3. "Easier movement": Groups of animals moving together (such as fish or birds) save energy. Many of the larger birds fly in flocks. Flying in flocks helps in reducing the energy needed. Many large birds fly in a V-formation, which helps individuals save 12–20 % of the energy they would need to fly alone. Red Knots "Calidris canutus" and Dunlins "Calidris alpina" were found in radar studies to fly 5 km per hour faster in flocks than when they were flying alone.