Cygnus columbianus, which is on China’s protection list for wild animals, are seen in the country’s northeastern Heilongjiang Province.
It is a sight for the bird watchers, as they are rarely spotted in the province.
Cygnus columbianus is the smallest of the holarctic swans.
Every March and April, after wintering in China’s largest fresh water lake Poyang Lake, they fly back to Russia by way of China’s eastern Bohai Gulf and northern Inner Mongolian Autonomous Region.
However, observers say the number of Cygnus columbianus in Heilongjiang has been on the rise in the past five years.
More than 90 Cygnus columbianus have been seen in the water near the Naoli River national natural reserve of Heilongjiang this year.
Observers say this shows Cygnus columbianus are altering their migration routes and researchers are studying what has caused the changes.