Caring for orphaned antelope is part of the daily work for patrol officers at the Sonam Dargye Station. [Photo by Wang Zhuangfei/China Daily]

Tens of thousands of Tibetan antelope gather around Zhuonai Lake to give birth every year.

The season is among the busiest for police like Zhan, who camp in tents while observing and protecting the creatures.

"It's overwhelming when we open the tent in the morning and are surrounded by countless antelope," he says.

There was no electricity in the early years. Officers used gas lamps at night and killed time by playing cards.

Zhan, who's now head of his team, patrols several days once a month. Five or more officers drive two or three vehicles as a caravan. They bring such necessary supplies as dry food, gasoline, tents and satellite phones.

"The satellite phones are our lifeline," he says.

"They're our only link to the outside world. There's no mobile signal in the wilderness."

He recalls a dramatic incident in 2003, when his team discovered suspicious tire tracks near a lake while undertaking a joint patrol with officers from another station.

Zhan and a couple of colleagues were approaching the vehicles when they realized the others had fallen behind because of car problems.

"The poachers' cars were right in front of us," he recalls. "We couldn't wait."