While we humans tend to stay inside during the cold winter months, setting the thermostat to extra cozy, birds are living outside - toughing out the snow and sub-zero temperatures. Without fleece, beanies or space heaters, how do those little guys make it through an entire cold season?

1. They use their body heat

Feathers do a lot to keep birds warm and comfortable. Beneath the smooth top feathers that we are accustomed to seeing are smaller, fluffier down feathers. These two layers work together to trap warm air close to the bird's body.

While feathers are vital, they’re just the first line of protection. At night, birds may hide away in tree cavities or roosting boxes, huddled together, using collective body heat to stay warm. The Common Redpoll, which sometimes spends its winters in the Arctic, will dig snow tunnels to escape the icy air.

2. They conserve energy

Several songbird species will actually lower their body temperature at night in what’s called “regulated hypothermia”. Maintaining their body temperature requires calories, so by lowering body temperature, they can conserve energy, letting them sleep through the night without the need to store lots of body fat or get up in search of a midnight snack.

3. They stash their food

Most birds will eat whatever the winter landscape has to offer, such as berries and seeds that still cling to dormant trees and shrubs. Some bird species, like chickadees, jays, nuthatches, and some woodpeckers, will spend their time late in the summer season storing thousands of bites of food, tucking them into the ground, in bark crevices, and even in man-made structures like house siding to save for winter. Rather than keeping one large “master stash,” they keep thousands of hiding spots, and are capable of recalling just about all of them!

In spite of these impressive survival skills, it can still be a tough life for a bird during winter. Think of your feeding station as a much-needed fuel stop for the birds, and fill your feeder with a high-energy blend like Lyric Fruit & Nut High Energy Wild Bird Mix.

A male and female cardinal rest on a branch. iStock/Thinkstock
Stashing acorns in tree bark is a common way birds store food in the spring for winter meals. iStock/Thinkstock