41-43 cm (16-17") Common along coast, rare inland except at Salton Sea. Largest of the black-headed gulls - crow-sized. Black head with broken white eye-ring; red bill; white underparts and tail; dark gray mantle blends into black wing tips. Similar Franklin's Gull has a white wing band between mantle and black wing tips.
Winter adult similar, but head white with smudge of gray behind eye, bill black.
Song: loud laugh.