Breeding Bird Atlas 1 Additional Accounts
Of all the species that have nested in Massachusetts, none is more surprising than the Manx Shearwater. Although this wideranging seabird breeds abundantly in Iceland, Great Britain, Brittany, Madeira, and the Azores, its first “confirmed” nesting in the western North Atlantic was not established until June 4, 1973. On that date, Augustus Ben David II fortuitously turned over a plank and discovered an adult shearwater incubating an egg (AB) at Penikese Island at the mouth of Buzzards Bay, Dukes County. On August 16, a single, well-grown chick appeared close to fledging (BOEM), an event that normally occurs approximately 70 days after hatching.
Although no further breeding confirmations for Massachusetts have been obtained, Manx Shearwaters were discovered nesting in Newfoundland in 1977, and, based on the increase of records in Gulf of Maine waters in recent years, future breeding attempts in the western Atlantic Ocean can be expected. Any Manx Shearwaters seen at dusk or heard vocalizing near offshore islands should be viewed as potential breeders. Also, birders having the opportunity to spend time at night on remote Bay State islands should keep an ear out for the nocturnal howls and screams that are characteristic of this species on its breeding grounds. Since Manx Shearwaters nest in burrows in the ground, any suspicious freshly excavated holes of appropriate size should be monitored closely. To date, the Massachusetts nesting stands as the only such record in the United States; however, the species historically nested in Bermuda.
As nonbreeders, Manx Shearwaters are regularly present over cool, surface, ocean waters north and east of Massachusetts from May to October, with a few records outside this period. They tend to be most numerous from midsummer to midfall and are most often encountered with flocks of other shearwater species.