Upwelling systems in the migration ecology of Roseate Terns (<i>Sterna dougallii</i>) breeding in northwest Europe

For migratory seabirds, staging and wintering areas may be important targets for conservation. Declines of Roseate Tern Sterna dougallii populations have led to conservation initiatives at breeding sites on both sides the North Atlantic. However, these could compromised by environmental conditions in non-breeding areas. The ecology Terns is poorly known we used light-level biologgers (geolocators) identify routes, from two European colonies. Most birds wintered off Ghanaian coast Gulf Guinea, but some further west Sierra Leone Liberia, or changed locations during winter. In areas, cold-water upwellings Guinea Current Large Marine Ecosystem (GCLME) provide vital foraging resources. Geolocations combination with temperature measurements satellite sea-surface data show that Canary (CCLME) were staging, particularly return migration which was slower than outward journey. These results emphasize importance productive Terns. GCLME CCLME are under threat over-exploitation, pollution climate change; effective environments will secure long-term future other seabirds.