This video from Nature: Leave it to Beavers highlights scientists' discoveries of the dramatic impact of beavers on two different ecosystems. Dr. Glynnis Hood discusses her findings in Elk Island National Park in Alberta, Canada where beavers were re-introduced in 1941. She found that ponds with active beaver populations had nine times more open water than similar ponds without beavers. The video also explores Susie Creek in Nevada, where Dr. Suzanne Foudy and Biologist Carol Evans observe that areas with beavers have lush vegetation, abundant wildlife, and significantly more water than nearby areas without beavers.