Every year, black-necked cranes spend winter in Lhundrub county of the Tibet autonomous region, and they return to the northern prairie in spring.

For Tibetan patrol officer Tenzin, the work of watching over the cranes is a glory.

"People consider it auspicious when the cranes return to their home villages," Tenzin was quoted as saying by the China News Service recently. Lhundrub county has become a natural reserve for the species.

Together with other patrol officers, the 59-year-old has been helping to keep the birds safe for nearly seven years.

Their efforts have paid off. The number of black-necked cranes in Tibet has grown to more than 8,000 from fewer than 2,000 at the end of the 20th century.

Listed as a first-class State-protected animal, the cranes are unique to the plateau region. The Tibetan people regard them as sacred.

Tenzin's main daily routine includes patrolling, feeding and rescuing.

"When I am on duty, I make sure the cranes are not chased by stray dogs," Tenzin said. "And I ensure the safety of any birds that are sick or injured."

According to the county's forestry and grassland bureau, there are between 2,000 and 2,200 black-necked cranes wintering in the county right now.

"The black-necked cranes mainly make their winter home around the county's two reservoirs," said Luo Qin, a staff member in the bureau.

"This winter our bureau has distributed more than 6,750 tons of wheat to nine patrol officers to guarantee the black-necked cranes have enough food."