Great Black-Backed Gull
2/13/2016 Illinois Ornithological Society's Gull Frolic North Point Marina Lake County, Illinois
Great Black-Backed Gull - 1st Cycle
Great Black-Backed Gull, Herring Gulls, Kumlien's Iceland Gull
Great Black-Backed Gull vs. Herring Gull
8/20/2014 Cape Cod, Massachusetts
8/18/2014 Cape Cod, Massachusetts
