Effects of Atlantic butterfish ( Peprilus triacanthus ) in diets of Common Terns ( Sterna hirundo ): a case study of climate change effects in the Gulf of Maine

Climate change and associated shifts in marine prey communities can alter food availability for foraging seabirds. This issue is illustrated the Gulf of Maine by northward shift Atlantic butterfish (Peprilus triacanthus; hereafter butterfish) their subsequent increase seabird diets. Here, we examine effects diets Common Tern (Sterna hirundo), a threatened species this region. Our objectives were to evaluate suitability tern chick diet through observing handling time feeding success, on growth, explore signs adaptive adults. The growth chicks studied three breeding seasons Seavey Island, New Hampshire, USA Maine. Prey items identified during feedings grouped into five categories: butterfish, herring, hake, other fish, invertebrates. Chicks weighed calculate rate, which was examined as response diet. Across categories, handled greatest amount (P < 0.001) but swallowed least 0.001). Furthermore, rates negatively with proportion There significant variation across different nests two years 0.05 2018 2019), some pairs never observed provisioning young. Although mechanism underlying individual specialization not known, that are fed fewer at an advantage. (or not) unsuitable particularly important because seawater warming expected increase, likely become even more prevalent