Seasonal variation in oceanographic habitat and behaviour of white-chinned petrels Procellaria aequinoctialis from Kerguelen Island

• Published in: Marine Ecology Progress Series
• Main Authors: Peron, C, Delord, K, Phillips, RA, Charbonnier, Y, Marteau, C, Louzao, M, Weimerskirch, H
• Format: Article in Journal/Newspaper
• Language: English
• Published: Inter-Research 2010
• Subjects: Biological Sciences; Ecology; Marine and Estuarine Ecology (incl. Marine Ichthyology); Antarctic; Kerguelen; Kerguelen Island; Antarc*; Sea ice
• Online Access: https://doi.org/10.3354/meps08785; http://ecite.utas.edu.au/92765

Marine environments experience seasonal variation in physical and biological parameters,with consequent changes in predator distributions. During the breeding period, proximity tosuitable feeding sites is essential for central place foragers, whereas during the non-breeding periodtheir distribution is relatively unconstrained. We combined light-based geolocation and satellitetracking to investigate seasonal variation in foraging grounds and behaviour of white-chinnedpetrels from Kerguelen Island. Birds were associated with highly productive areas throughout theyear. During breeding (summer), they performed long commuting trips from the colony to distant,productive Antarctic waters. Thereafter, birds migrated 5200 km westwards to the Benguelaupwelling system off Namibia and South Africa to spend the winter. This seasonal shift of foraginggrounds coincides with a change in activity patterns; much less time was spent in flight in winter thanin summer. Individual variability in the locations of foraging zones and seasonal/daily activity patternswas low. Trip durations were shorter during chick-rearing than incubation, although birds oftentravelled as far or farther, tracking the gradual break up of pack ice. Habitat use models revealed anassociation with distance to sea-ice edge and chlorophyll a gradient during incubation, whereas seasurface temperature and chlorophyll a gradient best explained habitat use during chick rearing.White-chinned petrels are likely to overlap with other marine predators and fisheries throughout theyear. Fishery bycatch constitutes the most significant direct threat to petrels at sea. Moreover, futureclimate-induced reductions in productivity could affect birds year-round.