Winter Warm-ups!

by Candace Larson, Master Naturalist

It’s winter, and if you’re cold on a clear, crisp Portland morning, imagine how a half-ounce chickadee must feel! Many birds migrate away from the colder regions in winter, but our friends spending the season here have myriad creative adaptations for staying warm. Many ducks and geese increase their fat reserves and add as much as 25% more down feathering as winter approaches. Songbirds poof out their feathers, which traps air close to the body. This layer of air gets heated by the bird’s warm core and increases the insulation value of the bird’s feathers by as much as 50%. Birds shiver to generate metabolic heat, and many birds, including our adorable northwest Bushtits, often roost communally on cold winter nights (aka cuddling!).

Black-capped Chickadee puffed up and perched on white branch with snow in the background.
Black-capped Chickadee, photo by Dana Orlosky.

Birds also have several clever strategies for keeping their unfeathered legs and feet from freezing. They often tuck these appendages close to their warm body while resting. And they have a super-effective blood-flow system in their legs, where the arteries delivering warm blood from the bird’s insulated body are nestled into a matrix of veins carrying cool blood back to the body. Heat is efficiently transferred from the warm arteries to the cool veins, reducing the energy required to keep the core of the bird nice and toasty. Birds’ feet do get quite cold, but they contain very little liquid, muscle, or nerve tissue, and the blood that does circulate through the feet moves fast enough to avoid freezing.

What can you do to offer a helping hand to our winter birds? Offering high-energy foods, plenty of clean, fresh water, and places for birds to shelter out of the wind and rain are all helpful. Make sure your windows are bird-safe and your kitty is also warm and cozy indoors!