Status and Distribution of Wintering Waterfowl in Narragansett Bay, Rhode Island, 2005-2014

Surveys of wintering waterfowl can aid in both identifying estuarine habitats currently being used by species of conservation concern so that the sites can be targeted for protection and restoration, and in providing a baseline assessment from which the effects of future changes in wintering habitat can be assessed. In an effort to better understand the local distribution of wintering waterfowl during the period 2005-2014, we undertook a study of waterfowl abundance and distribution in Narragansett Bay, RI, a moderate-sized estuary located in the northeastern US within the Atlantic Flyway. Overall waterfowl abundance in the Bay ranged from 15,002 individuals in 2006 to 26,163 individuals in 2010 and averaged 20,062 +/- 3393 individuals over the 10-y period. Species richness ranged from 1.80 to 10.8 per site; most of the sites with high species richness were located in the Upper Bay. Based on our counts from 67 ground locations, the Narragansett Bay waterfowl community was dominated by Aythya affinis (Lesser Scaup) and A. marila (Greater Scaup), Branta bernicla (Brant), and Branta canadensis (Canada Geese) over the survey period. Waterfowl-community composition indicated that the Upper Bay, an environment characterized by low wave-energy, shallow coves, sheltered embayments, and salt marshes, supported mostly dabbling ducks, geese, and swans. The Lower Bay, an environment characterized by higher wave-energy, rocky shorelines, and deeper open-water habitats, supported mostly sea ducks and other diving-duck species. Abundance over the survey period was relatively stable, and observed patterns of waterfowl distribution suggest that conservation actions to maintain shallow-water habitats, including efforts to protect and restore salt marsh habitat, will help to maintain resources needed by many of the waterfowl species wintering in the Bay.