More than 100 bald eagles, mostly juveniles and sub-adults, converged the past few days on the Hunt Unit of the Sauvie Island Wildlife Management Area's East Side, along Reeder Road.
Eagles don't fly or migrate together like geese, but do tend to roost communally during the winter before returning to the north.
It's unusually late for them to be on the way home, but then it hasn't been a very usual spring.
Mark Nebeker, Sauvie manager for the Oregon Department of Fish and Wildife, said eagles are spread across both east and west sides of the area.
He believes they may be drawn by carp, which spawn during April in shallow water as it recedes.