and endangered species portal

In biology, extinction is the termination of an organism or of a group of organisms (taxon), normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence.

More than 99 percent of all species, amounting to over five billion species, that ever lived on Earth are estimated to be extinct. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described. More recently, in May 2016, scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described.

Through evolution, species arise through the process of speciation—where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche—and species become extinct when they are no longer able to survive in changing conditions or against superior competition. The relationship between animals and their ecological niches has been firmly established. A typical species becomes extinct within 10 million years of its first appearance, although some species, called living fossils, survive with virtually no morphological change for hundreds of millions of years.

Mass extinctions are relatively rare events; however, isolated extinctions are quite common. Only recently have extinctions been recorded and scientists have become alarmed at the current high rate of extinctions. Most species that become extinct are never scientifically documented. Some scientists estimate that up to half of presently existing plant and animal species may become extinct by 2100.

A dagger symbol (†) placed next to the name of a species or other taxon is often done to indicate its status as extinct.

The Iberian lynx (Lynx pardinus), an endangered species.

An endangered species is a species which has been categorized as very likely to become extinct. Endangered (EN), as categorized by the International Union for Conservation of Nature (IUCN) Red List, is the second most severe conservation status for wild populations in the IUCN's schema after Critically Endangered (CR).

In 2012, the IUCN Red List featured 3079 animal and 2655 plant species as endangered (EN) worldwide. The figures for 1998 were, respectively, 1102 and 1197.

Many nations have laws that protect conservation-reliant species: for example, forbidding hunting, restricting land development or creating preserves. Population numbers, trends and species' conservation status can be found at the lists of organisms by population.

Selected article

Vaquita6 Olson NOAA.jpg
Vaquitas are the smallest and most endangered species of the cetacean order and are endemic to the northern end of the Gulf of California. The vaquita is stocky and has a classic porpoise shape. The species is distinguishable by the dark rings surrounding their eyes, patches on their lips, and a line that extends from their dorsal fins to their mouth. Their back is a dark grey that fades to a white underside. As vaquitas mature, the shades of grey lighten. Female vaquitas tend to grow to be a bit larger than the male. Females usually end up at a length of 140.6 cm (55.4 in), compared to the males 134.9 cm (53.1 in). The lifespan, pattern of growth, seasonal reproduction, and testis size of the vaquita are all similar to that of the harbour porpoise. The flippers are proportionately larger than other porpoises' and the fin is taller and more falcate. The skull is smaller and the rostrum is shorter and broader than in other members of the genus. The females are discernible from the males due to their larger size.


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Did you know...

  • ...that the song "The Lord God Bird" by Sufjan Stevens is about the possibly extinct ivory-billed woodpecker.
  • ...that the Vaquita is the rarest cetacean in the world with an estimated 30 individuals.
  • ...that the Chihuahuan vole was the largest subspecies of the Meadow vole (Microtus pennsylvanicus) and that is possibly extinct as no lifesigns were recorded in its only known habitat in the Ojo Galeana swamp in Chihuahua, Mexico since 1998.
  • ...that 9,300 year old fossil remains of the Steppe bison (Bison priscus) were unearthed in 2011?
  • ...that the Mastodon became extinct by climate change and not by overhunting as previously thought?
  • ...that only 2500 people lived on New Zealand when the last moa species became extinct in the 15th century.
  • ...that Walton Ford, a famous wildlife artist created a painting about the extinct elephant bird.
  • ...that the 24-rayed Sunstar Heliaster solaris from the Galapagos waters died out during the El Niño-Southern Oscillation event in 1983/1984
  • ... that the Christmas Island pipistrelle is possibly extinct after a survey in 2009 has failed to locate any individuals.
  • ... that the Banggai crow was rediscovered on Peleng in 2007 after it was only known by two museum specimens from the late 19th century.
  • ... that the extinct flightless Snipe-rail had the smallest wings of all known rail species in proportion to its body size.
  • ... that only 300 copies were published of Walter Rothschild's book Extinct Birds.
  • ... that cave lions were about 25 percent larger than the modern African Lions and Asiatic lions.



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Corvus hawaiiensis in grass.jpg
An attempt to release the captive reared Hawaiian crows into the wild failed in late 2016, after three of the five released birds have died.


Extinct and endangered species news

  • 22 November 2016 An auction at Billingshurst, West Sussex, fetches £346,300 for a nearly complete dodo skeleton.
  • 24 June 2016 A former captive individual of the Spix's macaw was spotted in the wilderness of Bahia 16 years after this species became extinct in the wild in Brazil.
  • 14 June 2016 The Bramble Cay melomys has declared officially extinct by the Australian government after it was last seen in 2009 and its very small habitat has been destroyed due to climate change.
  • 13 March 2016 Less than 50 individuals of the King Island scrubtit, a critically endangered subspecies of the scrubtit endemic to King Island, are known to survive.


...Archive

Extinct and endangered species topics

Extinction - Extinction event - Local extinction - Lists of extinct animals - List of extinct plants - Fossil - Holocene extinction - Cretaceous–Paleogene extinction event - Cambrian–Ordovician extinction event - Ordovician–Silurian extinction events - Triassic–Jurassic extinction event - Late Devonian extinction - Permian–Triassic extinction event - Signor–Lipps effect - Australian megafauna - Dwarf elephant - Pseudoextinction - Extinction vortex - Prehistoric reptile - Human overpopulation - Human extinction - Voluntary Human Extinction Movement - Evolution - Biodiversity - Invasive species - Breeding back - Lazarus taxon - Endangered species - Critically endangered - Vulnerable species - Least-concern species - Data deficient - BirdLife International - IUCN Red List - Endangered Species Act of 1973 - International Union for Conservation of Nature

Extinction events

Neoproterozoic
Palæozoic
Mesozoic
Cenozoic
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Millions of years before present

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The WikiProject for this topic is Extinction.

Other WikiProjects connected with extinction are:

See also Wikispecies, a Wikimedia project dedicated to classification of biological species.

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