Combination of At-Sea Activity, Geolocation and Feather Stable Isotopes Documents Where and When Seabirds Molt

摘要: Key facets of the foraging ecology seabirds during inter-breeding period still remain poorly understood because difficulty studying them at sea, including energy-demanding moulting stage. Here, extent to which three sympatric petrels (Antarctic and thin-billed prions, blue petrel) from subantarctic Kerguelen Islands modify their moult was investigated using a combination complementary tools, namely miniaturized saltwater immersion geolocators (GLS) isotopic method. Firstly, behaviour first characterized in petrel, reference species that is known renew its plumage autumn. GLS feather stable isotopes (13C as proxy birds’ habitat) indicated post-breeding petrel occurred Antarctic waters. Importantly, activity recorders showed marked by strong peak time spent daily sitting on water, thereafter declined lower values remaining winter months. Secondly, water used characterize contrasted strategies two prion species. As demonstrated, prions moulted cold waters where they fed primarily low trophic level prey, most likely krill (15N diet). By contrast, presented an unexpected pre-breeding longer duration took place further north, warm subtropical Interestingly, species, prion, renewed same within oceanic zone be previously undescribed hot spot seabird diversity Austral The study contributes growing body evidence closely-related exhibit various allowing ecological segregation sheds new light critical stage seabirds.