Biology at the Bird Feeder
~ by Jim Eagleman
It’ s time to inspect, repair, and stock the bird feeders. I’ m not alone. Millions of Americans maintain bird feeders, putting out one billion pounds of bird seed each year. This nearly year’ round pastime puts bird feeding on the chart as the second most popular outdoor pursuit we, as Americans, enjoy. What’ s the first? Gardening. Most gardeners, home landscapers, and backyard growers agree, while tending to plants, they enjoy the sights and sounds of our feathered friends.
To ornithologists— scientists who study birds— feeders are a significant wildlife management tool helping in the study of bird behavior. Most homeowners provide seed as an act of benevolence and enjoyment. We simply get satisfaction from watching birds.
When things get tough this coming winter— and they will— it seems obvious bird feeders will play a vital role in bird survival. But little scientific study has been done on the precise role winter feeders play in bird ecology and behavior. It is suspected that encouraging birds to collect at feeder sites may increase predation by accipiters such as the Sharp-shinned and Cooper’ s Hawks. Citizen science— us amateurs feeding, watching, and reporting what we see— adds to survival data. Having an ornithologist friend doesn’ t hurt, either. Even after retirement, I still confer with my DNR colleagues on matters of their specialties, new rules and laws, and just to catch up.
If I check the feeders, I’ ll bet at least a few chickadees have already made a visit. This year
’ round Indiana resident, a feisty, energetic songster,(“ chicka-dee-dee-dee”) is sure to be a regular— the Carolina typically here in the southern part, the Blackcapped further north. Researchers at the University of Vermont report that during long winter nights, chickadees lower their body temperatures by as much as eighteen degrees Fahrenheit, and keep their muscular heat generators running by shivering. To maintain that level of heat, they burn the equivalent of slightly more than one gram of body fat per day. They have to eat every day, or die. If they don’ t sit out a storm in some sheltered brush pile, there is evidence they can fall into a deep sleep, or torpor, to conserve energy when rough conditions make it too harsh for foraging. Staying dry and out of wind is of paramount importance.
An insect and spider consumer in summer, I once observed a flock of“ chicks” picking out fat in a deer carcass along a stream in our woods. In fall, they
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48 Our Brown County Nov./ Dec. 2016