christineotterstrom
Countercurrent Heat Exchange and Waterfowl
Waterfowl such as ducks and geese have an interesting adaptation that prevents their feet from freezing while making contact with ice, snow, and very cold water. These species employ what is called countercurrent heat exchange, where blood from the body travels through an artery down the legs and makes close contact with a vein containing blood that has cooled in the feet and is traveling the opposite direction to the body. The warm arterial blood cools as it reaches the feet, causing the feet to become close in temperature to the cold surface or water and in turn, lowering the rate of heat exchange. Conversely, the cool venous blood circulating back up to the core is warmed, as to not lower the body temperature. This adaptation makes it possible for these animals to only lose around 5% of their body temperature through their feet.
Photo taken at Beus Pond, Ogden, Utah. Feb 10, 2020
Countercurrent Heat Exchange and Waterfowl
Waterfowl such as ducks and geese have an interesting adaptation that prevents their feet from freezing while making contact with ice, snow, and very cold water. These species employ what is called countercurrent heat exchange, where blood from the body travels through an artery down the legs and makes close contact with a vein containing blood that has cooled in the feet and is traveling the opposite direction to the body. The warm arterial blood cools as it reaches the feet, causing the feet to become close in temperature to the cold surface or water and in turn, lowering the rate of heat exchange. Conversely, the cool venous blood circulating back up to the core is warmed, as to not lower the body temperature. This adaptation makes it possible for these animals to only lose around 5% of their body temperature through their feet.
Photo taken at Beus Pond, Ogden, Utah. Feb 10, 2020