Birds and bomb cyclones
Now that we’ve added a new term to our vocabularies and weathered the wild winds and brutal temperatures of the past week and its “bomb cyclone,” it’s time to reflect on the awe-inspiring survival strategies of our backyard birds and the role we can play in their welfare.
While we watched from the warmth of our homes as the “baroclinic midlatitude cyclone” delivered its “bombogenesis” (the beginning of a cyclone), the tiny and delicate feathered creatures that keep close company with us in exchange for seeds and suet somehow managed to make it through wind chill factors that could prove fatal to an unprepared human.
How do they do it? According to the Cornell Lab of Ornithology, when temperatures fall, appetites rise as birds consume additional calories to generate more heat. That makes it especially important to keep feeders full. Another strategy is to fluff up their feathers to keep out the cold as well as to trap body heat before it dissipates. Squatting onto those tiny feet or alternately lifting and tucking them into the body also helps. Huddling with other birds works, too. To conserve energy at night, chickadees and other species practice regulated hypothermia, dropping their body temperature by as much as 22° F. And a special form of shivering helps some birds to retain heat.
While foraging, birds make frequent adjustments to reduce their exposure to wind, such as moving to the other side of a tree, or perching among evergreen branches to consume their food. And at night, small cavities in trees or nooks in brush piles provide better protection than being exposed to the weather on a tree limb.
To help your feathered neighbors get through winter, hang a variety of feeders and foods. Woodpeckers prefer suet, while tube feeders filled with black oil sunflower seeds attract chickadees and finches. Fill a hopper feeder with mixed seeds, safflower or sunflower seeds to serve a diversity of birds and enjoy the show. Visit www.audubon.org/magazine/november-december-2010/audubon-guide-winter-bir... for more helpful tips.