Watch Clip
![](http://image.pbs.org/video-assets/RFq0JkJ-asset-mezzanine-16x9-CWArgLW.jpg?resize=410x)
The Disappearing Lake
2m 21s
/ TV-PG
As the water levels drop at Poyang Lake thousands of birds arrive to feed on the roots of aquatic plants that are uncovered. Critically endangered Siberian cranes travel the furthest; a month long journey for the unique feeding opportunity brought about by the changing water levels.