An antelope species, widely believed to be the source of the unicorn legend and hunted to extinction in the wild, has been brought back from the brink, conservationists said today as they unveiled the latest update on threatened species.

It is thought the last wild Arabian oryx was shot in 1972, but a successful captive breeding programme and reintroduction efforts mean its population now stands at 1,000 in its wild home of the Arabian peninsula.

It has moved from "endangered" to the less-serious category of "vulnerable" in the latest red list of threatened species, the International Union for Conservation of Nature (IUCN) said.

It is the first time a species that was once classified as extinct in the wild has improved its fortunes to such an extent, the IUCN said.

Razan Khalifa Al Mubarak, director general of the Environment Agency Abu Dhabi, said: "To have brought the Arabian oryx back from the brink of extinction is a major feat and a true conservation success story, one which we hope will be repeated many times over for other threatened species.

"It is a classic example of how data from the IUCN red list can feed into on-the-ground conservation action to deliver tangible and successful results."

Despite the conservation victory, the latest update of the red list reveals that of the 19 species of frogs, toads and salamanders added to the the list this year, eight are critically endangered.

They include a species of harlequin toad from Peru (Atelopus patazensis) and a dwarf species of salamander from Guatemala (Dendrotriton chujorum).

An estimated 41% of amphibians are at risk of extinction globally, making them one of the most threatened groups of species, with habitat loss, pollution, disease and invasive species all factors in their decline.

Elsewhere, two-thirds of reptiles only found in New Caledonia, in the Pacific, are at risk of extinction in the first assessment of the group of species.

The Siau Island tarsier, a primate from the tiny volcanic island of Siau in Indonesia, has been added to the red list as critically endangered, while its newly discovered cousin, the Wallace's tarsier, is classified as "data deficient" because not enough is known about it to say if it is under threat.

An assessment of all 248 lobster species found that more than one-third (35%) were data deficient, prompting calls from the IUCN for more surveys of little-known species to aid effective conservation action.

Simon Stuart, chairman of the IUCN's species survival commission, said: "The key to halting the extinction crisis is to target efforts towards eradicating the major threats faced by species and their environment; only then can their future be secured.

"The IUCN red list acts as a gateway to such efforts, by providing decision makers with a goldmine of information not only on the current status of the species, but also on existing threats and the conservation actions required."