Ever wonder how birds survive the cold winter weather? There is no question that it is hard for them, but they have some adaptations that get them through it.
Their feathers insulate them against the cold and the oils that they spread on them while preening add waterproofing. But their feet are bare ! you are saying. Like in a heat-exchange system, their blood passes through side-by-side capillaries on the way to and from the legs; incoming blood is warmed and outgoing blood is cooled. Less heat is lost that way. And they sometimes stand on one foot with the other tucked up in the feathers.
They puff up their feathers, which traps some insulating air. They can huddle together. They can sit in the sun. They find wind-sheltered places like the broad-leaved evergreen bush near porch, fence. They sometimes perch on warm human structures, like chimneys and outdoor lights.
