A pair of black swans was spotted Dec. 7 swimming in Yantian River, delighting locals with their red beaks, black plumage and elegant postures.

One Yantian River patroller said that egrets are quite commonly seen in the river, but it was the first time spotting black swans.

What brought the couple to the river? According to wild animal experts, the species is native to Australia and was introduced into China as an ornamental species. The experts believe that the swans may belong to a park, a zoo, or a university and are attracted by the favorable ecological environment in Yantian.

The experts called on the public not to drive the swans away, since they pose no harm to human for the time being and may fly away after a while.

Eighteen rivers in Yantian District have seen improved water quality and have reached Category-III and above water quality standards. The district has built 21.1 kilometers of greenways along the sea, rivers, lakes and reservoirs.