"If the current biological environment can be maintained, the lake is sure to become a paradise for whooper swans," said Li Laixing, an ornithologist at the Northwest Plateau Institute of Biology under the Chinese Academy of Sciences.

"Birds tend to change their migrating routes or destinations if they find attractive spots midway," said Li.

Amid deep ice and snow for thousands of years, warm springs scattered beneath rivers, lakes and wetlands on the Qinghai-Tibet Plateau have kept many places temperate, which are suitable for birds such as the whooper swan to live and propagate.

To date, more than 1,000 whooper swans have settled beside Qinghai Lake, which is the country's largest saltwater lake.

Years of research indicates that Spring Bay at the core area of the lake is a major paradise for whooper swans, where plenty of floating grass and schools of fish offer a rich food source for them, said Li.

Qinghai Lake is about midpoint of the whoopers' normal migrating route. While some will go no further, the stronger swans will travel the remaining two-fifths of the total route west to another winter shelter in the Xinjiang Uygur Autonomous Region.

"The whooper swans are very clever," said Li. "The weaker ones will sometimes choose a suitable place halfway rather than travel all the 4,000 kilometers to Xinjiang if they feel weak.

"The young often tend to follow the weak's example so they no longer have to suffer the long flight." He said that they could save their strength for migrating back.

Singing, dancing and claw prints of the whoopers are no longer strange to local residents, and have become something of an amusement.

During the lake's boom time, flocks of birds of other varieties and bird eggs can be found everywhere on the islands and lakesides, and warbles of birds can be heard miles away.

To protect the paradise for birds and echo the universal call for ecological environment protection, the country set up the state-level Qinghai Lake Natural Protection Zone at the end of 1997.

Ornithologists have also caught sight of white-headed geese and wild ducks.

In addition, large quantities of red sheldrakes and other duck species were also seen by the experts.

(eastday.com February 26, 2003)