Plum Island National Wildlife Refuge is a US Top 100 birding site. Its coastal marshes with vegetated dunes provide diverse habitats that support a rich diversity of birds year-round. Ocean viewing allows near-shore and occassionally off-shore pelagics to be seen. Sandy beaches support migrant and overwintering shorebirds, including breeding Piping Plovers. Leeside of the dunes support some mature stands of woody vegetation that serve as migrant traps and an extensive estuarine spartina marsh system. In Winter, Snowy Owls and offshore wintering waterbirds, including loons, grebes, gulls, and seaducks are regular.