As I walked by Boulder Creek near the library the other day, the usual flock of ducks was happily cackling, swimming, and preening. The shoreline and rocks in the creek were covered in snow. I was bundled in boots, coat, and a hat – barely warm. As I watched them go about their duck business as usual, I was glad I was not one of them.
The more practical side of me, however, reasoned that ducks were adapted to deal with the cold (yes, 15° in October). They wear a down coat, after all. But what about those feet??? Lots of other birds will fluff up their feathers and hunker down to protect their feet. But ducks (and other water birds) swim in frigid water and stand right on the ice. How can they do that? The scientific name is a counter-current heat exchange system. For us non-scientists, this means that the veins and arteries in ducks’ legs are packed close together. So warm blood heading down to the feet heats up the cold blood returning from the feet. That way the bird can maintain a constant body temperature. Not only that, but their feet are specially designed to withstand the cold because they have little nerve tissue or muscle. Their feet are made of mostly bones and tendons. Still, I’m glad I’m not a duck.