The cranes are edging south with the largest concentrations on Grettum and Dueholm flowages. The upper Phantom L. flock also remains. I didn't see any on the Refuge extension. The temperature this morning 14 degrees and the birds were roosting on the ice. Take off is precarious with lots of slipping down the icy runway. My curiosity finally pushed me to find the to answer the question of how those feet stay warm on the ice. They probably don't stay that warm but at least they don't freeze. Apparently there is a heat exchange between the blood flowing to the feet and the blood returning. As the warm blood heads toward the feet it transfers heat to the cold blood coming back resulting in warmed blood going to the heart and cooled, but still warm blood going to the feet. Why didn't I think of that?
