Bogor – Thousands of the world's frog species are on the brink of extinction and efforts to conserve them are urgently needed, the president of the Association of Southeast Asian Zoos said on Wednesday.

"It has been established that Indonesia has the largest number of frog species in Asia and the second largest in the world after Brazil," Jansen Manansang said on the sidelines of an international workshop on amphibians being held in Cisarua subdistrict. "However, certain species are on the brink of extinction."

Manansang said Indonesia's rice-field frog was among the endangered species as a result of the use of pesticides that drove the frogs from their natural habitat.

The survival of frogs is also threatened by global warming, which has promoted the spread of clyrid fungi infection throughout the world. "This condition has caused amphibians to come under pressure," he said.

These threats were highlighted in a global amphibian assessment, which reported that of the 5,918 amphibian species evaluated, 35 had become extinct, 1,896 were in critical condition and 2,604 on the brink of extinction.

In an effort to save amphibians, a number of groups cooperated to organize the Year of the Frog in 2008. Another group carried out a project that identified some 351 new species of frogs, but their conservation status was still unknown.

"This workshop is expected to issue recommendations on the conservation of amphibians in Indonesia and help familiarize the role of amphibians in protecting balance in the ecosystem," Manansang said.