Great Black-backed Gull at Caesar Creek

Larry Gara found a large juvenile gull at the beach at Caesar Creek State Park several days ago. (The Caesar Creek State Park beach is located in Warren County, Ohio, Delorme p. 65, D7) The immediate suspicion was that it was a Great Black-backed Gull. Larry's sighting aroused a good deal of interest because this would be a first for Caesar Creek.

The bird was back today Tuesday, 26 Sep)and was closely observed by a whole squad of competent birdwatchers (Larry, Rick Asamoto, Frank Fricke, Beth Mitchell, and your humble reporter). Compared to the Ring-billed Gulls that it was in with, it looked, in Beth's words, "like a moose." There were also three Herring Gulls reasonably nearby and the juvenile was significantly larger.

The most striking aspect of the bird was its enormous black bill, black all the way to the base. The head was very light except for much darker feathering around and behind the eye. The mantle feathers, scapulars and wing coverts were darker than we are used to seeing in juvenile Herring Gulls and were set off more contrastingly with the large white fringes. Overall, the back of the bird had a crisp, checkered appearance.

In flight, the rump contrasted strongly with the dark back. It appeared to be white with small, dark brown vermiculations. The tail showed a sharpish black terminal band. The wing feathers, both primaries and secondaries were dark brown with little variation along the length of the wing.

Taking all this into consideration, it is our opinion that the bird was indeed a Great Black-backed Gull, apparently still in juvenile plumage. At least three of the attendent birders have considerable experience with this species on Lake Erie and the Atlantic coast.

Numerous photos were taken by Frank, Rick and me. Here are three of the most instructive of mine.

Juvenile Great Black-backed Gull surrounded by Ring-billed Gulls, showing its great size. The bill is huge. Note that the GBGU is resting on its tarsi.

Great Black-backed Gull taking off from the beach, showing dark flight feathers, contrasting undertail coverts, and well-defined dark tail band.

A poor shot, taken as the bird passed directly up-sun, but it is the best view I have of the upper side of the tail. The mostly white coverts form one of the better field marks differentiating the juvenile Great Black-back from the juvenile Herring Gull.