Thursday, November 11, 2010

ONE-FIFTH OF WORLDS VERTEBRATE SPECIES THREATENED



The most comprehensive assessment of the world’s vertebrates (mammals, bird, amphibians, reptiles and fishes) confirms an extinction crisis with one-fifth of species threatened. However, the situation would be worse were it not for current global conservation efforts, according to a study launched by the International Union for Conservation of Nature (IUCN).

The study, coordinated by Dr Simon Stuart, Chair of IUCN’s Species Survival Commission and visiting professor at the University of Bath, used data for 25,000 species from The IUCN Red List of Threatened Species™, to investigate the status of the world’s vertebrates and how this status has changed over time.

The results show that, on average, 50 species of mammal, bird and amphibian move closer to extinction each year due to the impacts of agricultural expansion, logging, over-exploitation and invasive alien species.

The research, to be published in the international journal Science, involved 174 scientists from 115 institutions and 38 countries.

However, whilst the study confirms previous reports of continued losses in biodiversity, it also presents clear evidence of the positive impact of conservation efforts around the globe.

Results show that the status of biodiversity would have declined by nearly 20 per cent if conservation action had not been taken.

Dr Stuart said: “History has shown us that conservation can achieve the impossible, as anyone who knows the story of the White Rhinoceros in southern Africa is aware.”

“But this is the first time we can demonstrate the aggregated positive impact of these successes on the state of the environment.”

The study highlights 64 mammal, bird and amphibian species that have improved in status due to successful conservation action. This includes three species that were extinct in the wild and have since been re-introduced back to nature: the California Condor and the Black-footed Ferret in the United States, and Przewalski’s Horse in Mongolia.

Conservation efforts have been particularly successful at combating invasive alien species on islands. The global population of the Seychelles Magpie-robin, increased from fewer than 15 birds in 1965 to 180 in 2006 through control of introduced predators, like the Brown Rat, and captive-breeding and re-introduction programmes.

Another conservation success story is the ban on commercial whaling, which has seen the Humpback Whale move from Vulnerable to Least Concern.

The authors caution that their study represents only a minimum estimate of the true impact of conservation, highlighting that some nine per cent of threatened species have increasing populations. Their results show that conservation works, given resources and commitment.

They also show that global responses will need to be substantially scaled up, because the current level of conservation action is outweighed by the magnitude of threat.

(Photo: NOAA's National Ocean Service)

University of Bath

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