Alliant Energy Dam

The dam, with its open gates, keeps water down river ice-free, even in the coldest temperatures. Open water means good fishing—food—for eagles. Access to food is one key reason eagles gather along the Lower Wisconsin River. Concentrations of Bald Eagles feeding at the dam, however, do not occur all year long. Only when down river sites become frozen and off river sites become snow-covered do eagles gather at the dam. Still, it is easier for eagles to shift a few miles up-river during cold snaps than it is for individuals to migrate further south to places that still retain open water like Missouri. The dam thus serves as important habitat at an important time during the winter for Bald Eagles. In doing so, the dam allows eagles to concentrate along the Lower Wisconsin River in greater numbers than they would otherwise do.

While at the dam, after eagles catch some food, they may carry their lunch back to a grove of trees just south of the parking lot and perch in the trees. Sometimes other, fishless eagles alight from their perches along the river as the successful eagle returns and the intruders try to snatch a free lunch. To avoid thievery (called kleptoparasitism in behavioral science), some eagles will consume the newly acquired prey/carrion while still in flight, before returning to their perch. Ownership of food is only guaranteed if it resides in the stomach!  Watch for eagles to move their beak to their talons a few wing strokes after capturing prey to observe this subtle behavior. 

To reduce disturbance to eagles, people are strongly encouraged to stay in their vehicles. The more people stay in their cars, the better views observers will have. Besides, it is warmer in your car…