Sparrows and chickadees are likened to mail carriers. They move through woods, backyards and feeding stations on a regular route. Neither rain nor snow nor sleet will keep them from their appointed rounds. Each day as I watch my feeding stations I keep records of the transient visitors. These notes will become a part of Cornell University’s Project Feeder Watch. With this goal in mind I watch my feeder on a regular basis.
I noticed several wrens shivering one cold day last winter. I knew that shivering in humans was uncomfortable and could be a sign of hypothermia. Birds are different. They shiver to get warm. A bird is like a well-insulated home, but instead of burning wood or oil, it metabolizes food and harnesses the heat by shivering. So if there is a whole lot of shakin’ going on at your feeder, all is well for the birds.
With all the stories of fat and cholesterol harming humans, you may be surprised to learn that these things keep birds alive all winter. In autumn, the birds are voracious eaters, building up fat reserves against hard times. Migrating birds actually double their weight in fat deposits. Fat deposits form under the skin, in the muscles and in the peritoneal cavity. Birds do not accumulate fat in their heart muscles.
Birds convert fat to energy twice as efficiently as they do carbohydrates. Breads given to birds in cold months make them feel full, and this can cause their body temperatures to fall below 104 degrees during the night. Black oil sunflower seeds are the fattest and are the best choice for your feeder. The striped variety of sunflower seeds are a little less fatty, but are still a great choice. Many birds suffer dietary deficiencies in winter. A good feeding station provides minerals that the snow-covered natural world lacks. Seed-eating birds need grit to help them digest their food. Good sources of grit are cuttlefish bones and pieces of eggshell which replenish calcium. Fireplace ashes are rich in a variety of minerals, although ashes from newspapers contain toxic chemicals. I have even seen song birds congregating on roads to take the salt and sand that we use on the roads in snowy weather.
Birds do become possessive of their feeder stations. If I am gone all day, I may receive a scolding from the chickadee regulars stating that I am late in filling the station. Upon returning home from work one day, I was greeted by a host of birds assembled on the corral fence near my feeder. As I exited the car, they flew, and I went into the house. This particular day I had dropped my glove near the driver side of the car, and I went out to retrieve it. As I bent over to lift the glove from the ground, I was struck numerous times in the head by the troop of small birds which had assembled under my car to take advantage of the engine heat.
Bird feeding can be a great winter hobby and certainly does not go without surprises. Try setting up some feeding stations and you may have some seedy tales to share.