How Birds Keep Their Feet From Freezing in Frigid Temperatures

When the mercury drops, birds rely on a variety of strategies to withstand the cold. But one of the most interesting is an adaptation they’ve evolved to keep their bare legs and feet warm during the most brutal conditions. In fact, the system, called a countercurrent heat exchange, works so well that ducks and other waterfowl can stand on ice for hours without ever having to worry about injury. Check out the graphic below for how.