Rock River eagles stalk golden eye ducks
Some of the bald eagles in this video are juveniles who don't have all or any of their white head feathers yet. According to Wikipedia, it takes four years for immature eagles to attain adult plumage and the ability to reproduce.
We are seeing a lot of juvenile eagles on the Rock River.
Press play and then click the "Full screen" button in the bottom right corner of the video window for a larger view.