How do birds stay warm in the cold weather?
Birds use a variety of methods to keep warm including, shivering, fluffing feathers for insulation, roosting in groups, and tucking their bills and feet next to their body.
A bird's body heat warms the air between its feathers, So birds fluff up in the cold to trap as much air in their feathers as possible. The more trapped air, the warmer the bird. One way birds keep their legs and feet warm is to stand on one leg, while the other is tucked up warmly in its feathers.