Sunday, June 08, 2008

Extinction of the Caribbean Monk Seal

Caribbean monk seal -- taxidermied specimen at Harvard.

In a not-too-surprising announcement
, the U.S. Government has determined that the Caribbean Monk Seal is extinct.

This is not too surprising, because a Caribbean Monk Seal has not been seen for more than 50 years, and they were vanishingly rare for 100 years before that.

A look over the list of extinct mammals in the world suggests this extinction is indeed news-worthy because extinctions of mammals are very RARE.

Of all the mammals that have gone extinct in historical times, 10 are marsupials from Australia, 2 are ant eaters, 1 is a type of sea-cow, 29 are small rodents (mostly island-endemic species of mice and rats), 2 are types of pikas, 3 are types of shrews, 10 are species of bats, 5 are types of ungulates (gazelles and deer, more on them in a minute), and 4 are carnivores (1 island-endemic type of fox, 1 type of seal, 1 type of sea lion, 1 type of sea mink)

Animals that are not extinct because they were never a species include :
  • Aurochs which are now classified as simply a type of cow whose type has been recreated by backbreeding;

  • The Tarpan which is now classified as simply a type of wild horse whose type has been recreated by backbreeding;

  • Quaggas which have been shown to be nothing more than a coat-color variation of the Plains Zebra and which has also been recreated by backbreeding;

  • The Japanese Wolf which is simple a subspecies of wolf (Canis lupus) ;

  • The Mexican Grizzly which is simply a subspecies of brown bear (Ursus arctos);

  • The Bali Tiger which is simply a subspecies of tiger (Panthera tigris);

  • The Javan Tiger which is simply a subspecies of tiger (Panthera tigris);

  • The Barbary Lion which is simply a subspecies of African lion (Panthera leo) -- and it is a subspecies that appears to still exist in captivity;

  • The West African Black Rhinoceros which is simply a subspecies of black rhino (Diceros bicornis);

  • The Syrian Wild Ass, which is simply a species of Onager (Equus hemionus).

Of the 57 species that I have listed as exinct, some may not be species, some may never have existed, and some may still exist in the wild.

For example, I have included the Bluebuck among the extinct ungulates (it went extinct around 1800), even though the species is only known from four mounted specimens in museums, along with some bones and horns. While this animal is considered a species of the Hippotragus group which includes Sable (Hippotragus niger) and the Roan Antelope (Hippotragus equinus), I can find no evidence that actual DNA work has been done to confirm that this animal is not simply a local color variant of one or the other of these animals.

I have also included the Red Gazelle (Gazella rufina) in the ungulates list even though taxonomists now believe it is simply a variation of common Red-fronted Gazelle (Gazella rufifrons), and that the Red-fronted Gazelle is simply a variation of the Thompson's Gazelle (Gazella thomsoni);

Schomburgk's Deer is also included in the extinct ungulates, even though it probably still exists in Laos, as Schomburgk's Deer antler turned up in a medicine shop in 1999 and the country remains undersurveyed;

I include the Arabian Gazelle in the extinct ungulates list even though it is known from only one (!) example reportedly collected in the Farasan Islands in the Red Sea in 1825. There is considerable debate as to where this animal was actually collected (the gazelles now on the Farasan Islands are common Mountain Gazellem aka Gazella gazella), and whether it is simply a mislabeled Queen Sheba's Gazelle (see below).

Another "ungulate with issues" is the Queen Sheba's Gazelle. Though now listed as extinct, this designation is probably premature. This gazelle species was considered common in Yemen in 1955 and very little biological research has been done in remote part of this inhospitable country due to the rise of a marxist regime in South Yemen in 1969, and the rise of scores of local islamic warlords since the reunfication of the two Yemens in the 1990s. In addition, this gazelle may exist in captivity at the Al Wabra Wildlife Preserve in Quatar (see picture at right of an animal identified as a Queen Sheba's Gazelle).

Finally, just because a species is "written off" as extinct by the the International Union for the Conservation of Nature (IUCN) does not mean that this animal has in fact disappeared from the face of the earth. In fact, the IUCN has to announce the rediscovery of extinct species often enough that a term has been coined to describe the phenomenon -- Lazarus Species.

In the world of mammals, nine previously-listed extinct mammals have been rediscovered alive since the 1990s, including one of my favorite ugly mammals, the Cuban Solenodon (Solenodon cubanus), and one of my favorite cute mammals, the Mahogany Glider (Petaurus gracilis).

The Almiqui or Cuban Solenodon was recently rediscovered. >> To read more

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