Black-necked grebes flap and frolic on the West Lake. [Photo by Cheng Guolong/Tide News]

An ecological highlight delighted visitors at Hangzhou's West Lake on Jan 27, when a group of 11 black-necked grebes — rare migratory waterbirds under China's national second-class protection — were spotted landing and swimming together on the lake.

Experts say these birds are highly sensitive to water quality and habitat conditions and they usually stop briefly in Hangzhou during their winter migration, often for less than a day. The sighting of 11 at once is considered exceptional.

A group of 11 black-necked grebes enjoy a leisurely swim on the West Lake after their long-haul flight. [Photo by Cheng Guolong/Tide News]

Conservationists attribute the rare gathering to improved water quality and reduced human disturbance, which are turning West Lake into a reliable stopover for migratory birds.

Visitors are advised to observe from a distance, avoid feeding them, and refrain from using drones, to ensure the birds can rest safely before continuing their southbound journey.

Black-necked grebes are rare visitors to the West Lake. [Photo by Cheng Guolong/Tide News]