How Do Birds Survive the Winter Chill?

With cold weather is in full swing, many of our wildlife have made themselves scarce, waiting for warmer days to make their reappearance. One type of creature you can probably still catch sight of, however, is a bird! While some birds are migratory, skipping town to avoid the cold weather, others are with us all winter long. You might have some bird houses in your yard, but they probably don’t come with heat—so how do these animals keep warm through the season?

Chickadee_USFWSOne strategy is to put on layers. Instead of donning a sweater, some species of birds such as geese and grouse, grow a layer of down or an extra layer of soft and fluffy feathers that help insulate the birds’ bodies. Other species of birds become eating machines in an effort to pack on the fat, with some consuming as much as 60% of their body weight in food each day. In addition to adding another layer of insulation, this fat also fuels nighttime muscle movement…otherwise known as shivering! If you’ve ever paced at the bus stop on a chilly morning to keep warm, you know how helpful some physical exertion can be in fending off the cold. For birds, the same principle applies to shivering; by maintaining muscle contractions in the cold, dark nights, the birds can stay warm until morning.

There are also some strategies employed by our feathered friends which you and I would never try, such as controlled hypothermia. Black-capped Chickadees can let their body temperatures drop up to 25% in an effort to conserve their energy and make it through the nights, going from their normal 107.6°F to 80.6°F — that would be like one of us going from a healthy 98.6°F down to 74°F when it’s time for bed!

Give feathered friends a hand this winter by adding food and water sources to your yard, then sit back and enjoy some winter birdwatching. Providing a variety of feeders and foods will attract different species of birds – try suet, cracked corn, seeds and nuts. Once a few birds find your feast, others will likely follow. Providing a water source will also attract birds. Use a heated bird bath or place a bath in a sunny area where it’s less likely to freeze over. Don’t forget to clean feeders and baths regularly to prevent spreading disease, and remove old, wet seed that can breed bacteria.