Bald eagles are common in and around Scappoose Bay, and there's an eagle nest in a grove of cottonwoods not far from the abandoned rookery, as well as other active eagle nests around the bay. The rookery usually has lots of activity by this time. The great horned owls that used to nest in the cottonwoods left when the eagles moved in just a few trees away. I haven't witnessed eagles bothering the herons in past years, but it could easily occur without my seeing it. I did see a rookery abandoned years ago on the Scappoose lowlands when eagles took over one of the rookery nests.