CHANGSHA, Feb. 1 (Xinhua) -- Volunteers in central China's Hunan Province have spotted a group of endangered ducks during a recent observation.

A total of 49 Baer's pochard, a diving duck, were spotted Tuesday at Zhengbo Lake, part of Dongting Lake, China's second-largest freshwater lake, said Li Jianzhi, one of the volunteers.

"It was the biggest group of Baer's pochard ducks ever spotted at Zhengbo Lake," Li said.

The species breeds in northeast Asia and migrates south for winter. The migration usually starts in mid-October.

In March 2017, more than 20 Baer's pochard were spotted over Dongting Lake.

The species is listed as "critically endangered" by International Union for Conservation of Nature (IUCN).