Long-tailed Skua, Stercorarius longicaudus


Migratory connectivity between Arctic breeding grounds and oceanic wintering areas of seabirds

This PhD aims to elucidate the migration of an elusive (and therefore poorly studied) group of bird species: long-distance migratory Arctic-breeding pelagic seabirds, Arctic skua Stercorarius parasiticus, long-tailed skua S. longicaudus, Arctic tern Sterna paradisaea and red-necked phalarope Phalaropus lobatus. These species cover different trophic levels (phalaropes low, terns and skuas high) and functions in both the marine and tundra ecosystems, but all share the same breeding areas.

Conservation goals for migratory birds can only be achieved if the full migration cycle between breeding and non-breeding is understood. Especially in the light of expected developments in the Arctic (climate change, increase in shipping, oil and gas extraction, increase in fishing pressure), a thorough understanding of the connectivity of the Arctic with the oceans further south is paramount in conservation planning. Such information can be used to identify productive areas and areas of high conservation value.

Capitalising on international collaboration we have the unique possibility to carry out simultaneous field studies at four Arctic sites on the four focal seabird species. This project studies the two Scandinavian sites: Sletness (Norway) and Ammarnäs (Swedish Lapland). Combining recently developed technical tracking devices (light-based geolocators) and isotope signature analysis of feathers and egg material, opens the possibility to map resource use along individual migratory routes.

The work is expected to result in an overview of migration routes and wintering area use of North Atlantic breeding populations of Arctic and long-tailed skua, Arctic tern and red-necked phalarope. Furthermore, it will elucidate resource use along these routes.