Early in the morning of June 28, 1957, my ornithology class and I were treated to a spectacular aerial show by Ring-billed Gulls (Larus delawarensis). We were having breakfast at the time on the shore of Lake Michigan at Point La Barbe near St. Ignace, Mackinaw County, Michigan, and within view of Green Island where the gulls have a large nesting colony. The weather was warm, windless, and overcast. Preceding our arrival there had been a big, simultaneous "hatch" of may-flies (probably a species of Ephemera), with the result that myriads of them were now rising from the shore and proceeding skyward. Far above the shore, in both directions from us, dozens of Ring-billed Gulls were exerting themselves mightily to catch may-flies.