In the densely populated Kunming urban area, there is a Cuihu Lake, which is called Xiaoxi Lake. There are more than 200 acres of water surface, the lake is bright, the ancient trees are towering, the scenery is beautiful, and the tourists are weaving. From the early winter of 1985, there has been a rare spectacle in the world: from the snowy fields of Siberia, thousands of gull birds suddenly flew to the green grass and green flowers.