Ducks are designed to survive in an incredible range of climates. They do well in the heat of summer when they regularly dive into the cool water. In the winter it’s a whole different story. What about ducks and cold water?
In temperate climates, the water in winter is very cold, and it’s a good absorber of heat. If a human falls into icy water, hypothermia can occur in a very short time. How can a duck stay in the cold water in winter all day long?
For one thing, the feathers of a duck are waterproofed and provide incredible insulation from the cold. The waterproofing on the feathers is more concentrated on the outer feathers that contact the water. The cold water never actually reaches the duck’s skin. However, a duck’s feet do make contact with the cold water. Then why don’t their feet freeze?
The capillaries in a duck’s feet form a lace-like structure weaving among one another. This interweaving creates a counter-current heat exchange mechanism. Warm blood flows down the legs from the body and meets the colder blood coming back up, and heat is transferred between the close capillaries. The warm arterial blood supplies heat to the cooled blood, preserving the core temperature of the foot so that ducks and cold water are compatible.
The features built into ducks that allow them to survive in all kinds of conditions show great wisdom by the Master Designer.
© Roland Earnst