How do birds survive the winter?

  Being outside in the winter can be a real challenge for birdwatchers. Sub-freezing temperatures and a blanket of snow can make birding quite miserable. Fortunately for us, we have a choice. We can remain indoors during the harsh conditions, or brave the elements. But if you’re a bird, life isn’t so easy.

     On a bright and cold January morning, I had the pleasure of watching a beautiful flock of American Tree Sparrows feed delicately along the tops of some roadside weeds. I began to wonder, how can a half ounce bird endure a nine degree night and live to tell about it? Incredibly, no matter how cold the days in winter may get, birds have evolved a number of physical and behavioral adaptations to survive.

     The first rule of winter survival is finding food. Birds need to consume as much food as possible during the coldest of weather. This will help generate enough energy to sustain them throughout the night. If a bird does not find enough food to produce the necessary energy, it will perish. The most important food sources in winter include seeds, grains, various berries and fruits.

     Finding adequate shelter is also vital to a birds well being. For example, the dense shrubs and thick evergreens in my Canton yard provide an excellent barrier against the cold for both Mourning Doves and Dark-eyed Juncos. Species such as Black-capped Chickadees and White-breasted Nuthatches use tree cavities at night to escape the howling winter winds.

     Birds utilize a host of other techniques when dealing with frigid temperatures. One such technique involves the covering of extremities. To decrease heat loss, birds will tuck in their head, neck and legs as they sleep.   

     Feathers play an obvious role against the cold. Many species will double their amount of feathers during the winter as a way to help reduce the loss of heat. Birds will also fluff out their plumage as way of trapping warm air between their skin and feathers, creating an additional insulating layer.

     Finally, as a bird’s body temperature begins to fall, they will actually shiver as a means to produce additional body heat. This strategy can burn lots of fat reserves, but may prove life saving.

     All together, these heat-conserving methods allow birds to survive some of the most severe Connecticut winters. With that in mind, I hope their story of survival will inspire you to add a few new shrubs to your yard this upcoming spring.