During Spring migration you can see a mixture of gulls on the upperspillway. Before we got the flooding rain. Some of the black headed ones has pink breasts while others were white. Found out that was because they were newly arrived from their rich marine wintering grounds off the west coast of South America where something in their diet gives them that pink glow. It changes back to white once they have been here awhile. Large gulls are ring-billed, black headed gulls are Franklins and gulls with a dark splotch behind their eye are Bonaparte's.
Ring Billed gull (Larus delawarensis)
Franklin's gull (Leucophaeus pipixcan)
Bonaparte's gull (Chroicocephalus Philadelphia)