Asia's tiger population could be close to extinction with fewer than 3,500 tigers remaining in the wild and most clustered in fragmented areas making up less than 7 percent of their former range in Asia, a study says.
The study in the latest issue of the online journal PLoS Biology says saving tigers living in 42 sites across Asia from poachers, illegal loggers and the wildlife trade is crucial to prevent the species becoming extinct in the wild.
The cost of achieving this would be an additional US$35 million a year in funding for law enforcement and monitoring, the report's lead authors from the US-based Wildlife Conservation Society say.
The World Bank, global conservation organization IUCN and Panthera, a big cat environmental group, also contributed to the study.
"The tiger is facing its last stand as a species," John Robinson, executive vice president of conservation and science for the Wildlife Conservation Society, said in a statement.
Of the tigers remaining in the wild, only about 1,000 are breeding females.
The authors said in spite of decades of efforts by conservationists, much of the decline was being driven by demand for tiger body parts used in traditional medicine. Overhunting of prey and destruction of hunting grounds were other reasons.
Lead author Joe Walston from WCS and his co-authors identified 42 tiger "source sites" that contained breeding populations of tigers and which had the potential to seed the recovery of tigers across wider areas.
India had 18 sites, the Indonesian island of Sumatra eight and the Russian far east six, with others in Malaysia, Thailand, Laos and Bangladesh.
"Based on available data, no source site was identified in Cambodia, China, North Korea or Vietnam," said the study. And it added that there was no evidence of breeding populations of tigers in Cambodia, China Vietnam or North Korea.
Most of the 42 source sites were small, under pressure from encroachment and with small tiger populations.
"Only five, all of which are in India, maintain tiger populations close to 80 percent of their estimated carrying capacity," the study says.
"Thus, the recovery of populations in source sites alone would result in a 70 percent increase in the world's tiger population."
The study was issued ahead of a major U.N. conference in Japan next month at which nations are expected to agree on new targets to try to halt the decline in the loss of plant and animal species.
The authors calculate the annual cost of managing the source sites at $82 million, which included the cost of law enforcement, wildlife monitoring, community involvement and other factors.