Massachusetts is the 44th state in the nation for land area, encompassing only 10,554 square miles. But birders lucky enough to live here know that within its relatively small land area, Massachusetts boasts a remarkable variety of habitats and coastal areas that provide some of the best birding in the United States. The state can be divided into distinct regions each with differing character and bird diversity: Greater Boston, the North Shore, the South Shore, Cape Cod and the Islands, Central, and Western Massachusetts. As of 2014, there are 501 accepted species on the Massachusetts state checklist.
There is no bad season to go birding in Massachusetts. Those who brave the sometimes chilly winter temperatures can find spectacular numbers of sea ducks on the coast, as well as alcids, such as Razorbill, Black Guillemot and Dovekie. Purple Sandpipers are a regular shorebird in the winter months. Snowy owl is present in most years here. The Massachusetts coast is also excellent for some of the more unusual gulls of the eastern United States, including regular Iceland, Glaucous, Little, and common Black-headed Gulls. During irruption years, central and western parts of the state as well as coastal areas can see good numbers of winter finches such as Red and White-winged Crossbills, Redpolls and Pine Grosbeaks, as well as Bohemian Waxwings.
Spring migration is a highlight for birders in Massachusetts, with warblers, vireos and other neo-tropical migrants found across the state from Mt. Auburn Cemetery in Cambridge/Watertown, to the Connecticut River valley and Berkshire Mountain range, typically peaking from the end of April through the first three weeks of May. In summer, breeding birds to look for include Piping Plover and terns all along the coast, from Salisbury to Cape Cod and southeast Massachusetts. Raptors and rarer breeding birds such as Cerulean and Mourning Warblers can be found in the southeastern, central and western parts of the state.
Around late July to August, fall migration begins, with a focus on shorebirds in coastal areas such as Parker River National Wildlife Refuge, the southern shores, and throughout Cape Cod. Out-of-state birders come for late summer pelagic trips to the deep offshore canyons, as these offer one of the most regular opportunities in the United States to see rarities like the White-faced Storm-Petrel, Bridled Tern, and other ocean-travelers. Throughout the fall, an extended land bird migration continues through October and November, when ducks, loons and grebes begin to arrive back on rivers, ponds, and reservoirs; raptors entertain birders in eastern, central and western parts of the state as they migrate to their wintering grounds.