White willow (Salix alba) tree with base of trunk almost chewed through by Eurasian beaver (Castor fiber), Narew marshes, Podlaskie, Poland. MORE INFO: Beaver activity is crucial in keeping Poland's ancient marshes open and free of encroaching bushes and trees and their dams also help to maintain high water levels.

White willow (Salix alba) on a sandbank, dawn, shore, water, summer, Bondensee, Bregenz, Vorarlberg, Austria, Europe