- They have wings, which are modified forelimbs that are adapted for flight.
- Their wings are covered in feathers, which are lightweight and provide lift.
- They have a strong flight musculature that allows them to flap their wings and generate lift.
- They have a streamlined body shape that reduces drag.
- They have hollow bones that reduce their weight.
Ducks can swim because:
- They have webbed feet, which help them to propel themselves through the water.
- Their feathers are waterproof, which helps them to stay dry and buoyant.
- They have a streamlined body shape that reduces drag.
- They have a layer of fat under their skin that helps to insulate them and keep them warm in the water.