In the Wanda mountains, near the China-Russia border, dense forest cover is sparse and any animal seen up to 500 meters away is easily tracked down. It's hard to imagine that this is where Siberian tigers roam as they usually prefer to skulk in the shadows of thick forests.

Wild?Siberian tigers. [File photo]

"We used to see roe deer a decade ago while driving by, but now, even a squirrel is rare," said Cao Zhiquan, chief of the Qiyuan Forest Farm under the Dongfanghong Forestry Bureau, northeast China's Heilongjiang province.

Winter is a tough season for the rare wild Siberian tigers as their prey, mainly red and roe deer as well as wild boars, become scarce -- sometimes dying from not having enough to eat or a hunter's bullet.

The ecology of the Wanda mountains has deteriorated from over-logging. Although the Chinese government has started a natural forest conservation project, restricting or banning the logging of natural forests in 2000, the broken food chain is still threatening the endangered tiger species, said Jiang Guangshun, a senior researcher of China's tiger protection project under the World Wildlife Fund (WWF).

"The number of red deer, tigers' favorite food, has greatly decreased," said Jiang.

Apart from the worsening environment, poaching is another big threat for tigers in winter, said Qiu Xiaoping, a police officer with border control section in the city of Shuangyashan.

"Paw prints of tigers are easier to be seen in the snow, and once poachers start tracking, it's hard for the animals to escape," said Qiu.

There are only about 20 wild Siberian tigers left in China, and according to Xinhua's calculation, seven have been found dead since 1993. Most of their deaths were related to human activities.

The latest case was in late October, when a 200-kg male tiger body was found with wire around its neck in a village in the township of Fuyuan, Mishan city.

Last November, leaders from 13 countries, including China and Russia, committed to back the international tiger recovery program, which aims to double the number of tigers in the wild by 2022.

Over the past year, all 13 forest farms under the forestry bureau have been allocated with part-time tiger observers.

Gao Kejiang, an observer with the Wulindong Forest Farm, said he was equipped with a digital camera and global positioning system.

"Anyone who finds tiger signs will report to us," said Gao.

Cao said the bureau also was performing a thorough campaign to clear traps that threaten the tigers and their prey, and was seeking cooperation opportunities with international wild animal protection organizations.

He also advised establishing Siberian tiger natural reserves.