These 14 species were recorded along the Niagara River on 25 NOV 1995 by four birders from Ontario (Willie D’ Anna, Dean Di Tommaso, Rob French and Nancy French). Here is the list of birds they saw in less than 24 hours: Franklin’s Gull, Little Gull, Bonaparte’s Gull, Ring‐billed Gull, California Gull, Herring Gull, Thayer’s Gull, Kumlien's Iceland Gull, Lesser Black‐backed Gull, Glaucous Gull, Great Black‐backed Gull, Sabine’s Gull, Black‐legged Kittiwake and Ross’s Gull. The birds were observed along a 30 mile stretch.
|Gulls in late fall at Niagara Falls. Drawing: Peter Lorimer|
There have also been rumors of a 14-gull day in South Dakota, outside of the Pierre area. I've not been able to confirm this record.