During the winter months especially when it is snowing or icy you may wonder how your garden birds manage to keep warm during the freezing conditions. Although they have adapted well to harsh conditions, the cold is a difficult time for them and some will not survive. Birds are warm-blooded, having a higher metabolism and body temperature than humans. The average bird’s body temperature is 40°C, which will fluctuate during the day depending on climate and activity. However, the challenge for your garden birds in their quest for survival is maintaining this high temperature when the winter months arrive.
Their main insulation against the cold is their feathers and they grow extra feathers during the late autumn to give them more protection during the winter. The oil that coats their feathers also provides another layer of insulation which has the dual purpose of keeping them protected from the rain. You may have noticed during the colder months your garden birds appear to look chunkier than normal. This is caused by them fluffing their feathers to trap warm air beneath them.
Garden birds’ legs and feet are covered in scales which further helps reduce heat loss. You may have witnessed birds standing on one leg in the cold or crouched over to cover both legs with feathers. They are also able to tuck their bills into the feathers at their shoulders. On the sunny days during the winter, birds will turn their backs to the sun and raise their feathers to absorb the maximum solar heat. On very cold days they will shiver to raise their metabolic rate and generate more body heat. Shivering is an effective but short term way to stay warm if sources are not available. In the winter you may see large flocks of birds gathered together in small spaces to share body heat. They will roost in shrubs and trees, empty bird houses and other spots that have residual heat from the day’s sunlight.
During the night birds will enter a state of torpor, reducing their metabolism to lower their body temperature to maintain the correct heat. Garden birds start to build up their fat reserves during Autumn in preparation for winter to provide the extra insulation and energy for generating the body heat they need. You can help your garden birds survive and prevent starvation during the cold winter months by providing them with energy-rich suet balls, suet pellets, suet cakes and suet blocks alongside peanuts, sunflower hearts and Ultiva® seed blends, all of which you can find on our website.