Tiny but Tough

Illustrated by Sarah Pullen

Did you know...

Some birds don’t migrate south for the winter but stay here through the severe cold. Birds have higher metabolisms and body temperatures than humans; the average bird’s body temperature is 40 degrees Celsius!

So, how do they keep warm? Most birds follow a simple formula: maximize calorie consumption and minimize calorie spending.

Chickadees brave the winter in their bare uninsulated legs and feet, yet their toes remain flexible and functional at all temperatures, whereas ours, if that small, would freeze into blocks of ice in seconds. 

Don’t they get cold? They do! But chickadee feet don’t freeze, and that’s because their foot temperature is regulated near the freezing point and may stay cold even as body temperature stays high. If chickadee feet were the same temperature as its body, it would lose heat very rapidly, and it would spend a lot of energy trying to eat enough to stay warm.

Chickadees in winter travel in groups so when one finds something to eat, its neighbours notice and join in. Food options are broad—from various seeds, spiders, and spider eggs, to insects and their pupae.

Birds retain heat in their body core by fluffing out their feathers which makes them look very puffy and at night, they seek shelter in tree holes or other crevices, and reduce body temperature to save calories.

What can you do to help?

Offer good food high in fat and calories to give birds plenty of energy to generate heat.
Keep bird feeders full of nutritious seed no matter what the weather.
Offer water. Birds can melt snow to drink if necessary but doing so lowers their body temperature. Can you install a heated bird bath?