European bison
European bison feed predominantly on grasses, although they also browse on shoots and leaves; in summer, an adult male can consume 32 kg of food in a day. European bison in the Białowieża Forest in Poland have traditionally been fed hay in the winter for centuries, and large herds may gather around this diet supplement. European bison need to drink every day, and in winter can be seen breaking ice with their heavy hooves. Despite their usual slow movements, European bison are surprisingly agile and can clear 3-m-wide streams or 2-m-high fences from a standing start.