A fifth of the world’s mammals, birds, fish, reptiles and amphibians are under threat of extinction, a major report warned yesterday as governments continued to discuss efforts to tackle losses to the natural world.
A study examining the status of more than 25,000 vertebrate species on the International Union for Conservation of Nature Red List of Threatened Species found the number at risk of extinction was increasing.
According to the research in the journal Science, on average 52 species of mammals, birds and amphibians slide a step closer to extinction each year, moving into a more threatened category on the Red List.
But without conservation action the situation would be much worse, with an additional 20 per cent of species moving into a more threatened category, the report estimated.
Work to conserve species has helped a number of animals turn their fortunes round, from the black-footed ferret, which became extinct in the wild before being reintroduced in the US, to the white rhino and the humpback whale.
According to information from the IUCN Red List, which assesses species on the level of extinction risk they face and considers them to be under threat if they fall into the categories of vulnerable, endangered or critically endangered, 19 per cent of vertebrates are threatened.
The percentage of each group of invertebrates under threat ranged from 13 per cent of birds to 41 per cent of amphibians, the study found.
But 64 species had seen an improvement in their status as a result of work to help protect them and their habitat.
Others have not have not seen their Red List status improve as a result of conservation, but without it they would be declining - and in the case of some species, such as the black stilt, a wading bird only found in New Zealand, would have gone extinct, the study found.
Simon Stuart, chairman of the IUCN’s species survival commission and an author of the study, said history showed “conservation can achieve the impossible”, as in the case of the white rhino in southern Africa.
But the researchers warned that long-term investment is needed to prevent species disappearing; action has been under way for 30 years to protect the golden lion tamarin and for 115 years for the white rhino.
And the current level of action is far outweighed by the scale of the threat to the world’s wildlife.
Amongst vertebrates – animals with a backbone – the main threats are agricultural expansion, logging, over-exploitation and the impact of invasive alien species.
The study said that the increase in extinction risk was most marked in South East Asia where plantations of crops such as oil palm, logging for timber, conversion of land to rice paddies and hunting have all hit wildlife.
A separate report by the Zoological Society of London warned that it was not just threatened species which were suffering, but that common animals were also declining – with knock-on effects on services people rely on, such as pollination of crops.
The Evolution Lost report said populations of mammal, bird, reptile, amphibian and fish species had declined on average by 30 per cent in the past 40 years.
Over the past decades, land mammal populations are estimated to have declined by a quarter, marine fish by a fifth and freshwater fish by up to 65 per cent.