CHENGDU - China has started its once-a-decade  census of endangered giant pandas, according to forestry authorities in southwest Sichuan Province, a major habitat of the rare species.

The census, the fourth since it was first launched in the 1970s, began Sunday with a pilot survey in the Wanglang National Reserve in the city of Mianyang, which is believed to have the largest number of wild pandas in the country, said Yang Xuyu, an official with the provincial forestry administration, on Monday.

About 70 trackers are currently being trained at the nature reserve and will start their work in two or three days, Yang said.

The pilot survey is expected to end by early July, and then the nationwide census will start, he said.

The trackers will collect panda droppings for DNA analysis, which will allow zoologists to track individual pandas and accurately estimate the number of pandas living in the wild, said Chen Youping, director of the reserve's administrative bureau.

The census is expected to ascertain not only the number of wild pandas but also their living conditions, age structure and change of habitat.

The previous census ten years ago counted 1,596 wild pandas in China with 1,206 of them living in Sichuan, including 230 in the Wanglang reserve and its nearby regions.