: Non-breeder. early Jun-mid Aug except in the large nightly gull roosts on Mount Desert Rock where from mid Jun. from land. Most records are of sub-adults
: from land, mid Apr-late May and late Aug-early Nov with peak early-mid Sep and to mid Nov. mid Mar-late May and mid Aug-mid Nov. Coastal points with concentrations of large gulls are good places to look as is Schoodic Point where visible gull movement is often evident. to late Aug-early Sep in the big evening gull roosts on Mount Desert Rock.
: but increasing mid Nov-early Mar at Schoodic Point and along the eastern edge of MDI.
Miscellany: Lesser Black-backs were virtually unknown in North America before 1950 but as their breeding range expanded from western Europe west across Iceland and in the 1990s Greenland, their numbers on this side of the Atlantic increased to the point where some wintering groups along the East Coast and in Delaware Bay now number in the hundreds. At present, Lesser Black-back has not been detected breeding in the U.S. but single birds have paired with Herring Gulls, and confirmed breeding at some point soon seems inevitable.
Last Updated: August 25th, 2024