Audubon Magazine Bird Science

How Birds Keep Their Feet From Freezing in Frigid Temperatures

Ever wonder how ducks can stand on ice for hours? The key is this clever physiological adaptation.
A Mallard walks along the frozen surface of icy water.
Mallard. Photo: Marti Phillips/Audubon Photography Awards
By Andrew Del-Colle
Digital Editorial Director, Audubon magazine
Published January 26, 2026
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When the mercury drops, birds rely on a variety of strategies to keep warm. 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 or even discomfort. Check out the graphic below for how.