Inter-Research > MEPS > v671 > p207-218  
Marine Ecology Progress Series

via Mailchimp

MEPS 671:207-218 (2021)  -  DOI:

Post-fledging movements, mortality and migration of juvenile northern gannets

Jude V. Lane1,*, Christopher J. Pollock1, Ruth Jeavons1, Maggie Sheddan2, Robert W. Furness3, Keith C. Hamer1

1School of Biology, University of Leeds, Leeds LS2 9JT, UK
2Scottish Seabird Centre, North Berwick EH39 4SS, UK
3MacArthur Green, Glasgow G20 6NT, UK
*Corresponding author:

ABSTRACT: Studying the at-sea movements and behaviour of juvenile seabirds is logistically challenging, but new technologies now allow tracking birds on their first migration, giving a more complete picture of population-level spatial ecology. We investigated the post-fledging migration of juvenile northern gannets Morus bassanus from the world's largest colony, at Bass Rock, Scotland. We first examined the movements and survival of 38 juveniles over their initial days at sea with GPS precision for up to 53 d post-fledging. We then compared their migration journeys with those of 35 adults tracked with geolocators. Almost one-third of juveniles died within 2 mo of leaving the colony, and this mortality was often associated with apparent uncertainties in their direction of migration, including marked, abrupt and often repeated changes in bearing within the North Sea. Both juveniles and adults then migrated as far as the Canary Current Large Marine Ecosystem (CCLME) off the Atlantic coast of West Africa, initially taking both clockwise and counter-clockwise routes around the UK. Juveniles covered a distance each day similar to that of adults, but they reached the CCLME much more quickly, mainly because they travelled more directly, staying close to the coast throughout most of their migration, whereas adults additionally spent long periods over relatively restricted areas of ocean further offshore. The CCLME is a hotspot of unregulated fishing activity, and our findings highlight the importance of this region across different age-classes of birds, echoing previous calls that the regional strengthening of marine conservation should be a high priority.

KEY WORDS: Mortality · Migration · GPS tracking · Northern gannet · Morus bassanus · Juvenile

Full text in pdf format
Supplementary material
Cite this article as: Lane JV, Pollock CJ, Jeavons R, Sheddan M, Furness RW, Hamer KC (2021) Post-fledging movements, mortality and migration of juvenile northern gannets. Mar Ecol Prog Ser 671:207-218.

Export citation
Share:    Facebook - - linkedIn

 Previous article Next article