Browsing by Author "Fukuda, Akira"
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- Age-related variation in foraging behaviour in the wandering albatross at south georgia : No evidence for senescencePublication . Froy, Hannah; Lewis, Sue; Catry, Paulo; Bishop, Charles M.; Forster, Isaac P.; Fukuda, Akira; Higuchi, Hiroyoshi; Phalan, Ben; Xavier, José C.; Nussey, Daniel H.; Phillips, Richard A.Age-related variation in demographic rates is now widely documented in wild vertebrate systems, and has significant consequences for population and evolutionary dynamics. However, the mechanisms underpinning such variation, particularly in later life, are less well understood. Foraging efficiency is a key determinant of fitness, with implications for individual life history trade-offs. A variety of faculties known to decline in old age, such as muscular function and visual acuity, are likely to influence foraging performance. We examine age-related variation in the foraging behaviour of a long-lived, wide-ranging oceanic seabird, the wandering albatross Diomedea exulans. Using miniaturised tracking technologies, we compared foraging trip characteristics of birds breeding at Bird Island, South Georgia. Based on movement and immersion data collected during the incubation phase of a single breeding season, and from extensive tracking data collected in previous years from different stages of the breeding cycle, we found limited evidence for age-related variation in commonly reported trip parameters, and failed to detect signs of senescent decline. Our results contrast with the limited number of past studies that have examined foraging behaviour in later life, since these have documented changes in performance consistent with senescence. This highlights the importance of studies across different wild animal populations to gain a broader perspective on the processes driving variation in ageing rates.
- Foraging behaviour of four albatross species by night and dayPublication . Phalan, Ben; Phillips, Richard A.; Silk, Janet R. D.; Afanasyev, Vsevolod; Fukuda, Akira; Fox, James; Catry, Paulo; Higuchi, Hiroyoshi; Croxall, John P.We integrated information from satellite transmitters, GPS loggers and wet/dry activity loggers to compare the at-sea behaviour of 4 sympatric albatross species by night and day: wandering Diomedea exulans, grey-headed Thalassarche chrysostoma, black-browed T. melanophrys and light-mantled sooty Phoebetria palpebrata (in total, 350 foraging trips by 101 individuals). Trip duration, distance and maximum range varied more within species between stages (incubation, broodguard and post-brood) than between species at the same stage, implying that reproductive constraints are more important than interspecific competition in shaping foraging behaviour. Wandering albatrosses spent more time on the water in fewer, longer bouts than other species. The proportion of time spent on the water was similar among the 3 smaller species. The partitioning of foraging activity between day and night varied little between species: all landed and took off more often, but spent less time overall on the water during the day than at night. This supports observations that albatrosses forage most actively during daylight, even though many of their fish and squid prey approach the surface only at night. Albatrosses were more active on bright moonlit nights, seem to have no fixed daily requirement for sleep, rest or digestion time on the water, can navigate in darkness, and are probably unhindered by the slight reduction in mean wind strength at night. They are probably less active at night because their ability to see and capture prey from the air is reduced and it is then more energy-efficient for them to rest or to catch prey using a ‘sit-and-wait’ foraging strategy.
- Global political responsibility for the conservation of albatrosses and large petrelsPublication . Beal, Martin; Dias, Maria P.; Phillips, Richard A.; Oppel, Steffen; Hazin, Carolina; Pearmain, Elizabeth J.; Adams, Josh; Anderson, David J.; Antolos, Michelle; Arata, Javier; Arcos, José Manuel; Arnould, John P. Y.; Awkerman, Jill; Bell, Elizabeth; BELL, Mike; Carey, Mark; Carle, Ryan; Clay, Thomas A.; Cleeland, Jaimie; Colodro, Valentina; Conners, Melinda; Flores, Marta Cruz; Cuthbert, Richard; Delord, Karine; Deppe, Lorna; Dilley, Ben J.; Dinis, Herculano; Elliott, Graeme; De Felipe, Fernanda; Felis, Jonathan; Forero, Manuela G.; Freeman, Amanda; Fukuda, Akira; González-Solís, Jacob; Granadeiro, J. P.; Hedd, April; Hodum, Peter; Igual, Jose Manuel; Jaeger, Audrey; Landers, Timothy; Le Corre, Matthieu; Makhado, Azwianewi; Metzger, Benjamin; Militão, Teresa; Montevecchi, William A.; Pujol, Virginia Morera; Herrero, Leia Navarro; Nel, Deon; Nicholls, David; Oro, Daniel; Ouni, Ridha; Ozaki, Kiyoaki; Quintana, Flavio; Ramos, Raül; Reid, Tim; Reyes-González, José Manuel; Robertson, Christopher; Robertson, Graham; Romdhane, Mohamed Salah; Ryan, Peter G.; Sagar, Paul; Sato, Fumio; Schoombie, Stefan; Scofield, Richard; Shaffer, Scott; Shah, Nirmal Jivan; Stevens, Kim L.; Surman, Christopher; Suryan, Robert M.; Takahashi, Akinori; Tatayah, Vikash; Taylor, Graeme; Thompson, David R.; Torres, Leigh; Walker, Kath; Wanless, Ross; Waugh, Susan M.; Weimerskirch, Henri; Yamamoto, Takashi; Zajkova, Zuzana; Zango, Laura; Catry, PauloMigratory marine species cross political borders and enter the high seas, where the lack of an effective global management framework for biodiversity leaves them vulnerable to threats. Here, we combine 10,108 tracks from 5775 individual birds at 87 sites with data on breeding population sizes to estimate the relative year-round importance of national jurisdictions and high seas areas for 39 species of albatrosses and large petrels. Populations from every country made extensive use of the high seas, indicating the stake each country has in the management of biodiversity in international waters. We quantified the links among national populations of these threatened seabirds and the regional fisheries management organizations (RFMOs) which regulate fishing in the high seas. This work makes explicit the relative responsibilities that each country and RFMO has for the management of shared biodiversity, providing invaluable information for the conservation and management of migratory species in the marine realm.