How do birds stay warm in the winter?
Birds have a number of ways to beat the cold, but none so important as their feathers. You may have noticed how on a very cold day the birds at your feeder seem rounder and more puffed-up than usual. This is a way of keeping warm by raising the feathers to create pockets of warm air and enhance insulation. In addition, may species change their plumage, molting into a fresh thick set of feathers prior to the colder months. Especially helpful are the very fluffy and soft body feathers known as down. These feathers provide super insulation, much like the goose down we use in coats and comforters. At night, birds can dramatically slow down their body’s metabolic rate (the rate at which the body consumes energy), and lower their body temperature, to conserve energy. During very cold nights, small birds such as chickadees and nuthatches may find a tree cavity or birdhouse where they can spend the night, huddled together with several other birds of the same species. Such communal roosting per
