Many, if not most, birds migrate <answer>in flocks</answer>. For larger birds, flying <answer>in flocks</answer> reduces the energy cost. Geese in a V-formation may conserve 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/h (3.1 mph) faster <answer>in flocks</answer> than when they were flying alone.
How do most birds migrate?
in flocks