While birds are equipped to withstand most winter weather, they obviously can't turn up the thermostat, throw on an extra blanket or whip up a warm cup of cocoa. However, there are a number of ways you can help make survival easier by providing food, an open source of water and protection from the elements.
The Importance of Keeping Your Feeders Full
Food is the most essential element, providing birds with the energy, stamina and nutrition they need. To stay warm, birds will expend energy very quickly, some losing up to 10% of their body weight on extremely cold nights, and this fat must be replaced every day.
Normally, birds that come to feeders obtain only about 20% of their daily calories from food offered in feeders; the rest come from natural food sources. In contrast, during periods of cold weather, your birds may use your feeders to load up on calories as a means of survival.
The Importance of a Reliable, Open Source of Water
Birds continue to need a source of water for drinking to maintain their metabolism during dry, cold weather. Clean feathers help birds stay warm, and a bird bath is often the only way for some birds to drink and keep their feathers in top condition when it’s cold.
Most birds adjust their feathers to create air pockets, which help them keep warm. The soft, fluffy down feathers are puffed up with air to create a warm blanket around the bird. The body feathers lie on top of each other, overlapping like shingles on a roof. Small interlocking barbules, or “hairs,” zip their feathers together to create an airtight windbreaker. Also, most birds preen their feathers with the oil produced by a gland on their backs near their tails to create a waterpoof rain coat. Research has shown that a chickadee with well-maintained feathers can create a 70° (F) layer of insulation between the outside air and its skin.
Protection from the Elements
Birds need a place to escape the elements. Installing roosting and nesting boxes in your backyard can give birds a warm, dry place to stay overnight. Shelter is also necessary for protection against natural predators, such as birds of prey and cats.
Source: WBU Nature News http://www.wbu.com/news/naturenews.html