XINING - Pregnant Tibetan antelopes have begun their annual migration to a lake deep within the Hoh Xil Nature Reserve in Qinghai province to give birth, the reserve's management bureau said on Tuesday.

At around 7:30 pm on May 3, about 50 Tibetan antelopes were seen crossing the Qinghai-Tibet highway to Zonag Lake in Hoh Xil, which is known as the "delivery room" for the migratory species.

Every year, tens of thousands of the expectant antelope mothers migrate to the lake between the end of May and early June. They usually depart the area with their offspring in August.

The animals usually mate in December and give birth in late June or early July.

The Tibetan antelope is mostly found in the Tibet autonomous region, Qinghai and the Xinjiang Uygur autonomous region. The animals are a Class 1 protected species in China.

The antelope population declined sharply from 200,000 to 20,000 in the 1980s because of illegal hunting. The population has since recovered, thanks to measures taken to protect habitat and stricter enforcement of the hunting ban.

In July, Hoh Xil became a world heritage site.

Xinhua