Wednesday, January 8, 2014

Extremely Cold Woodpecker and Dove

On Monday morning, temperatures in Northfield fell below −20 degrees F. This Downy Woodpecker had more problems than the cold. The bird is severely wounded, with feathers missing from the lower back. Hanging from the wound is what appears to be a mostly decomposed leaf. Perhaps this leaf frozen to the bird has acted like a bandage.

Also at the feeder this frigid day was the Mourning Dove in the bottom photo.  Most birds in the cold seek shelter. Once on a similarly cold day in South Dakota, I found a Mourning Dove that had dug itself a snow cave—but froze anyway. Birds survive extreme cold by having seasonal increases in metabolic rates and by lowering their body temperatures at night (Natural Source). Birds normally maintain body temperatures of around 106 degrees. They accomplish this body temperature by fluffing their feathers and growing additional down during the winter. Birds also maintain high levels of fat. Most birds shiver by twitching their muscles. Many birds can shunt blood away from their extremeties and towards their internal organs (Yuhas 2013). 

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