This report summarizes the results of a study conducted during 12 field days over a four-month period (December 2005, January, February, and March 2006) to document the use of Nantucket Sound by Longtailed Ducks (Clangula hyemalis) during the 2005-2006 winter season. This report is a continuation of studies that began in March 2002 at the suggestion of the U.S. Fish and Wildlife Service (USFWS), the Massachusetts Division of Fisheries and Wildlife (MADFW), and the Massachusetts Audubon Society (Mass Audubon).
Long-tailed Ducks are migratory, breeding in extensive portions of northern Canada and Alaska, and wintering on both coasts of North America and the Great Lakes (Robertson and Savard, 2002). Locally, Long-tailed Ducks are reported to arrive in numbers around Nantucket Sound during mid-November, and are usually present until mid-April, when the birds begin departing for the arctic breeding grounds (Davis 1997). Long-tailed Ducks roost at night in Nantucket Sound (Veit and Petersen, 1993) and then fly in large flocks over Nantucket Island and Tuckernuck Island to forage over the Nantucket Shoals during the day (Veit and Petersen 1993, Davis 1997). A large roost was discovered in the southern portion of Nantucket Sound, north of Tuckernuck Island during a preliminary survey flight conducted in December 2001 (USACE, 2004). However, Long-tailed duck roosting locations and movements are not well understood—it is not known if individuals follow the same daily flight patterns between Nantucket Sound and Nantucket Shoals or if there is a consistent nighttime roosting area in Nantucket Sound. Flight timing, and whether or not all of the local winter population follows this flight pattern on a daily basis, is also unknown.