: Breeds. May-Sep in typically small ( +/- 30 pairs) but widely scattered saltwater colonies on mostly small unpopulated islands. to and year around. Visits open freshwater lakes to bathe.
: to Mar-Apr and Oct-Nov and .
Miscellany: Great Black-backed Gulls didn't nest in Maine until the early in the 20th century but expanded rapidly through the mid century, arguably because edible waste, whether from fish processing plants or garbage dumps, sharply increased their winter survival. With the closure of most fish processing plants and fewer open dumps, numbers over the last 30 years have declined an estimated 30%. In recent years, possible predation of adults, young and/or eggs by Bald Eagles and perhaps Mink have been a concern.
Last Updated: June 2nd, 2022