Holmsten 1948 Herring Gulls 15 Aug. Holkham Bay Alaska. The more I watch the markings on the primaries the more uncertain I am about telling the exact difference between the Glaucous-Glaucous winged and Herring. They all fly in the same groups, along with immature ones, showing a range from pure white to black with white spots on the primaries. 22 Aug Holkham Bay - Alaska. A flock of about 50 has been sitting on the beach of Ben J. Directly across from Seal Rock, when the tide was out. They have congregated there about the time that the focus is uncovered. This has been regular for the past three days.