mergansers are back

So far, the robins, geese, mallards have returned. The mourning doves, blue jays, woodpeckers, chickadees are our winter feathered friends. As our shore line slowly increases and the ice melts, I've noticed the mergansers, a diving duck, has been back. They dive at the edge of the ice. I know that our birds follow their food sources and return as the land melts, and bugs (Robins), greens (mallards) and fish (mergansers) are available. As the lake slowly opens up they return. Yesterday, we must have lost about 6' of lake ice as it slowly melts. The mallards still land on the ice, not gracefully, I might add. Birds have high metabolic rates that keep them warm in winter. They shiver, as we do, to keep warm and fluff up their feathers for insulation. But those feet!

I commented on how it looks so cold seeing the mallards sitting on the ice, and my geek son-in-law (who knew?) told me that they have specially designed feet and legs to keep them warm.

The veins and arteries exchange heat. The venous blood, as it returns from the feet, is heated by the arterial blood flowing south. Unlike humans, who lose heat from our extremities and can suffer frostbite (lack of circulation in face, feet and hands) the ducks feet do not lose heat and their core temperatures are not affected by cold feet.