Colombian spider monkeys, Galapagos snails, unique South African rabbits and one of the world's largest freshwater fish are in stark danger of extinction, a nature body warned today.

Also under threat of disappearing in the near future, according to the Swiss-based World Conservation Union (IUCN), are the 21 species of albatross, dozens of types of shark and rayfish and Mediterranean dolphins.

All are among a total of 12,259 varieties of animal, plant and water life described as critically-endangered in this year's version of the IUCN's Red List, the key reference for biologists tracking the state of the planet's health.

And, according to the inter-governmental organisation which works with civil society groups and scientists around the globe, it is largely humans' fault.

"Places such as the Galapagos, Hawaii and the Seychelles are famed for their beauty, their diversity of plants, animals and ecosystems," said IUCN Director General Achim Steiner, introducing the 2003 list.

"But the Red List tells us that human activities are leading to a swathe of extinctions that could make these islands ecologically and aesthetically barren."

The IUCN said studies show that Indonesia, Brazil, China and Peru have the highest number of endangered birds and mammals while plants are most under threat in Ecuador, Malaysia and Sri Lanka as well as in Indonesia and Brazil.

All are countries where industrialisation, forest clearance and tourism have developed rapidly in recent decades.

The Red List includes extinctions that have been recorded since the start of the 16th century, by this year totalling 762.

But biologists say that there are almost certainly hundreds, if not thousands, more as so many species, especially of the smallest animals, insects and plants, go unrecorded.

Humans to blame
Island populations of native plants and animals disappear with the arrival of stronger species, often brought by boat or plane or to provide food for settlers, like goats that have devastated parts of Charles Darwin's "workshop of evolution", Ecuador's Galapagos.

There was a similar picture on the islands of Hawaii where there has been rapid housing development, hotel construction and intensive farming. "The future for Hawaiian flora looks grim," the IUCN said.

The spider monkey in Colombia and Venezuela, and its black howler cousin in Mexico, have been driven into smaller and smaller areas by urban growth, agriculture and cattle ranching.

And the population of the Giant Catfish of Southeast Asia's Mekong River, which grows up to three metres long and can weigh 300 kg, has dropped by 80% since 1990 from over-fishing and blocking of its migratory routes by dams.

But the IUCN said the downward spiral could be stopped -- exemplified by governments and peoples who had made conscious efforts to save species like the Arabian oryx and the white rhino. "By working together, we can help conserve what remains of the earth's biodiversity," said Red List compiler Craig Hilton-Taylor.