Musing:
We know that Bald Eagles are quite social away from their breeding grounds. They congregate in large mixed-age groups, roost together, squabble and chase over food, and sometimes hunt cooperatively. Even breeding eagles occasionally accept migrants and wanderers, especially in late summer and early fall. Food attracts eagles, eagles attract eagles, and eagles tend to return to nest in their region of origin, so it isn't surprising that we're seeing more eagles in and around Decorah and at N2B.
But what about multiple nests? We've talked about them as a symbol of fitness, as a way to escape parasites or predators, and as something that eagles are programmed to do. But perhaps there is an advantage to establishing a group of non-cooperative nests in the same region, if food supplies support it. Maybe fledglings have higher survival rates if they can form a post-dispersal crèche. Or maybe a large eagle presence deters (non-eagle) competitors and predators, benefitting the population as a whole. It's something we'll be looking into!
