During December, birds spend the long, cold nights in a protected place, sheltered from rain and safe from nighttime predators. Small forest birds, such as nuthatches and creepers, may spend the night huddled together in tree cavities. Birds like this male Mallard fluff up their feathers for insulation, hunker down over their legs and feet, and turn their heads around to poke their beaks under their shoulder feathers. Learn more at BirdNote.org.