Nature Walk: Bird Insulation
Survival for birds in winter is about feather design, grooming, available flood supplies, fat reserves and protection from wind. Feathers are a bird's first and most important defense against cold. Birds groom contour feathers with oil to make them water resistant. Beneath this outer covering, down feathers trap air and provide a critical insulation barrier. One can see this cardinal has fluffed its feathers, which increases the dead air space and their potential to insulate.
How are you stay