After a few soggy days of the loons paying little attention to the nest area, they are now back on a regular basis. In this videohttps://youtu.be/csId0j2_rLU, we see one of the pair back on the primary nest, giving it a test fit and adding more material.
Notice the black flies on and circling the head and neck. These are most likely Simulium annulus, a species of black fly that specializes on attacking loons. During a particularly heavy black fly year loons have been known to abandon nests. What we see here is not a particularly heavy infestation. Let’s hope it doesn’t become a problem.