MEPS

Marine Ecology Progress Series

MEPS is a leading hybrid research journal on all aspects of marine, coastal and estuarine ecology. Priority is given to outstanding research that advances our ecological understanding.

Online: ISSN 1616-1599

Print: ISSN 0171-8630

DOI: https://doi.org/10.3354/meps

Impact Factor2.1 (JCR 2025 release)

Article Acceptance Rate52.2% (2024)

Average Time in Review216 days (2024)

Total Annual Downloads2.970.199 (2025)

Volume contents
Mar Ecol Prog Ser 730:113-129 (2024)

Atlantic populations of a declining oceanic seabird have complex migrations and weak migratory connectivity to staging areas

ABSTRACT: Anthropogenic change is impacting ecosystems globally, causing declines in biodiversity. Long-distance migrants are particularly susceptible, as they depend on conditions over large geographical scales and are likely to experience a greater range of pressures. One long-distance migrant that has experienced substantial declines across the North-East Atlantic is the Arctic skua Stercorarius parasiticus. However, little is known about their migratory routes or strategies. We tracked 131 Arctic skuas from Scotland, the Faroe Islands, Norway and Svalbard between 2009 and 2019 using geolocators. To investigate migration strategies, we applied a hidden Markov model, using saltwater immersion data to infer stopovers and transit flights. Skuas used several discrete staging areas during migration, with an area of high marine productivity in the mid-North Atlantic being of high importance. Individuals from the different breeding populations overlapped extensively in staging areas, resulting in weak spatial connectivity between breeding and staging areas during southbound (rM = 0.25, 95% CI = 0.09-0.42; 0 = weak connectivity, 1 = strong connectivity) and northbound (rM = 0.16, 95% CI = -0.02 to 0.33) migration. Variation in migration strategies was driven by individuals from Svalbard, which belong to a population that is declining less than the other populations tracked. The relative location of wintering areas also influenced migration strategies. Individuals migrating further spent a smaller proportion of their migration at stopovers than those wintering closer. Identifying the non-breeding distribution, migration strategies and weak migratory connectivity of Arctic skuas provides a vital step towards linking conditions during migration to population dynamics and prioritising future research and conservation actions.

KEYWORDS

Nina J. O’Hanlon (Corresponding Author)

  • British Trust for Ornithology Scotland, Beta Centre (Unit 15), Stirling University Innovation Park, Stirling FK9 4NF, UK
nina.ohanlon@bto.org

Rob S. A. van Bemmelen (Co-author)

  • Wageningen Marine Research, Haringkade 1, 1976 CP IJmuiden, the Netherlands

Katherine R. S. Snell (Co-author)

  • Max Planck Institute of Animal Behavior, Am Obstberg 1, 78315 Radolfzell, Germany

Greg J. Conway (Co-author)

  • British Trust for Ornithology, The Nunnery, Thetford, Norfolk IP24 2PU, UK

Chris B. Thaxter (Co-author)

  • British Trust for Ornithology, The Nunnery, Thetford, Norfolk IP24 2PU, UK

Helen Aiton (Co-author)

  • Cuppar, Evie, Orkney, UK

David Aiton (Co-author)

  • Cuppar, Evie, Orkney, UK

Dawn E. Balmer (Co-author)

  • British Trust for Ornithology, The Nunnery, Thetford, Norfolk IP24 2PU, UK

Sveinn Are Hanssen (Co-author)

  • Norwegian Institute for Nature Research, Sognsveien 68, 0855 Oslo, Norway

John R. Calladine (Co-author)

  • British Trust for Ornithology Scotland, Beta Centre (Unit 15), Stirling University Innovation Park, Stirling FK9 4NF, UK

Sjúrður Hammer (Co-author)

  • Faculty of Science and Technology, University of the Faroe Islands, Vestarabryggja 15, 100 Tórshavn, Faroe Islands

Sarah J. Harris (Co-author)

  • British Trust for Ornithology, The Nunnery, Thetford, Norfolk IP24 2PU, UK

Børge Moe (Co-author)

  • Norwegian Institute for Nature Research, PO Box 5685 Torgarden, 7485 Trondheim, Norway

Hans Schekkerman (Co-author)

  • SOVON, Toernooiveld 1, 6525 ED Nijmegen, the Netherlands

Ingrid Tulp (Co-author)

  • Wageningen Marine Research, Haringkade 1, 1976 CP IJmuiden, the Netherlands

Elizabeth M. Humphreys (Co-author)

  • British Trust for Ornithology Scotland, Beta Centre (Unit 15), Stirling University Innovation Park, Stirling FK9 4NF, UK