: Non-breeder. to mid Jun-mid-late Oct with from late May and to early Nov. Peak numbers from mid Jul-early Oct. Seen on close to 100% of the Bar Harbor based whalewatch cruises in this period, assuming reasonable visibility. from land.
Miscellany: Great Shearwaters nest on south Atlantic islands and travel to the northern hemisphere for their ‘ .' Numbers in the Gulf of Maine vary from year to year (as with whales) depending on the food supply. Great Shearwater feeds at night, mostly on squid, and during the day rest on the water, sometimes in sizable flocks.
Last Reviewed: June 19th, 2026