Tag Archives: extinctions

more extinctions on the way

The western gorilla is “critically endangered” — close to extinction — and all the great apes are in trouble. A number of corals have moved to more endangered positions; the Asian crocodile “Gharial” has moved to critically endangered — only 182 breeding adults in 2006. A number of vultures have declined — largely because of drugs given to livestock and intentional poisonings of carcasses. Here in North America, 90 reptile species are threatened with extinction and 738 are threatened. The Wild Apricot tree in Asia has been declared Endangered, and a Malaysian herb has officially been declared extinct.

All this is from the new report from the IUCN (World Conservation Union), which maintains a “Red List” of threatened species. The Red List of Threatened Species lists 41,415 species in all, listing the threatened species from “vulnerable”, “endangered”, to “critically endangered”. The “critically endangered” category faces an “extremely high risk of extinction in the wild”, based on rapid decline in population (more than 90% in last 10 years or 3 generations) or range, or extremely small numbers of mature individuals — e.g., fewer than 250.

The 2007 reports lists for “critically endangered”: 1 in 4 mammals, 1 in 8 birds, 1 in 3 amphibians, and 70% of all plants that have been studied are threatened with extinction — a total of 16,306 species in all, an increase of 188 from last year’s list of endangered species. The numbers of threatened species are increasing across almost all the major taxonomic groups. Extinction rates are 100-1000 times higher than natural background rates. Species in the tropics are still at the greatest risk. Australia, Brazil, China, and Mexico hold large numbers of threatened species. Continental extinctions are becoming as common as island extinctions.

On the math: Does the “increase of 188” count species that went extinct last year? The IUCN is not counting the Yangtze River dolphin as extinct, although the most recent survey concluded that they were likely extinct. But, say there were 10 extinctions last year, then that would be 198 species added to the critically endangered list, and 10 taken off as they were moved to extinct. Something to figure out.

I think I want a Battlestar Galactica-like survivors count for Earth. 2007 Sept. 13 CE, survivors count:

  • 6,000 species of mammal (of which the Yangtze River dolphin was one);
  • 10,000 species of birds;
  • 8,000 species of reptiles;
  • 13,000 species of freshwater species;
  • 6,000 species of amphibian.

AP 9/13 via boston.com, Red List Categories & Criteria v.3.1, Introduction to the IUCN Red List of Threatened Species, IUCNredlist.org, “Extinction Crisis Escalates” (9/12 press release from IUCN).

freshwater dolphin extinction

Yangtze River freshwater dolphin
One of the last Yangtze River
freshwater dolphins.
Photo from CNN/Reuters.

One of only four species of river dolphin is officially extinct; the last member of the species probably died sometime in the last few months. Just thirteen were found in the last survey a few years ago, and the 2006 survey found none. The last member in captivity died in 2002. [Turvey et al, Journal of the Royal Society Biology Letters (2007/8/7); media coverage in CNN;
channel 4
; allheadlinenews
]

Douglas Adams wrote movingly about the Yangtze River dolphin in Last Chance to See, excerpts of which are posted at flying squid blog. The dolphins — which are extinct as a result of human activity, including the Three Gorges Dam — had a hard life over the last decades. They navigated by echolocation, and all the human activity in the Yangtze created constant white noise. It’s unspeakably sad to imagine the experiences of the last Yangtze River dolphins.

The Yangtze River dolphin is the first large mammalian species to go extinct in fifty years, and the first cetacean species to die from human causes in modern history. The other three river dolphin species are also endangered.

Incredibly fucked up.