1
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Martins FMS, Godinho R, Palma L. Cores, edges and beyond: insights into the phylogeography of frigatebirds with a focus on ultraperipheral and endemic populations. CONSERV GENET 2022. [DOI: 10.1007/s10592-022-01466-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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2
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De Pascalis F, Austin RE, Green JA, Arnould JPY, Imperio S, Maugeri M, Haakonsson J, Cecere JG, Rubolini D. Influence of rainfall on foraging behavior of a tropical seabird. Behav Ecol 2021. [DOI: 10.1093/beheco/arab134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Acquiring resources for self-maintenance and reproduction is a key challenge for wild animals, and the methods that individuals employ are, in part, shaped by environmental conditions that vary in time and space. For birds, rainfall may affect behavior, impairing senses and increasing energetic costs, but its consequences on movement patterns are poorly explored. We investigated the influence of rainfall on the foraging behavior of the magnificent frigatebird, Fregata magnificens. This peculiar tropical seabird lacks feather waterproofing and is known to track environmental conditions while searching for food. Thus, its foraging behavior should be highly sensitive to the effects of rainfall. By GPS-tracking chick-rearing adults, we showed that frigatebirds did not avoid areas with rainfall during foraging trips, nor did rainfall influence trip characteristics. However, rainfall decreased time devoted to foraging and increased time spent perching. Moreover, it affected flight mode, inducing birds to fly slower and at lower altitudes. Wind speed, which was not correlated with rainfall, only affected behavior during night-time, with strong winds decreasing time spent perching. Our results indicate that rainfall does not affect the spatial distribution of foraging frigatebirds but does alter fine-scale foraging behavior by reducing flight activity. We suggest that the ongoing environmental change in this region, including an increase in rainfall events, has the potential to impair foraging and negatively affect fitness.
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Affiliation(s)
- Federico De Pascalis
- Dipartimento di Scienze e Politiche Ambientali, Università degli studi di Milano, via Celoria 2, 20133 Milano, Italy
- School of Environmental Sciences, University of Liverpool, 4 Brownlow Street, L69 3GP Liverpool, UK
| | - Rhiannon E Austin
- School of Environmental Sciences, University of Liverpool, 4 Brownlow Street, L69 3GP Liverpool, UK
| | - Jonathan A Green
- School of Environmental Sciences, University of Liverpool, 4 Brownlow Street, L69 3GP Liverpool, UK
| | - John P Y Arnould
- School of Life and Environmental Science, Deakin University, 221 Burwood Highway, 3125 Burwood, Australia
| | - Simona Imperio
- Area Avifauna Migratrice, ISPRA, via Ca’ Fornacetta 9, 40064 Ozzano dell’Emilia, Italy
- Istituto di Geoscienze e Georisorse, IGG CNR, Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Maurizio Maugeri
- Dipartimento di Scienze e Politiche Ambientali, Università degli studi di Milano, via Celoria 2, 20133 Milano, Italy
| | - Jane Haakonsson
- Department of Environment, Cayman Islands Government, 580 North Sound Road, KY1-1002 Grand Cayman, Cayman Islands
| | - Jacopo G Cecere
- Area Avifauna Migratrice, ISPRA, via Ca’ Fornacetta 9, 40064 Ozzano dell’Emilia, Italy
| | - Diego Rubolini
- Dipartimento di Scienze e Politiche Ambientali, Università degli studi di Milano, via Celoria 2, 20133 Milano, Italy
- Istituto di Ricerca sulle Acque, IRSA CNR, Via del Mulino 19, 20861 Brugherio, Italy
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3
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Jones DC, Ceia FR, Murphy E, Delord K, Furness RW, Verdy A, Mazloff M, Phillips RA, Sagar PM, Sallée JB, Schreiber B, Thompson DR, Torres LG, Underwood PJ, Weimerskirch H, Xavier JC. Untangling local and remote influences in two major petrel habitats in the oligotrophic Southern Ocean. GLOBAL CHANGE BIOLOGY 2021; 27:5773-5785. [PMID: 34386992 DOI: 10.1111/gcb.15839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/29/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
Ocean circulation connects geographically distinct ecosystems across a wide range of spatial and temporal scales via exchanges of physical and biogeochemical properties. Remote oceanographic processes can be especially important for ecosystems in the Southern Ocean, where the Antarctic Circumpolar Current transports properties across ocean basins through both advection and mixing. Recent tracking studies have indicated the existence of two large-scale, open ocean habitats in the Southern Ocean used by grey petrels (Procellaria cinerea) from two populations (i.e., Kerguelen and Antipodes islands) during their nonbreeding season for extended periods during austral summer (i.e., October to February). In this work, we use a novel combination of large-scale oceanographic observations, surface drifter data, satellite-derived primary productivity, numerical adjoint sensitivity experiments, and output from a biogeochemical state estimate to examine local and remote influences on these grey petrel habitats. Our aim is to understand the oceanographic features that control these isolated foraging areas and to evaluate their ecological value as oligotrophic open ocean habitats. We estimate the minimum local primary productivity required to support these populations to be much <1% of the estimated local primary productivity. The region in the southeast Indian Ocean used by the birds from Kerguelen is connected by circulation to the productive Kerguelen shelf. In contrast, the region in the south-central Pacific Ocean used by seabirds from the Antipodes is relatively isolated suggesting it is more influenced by local factors or the cumulative effects of many seasonal cycles. This work exemplifies the potential use of predator distributions and oceanographic data to highlight areas of the open ocean that may be more dynamic and productive than previously thought. Our results highlight the need to consider advective connections between ecosystems in the Southern Ocean and to re-evaluate the ecological relevance of oligotrophic Southern Ocean regions from a conservation perspective.
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Affiliation(s)
- Daniel C Jones
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Filipe R Ceia
- Department of Life Sciences, Marine and Environmental Sciences Centre, University of Coimbra, Coimbra, Portugal
| | - Eugene Murphy
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Karine Delord
- Centre d'Etudes Biologiques de Chizé, UMR 7372 du CNRS-La Rochelle Université, Villiers-en-Bois, France
| | - Robert W Furness
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Ariane Verdy
- Scripps Institution of Oceanography, UCSD, San Diego, California, USA
| | - Matthew Mazloff
- Scripps Institution of Oceanography, UCSD, San Diego, California, USA
| | - Richard A Phillips
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Paul M Sagar
- National Institute of Water and Atmospheric Research Ltd, Christchurch, New Zealand
| | | | - Ben Schreiber
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
- Centre for Mathematical Sciences, University of Cambridge, Cambridge, UK
| | - David R Thompson
- National Institute of Water and Atmospheric Research Ltd, Wellington, New Zealand
| | - Leigh G Torres
- Geospatial Ecology of Marine Megafauna Lab, Department of Fisheries and Wildlife, Marine Mammal Institute, Oregon State University, Corvallis, Oregon, USA
| | - Philip J Underwood
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Henri Weimerskirch
- Centre d'Etudes Biologiques de Chizé, UMR 7372 du CNRS-La Rochelle Université, Villiers-en-Bois, France
| | - José C Xavier
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
- Department of Life Sciences, Marine and Environmental Sciences Centre, University of Coimbra, Coimbra, Portugal
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4
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Baudena A, Ser-Giacomi E, D’Onofrio D, Capet X, Cotté C, Cherel Y, D’Ovidio F. Fine-scale structures as spots of increased fish concentration in the open ocean. Sci Rep 2021; 11:15805. [PMID: 34349142 PMCID: PMC8338936 DOI: 10.1038/s41598-021-94368-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 06/24/2021] [Indexed: 02/07/2023] Open
Abstract
Oceanic frontal zones have been shown to deeply influence the distribution of primary producers and, at the other extreme of the trophic web, top predators. However, the relationship between these structures and intermediate trophic levels is much more obscure. In this paper we address this knowledge gap by comparing acoustic measurements of mesopelagic fish concentrations to satellite-derived fine-scale Lagrangian Coherent Structures in the Indian sector of the Southern Ocean. First, we demonstrate that higher fish concentrations occur more frequently in correspondence with strong Lagrangian Coherent Structures. Secondly, we illustrate that, while increased fish densities are more likely to be observed over these structures, the presence of a fine-scale feature does not imply a concomitant fish accumulation, as other factors affect fish distribution. Thirdly, we show that, when only chlorophyll-rich waters are considered, front intensity modulates significantly more the local fish concentration. Finally, we discuss a model representing fish movement along Lagrangian features, specifically built for mid-trophic levels. Its results, obtained with realistic parameters, are qualitatively consistent with the observations and the spatio-temporal scales analysed. Overall, these findings may help to integrate intermediate trophic levels in trophic models, which can ultimately support management and conservation policies.
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Affiliation(s)
- Alberto Baudena
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France ,Sorbonne Université,CNRS, Laboratoire d’Océanographie de Villefranche, UMR 7093 LOV, Villefranche-sur-Mer, France
| | - Enrico Ser-Giacomi
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France ,grid.116068.80000 0001 2341 2786Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 02139 Cambridge, MA USA
| | - Donatella D’Onofrio
- grid.435667.50000 0000 9466 4203Institute of Atmospheric Sciences and Climate, National Research Council (CNR-ISAC), Torino, Italy ,grid.5477.10000000120346234
Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, The Netherlands
| | - Xavier Capet
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France
| | - Cedric Cotté
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France
| | - Yves Cherel
- grid.452338.b0000 0004 0638 6741Centre d’Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Francesco D’Ovidio
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France
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5
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Mott R, Herrod A, Clarke RH. Transboundary priorities for protection of frigatebird non-breeding habitat in a heavily impacted region. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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6
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Zaluski S, Soanes LM, Bright JA, George A, Jodice PGR, Meyer K, Woodfield-Pascoe N, Green JA. Potential threats facing a globally important population of the magnificent frigatebird Fregata magnificens. TROPICAL ZOOLOGY 2019. [DOI: 10.1080/03946975.2019.1682352] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Susan Zaluski
- Jost Van Dykes Preservation Society, Jost Van Dyke, British Virgin Islands
| | - Louise M. Soanes
- School of Environmental Sciences, University of Liverpool, Liverpool, United Kingdom
- Life Sciences, University of Roehampton, London, United Kingdom
| | - Jenny A. Bright
- Royal Society for the Protection of Birds, The Lodge, Bedfordshire, United Kingdom
| | - Atoya George
- Conservation and Fisheries Department, British Virgin Islands Government, Road Town, Tortola, British Virgin Islands
| | - Patrick G. R. Jodice
- U.S. Geological Survey, South Carolina Cooperative Fish and Wildlife Research Unit, Clemson University, Clemson, South Carolina, USA
| | - Ken Meyer
- Avian Research and Conservation Institute, 411 N.E 7th Street, Gainesville, Florida 32601, USA
| | | | - Jonathan A. Green
- School of Environmental Sciences, University of Liverpool, Liverpool, United Kingdom
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7
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Corbeau A, Prudor A, Kato A, Weimerskirch H. Development of flight and foraging behaviour in a juvenile seabird with extreme soaring capacities. J Anim Ecol 2019; 89:20-28. [DOI: 10.1111/1365-2656.13121] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 09/23/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Alexandre Corbeau
- Centre d’Études Biologiques de Chizé UMR7372 CNRS‐La Rochelle Université Villiers en Bois France
| | - Aurélien Prudor
- Centre d’Études Biologiques de Chizé UMR7372 CNRS‐La Rochelle Université Villiers en Bois France
| | - Akiko Kato
- Centre d’Études Biologiques de Chizé UMR7372 CNRS‐La Rochelle Université Villiers en Bois France
| | - Henri Weimerskirch
- Centre d’Études Biologiques de Chizé UMR7372 CNRS‐La Rochelle Université Villiers en Bois France
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8
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Grecian WJ, Lane JV, Michelot T, Wade HM, Hamer KC. Understanding the ontogeny of foraging behaviour: insights from combining marine predator bio-logging with satellite-derived oceanography in hidden Markov models. J R Soc Interface 2019; 15:rsif.2018.0084. [PMID: 29875281 PMCID: PMC6030624 DOI: 10.1098/rsif.2018.0084] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/09/2018] [Indexed: 11/18/2022] Open
Abstract
The development of foraging strategies that enable juveniles to efficiently identify and exploit predictable habitat features is critical for survival and long-term fitness. In the marine environment, meso- and sub-mesoscale features such as oceanographic fronts offer a visible cue to enhanced foraging conditions, but how individuals learn to identify these features is a mystery. In this study, we investigate age-related differences in the fine-scale foraging behaviour of adult (aged ≥ 5 years) and immature (aged 2–4 years) northern gannets Morus bassanus. Using high-resolution GPS-loggers, we reveal that adults have a much narrower foraging distribution than immature birds and much higher individual foraging site fidelity. By conditioning the transition probabilities of a hidden Markov model on satellite-derived measures of frontal activity, we then demonstrate that adults show a stronger response to frontal activity than immature birds, and are more likely to commence foraging behaviour as frontal intensity increases. Together, these results indicate that adult gannets are more proficient foragers than immatures, supporting the hypothesis that foraging specializations are learned during individual exploratory behaviour in early life. Such memory-based individual foraging strategies may also explain the extended period of immaturity observed in gannets and many other long-lived species.
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Affiliation(s)
- W James Grecian
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK .,Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews KY16 8LB, UK
| | - Jude V Lane
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Théo Michelot
- School of Mathematics and Statistics, University of Sheffield, Sheffield S3 7RH, UK
| | - Helen M Wade
- Scottish Natural Heritage, Battleby, Redgorton, Perth PH1 3EW, UK
| | - Keith C Hamer
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
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9
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El Aouni A, Daoudi K, Yahia H, Minaoui K, Benazzouz A. Surface mixing and biological activity in the North-West African upwelling. CHAOS (WOODBURY, N.Y.) 2019; 29:011104. [PMID: 30709139 DOI: 10.1063/1.5067253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 12/24/2018] [Indexed: 06/09/2023]
Abstract
Near-shore water along the North-West African margin is one of the world's major upwelling regions. It is associated with physical structures of oceanic fronts which influence the biological productivity. The study of these coherent structures in connection with chlorophyll concentration data is of fundamental importance for understanding the spatial distributions of the plankton. In this work, we study the horizontal stirring and mixing in different upwelling areas using Lagrangian coherent structures (LCSs). These LCSs are calculated using the recent geodesic theory of LCSs. We use these LCSs to study the link between the chlorophyll fronts concentrations and surface mixing, based on 10 years of satellite data. These LCSs move with the flow as material lines, thus the horizontal mixing is calculated from the intersection of these LCSs with the finite time Lyapunov exponent maps. We compare our results with those of a recent study conducted over the same area, but based on finite size Lyapunov exponents (FSLEs), whose output is a plot of scalar distributions. We discuss the differences between FSLE and geodesic theory of LCS. The latter yields analytical solutions of LCSs, while FSLEs can only provide LCSs for sharp enough ridges of nearly constant height.
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Affiliation(s)
- Anass El Aouni
- Geostat Team, INRIA Bordeaux Sud-Ouest, 33400 Talence, France
| | - Khalid Daoudi
- Geostat Team, INRIA Bordeaux Sud-Ouest, 33400 Talence, France
| | - Hussein Yahia
- Geostat Team, INRIA Bordeaux Sud-Ouest, 33400 Talence, France
| | - Khalid Minaoui
- University Mohammed V, Faculty of Sciences, LRIT, 10106 Rabat, Morocco
| | - Aïssa Benazzouz
- The Higher Institute of Maritime Studies, 20000 Casablanca, Morocco
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10
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The role of submesoscale currents in structuring marine ecosystems. Nat Commun 2018; 9:4758. [PMID: 30420651 PMCID: PMC6232172 DOI: 10.1038/s41467-018-07059-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 10/10/2018] [Indexed: 11/16/2022] Open
Abstract
From microbes to large predators, there is increasing evidence that marine life is shaped by short-lived submesoscales currents that are difficult to observe, model, and explain theoretically. Whether and how these intense three-dimensional currents structure the productivity and diversity of marine ecosystems is a subject of active debate. Our synthesis of observations and models suggests that the shallow penetration of submesoscale vertical currents might limit their impact on productivity, though ecological interactions at the submesoscale may be important in structuring oceanic biodiversity. Short-lived three-dimensional submesoscale currents, responsible for swirling ocean color chlorophyll filaments, have long been thought to affect productivity. Current research suggests they may not be effective in enhancing phytoplankton growth, but may have important contributions to biodiversity.
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11
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Abrahms B, Scales KL, Hazen EL, Bograd SJ, Schick RS, Robinson PW, Costa DP. Mesoscale activity facilitates energy gain in a top predator. Proc Biol Sci 2018; 285:rspb.2018.1101. [PMID: 30135161 DOI: 10.1098/rspb.2018.1101] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/24/2018] [Indexed: 01/29/2023] Open
Abstract
How animal movement decisions interact with the distribution of resources to shape individual performance is a key question in ecology. However, links between spatial and behavioural ecology and fitness consequences are poorly understood because the outcomes of individual resource selection decisions, such as energy intake, are rarely measured. In the open ocean, mesoscale features (approx. 10-100 km) such as fronts and eddies can aggregate prey and thereby drive the distribution of foraging vertebrates through bottom-up biophysical coupling. These productive features are known to attract predators, yet their role in facilitating energy transfer to top-level consumers is opaque. We investigated the use of mesoscale features by migrating northern elephant seals and quantified the corresponding energetic gains from the seals' foraging patterns at a daily resolution. Migrating elephant seals modified their diving behaviour and selected for mesoscale features when foraging. Daily energy gain increased significantly with increasing mesoscale activity, indicating that the physical environment can influence predator fitness at fine temporal scales. Results show that areas of high mesoscale activity not only attract top predators as foraging hotspots, but also lead to increased energy transfer across trophic levels. Our study provides evidence that the physical environment is an important factor in controlling energy flow to top predators by setting the stage for variation in resource availability. Such understanding is critical for assessing how changes in the environment and resource distribution will affect individual fitness and food web dynamics.
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Affiliation(s)
- Briana Abrahms
- NOAA Southwest Fisheries Science Center, Environmental Research Division, Monterey, CA, USA .,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Kylie L Scales
- School of Science and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Elliott L Hazen
- NOAA Southwest Fisheries Science Center, Environmental Research Division, Monterey, CA, USA.,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Steven J Bograd
- NOAA Southwest Fisheries Science Center, Environmental Research Division, Monterey, CA, USA
| | - Robert S Schick
- Marine Geospatial Ecology Lab, Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Patrick W Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
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12
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Sachs G, Weimerskirch H. Flight of frigatebirds inside clouds – energy gain, stability and control. J Theor Biol 2018; 448:9-16. [DOI: 10.1016/j.jtbi.2018.03.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 02/27/2018] [Accepted: 03/12/2018] [Indexed: 11/28/2022]
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13
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Lehahn Y, d'Ovidio F, Koren I. A Satellite-Based Lagrangian View on Phytoplankton Dynamics. ANNUAL REVIEW OF MARINE SCIENCE 2018; 10:99-119. [PMID: 28961072 DOI: 10.1146/annurev-marine-121916-063204] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The well-lit upper layer of the open ocean is a dynamical environment that hosts approximately half of global primary production. In the remote parts of this environment, distant from the coast and from the seabed, there is no obvious spatially fixed reference frame for describing the dynamics of the microscopic drifting organisms responsible for this immense production of organic matter-the phytoplankton. Thus, a natural perspective for studying phytoplankton dynamics is to follow the trajectories of water parcels in which the organisms are embedded. With the advent of satellite oceanography, this Lagrangian perspective has provided valuable information on different aspects of phytoplankton dynamics, including bloom initiation and termination, spatial distribution patterns, biodiversity, export of carbon to the deep ocean, and, more recently, bottom-up mechanisms that affect the distribution and behavior of higher-trophic-level organisms. Upcoming submesoscale-resolving satellite observations and swarms of autonomous platforms open the way to the integration of vertical dynamics into the Lagrangian view of phytoplankton dynamics.
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Affiliation(s)
- Yoav Lehahn
- Department of Marine Geosciences, University of Haifa, Haifa 3498838, Israel;
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Francesco d'Ovidio
- Sorbonne Université (UPMC Paris 6/CNRS/IRD/MNHN), LOCEAN-IPSL, 75005 Paris, France;
| | - Ilan Koren
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel;
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14
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Bras YL, Jouma’a J, Guinet C. Three-dimensional space use during the bottom phase of southern elephant seal dives. MOVEMENT ECOLOGY 2017; 5:18. [PMID: 28861272 PMCID: PMC5577837 DOI: 10.1186/s40462-017-0108-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 08/18/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND In marine pelagic ecosystems, the spatial distribution of biomass is heterogeneous and dynamic. At large scales, physical processes are the main driving forces of biomass distribution. At fine scales, both biotic and abiotic parameters are likely to be key determinants in the horizontal and vertical distribution of biomass, with direct consequences on the foraging behaviour of diving predators. However, fine scale three-dimensional (3D) spatial interactions between diving predators and their prey are still poorly known. RESULTS We reconstructed and examined the patterns of southern elephant seals 3D path during the bottom phase of their dives, and related them to estimated prey encounter density. We found that southern elephant seal tracks at bottom are strongly dominated by a single horizontal direction. In high prey density areas, seals travelled shorter distances but their track remained strongly orientated according to a main linear direction. Horizontal, and more importantly, vertical deviations from this main direction, were related negatively to the estimated prey density. We found that prey encounter density decreased with diving depth but tended to be more predictable. CONCLUSION Southern elephant seal behaviour during the bottom phase of their dives suggest that the prey are dispersed and distributed into layers in which their density relates to the vertical spread of the layer. The linear trajectories performed by the elephant seals would allow to explore the largest volume of water, maximizing the opportunities of prey encounter, while travelling great horizontal distances.
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Affiliation(s)
- Yves Le Bras
- Centre d’Études Biologiques de Chizé, UMR 7372, CNRS-ULR, Villiers-en-bois, 79360 France
| | - Joffrey Jouma’a
- Centre d’Études Biologiques de Chizé, UMR 7372, CNRS-ULR, Villiers-en-bois, 79360 France
| | - Christophe Guinet
- Centre d’Études Biologiques de Chizé, UMR 7372, CNRS-ULR, Villiers-en-bois, 79360 France
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15
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Cox SL, Miller PI, Embling CB, Scales KL, Bicknell AWJ, Hosegood PJ, Morgan G, Ingram SN, Votier SC. Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots. ROYAL SOCIETY OPEN SCIENCE 2016; 3:160317. [PMID: 27703698 PMCID: PMC5043317 DOI: 10.1098/rsos.160317] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 08/19/2016] [Indexed: 06/06/2023]
Abstract
Oceanic fronts are key habitats for a diverse range of marine predators, yet how they influence fine-scale foraging behaviour is poorly understood. Here, we investigated the dive behaviour of northern gannets Morus bassanus in relation to shelf-sea fronts. We GPS (global positioning system) tracked 53 breeding birds and examined the relationship between 1901 foraging dives (from time-depth recorders) and thermal fronts (identified via Earth Observation composite front mapping) in the Celtic Sea, Northeast Atlantic. We (i) used a habitat-use availability analysis to determine whether gannets preferentially dived at fronts, and (ii) compared dive characteristics in relation to fronts to investigate the functional significance of these oceanographic features. We found that relationships between gannet dive probabilities and fronts varied by frontal metric and sex. While both sexes were more likely to dive in the presence of seasonally persistent fronts, links to more ephemeral features were less clear. Here, males were positively correlated with distance to front and cross-front gradient strength, with the reverse for females. Both sexes performed two dive strategies: shallow V-shaped plunge dives with little or no active swim phase (92% of dives) and deeper U-shaped dives with an active pursuit phase of at least 3 s (8% of dives). When foraging around fronts, gannets were half as likely to engage in U-shaped dives compared with V-shaped dives, independent of sex. Moreover, V-shaped dive durations were significantly shortened around fronts. These behavioural responses support the assertion that fronts are important foraging habitats for marine predators, and suggest a possible mechanistic link between the two in terms of dive behaviour. This research also emphasizes the importance of cross-disciplinary research when attempting to understand marine ecosystems.
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Affiliation(s)
- S L Cox
- Marine Biology and Ecology Research Centre, Plymouth University, Plymouth PL4 8AA, UK; Marine Physics Research Group, Plymouth University, Plymouth PL4 8AA, UK
| | - P I Miller
- Plymouth Marine Laboratory , Prospect Place, Plymouth PL1 3DH , UK
| | - C B Embling
- Marine Biology and Ecology Research Centre , Plymouth University , Plymouth PL4 8AA , UK
| | - K L Scales
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK; Institute of Marine Sciences, University of California, Santa Cruz, CA 95064, USA; National Oceanic and Atmospheric Administration (NOAA), Southwest Fisheries Science Centre, Environmental Research Division, 99 Pacific Street, Suite 255A, Monterey, CA 93940, USA
| | - A W J Bicknell
- Environment and Sustainability Institute , University of Exeter , Penryn TR10 9FE , UK
| | - P J Hosegood
- Marine Physics Research Group , Plymouth University , Plymouth PL4 8AA , UK
| | - G Morgan
- RSPB , Ramsey Island, St David's, Pembrokeshire SA62 6PY , UK
| | - S N Ingram
- Marine Biology and Ecology Research Centre , Plymouth University , Plymouth PL4 8AA , UK
| | - S C Votier
- Environment and Sustainability Institute , University of Exeter , Penryn TR10 9FE , UK
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16
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Rattenborg NC, Voirin B, Cruz SM, Tisdale R, Dell'Omo G, Lipp HP, Wikelski M, Vyssotski AL. Evidence that birds sleep in mid-flight. Nat Commun 2016; 7:12468. [PMID: 27485308 PMCID: PMC4976198 DOI: 10.1038/ncomms12468] [Citation(s) in RCA: 154] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 07/06/2016] [Indexed: 02/06/2023] Open
Abstract
Many birds fly non-stop for days or longer, but do they sleep in flight and if so, how? It is commonly assumed that flying birds maintain environmental awareness and aerodynamic control by sleeping with only one eye closed and one cerebral hemisphere at a time. However, sleep has never been demonstrated in flying birds. Here, using electroencephalogram recordings of great frigatebirds (Fregata minor) flying over the ocean for up to 10 days, we show that they can sleep with either one hemisphere at a time or both hemispheres simultaneously. Also unexpectedly, frigatebirds sleep for only 0.69 h d−1 (7.4% of the time spent sleeping on land), indicating that ecological demands for attention usually exceed the attention afforded by sleeping unihemispherically. In addition to establishing that birds can sleep in flight, our results challenge the view that they sustain prolonged flights by obtaining normal amounts of sleep on the wing. Whether and how birds sleep during long-distance flights has remained a mystery. Here, Rattenborg and colleagues show for the first time that frigatebirds can sleep during flight, but do so in remarkably small amounts.
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Affiliation(s)
- Niels C Rattenborg
- Avian Sleep Group, Max Planck Institute for Ornithology, Seewiesen 82319, Germany
| | - Bryson Voirin
- Avian Sleep Group, Max Planck Institute for Ornithology, Seewiesen 82319, Germany.,California Academy of Sciences, San Francisco, California 94118, USA
| | - Sebastian M Cruz
- Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology, Radolfzell 78315, Germany
| | - Ryan Tisdale
- Avian Sleep Group, Max Planck Institute for Ornithology, Seewiesen 82319, Germany
| | | | - Hans-Peter Lipp
- Institute of Anatomy, University of Zurich, Zurich 8057, Switzerland.,Institute of Evolutionary Medicine, University of Zurich, Zurich 8057, Switzerland.,School of Laboratory Medicine and Medical Sciences, Department of Physiology, Kwazulu-Natal University, Durban 4000, South Africa
| | - Martin Wikelski
- Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology, Radolfzell 78315, Germany.,Department of Biology, University of Konstanz, Konstanz 78457, Germany
| | - Alexei L Vyssotski
- Institute of Neuroinformatics, University of Zurich and Swiss Federal Institute of Technology (ETH), Zurich 8057, Switzerland
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17
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Mendez L, Cotté C, Prudor A, Weimerskirch H. Variability in foraging behaviour of red-footed boobies nesting on Europa Island. ACTA OECOLOGICA 2016. [DOI: 10.1016/j.actao.2015.10.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Della Penna A, De Monte S, Kestenare E, Guinet C, d’Ovidio F. Quasi-planktonic behavior of foraging top marine predators. Sci Rep 2015; 5:18063. [PMID: 26666350 PMCID: PMC4678296 DOI: 10.1038/srep18063] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 11/09/2015] [Indexed: 11/09/2022] Open
Abstract
Monitoring marine top predators is fundamental for assessing the health and functioning of open ocean ecosystems. Although recently tracking observations have substantially increased, factors determining the horizontal exploration of the ocean by marine predators are still largely unknown, especially at the scale of behavioral switches (1-100 km, days-weeks). It is commonly assumed that the influence of water movement can be neglected for animals capable of swimming faster than the current. Here, we challenge this assumption by combining the use of biologging (GPS and accelerometry), satellite altimetry and in-situ oceanographic data (ADCP and drifting buoys) to investigate the effect of the mesoscale ocean dynamics on a marine predator, the southern elephant seal. A Lagrangian approach reveals that trajectories of elephant seals are characterized by quasi-planktonic bouts where the animals are horizontally drifting. These bouts correspond to periods of increased foraging effort, indicating that in the quasi-planktonic conditions energy is allocated to diving and chasing, rather than in horizontal search of favourable grounds. These results suggest that mesoscale features like eddies and fronts may act as a focal points for trophic interactions not only by bottom-up modulation of nutrient injection, but also by directly entraining horizontal displacements of the upper trophic levels.
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Affiliation(s)
- Alice Della Penna
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7159, LOCEAN-IPSL CNRS/UPMC/IRD/MNHN, F-75005, Paris, France
- Univ Paris Diderot Cité, 5 Rue Thomas Mann, 75013 Paris, France
- CSIRO-UTAS Quantitative Marine Science Program, IMAS, Private Bag 129, Hobart, Tasmania 7001, Australia
| | - Silvia De Monte
- Ecole Normale Supérieure, Institut de Biologie de l’ENS (IBENS), UMR CNRS 8197 and INSERM U1024, 46 rue d’Ulm, F-75005 Paris, France
| | - Elodie Kestenare
- Laboratoire d’Etudes en Géophysique et Océanographie Spatiales (LEGOS), Université de Toulouse III (OMP) and IRD, Toulouse, France
| | - Christophe Guinet
- Centre d’Etudes Biologiques de Chizé, 79360 Villiers-en-Bois, France
| | - Francesco d’Ovidio
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7159, LOCEAN-IPSL CNRS/UPMC/IRD/MNHN, F-75005, Paris, France
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19
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Bon C, Della Penna A, d’Ovidio F, Y.P. Arnould J, Poupart T, Bost CA. Influence of oceanographic structures on foraging strategies: Macaroni penguins at Crozet Islands. MOVEMENT ECOLOGY 2015; 3:32. [PMID: 26396739 PMCID: PMC4578264 DOI: 10.1186/s40462-015-0057-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 09/06/2015] [Indexed: 05/26/2023]
Abstract
BACKGROUND In the open ocean, eddies and associated structures (fronts, filaments) have strong influences on the foraging activities of top-predators through the enhancement and the distribution of marine productivity, zooplankton and fish communities. Investigating how central place foragers, such as penguins, find and use these physical structures is crucial to better understanding their at-sea distribution. In the present study, we compared the travel heading and speed of the world's most abundant penguin, the Macaroni penguin (Eudyptes chrysolophus), with the distribution of surface physical structures (large-scale fronts, eddies and filaments). RESULTS The study was performed during December 2012 in the Crozet Archipelago (46.42° S; 51.86° E), South Indian Ocean. Six males at incubation stage were equipped with GPS loggers to get their trajectories. We used Eulerian and Lagrangian methods to locate large-scale fronts, mesoscale eddies (10-100 km) and part of the sub-mesoscale structures (<10 km, filaments) at the surface of the ocean. By comparing the positions of birds and these structures, we show that Macaroni penguins: i) target the sub Antarctic Front; ii) increase their foraging activity within a highly dynamic area, composed of eddy fields and filamentary structures; and iii) travel in the same direction as the predominant currents. CONCLUSIONS We show that penguins adjust their travel speed and movement during their whole trips in relation with the oceanographic structures visited. At a large scale, we hypothesize that Macaroni penguins target the sub Antarctic Front to find profitable patches of their main prey. At finer scale, Macaroni penguin may adopt a horizontal drifting behavior in strong currents, which could be a way to minimize costs of displacement.
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Affiliation(s)
- Cecile Bon
- />Centre d’Etudes Biologiques de Chizé, UMR 7372, CNRS - Université de La Rochelle, 79360 Villiers en Bois, France
| | - Alice Della Penna
- />Sorbonne Universités, UPMC Université Paris 06, UMR 7159, LOCEAN-IPSL, F-75005, Paris, France/Université Paris-Diderot/CSIRO-UTAS Quantitative Marine Science Program, IMAS, Private Bag 129, Hobart, TAS 7001 Australia
| | - Francesco d’Ovidio
- />Sorbonne Universités, UPMC Université Paris 06, UMR 7159, LOCEAN-IPSL, F-75005 Paris, France
| | - John Y.P. Arnould
- />School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, Deakin University, 221 Burwood Highway, Burwood, VIC 3125 Australia
| | - Timothée Poupart
- />Centre d’Etudes Biologiques de Chizé, UMR 7372, CNRS - Université de La Rochelle, 79360 Villiers en Bois, France
| | - Charles-André Bost
- />Centre d’Etudes Biologiques de Chizé, UMR 7372, CNRS - Université de La Rochelle, 79360 Villiers en Bois, France
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20
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McGillicuddy DJ. Mechanisms of Physical-Biological-Biogeochemical Interaction at the Oceanic Mesoscale. ANNUAL REVIEW OF MARINE SCIENCE 2015; 8:125-159. [PMID: 26359818 DOI: 10.1146/annurev-marine-010814-015606] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Mesoscale phenomena are ubiquitous and highly energetic features of ocean circulation. Their influence on biological and biogeochemical processes varies widely, stemming not only from advective transport but also from the generation of variations in the environment that affect biological and chemical rates. The ephemeral nature of mesoscale features in the ocean makes it difficult to elucidate the attendant mechanisms of physical-biological-biogeochemical interaction, necessitating the use of multidisciplinary approaches involving in situ observations, remote sensing, and modeling. All three aspects are woven through this review in an attempt to synthesize current understanding of the topic, with particular emphasis on novel developments in recent years.
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Affiliation(s)
- Dennis J McGillicuddy
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543;
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21
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Hennicke JC, James DJ, Weimerskirch H. Sex-Specific Habitat Utilization and Differential Breeding Investments in Christmas Island Frigatebirds throughout the Breeding Cycle. PLoS One 2015; 10:e0129437. [PMID: 26098941 PMCID: PMC4476668 DOI: 10.1371/journal.pone.0129437] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 05/10/2015] [Indexed: 11/19/2022] Open
Abstract
In seabirds, equal bi-parental care is the rule, as it is considered crucial for raising chicks successfully because seabirds forage in an environment with unpredictable and highly variable food supply. Frigatebirds forage in poor tropical waters, yet males reduce and even stop parental care soon after chick brooding, leaving the female to provision the chick alone for an extended fledging period. Using bird-borne tracking devices, male and female Christmas Island Frigatebirds (Fregata andrewsi) were investigated during the brooding, late chick rearing and post-fledging period to examine whether sexes exhibit foraging strategies that may be linked to differential breeding investments. During brooding, males and females showed similar foraging behaviour under average marine productivity of oceanic waters close to the colony, but males shifted to more distant and more productive habitats when conditions deteriorated to continue with reduced chick provisioning. During the late chick rearing period, females progressively increased their foraging range to the more distant but productive marine areas that only males had visited during brooding. Birds spent the non-breeding period roosting in highly productive waters of the Sunda Shelf. The sex-specific utilisation of three different foraging habitats with different primary productivity (oceanic, coastal, and shelf areas) allowed for temporal and spatial segregation in the exploitation of favourable habitats which seems to enable each sex to optimise its foraging profitability. In addition, post-fledging foraging movements of females suggest a biennial breeding cycle, while limited information on males suggests the possibility of an annual breeding cycle.
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Affiliation(s)
- Janos C. Hennicke
- Marine Top Predator Group, Centre d’Etudes Biologiques de Chizé, CEBC–CNRS, Villiers-en-Bois, France
- Department of Ecology and Conservation, University of Hamburg, Hamburg, Germany
- * E-mail:
| | | | - Henri Weimerskirch
- Marine Top Predator Group, Centre d’Etudes Biologiques de Chizé, CEBC–CNRS, Villiers-en-Bois, France
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22
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Thiers L, Louzao M, Ridoux V, Le Corre M, Jaquemet S, Weimerskirch H. Combining Methods to Describe Important Marine Habitats for Top Predators: Application to Identify Biological Hotspots in Tropical Waters. PLoS One 2014; 9:e115057. [PMID: 25494047 PMCID: PMC4262456 DOI: 10.1371/journal.pone.0115057] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 11/14/2014] [Indexed: 11/18/2022] Open
Abstract
In tropical waters resources are usually scarce and patchy, and predatory species generally show specific adaptations for foraging. Tropical seabirds often forage in association with sub-surface predators that create feeding opportunities by bringing prey close to the surface, and the birds often aggregate in large multispecific flocks. Here we hypothesize that frigatebirds, a tropical seabird adapted to foraging with low energetic costs, could be a good predictor of the distribution of their associated predatory species, including other seabirds (e.g. boobies, terns) and subsurface predators (e.g., dolphins, tunas). To test this hypothesis, we compared distribution patterns of marine predators in the Mozambique Channel based on a long-term dataset of both vessel- and aerial surveys, as well as tracking data of frigatebirds. By developing species distribution models (SDMs), we identified key marine areas for tropical predators in relation to contemporaneous oceanographic features to investigate multi-species spatial overlap areas and identify predator hotspots in the Mozambique Channel. SDMs reasonably matched observed patterns and both static (e.g. bathymetry) and dynamic (e.g. Chlorophyll a concentration and sea surface temperature) factors were important explaining predator distribution patterns. We found that the distribution of frigatebirds included the distributions of the associated species. The central part of the channel appeared to be the best habitat for the four groups of species considered in this study (frigatebirds, brown terns, boobies and sub-surface predators).
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Affiliation(s)
- Laurie Thiers
- Centre d'Études Biologiques de Chizé, Station d'Ecologie de Chizé-La Rochelle UMR 7372, Centre National de la Recherche Scientifique, 79360, Villiers en Bois, France
| | - Maite Louzao
- Instituto Español de Oceanografía, CO Xixón, Camín de l'Arbeyal s/n, 33212, Xixón, Spain
| | - Vincent Ridoux
- Centre d'Études Biologiques de Chizé, Station d'Ecologie de Chizé-La Rochelle UMR 7372, Centre National de la Recherche Scientifique, 79360, Villiers en Bois, France
- Observatoire PELAGIS, CNRS, Université de La Rochelle UMS 3462, 5 allée de l'Océan, 17000, La Rochelle, France
| | - Matthieu Le Corre
- Université de la Réunion, Laboratoire ECOMAR (FRE 3560 CNRS), Avenue René Cassin, CS 92003 97744, Saint Denis Cedex 9, Ile de la Réunion, France
| | - Sébastien Jaquemet
- Université de la Réunion, Laboratoire ECOMAR (FRE 3560 CNRS), Avenue René Cassin, CS 92003 97744, Saint Denis Cedex 9, Ile de la Réunion, France
| | - Henri Weimerskirch
- Centre d'Études Biologiques de Chizé, Station d'Ecologie de Chizé-La Rochelle UMR 7372, Centre National de la Recherche Scientifique, 79360, Villiers en Bois, France
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23
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Soanes LM, Arnould JPY, Dodd SG, Milligan G, Green JA. Factors affecting the foraging behaviour of the European shag: implications for seabird tracking studies. MARINE BIOLOGY 2014; 161:1335-1348. [PMID: 24882884 PMCID: PMC4033789 DOI: 10.1007/s00227-014-2422-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 03/08/2014] [Indexed: 05/22/2023]
Abstract
Seabird tracking has become an ever more popular tool to aid environmental procedures such as the designation of marine protected areas and environmental impact assessments. However, samples used are usually small and little consideration is given to experimental design and sampling protocol. European shags Phalacrocorax aristotelis were tracked using GPS technology over three breeding seasons and the following foraging trip characteristics: trip duration, trip distance, maximum distance travelled from the colony, size of area used and direction travelled from colony were determined for each foraging trip. The effect of sex, year of study, breeding site, number and age of chicks and the timing of tracking on foraging behaviour were investigated using a General Estimation Equation model. A range of sampling scenarios reflecting likely field sampling were also tested to compare how foraging behaviour differed depending on composition of the sample of birds tracked. Trip distance, trip duration, maximum distance travelled and size of area used were all significantly affected by the breeding site, and the number of chicks a tracked adult was raising. The effect of sex was also seen when examining trip distance, trip duration and the maximum distance travelled. The direction travelled on a foraging trip was also significantly affected by breeding site. This study highlights the importance of sampling regime and the influence that year, sex, age, number of chicks and breeding site can have on the foraging trip characteristics for this coastal feeding seabird. Given the logistical and financial constraints in tracking large numbers of individuals, this study identifies the need for researchers to consider the composition of their study sample to ensure any identified foraging areas are as representative as possible of the whole colony's foraging area.
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Affiliation(s)
- L. M. Soanes
- School of Environmental Sciences, University of Liverpool, Liverpool, L69 3GP UK
| | - J. P. Y. Arnould
- School of Life and Environmental Sciences, Deakin University, Burwood, 3215 Australia
| | - S. G. Dodd
- Royal Society for the Protection of Birds, North Wales Office, Bangor, LL57 4FD UK
| | - G. Milligan
- School of Environmental Sciences, University of Liverpool, Liverpool, L69 3GP UK
| | - J. A. Green
- School of Environmental Sciences, University of Liverpool, Liverpool, L69 3GP UK
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24
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Shepard ELC, Lambertucci SA. From daily movements to population distributions: weather affects competitive ability in a guild of soaring birds. J R Soc Interface 2013; 10:20130612. [PMID: 24026471 PMCID: PMC3785828 DOI: 10.1098/rsif.2013.0612] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 08/21/2013] [Indexed: 11/12/2022] Open
Abstract
The ability of many animals to access and exploit food is dependent on the ability to move. In the case of scavenging birds, which use soaring flight to locate and exploit ephemeral resources, the cost and speed of movement vary with meteorological factors. These factors are likely to modify the nature of interspecific interactions, as well as individual movement capacity, although the former are less well understood. We used aeronautical models to examine how soaring performance varies with weather within a guild of scavenging birds and the consequences this has for access to a common resource. Birds could be divided broadly into those with low wing loading that are more competitive in conditions with weak updraughts and low winds (black vultures and caracaras), and those with high wing loading that are well adapted for soaring in strong updraughts and moderate to high winds (Andean condors). Spatial trends in meteorological factors seem to confine scavengers with high wing loading to the mountains where they out-compete other birds; a trend that is borne out in worldwide distributions of the largest species. However, model predictions and carcass observations suggest that the competitive ability of these and other birds varies with meteorological conditions in areas where distributions overlap. This challenges the view that scavenging guilds are structured by fixed patterns of dominance and suggests that competitive ability varies across spatial and temporal scales, which may ultimately be a mechanism promoting diversity among aerial scavengers.
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Affiliation(s)
- Emily L C Shepard
- Department of Biosciences, College of Science, Swansea University, Swansea SA2 8PP, UK.
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