Abstract: Breeding failure is expected to induce behavioural changes in central place foragers. Indeed, after a failed reproductive attempt, breeding individuals are relieved from having to return to their breeding site for reproductive duties and thus are less constrained than successful breeders in their movements during the remainder of the breeding season. Accordingly, they are expected to adjust their behaviour, travelling longer in distance and/or time to reach foraging grounds. They are also expected to use different foraging areas to decrease local intra-specific competition with successful breeders. We compared the at-sea behaviour and habitat use of successful and failed Indian yellow-nosed albatrosses nesting in Amsterdam Island, Southern Indian Ocean, during 2 chick-rearing seasons. Failed breeders exhibited the same at-sea foraging behaviour, travelling as far and as long as successful breeders. They also spent the same amount of time on their nest between at-sea trips. Nevertheless, habitat models revealed partial spatial segregation of failed breeders, which used specific foraging areas characterized by deeper and colder waters in addition to the areas they shared with successful breeders. Our study shows the importance of combining a range of analytical methods (spatial analysis, behavioural inferences with advanced movement models and habitat models) to infer the at-sea behaviour and habitat use of seabirds. It also stresses the importance of considering individual breeding status when aiming to understand the spatial distribution of individuals, especially when this information may have conservation implications.

Abstract: Conceived as a baseline for the management and conservation of the marine protected area of the French Southern Territories (réserve naturelle nationale des Terres australes françaises), the checklist of marine macroalgae of the Kerguelen Islands was updated based on an extensive review of the literature and scientific databases, from the first report of the Ross expedition, in 1840, to the most recent works. This work was also conceived as a starting point for forthcoming investigations using molecular systematics tools and for monitoring the effects of global change on sub-Antarctic marine ecosystems. After a brief history of scientific campaigns, a list of 166 species was established (103 Rhodophyta, 35 Chlorophyta and 28 Ochrophyta [Phaeophyceae]). Molecular systematics studiess have shown the existence of recurrent discrepancies between the established, morphology-based taxonomy and molecular species delimitation, calling for a revision of systematics. Nevertheless, a first analysis of biogeographical affinities of the marine flora of the Kerguelen Islands is carried out and preliminary results are partially congruent with the main regions currently recognized in the Southern Ocean suggesting the importance of long-distance dispersal to explain the observed distribution patterns.

Abstract: The eradication of invasive mammals on islands is important for protecting seabird populations and insular ecosystems. However, the impacts of such eradications are insufficiently known because monitoring of potentially beneficiary species is often sporadic and limited. We performed a survey of all seabird species on Saint-Paul Island, southern Indian Ocean, 20 years after successful eradication of invasive black rat (Rattus rattus) and European rabbit (Oryctolagus cuniculus). Using complementary sampling designs including adaptive cluster sampling, stratified random sampling and entire sampling, we estimated population changes and colonization by new seabird species. A total of 13 seabird species were found breeding on Saint-Paul post-eradication compared to six before the eradication. Among the seven species that colonized the island, five (MacGillivray’s prion Pachyptila macgillivrayi, fairy prion P. turtur, white-bellied storm petrel Fregetta grallaria, Antarctic tern Sterna vittata, sooty tern Onychoprion fuscatus) had relictual populations breeding on a nearby islet, and one (brown skua Catharacta antarctica) was a new breeding species. We also found breeding subantarctic little shearwaters Puffinus elegans. For species that were breeding on the Saint Paul pre-eradication, the mean annual population growth rate was 1.030 ± 0.093 (SE). Species known to be vulnerable to rat predation (prions, great-winged petrel Pterodroma macroptera, flesh-footed shearwater Puffinus carneipes, subantarctic little shearwater, white-bellied storm petrel, Antarctic tern) had the highest population growth rates. Two decades after the eradication of invasive mammals on a remote oceanic island, seabird populations were high beneficiaries. These findings further highlight the importance of invasive mammal eradication on islands as a conservation tool. Results are encouraging for the planned eradication of invasive mammals from nearby Amsterdam Island, and suggest this will mainly benefit terns and small burrowing petrels.

Abstract: The TUKISIK (Tukisigasuaqatigit: Understanding together) is a scientific program, ongoing since 2014, concerning human-environment interactions, reinforcing links between scientists and several communities.

Abstract: The period of emancipation in seabirds, when juveniles change from a terrestrial existence to a life at sea, is associated with many challenges. Apart from finding favourable foraging sites, they have to develop effective prey search patterns and physiological capacities that enable them to capture sufficient prey to meet their energetic needs. Animals that dive to forage, such as king penguins (Aptenodytes patagonicus), need to acquire an adequate breath-hold capacity, allowing them to locate and capture prey at depth. To investigate the ontogeny of their dive capacity and foraging performance, we implanted juvenile king penguins before their first departure to sea and also adult breeders with a data-logger recording pressure and temperature. We found that juvenile king penguins possess a remarkable dive capacity when leaving their natal colony, enabling them to conduct dives in excess of 100 m within their first week at sea. Despite this, juvenile dive/foraging performance, investigated in relation to dive depth, remained below the adult level throughout their first year at sea, probably reflecting physiological limitations as a result of incomplete maturation. A significantly shallower foraging depth of juveniles, particularly during their first 5 months at sea, could also indicate differences in foraging strategy and targeted prey. The initially greater wiggle rate suggests that juveniles fed opportunistically and also targeted different prey from adults and/or that many of the wiggles of juveniles reflect unsuccessful prey-capture attempts, indicating a lower foraging proficiency. After 5 months, this difference disappeared, suggesting sufficient physical maturation and improvement of juvenile foraging skills.