Very rare visitor. 2 distinct ssp: Mew (brachyrhychus) from W coast and Common (canus) from Europe. ID: 3-yr gull. Both smaller than similar RBGU with shorter and thinner (more pointed) bill. Mantle darker gray. Larger mirrors. Compared to MEGU, adult Common has crisper head markings, typically greener bare parts with poorly-defined ring (usually absent in MEGU). 1st-year: Common also has crisper head markings, more defined tail pattern, and generally darker plumage with contrasting pale fringes.