By Shawn McClain
Have you ever wondered how ducks and peafowl survive the winter? Maybe you have asked about Kingwood’s ducks and peafowl. You probably have heard us say “they are quite hearty to this climate and we assist them with shelter and high protein food through the winter months.” The heartiness of these interesting birds came to light this past winter when an old Kingwood newsletter surfaced. In this newsletter, the birds were mentioned and explained how their arteries and body temperature aid them in cold weather.
Finding this interesting, I had to do a little more reading. Ducks, as well as many other birds, have a counter-current heat exchange system between the arteries and veins in their legs. Warm arterial blood flowing to the feet passes close to cold venous blood returning from the feet. The arterial blood warms up the venous blood, dropping in temperature as it does so. This means that the blood that flows through the feet is relatively cool. This keeps the feet supplied with just enough blood to provide tissues with food and oxygen, and just warm enough to avoid frostbite.
Physical adaptations that are also note worthy are the scales on their legs and feet which insulate from the cold and snow. Feathers provide remarkable insulation against the cold starting in late fall. The oil that coats birds’ feathers from their gland also provides insulation as well as waterproofing. Built up fat reserves serve as insulation and extra energy for generating body heat. Many birds will gorge during the fall when food sources are abundant, giving them an extra fatty layer before winter arrives.
Behavioral adaptations that occur in our environment include fluffing feathers out to create air pockets for additional insulation in cold temperatures. It is not unusual to see a bird standing on one leg or crouched to cover both legs with its feathers to shield them from the cold. Birds can also tuck their bills into their shoulder feathers for protection and to breathe air warmed from body heat.
On sunny winter days, they will turn their backs to the sun (exposing the largest surface of their bodies to the heat) and often move next to the brick walls which absorb and reflect heat. We place straw on the ground to insulate the birds from the cold ground. They will gather in flocks during the day, and at night crowd together in a small, tight space to share body heat. Roosting in shrubbery or trees are also popular locations that help to conserve heat. Even individual birds choose roosting spots that may have residual heat from the day’s sunlight, such as close to the trunk of a tree or near any dark surface.