A new list of the most critically endangered mammals in the world features dozens of regognizable faces, including the orangutan, blue whale and Bactrian camel.
The list was published last month by a global team of scientists led by the Zoological Society of London and is available at http://www.edgeofexistence.org. The researchers set out to rank "Evolutionarily Distinct and Globally Endangered" (EDGE) species.
Most lists of endangered species only take into account such factors as total size of the wild population, the severity of threats to their habitats and the likelihood of near-term extinction.
Terms such as "threatened," "endangered" and "critically endangered" are used to describe increasingly dire situations for populations in the wild.
The EDGE list takes into account two additional factors that make the compilation unique.
First, the rankings give preference to species that are evolutionarily distinct, or the most biologically different from other living species. Although the loss of any species is a tragedy, the scientists at the EDGE project argue that some species are more unique than others.
For example, there is only one species of giant panda and two living species of elephants. If any of these were to die out, there would be no other animals that could replace them ecologically or for research into their evolutionary origins.
On the other hand, there are 38 species of mice in the wild, many of which are nearly identical in their genetic makeup and ecological niche. If one were to die out, another closely related species could take its place.
The other criterion for EDGE species is the degree to which conservationists are already concerned with the animals. The researchers want conservationists to pay more attention to these underrepresented animals.
Many of these animals are critical players in their ecosystems with unique evolutionary histories, but without the "cute" or "awesome" factor of more recognizable species.
One example is the long-beaked echidna, which is ranked at number two on the list. This animal, found only in New Zealand, is a close relative of the platypus and is one of only a handful of primitive egg-laying mammals still existent today.
Another is the northern hairy-nose wombat, a marsupial (like their more famous cousins, kangaroos) that burrows underground to hide during the day. Only one small colony remains, consisting of just 115 animals.
Still, it is the more famous animals that attract much of the attention on the list. They include both African and Asian elephants, four species of rhinoceros, and seven different monkeys and apes, including the orangutan.
Three out of four freshwater river dolphins are critically endangered, including the Chinese River Dolphin, which occupies the number one spot on the list. Last year, an extensive survey of the Yangtze river failed to find any remaining specimens.
As a result, the dolphin is believed to be functionally extinct, meaning there are not likely to be enough individuals to sustain a population in the wild.
Another sad standout is the blue whale, the largest animal in the world. Although the population was once over 200,000, current estimates place the number closer to 5,000.
Each of these 100 species represents a unique lineage that will die out forever if significant action is not taken immediately.
