Relationships between isotopic ratios, body condition and breeding success in a High Arctic seabird community

• Published in: Marine Ecology Progress Series
• Main Authors: Hovinen, Johanna E.H., Tarroux, Arnaud, Ramírez Benítez, Francisco José, González Forero, Manuela, Descamps, Sébastien
• Format: Article in Journal/Newspaper
• Language: English
• Published: Inter-Research 2019
• Subjects: Ocells marins; Nutrició animal; Àrtic; Oceà; Sea birds; Animal nutrition; Arctic Ocean; Alle alle; Black-legged Kittiwake; brünnich's guillemot; Glaucous Gull; Larus hyperboreus; little auk; rissa tridactyla; Svalbard; Uria lomvia; uria
• Online Access: http://hdl.handle.net/2445/149156

Predators such as seabirds are often used as bio-indicators of the marine environment. This is based on the assumption that changes in seabird populations are driven by changes in their prey. We tested this assumption in a High Arctic seabird community by assessing the relationships between the diet, body condition, and breeding performance of 4 ecologically different species: the little auk Alle alle, black-legged kittiwake Rissa tridactyla, Brünnich's guillemot Uria lomvia, and glaucous gull Larus hyperboreus, breeding in Svalbard, Norway. Interannual changes in seabird diet (2009-2015) were assessed by estimating their carbon and nitrogen isotopic ratios (δ15N and δ13C) during the breeding and non-breeding seasons (i.e. using blood and feather tissues). We found interannual variation in the isotopic ratios during both seasons in all 4 species. These variations differed among species, thus suggesting dietary changes, instead of changes in isotopic baselines, as the most plausible mechanism underlying such patterns. We also found that seabirds had a lower average hatching success when the average δ15N during the previous non-breeding season was higher. Our results suggest that changes in the average prey composition during the non-breeding season may partially explain changes in breeding performance of Svalbard seabirds.