Carry-over effects of food supplementation on recruitment and breeding performance of long-lived seabirds

Supplementation of food to wild animals is extensively applied as a conservation tool to increase local production of young. However, in long-lived migratory animals, the carry-over effects of food supplementation early in life on the subsequent recruitment of individuals into natal populations and their lifetime reproductive success are largely unknown. We examine how experimental food supplementation early in life affects: (i) recruitment as breeders of kittiwakes Rissa tridactyla born in a colony on Middleton Island (Alaska) between 1996 and 2006 (n = 1629) that bred in the same colony through 2013 (n = 235); and (ii) breeding success of individuals that have completed their life cycle at the colony (n = 56). Birds were raised in nests that were either supplemented with food (Fed) or unsupplemented (Unfed). Fledging success was higher in Fed compared with Unfed nests. After accounting for hatching rank, growth and oceanic conditions at fledging, Fed fledglings had a lower probability of recruiting as breeders in the Middleton colony than Unfed birds. The per-nest contribution of breeders was still significantly higher for Fed nests because of their higher productivity. Lifetime reproductive success of a subset of kittiwakes that thus far had completed their life cycle was not affected by the food supplementation during development. Our results cast light on the carry-over effects of early food conditions on the vital rates of long-lived animals and support food supplementation as an effective conservation strategy for long-lived seabirds

Breeding together, wintering oceans apart: divergent migratory movements of thick-billed and common murres from St Lawrence Island, Northern Bering Sea

The Tenth Symposium on Polar Science/Ordinary sessions: [OB] Polar Biology, Wed. 4 Dec. / 3F Multipurpose conference room, National Institute of Polar Researc

Temporal dynamics of nutritional stress and diet of rhinoceros auklets breeding on two distant colonies in Japan

The Tenth Symposium on Polar Science/Ordinary sessions : [OB] Polar Biology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc

Seabirds and the circulation of Lyme borreliosis bacteria in the North Pacific

Seabirds act as natural reservoirs to Lyme borreliosis spirochetes and may play a significant role in the global circulation of these pathogens. While Borrelia burgdorferi sensu lato (Bbsl) has been shown to occur in ticks collected from certain locations in the North Pacific, little is known about interspecific differences in exposure within the seabird communities of this region. We examined the prevalence of anti-Bbsl antibodies in 805 individuals of nine seabird species breeding across the North Pacific. Seroprevalence varied strongly among species and locations. Murres (Uria spp.) showed the highest antibody prevalence and may play a major role in facilitating Bbsl circulation at a worldwide scale. Other species showed little or no signs of exposure, despite being present in multispecific colonies with seropositive birds. Complex dynamics may be operating in this wide scale, natural hostparasite system, possibly mediated by the host immune system and host specialization of the tick vector

Foraging ecology of thick-billed murres in the Bering Sea: variability in relation to ocean thermal structure

第4回極域科学シンポジウム横断セッション：[IA] 「急変する北極気候システム及びその全球的な影響の総合的解明」―GRENE北極気候変動研究事業研究成果報告2013―11月12日（火） 国立極地研究所 ２階大会議

Differential responses of seabirds to climate variability over two years in the southeast Bering Sea

第6回極域科学シンポジウム分野横断セッション：[IA] 急変する北極気候システム及びその全球的な影響の総合的解明―GRENE北極気候変動研究事業研究成果報告2015―11月19日（木）　国立極地研究所１階交流アトリウ

繁殖期間中、夜間に深い海域のハダカイワシを表層で採るアカアシミツユビカモメ

第6回極域科学シンポジウム分野横断セッション：[IA] 急変する北極気候システム及びその全球的な影響の総合的解明―GRENE北極気候変動研究事業研究成果報告2015―11月19日（木）　国立極地研究所１階交流アトリウ

Inter-Colony Comparison of Diving Behavior of an Arctic Top Predator: Implications for Warming in the Greenland Sea

The goal of this study was to assess how diverse oceanographic conditions and prey communities affect the foraging behavior of little auks Alle alle. The Greenland Sea is characterized by 3 distinct water masses: (1) the East Greenland Current (EGC), which carries Arctic waters southward; (2) the Sørkapp Current (SC), which originates in the Arctic Ocean but flows north along the west coast of Spitsbergen; and (3) the West Spitsbergen Current (WSC), which carries warm Atlantic-derived water north. Each of these 3 water masses is characterized by a distinct mesozooplankton community. Little auks breeding adjacent to the EGC have access to large, lipid-rich Calanus copepods, whereas those adjacent to the SC have medium sized prey, while those near the WSC are limited to even smaller, less profitable prey. We used time−depth recorders to compare the time allocation and diving behavior of little auks adjacent to each of these 3 water masses. We predicted that birds in the EGC would not have to forage as intensively as those in the SC or WSC. We found that little auks foraging in the EGC spent less time at sea, spent less time flying, dived less often, made fewer long, deep dives, and made fewer V-shaped searching dives. This indicates that the EGC provides a more favorable foraging environment than do the warmer water masses to the east. Comparing the foraging behavior of little auk populations confined to Arctic versus Atlantic-influenced waters can provide insight into the potential impacts of future warming in the Greenland Sea