Throwback Thursday: Chickadee Energetics by Kent McFarland
Originally Posted: 12/28/11
Black-capped Chickadees weigh less than a half-ounce or about the same as two nickels in the palm of your hand. As early winter temperatures bounce up and down here in New England as fast as the chickadees at my feeders, it got me wondering how these tiny birds can survive a cold winter night.
Each night they are confronted with the very high energetic demands of staying alive. If they don’t have adequate energy stores to burn, they may not see the light of day. To compensate for the long and cold nights during winter, chickadees increase proteins associated with intracellular lipid transport. Each evening when they go to roost, they have enough fat stores to supply just a bit more energy than they will need overnight.
More fat to burn isn’t the only answer. Chickadees also have metabolic tricks to save valuable energy. Their daytime body temperature is generally cooking at about 108 F. But on a cold winter night they can crank it down by 18 to 22 degrees into a hypothermic state. One study showed that when a chickadee was exposed to 32 F nighttime temperatures, they could reduce their hourly metabolic expenditure by 23 percent.
Each evening as the sun is dropping below the hills and the chickadees are flitting back and forth to my feeders, I know it’s a metabolic race for them to survive another night in the north woods. And for me, I’ll rely on stored energy from the sun and toss another log into the stove.