(Some herring x glaucous-winged hybrids very like Thayer’s ... linked to egging and competition with expanding great black-backed gull populations.

Medium-size, 3-cycle gull with sloping head, medium-size bill. On adult, note yellow legs, pale eyes, and neat “ring bill.” Breeding adult: pale gray upperparts; black wing tip with white ...

In the summer, an adult little gull has a full black hood that covers its head ... The bird’s upper wing is grey, its underwing is slightly darker, and it has a blackish rear half.