"Seward Gull" - Glaucous-winged Gull X Glaucous Gull (Larus glaucescens, Larus hyperboreus, Larus glaucescens x Larus hyperboreus)

The Glaucous-winged Gull is notorious for hybridizing with other gulls including Western, Herring, Glaucous and Slaty-backed Gulls producing a bewildering variety of intermediates to challenge birders. With its slim bicolored bill and white wing-tips, this individual looks superficially like an immature Glaucous Gull. However the blended wing coverts contrasting with fresh gray mantle feathers in a first cycle bird suggests it is likely a hybrid with Glaucous. Glaucous Gulls usually retain juvenile plumage through spring and show crisper more patterned wing coverts and tail than seen here. This hybrid combination is sometimes referred to as the "Seward Gull" named for the Seward Peninsula in Alaska where this hybrid combination is fairly common. They are scarce winter visitors to California.