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 Emilia Heidi, Tarroux, Arnaud, Ramirez, Francisco, Forero, Manuela, Descamps, Sébastien
• Format: Text
• Language: English
• Published: 2019
• Subjects: Diet; Marine birds; Svalbard; Carry-over effects; Reproductive output; Stable isotopes; Trophic level; Nitrogen; Carbon; VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480; Arctic; Norway; Alle alle; Black-legged Kittiwake; Glaucous Gull; Larus hyperboreus; little auk; rissa tridactyla; Uria lomvia; uria
• Online Access: http://hdl.handle.net/11250/2620082; https://doi.org/10.3354/meps12886

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 nonbreeding 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. acceptedVersion