By the time the River's narrows are gorged with grinding, piling ice, it is usually late December or well into January. For weeks the rough, opaque ice has blocked out such sunlight as there is. Submerged aquatic plants in the backwaters are unable to respire and produce oxygen, ice cover has prevented wind from aerating the water, and yet a certain biological demand is being made of the River. Even though all metabolisms have slowed, oxygen is still being used faster than it can be replenished in many areas. The winter fish-kill begins. Gizzard shad are among the first to die; they perish in vast numbers under the ice and are carried downstream through the channel dams and into the open River just beyond. Here, awaiting the dead fish, are bald eagles.
It is no wonder that some people here at the lower end of the Upper Mississippi wonder about the general concern for the eagles. On January 2, 1984, I counted fifty-one eagles perched in the trees below Lock and Dam 26; there were nine in one big cottonwood. Now and then one of the great birds would launch itself out over the open water, seeming to know exactly where to go, snatching a dead fish from the surface and easily competing with those other masters of dead-fish-snatching, the scavenger gulls. The harder the winter and the heavier the River ice, the greater the concentrations of our bald eagles. There are periods when up to two hundred eagles can be seen on the Mississippi and lower Illinois within forty miles of where I'm writing this.
They no longer nest here at Pool 26, and our Eagle's Nest Island is only a place name. But in winter they may be so common that they hardly cause comment. I walked from my house down through Hop Hollow to the River one day, tracking a wayward retriever puppy in several inches of new powder snow. It was fine weather, cold and quiet and perfectly clear, a day of alabaster and long blue tree shadows. There was suddenly another shadow, a moving one, crossing my trail. Then another, and another. I looked up to see eight bald eagles through the treetops just above me. Five were adults marked with white heads and tails and dark bodies; the others were brown-and-white juveniles. They milled silently above the trees from which I had started them, little more than fifty yards away but moving off. It isn't everyday that you'll flush a covey of bald eagles, and I watched slack-jawed while they vanished beyond the blufftop. Then came the chill of realizing that somewhere nearby, maybe even under the roost itself, there was a plump, ingenuous black Lab puppy that a bald eagle could see in that white snow with its head tucked under its wing. The pup's registered name, however, was Milo Lucky Streak—and he soon appeared, safe but lonely, gallumphing toward me with happy welcoming noises.
From John Madson's Up on the River: People and Wildlife of the Upper Mississippi
