It’s amazing to me where my mind goes sometimes. As I was driving to work I passed the Norton reservoir and noticed that the ice has melted in the recent warm spell. (January Thaw). Out in the middle were about 5 or 6 swans. Made me cold just to see them but then I wondered, why aren’t their feet cold?

 I thought it would be a short , easy answer to share but even the short answer I found on Askanaturalist.com wasn’t so short.

Let me see if I can give you the Reader’s Digest Condensed version.

 Warm blood flowing from the body into the legs and feet passes close to the veins carrying the cold blood back to the body. This warm blood starts warming the cold blood and in doing so loses some of its heat so by the time it reaches the feet it’s cooled off. This keeps the feet just warm enough to avoid frostbite.

 This also reduces heat loss to the outside environment. When we go out without a hat we lose a lot of heat from our head but since the blood in the duck’s feet  has already cooled , it doesn’t lose much heat to outside air, water etc.

Literally “pretty cool”.

 To take it a bit further, are they uncomfortable at all in the cold?

It seems that the answer is no. Since their feet aren’t “cold” they can sit on that ice with their feathers all fluffed out and be quite content. We know those feathers are warm. That’s why we have down comforters, down sleeping bags and down winter coats. We think their feathers are pretty warm too!

 If you want to read the more extensive version with the details about the arterial blood and venous blood heat exchange, here’s the link. They have nifty diagrams too.

http://askanaturalist.com/why-don%E2%80%99t-ducks%E2%80%99-feet-freeze/