HARBIN, Aug. 6 (Xinhua) -- The Siberian tiger population has exceeded 700, with more than 80 born this year, at the Siberian Tiger Park in northeast China.

The world's biggest artificial breeding base for Siberian tigers, the park in Harbin, capital of Heilongjiang Province, expects at least another 20 tigers to be born this year, said Liu Dan, an official at the park.

The park housed more than 620 Siberian tigers at the end of last year.

It has more than 200 female tigers of reproductive age, of which at least 50 are capable of giving birth this year.

Siberian tigers have a 105-day gestation period, and those living in the wild wait until their cubs are two years old before mating again. However, a captive female tiger can give birth twice a year.

The park sent 12 fully-grown artificially bred tigers to a virgin forest on Changbai Mountain in neighboring Jilin Province in 2002 where they underwent a four-year training program on surviving in the wild.

In the forest, each tiger established its own territory. A grown tiger usually lives in an area with a diameter of 100 to 300 kilometers, using urine to mark the boundary.

Fifteen cubs aged about two arrived in the forest from the breeding base in June to begin another training program.

The park was established in 1986 with just eight tigers and its population is nearly half of the total in China.

A survey by Chinese, American and Russian experts, organized by the United Nations Development Program, found in 1999 that only five to seven wild Siberian tigers were known to exist in the wild in Heilongjiang Province.

Siberian tigers, also known as Amur or Manchurian tigers, are among the world's 10 most endangered species and mostly live in northeast China and the Far East area of Russia. They are estimated to number just 400 in the wild, of which 10 to 17 live in northeast China.

Chinese scientists have adopted a series of measures to increase the survival rate of captive-bred Siberian tigers, such as DNA testing, regular health checks, and timely treatment and prevention of diseases.

The survival rate of cubs in the park exceeded 90 percent, said Liu Dan. Enditem