The population of rare Black-necked Cranes wintering in west China's Tibet Autonomous Region this year hit a record high to 6,900, 3,000 more than that of 1992, according a recent survey.

The January 2007 joint survey by the Tibet Plateau Institute of Biology and the International Crane Foundation also found close to 32,000 Bar-headed Geese, more than double the population of 15 years ago, in Tibet.

At a time when most Asian water birds were declining, this discovery was especially surprising, said the survey.

Unlike most of China's large wildlife, the Black-necked Cranes live very close to people, descending from alpine meadows to winter in farming areas of nearby valleys, according to the research team.

"The farmlands in southern Tibet provide a perfect combination of harvested grain fields for feeding and rivers for nighttime roosting," said Professor Tsamchu Drolma from the Tibet Plateau Institute of Biology and co-leader of the expedition.

The team of researchers covered more than 2,600 km over 11 days, searching Lhasa, Yarlung, and Nyang River valleys and their tributaries for the birds.

"We were delighted by how many the numbers have grown. The creation of the Yarlung Zangbo River Middle Reaches Black-necked Crane Nature Reserve along with better wildlife protection by the Tibet Forestry Department and public awareness has made a big difference for both of these species," said Dr. Mary Anne Bishop, expedition leader from the International Crane Foundation.

Over 76 percent of the cranes and 48 percent of the geese were found within boundaries of the new nature reserve, according to the survey.

Another factor contributing to the recovery of the Black-necked Crane may be warming conditions in Tibet, which lead to better survival of the cranes, said experts.

But over the long-term, climate change could lead to reduced water in Tibet and less wetland areas suitable for nesting cranes and geese, they analyzed.

Temperatures have risen 0.42 Celsius degree each decade since the 1980s, according to the Chinese Academy of Meteorological Sciences.

The Black-necked Crane was the least known of the world's cranes until recent decades. In 1993, its population was estimated at about 5,600. The 2007 survey, combined with other recent studies, indicated a world population of over 11,000.

The Black-necked Crane is the only one of the world's 15 crane species that inhabits high altitude wetlands, with the species mainly limited to the Qinghai-Tibetan Plateau and adjacent areas. Smaller numbers also appear in Bhutan, India, and China's Yunnan-Guizhou Plateau.

(Xinhua News Agency February 21, 2007)