according to Russian scientists who have pioneered a method that uses sniffer dogs to count Siberian tigers, conservationists have overestimated the number of the endangered species. Last year, a survey backed by the World Wide Fund for Nature ( wwf ), estimated that there were between 415 to 475 animals living in Russia's far east, between the Amur River and the Pacific coast. This was twice the number counted in previous surveys and raised hopes that the tiger was winning its battle against extinction. "The wwf estimated the number of tigers by counting their tracks in the snow," says Sergei Shaitarov of the Tiger Protection Society in Vladivostok. The problem with this approach, he says, is that it is easy to count the same tiger in different places.

The new technique uses German shepherds that have been trained to distinguish between the odours of different tigers by rewarding a correct match. The Lazovsky team trained the dogs to distinguish between the odours of circus tigers. A survey in the Lazovsky reserve puts the number of tigers at 12, rather than 22 as estimated by the wwf.