NAGOYA, Japan (Reuters) - About a fifth of the world’s vertebrates are threatened with extinction, a major review has found, highlighting the plight of nature that is the focus of global environment talks underway in Japan.

The study by more than 170 scientists across the globe used data for 25,000 species from the International Union for Conservation of Nature’s (IUCN) Red List of threatened species and examined the status of the world’s mammals, birds, amphibians, reptiles and fishes.

The authors found, on average, 50 species of mammals, birds and amphibians move closer to extinction each year because of expansion of farms and plantations, logging and over-hunting. Another factor was competition from other species, particularly those introduced from other areas.

But the study, published in the journal Science, also found that conservation efforts had curbed the overall rate of loss.

It highlighted 64 mammal, bird and amphibian species that have improved in status, including three species that were extinct in the wild and have been re-introduced: the California Condor, the black-footed ferret in the United States and Przewalski’s horse in Mongolia.

Delegates from nearly 200 countries are holding two weeks of talks in the Japanese city of Nagoya to set new 2020 targets to protect plant and animal species, draft a protocol to share genetic resources between countries and companies and allocate more funding to protect nature.

CLEAR EVIDENCE

The United Nations says Nagoya needs to agree tougher targets to save forests, reefs, rivers and wetlands that underpin livelihoods and economies. Preserving the richness of species is vital to ecosystems and the services they provide, such as clean water, fisheries and pollination of crops.

“This is clear evidence for why we absolutely must emerge from Nagoya with a strategic plan of action to direct our efforts for biodiversity in the coming decade,” said Julia Marton-Lefevre, director-general of IUCN, which groups governments, scientists and conservation groups.

The study found Southeast Asia suffered the most dramatic recent losses largely because of rapid expansion of palm oil plantations and rice crops and logging.

A separate study published in Science said the world’s biological diversity would continue to decline this century, but the rate could be slowed with the right policy choices.

Scientists from nine countries compared five recent global environmental assessments and peer-reviewed studies examining likely future changes in biodiversity.

Co-leader of the study, Paul Leadley of the University Paris-Sud, France, said doing nothing would lead to catastrophic biodiversity loss.

He said slowing climate change and deforestation could curb the loss of species, but this needed better policies to avoid large-scale conversion of forests for biofuel plantations.

The study said differences in policy action taken now could either lead to an increase in global forest cover of about 15 percent in the best case or losses of more than 10 percent in the worst case by 2030.