In addition to the diagnostic black underwings, look for structural differences, including daintier impression, smaller bill, and very rounded wings. The latter feature provides a different overall flight impression even at a distance.
Among Bonaparte's Gulls in spring migration along Back River and the Susquehanna River.
Usually found in large flocks of Bonaparte's Gulls.
There are 67 records in the project database.
GA | AL | WA | FR | CL | MO | HO | BA | BC | HA | CE | PG | AA | CV | CH | SM | KE | QA | CN | TA | DO | WI | SO | WO |