Chickadees active in harsh cold [UPDATED]Published 9:52am Tuesday, February 5, 2013 Updated 11:53am Tuesday, February 5, 2013
Every year when the first real arctic cold blast settles in, I watch the activity at the feeders with a bit of wonder. The birds, mostly chickadees, scramble around seemingly immune to the piercing weather conditions. I think to myself, how can a bird that weighs less than a third of an ounce possibly survive such miserable winter days?
I have learned that they become voracious eaters during periods of extreme cold weather, consuming as much as 20 times the amount of food as in summer. Estimates are that in winter when the temperature remains above the zero mark, chickadees need to eat the equivalent of 150 sunflower seeds a day to stay warm. When it dips into the subzero, they increase their food intake to about 250 sunflower seeds a day. Of necessity, they become eating machines in order to survive the long winter nights.
Another intrigue to their survival is their habit of hiding and storing food in hundreds if not thousands of tiny hiding places. So if we forget to replenish our feeders, or as in the case of strictly forest dwelling chickadees, they can remember for relatively short periods the location of these caches and seek them out as need requires.
Similarly, chickadees are one of only a few bird species that are capable of improving survival by lowering their night time body temperature. On cold winter evenings they can lessen their temp by as much as 20 degrees. During this state of “nocturnal hypothermia” fewer calories are burned and their energy is conserved. Chickadees (and some other birds) will also huddle together at night in an old woodpecker hole or nest box and fluff their feathers to stay warm.
Most of us have a pulse of somewhere between 60 to 80 beats per minute so consider this; the heart rate of a chickadee at rest is about 540 beats per minute. With bitter cold weather like we have had lately, this increases to nearly 1,000 beats per minute. Again, the faster beating heart is a mechanism to stay warm.
Chickadees are curious birds, and without doubt one of my personal favorites. They have an authoritative call and will investigate everything in their territory. They are quick to discover bird feeders or that boned out deer carcass I hung out in the woods for them to pick at. In winter they form loose flocks of six to 10 birds. They have a complex language, and are able to identify individuals in their group or birds of neighboring flocks. Unfortunately for chickadees and most other wild birds, their average life span is less than two or three years.