Seabird Diets in a Warming Climate: An Assessment of the Relationships of Terns (Sterna sp.) and their Prey in the Northern Breeding Range

The Northeast coast of the United States is an important area for a variety of native nesting seabirds including Common, Least, Arctic, and the federally endangered Roseate terns. These species migrate to the Northeast region to take advantage of highly productive waters during late spring and early summer to breed and raise their young. During this period, adults are highly dependent on local prey resources to support chick growth and survival. Long-term diet studies show terns are highly dependent on a few select prey groups, potentially making seabird populations sensitive to changes in prey distribution. This sensitivity is particularly important as many prey species are shifting to new areas in response to climate change.  

However, recent research has shown that as Common tern’s preferred prey are becoming less available due to warming conditions, they may switch to other species and alter their diets. Understanding the changes in dependence on historically important prey resources provides critical indicators of how resilient seabirds are to changing climate conditions. The proposed project will combine existing data and monitoring protocols to develop ecological models with three goals in mind. The first goal is to identify novel relationships between terns and prey resources throughout their Northern breeding range. The second goal is to evaluate the relationship between tern diet, climate change drivers, and productivity. The third goal is to develop a standardized framework and set of tools for assessing seabird diet and seabird population dynamics.  

Work will be conducted in cooperation with seabird mangers from State and Federal agencies and non-governmental organizations that monitor breeding colonies along the Northeast coast from Virginia to Canada. Results will provide important insights into the energetic needs of seabirds in cold and warm water habitats and increase understanding of seabird resilience to changing environmental conditions and prey habitats due to climate change.