More than 3,000 wild swans returned to the Bayanbulak Swan National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region on March 24. Bayanbulak is China's largest swan reserve. Regarded as angels by Mongolian herdsmen, swans not only find the environmental conditions favorable, but also receive exceptional care from local volunteers. As many as 131 species of wild birds, including wild swans, stay at the nature reserve.