Testing assumptions of central place foraging theory: A stud

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TitleTesting assumptions of central place foraging theory: A study of AdÃ©lie penguins Pygoscelis adeliae in the Ross SeaAbstractWe investigated central place foraging (CPF) in the context of optimal foraging theory in AdÃ©lie penguins Pygoscelis adeliae of the southern Ross Sea by using satellite tracking and time-depth recorders to explore foraging at two spatio-temporal scales: within the day-to-day (sub-mesoscale: single foraging trip, 10s of km2) and the entire breeding season (mesoscale: trips by multiple individuals across the collective foraging area, 100s of km2). Specifically, we examine whether three basic assumptions of the Orians-Pearson CPF model, shown to occur in other CPF species, are met: 1) within a patch, the rate of prey acquisition declines with time spent in that patch; 2) food is distributed in discrete patches and is not available between those patches; and 3) CPF species have knowledge of the potential (or average, at least) feeding rate within their universe of patches, and use this knowledge to determine their foraging strategy when planning or engaging in a foraging trip. We found that prey consumption rates did not decline with time spent in patches, and penguins foraged to some degree most of the time when at sea. Food availability, as measured by foraging dive rate, appeared to be predictable within the same day at the same location, but predictability broke down after 2 d at distances > 10 km away. We conclude that the assumptions of the Orians-Pearson CPF model are not a good fit to the circumstances of Ross Sea penguins, which clearly are central place foragers. Copyright 2014 The Authors.AcknowledgementsThe data were collected and analyzed, and the paper written under NSF grants OPP 0440643 and ANT 0944411, and NZ Ministry of Science and Innovation grants C09X0510 and C01X1001. However, conclusions drawn do not necessarily reflect those of the National Science Foundation. Instruments were attached to penguins under ACA permit 2006-010 from NSF (Antarctic Treaty), IACUC permit 878 through California State Univ., San Jose and AEC Permit 05/09/01 through Landcare Research, NZ. We are thankful for field assistance provided by Kerry Barton, Brian Karl, and others at Cape Bird. Logistical support was provided by the U.S. Antarctic Research Program and Antarctica NZ. Subject editor Y. Watanuki provided valuable comments that improved the paper. Thank you. Point Blue contribution #1917.Funding Details0440643, NSF, National Science Foundation; 0944411, NSF, National Science Foundation

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1st AuthorFord, R.AuthorFord, R.Ainley, D.LescroÃ«l, A.Lyver, P.Toniolo, V.Ballard, G.Year2015JournalJournal of Avian BiologyVolume46Number2Pages193-205DOI10.1111/jav.00491URLhttps://www.scopus.com/inward/recor.....419b51302dcb4e1abe3a9a260Keywordsbreeding seasoncentral place foragingfood availabilityhypothesis testingoptimum foraging theoryprey capturesatellite imageryseabird, Ross SeaSouthern Ocean, Pygoscelis adeliaeSpheniscidae, rank5ProgrammeK122 - Protecting the Ross Sea Ecosystem/Penguin contaminants project

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TypeArticleCitationFord, R., Ainley, D., LescroÃ«l, A., Lyver, P., Toniolo, V. and Ballard, G. (2015). Testing assumptions of central place foraging theory: A study of Adelie penguins Pygoscelis adeliae in the Ross Sea. Journal of Avian Biology, 46(2): 193-205 IdentifierFord2015Relevancerank5

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K122 - Protecting the Ross Sea Ecosystem/Penguin contaminants project