Why a duck’s feet don’t freeze in winter and other chilly questions

BANGOR DAILY NEWS • December 10, 2021

We were driving across the Mount Desert Island causeway the other day when I spotted a group of ducks bobbing in the ocean waves. First, it reminded me of the opportunities to spot birds along the Maine coast during the winter. Second, I’m not the first person to observe a duck swimming through frigid water and wonder: Aren’t their feet frozen? A coldwater duck has special vein structures that exchange heat high up in the leg so that the blood that’s flowing down to the foot is fairly cold (and the blood flowing up into its body remains warm). That way, the foot doesn’t lose much heat when it comes into contact with cold water or ice. It simply doesn’t have the heat to lose. ~ Aislinn Sarnacki