This stretch of cold weather is going to be hard on our wintering birds, particularly the smallest ones. While feeding birds is, most of the time, done more for our enjoyment than their benefit, that changes when the weather goes brutally cold. Seed and suet offer easily found energy needed to keep tiny bodies warm and working. Smaller animals, like chickadees, need more energy per unit of weight than do larger animals. This is because they lose heat more quickly. Let's say a chickadee is equal to a one-ounce cube. That cube has six square inches of surface surrounding one cubic inch of volume. Double the weight of the bird. That two-ounce cube has 24 square inches of surface covering eight cubic inches of space. The smaller bird has a heat-loss ratio of six to one. The larger bird has a ratio of three to one. It takes more energy to keep the smaller body alive. Fill those feeders. Black oil sunflower seed is a good choice. Suet is a good choice. Keep the feeder ports free of snow. This is a time of year when your feeders can make a difference. (Watch the StarTrib's Home and Garden pages, in the Variety section on Wednesdays, for a more complete discussion of small birds and cold weather.)
