MORE than 3,000 animals and plants will be added to the Red List of Endangered Species today, amid fresh warnings that global biodiversity is declining at an unprecedented rate.

A record 15,589 species — 7,266 animals and 8,323 plants and lichens — are known to be at risk of extinction, but the true number is likely to be even higher, according to a report from the IUCN, the world conservation union.

At least 15 species have died out over the past 20 years, and another 12 now survive only in captivity. Many more, however, are thought to have gone extinct without having been recorded, while a conservative approach to declaring species lost means that others not yet formally classed as extinct have probably died out.

The 3,330 species newly assessed as threatened include the fabulous green sphinx moth, from the Hawaiian island of Kaua’i, and the African begonia from Cameroon. Most of the new additions are amphibians, and have joined the Red List after the recent Global Amphibian Assessment that revealed one in three species of frog, toad, newt and salamander were under threat.

The Jambato toad from Ecuador, the golden toad from Costa Rica and the kama’o bird from Hawaii are among the species declared extinct in the past two decades. Britain has nine critically endangered species — the category at greatest risk — including the slender-billed curlew, the sociable lapwing and Spengler’s freshwater mussel. Another 49 species are classed as endangered or vulnerable, including the Atlantic cod and the Scottish wildcat.

The corncrake and the European otter, however, have been removed from the threatened list this year, after successful conservation efforts. Further good news has emerged from New Zealand, where storm petrel have been sighted again for the first time since the bird was presumed extinct in the 19th century. They are now classed as critically endangered.

Craig Hilton-Taylor, the IUCN Red List programme officer, said that the species included on the list represent the tip of an iceberg, as scientists do not yet have sufficient data to assess most of the world’s biodiversity.

Between 1.6 million and 1.9 million species are known to science, but the total is usually estimated at between 10 million and 30 million — and many of those described and classified are poorly understood.

Dr Hilton-Taylor said: “There is still much to be discovered about key species-rich habitats, such as tropical forests, marine and freshwater systems, or particular groups, such as invertebrates, plants and fungi, which make up the majority of biodiversity.”

Among plants only the conifers and cycads have been comprehensively evaluated, with 25 per cent and 52 per cent of species declared threatened respectively. Global studies of other groups have found that 12 per cent of birds, 23 per cent of mammals, 32 per cent of amphibians and 42 per cent of turtles and tortoises are under threat, but there has been no comprehensive assessment of marine or insect life, which account for most of global biodiversity.

The gravest threat to species lies in ecological changes triggered by human beings, such as global warming, industrial pollution and habitat loss. Experts said that intensive conservation efforts are needed to address a biodiversity crisis that has become the world’s sixth major mass extinction.

Russell Mittermeier, the president of the charity Conservation International, said: “This should serve as a wake-up call to take immediate action to prevent further species loss.

“It is not too late to act. We need better-funded efforts focused on those animals and plants on the brink of extinction, and on those areas where such species are concentrated.”

Achim Steiner, the IUCN director-general, said: “The situation facing our species is serious and getting worse. We must refocus and rethink the way in which society must respond to this global threat.”

BRITISH: AT RISK

Critically endangered
Common sturgeon, Acipenser sturio, fish
Spengler’s Freshwater Mussel, Margaritifera auricularia, mollusc
Slender-billed curlew, Numenius tenuirostris, bird
Sociable lapwing, Vanellus gregarius, bird
Ley’s whitebeam, Sorbus leyana, tree
Scottish wildcat, Felis silvestris grampia, cat

Endangered
Atlantic halibut, Hippoglossus hippoglossus, fish
Common skate, Dipturus batis, fish

WORLD: EXTINCT

Hawaiian thrush (kama’o), Myadestes myadestinus, bird
Kauai ’o’o, Moho braccatus, Hawaiian bird
Atitlán grebe, Podilymbus gigas, Guatemalan bird
Jambato toad, Atelopus ignesens, amphibian
Haha, Cyanea dolichopoda, Hawaiian plant