By Michael McCarthy, Environment Editor
The Independent, UK
Gorillas, vultures, corals, Asian crocodiles and even seaweeds are joining thousands of other species on the slide towards extinction, according to the latest edition of the Red List, the international catalogue of threatened wildlife, published yesterday.
In the past 12 months there have been nearly 200 to the list, which is published by the Swiss-based International Union for the Conservation of Nature (IUCN), taking the number of threatened species worldwide from 16,118 to 16,306.
This means that one in four of the world's mammals, one in eight birds, one third of all amphibians and 70 per cent of the world's assessed plants on the current list are in now in jeopardy. "Life on Earth is disappearing fast and will continue to do so unless urgent action is taken," the IUCN said yesterday.
The Red List is recognised as the most reliable evaluation of the conservation status of the world's species. It classifies them according to their extinction risk, through the categories extinct, critically endangered, endangered and vulnerable. Once an organism is classified as critically endangered, extinction is very close.
A grim statistic contained in the latest list is that the western gorilla (Gorilla gorilla) has moved from endangered to critically endangered, after the discovery that the main subspecies, the western lowland gorilla (Gorilla gorilla gorilla), has been severely depleted by the commercial bushmeat trade, and the Ebola virus.
Their population has declined by more than 60 per cent over the past 20 to 25 years, with about one third of the total population found in protected areas killed by the Ebola virus over the past 15 years.
The change has been revealed in a depressing reassessment of the status of the great apes, which shows the orang-utan, in particular, to be in desperate trouble. The Sumatran orangutan (Pongo abelii) remains in the critically endangered category and the Bornean orang-utan (Pongo pygmaeus) in the endangered category. Both are threatened by habitat loss due to illegal and legal logging and forest clearance for palm oil plantations. In Borneo, the Red List says, the area planted with oil palms increased from 2,000 sq km to 27,000 sq km between 1984 and 2003, leaving just 86,000 sq km of habitat available to the species throughout the island.
Another striking feature of the new list is that corals have been assessed and added to the list for the first time. Ten species from the Galapagos islands have entered the list, with two in the critically endangered category and one in the vulnerable category. Wellington's solitary coral (Rhizopsammia wellingtoni) has been listed as critically endangered (possibly extinct).
The main threats to these species are the effects of the El Niño warm water phenomenon in the Pacific Ocean, and climate change. In addition, 74 seaweeds from the Galapagos have been added to the list, 10 of them listed as critically endangered, with six of those highlighted as possibly extinct. The coldwater species are threatened by climate change and the rise in sea temperature that characterises El Niño. The seaweeds are also indirectly affected by overfishing, which removes predators from the food chain, resulting in an increase of sea urchins, and other herbivores that overgraze the algae.
The Gharial crocodile (Gavialis gangeticus), found in India and Nepal, is also facing threats from habitat degradation, and it too has moved from endangered to critically endangered. Its population has declined by 58 per cent, from 436 breeding adults in 1997 to just 182 in 2006. Dams, irrigation projects, sand mining and artificial embankments have all encroached on its habitat, reducing its domain to just 2 per cent of its former range.
Asia faces a further wildlife crisis with enormous declines in its populations of vultures, which are important as scavengers. The declines have been driven by the use on cattle of the anti-inflammatory drug diclofenac, which is fatal to the birds when they consume it in cattle carcasses. The red-headed vulture (Sarcogyps calvus) has moved from near-threatened to critically endangered, while the Egyptian vulture (Neophron percnopterus) has moved from least concern to endangered.
One of the saddest accounts of all concerns China's Yangtze river dolphin, or baiji, (Lipotes vexillifer), which was thought to be the world's rarest mammal, but may now have gone completely. After an intensive, but fruitless, search last November and December, it has been listed as critically endangered (possibly extinct).
The dolphin has not been placed in a higher category as further surveys are needed before it can be definitively classified as extinct. A possible sighting in late August 2007 is currently being investigated by Chinese scientists. The main threats to the species include fishing, river traffic, pollution and degradation of habitat.
Some good news...
There is one ray of hope in this year's Red List – the improving position of one of the world's rarest birds, the echo parakeet from Mauritius. Destruction of its forest habitat through farming and the spread of introduced species such as feral pigs, devastated its numbers, and by the end of the 1970s there were only 10 or so known individuals. But a captive breeding programme, run by the Mauritian Wildlife Foundation and the Government of Mauritius, with the support of the Durrell Wildlife Conservation Trust and the World Parrot Trust, saw 139 captive birds returned to the wild between 1997 and 2005, and this has successfully re-established the population.
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