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Eby A, Patterson A, Whelan S, Elliott KH, Gilchrist HG, Love OP. Influence of sea ice concentration, sex and chick age on foraging flexibility and success in an Arctic seabird. CONSERVATION PHYSIOLOGY 2024; 12:coae057. [PMID: 39247178 PMCID: PMC11381092 DOI: 10.1093/conphys/coae057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 04/14/2024] [Accepted: 04/19/2024] [Indexed: 09/10/2024]
Abstract
Declining sea ice and increased variability in sea ice dynamics are altering Arctic marine food webs. Changes in sea ice dynamics and prey availability are likely to impact pagophilic (ice-dependent and ice-associated) species, such as thick-billed murres (Uria lomvia), through changes in foraging behaviour and foraging success. At the same time, extrinsic factors, such as chick demand, and intrinsic factors, such as sex, are also likely to influence foraging behaviour and foraging success of adult murres. Here, we use 3 years of data (2017-2019) to examine the impacts of environmental conditions (sea ice concentration and sea surface temperature), sex and chick age (as a proxy for chick demand) on foraging and diving behaviour (measured via biologgers), energy expenditure (estimated from activity budgets) and foraging success (measured via nutritional biomarkers) of thick-billed murres during the incubation and chick-rearing stages at Coats Island, Nunavut. Murres only exhibited foraging flexibility to environmental conditions during incubation, which is also the only stage when ice was present. When more ice was present, foraging effort increased, murres foraged farther and made deeper dives, where murres making deeper dives had higher foraging success (greater relative change in mass). During incubation, murre behaviour was also influenced by sex of the individual, where males made more and shorter trips and more dives. During chick-rearing, murre behaviour was influenced primarily by the sex of the individual and chick age. Males made shallower dives and fewer dive bouts per day, and more dives. Birds made longer, deeper dives as chicks aged, likely representing increased intra-specific competition for prey throughout the season. Our results suggest variation in sea ice concentration does impact foraging success of murres; however, sex-specific foraging strategies may help buffer colony breeding success from variability in sea ice concentration.
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Affiliation(s)
- Alyssa Eby
- Department of Integrative Biology, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada
| | - Allison Patterson
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Road, Ste Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| | - Shannon Whelan
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Road, Ste Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| | - Kyle H Elliott
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Road, Ste Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| | - H Grant Gilchrist
- Environment and Climate Change Canada, National Wildlife Research Centre, 1125 Colonel By Drive, Raven Road, Ottawa, ON, K1A OH3, Canada
| | - Oliver P Love
- Department of Integrative Biology, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada
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Carreiro AR, Ramos JA, Mata VA, Matos DM, dos Santos I, Araújo PM, Rodrigues I, Almeida NM, Militão T, Saldanha S, Paiva VH, Lopes RJ. High-throughput sequencing reveals prey diversity overlap between sympatric Sulids in the tropical Atlantic. FOOD WEBS 2022. [DOI: 10.1016/j.fooweb.2022.e00258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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3
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Colominas-Ciuró R, Cianchetti-Benedetti M, Michel L, Dell'Omo G, Quillfeldt P. Foraging strategies and physiological status of a marine top predator differ during breeding stages. Comp Biochem Physiol A Mol Integr Physiol 2021; 263:111094. [PMID: 34653609 DOI: 10.1016/j.cbpa.2021.111094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 10/08/2021] [Accepted: 10/08/2021] [Indexed: 11/16/2022]
Abstract
Habitat characteristics determine the presence and distribution of trophic resources shaping seabirds' behavioural responses which may result in physiological consequences. Such physiological consequences in relation to foraging strategies of different life-history stages have been little studied in the wild. Thus, we aim to assess differences in oxidative status, condition (fat stores, i.e. triglyceride levels, TRI), stress (Heterophil/Lymphocyte (H/L) ratio), and leukocyte profiles between incubation and chick rearing highlighting the role of foraging strategies in a seabird (Calonectris diomedea). Chick rearing was more energetically demanding and stressful than incubation as demonstrated by high stress levels (H/L ratio and leukocytes) and lower body stores (assessed by TRI and the increment of weight) due to the high energy requirements of rearing chicks. Also, our results make reconsider the simplistic trade-off model where reproduction increases metabolism and consequently the rate of oxidative stress. In fact, high energy expenditure (VeDBA) during chick rearing was correlated with low levels of oxidative damage likely due to mechanisms at the level of mitochondrial inner membranes (uncoupling proteins or low levels of oxygen partial pressure). Further (more distant) and longer (more days) foraging trips were performed during incubation, when antioxidants showed low levels compared to chick rearing due to incubation fasting, a change in diet, or a combination of these factors; but unlikely because of oxidative shielding since no relation was found between oxidative damage and antioxidant capacity. Males showed higher numbers of monocytes which were positively correlated with antioxidant capacity compared to females, suggesting sexual differences in immune profiles. Species-specific costs and energetic demands of different breeding phases trigger behavioural and physiological adjustments.
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Affiliation(s)
- R Colominas-Ciuró
- Dept. Evolutionary Ecology, Museo Nacional de Ciencias Naturales, 28006 Madrid, Spain; Dept. Ecology, Physiology & Ethology. CNRS, University of Strasbourg, Institut Pluridisciplinaire Hubert Curien, UMR 7178, 67087 Strasbourg, France..
| | - M Cianchetti-Benedetti
- Behavioural Ecology & Ecophysiology Group, Department of Animal Ecology & Systematics, Justus-Liebig University Giessen, D-35392 Giessen, Germany; Ornis Italica, 00199 Rome, Italy
| | - L Michel
- Behavioural Ecology & Ecophysiology Group, Department of Animal Ecology & Systematics, Justus-Liebig University Giessen, D-35392 Giessen, Germany
| | | | - P Quillfeldt
- Behavioural Ecology & Ecophysiology Group, Department of Animal Ecology & Systematics, Justus-Liebig University Giessen, D-35392 Giessen, Germany
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Abstract
Sympatric species must sufficiently differentiate aspects of their ecological niche to alleviate complete interspecific competition and stably coexist within the same area. Seabirds provide a unique opportunity to understand patterns of niche segregation among coexisting species because they form large multi-species colonies of breeding aggregations with seemingly overlapping diets and foraging areas. Recent biologging tools have revealed that colonial seabirds can differentiate components of their foraging strategies. Specifically, small, diving birds with high wing-loading may have small foraging radii compared with larger or non-diving birds. In the Gulf of St-Lawrence in Canada, we investigated whether and how niche differentiation occurs in four incubating seabird species breeding sympatrically using GPS-tracking and direct field observations of prey items carried by adults to chicks: the Atlantic puffin (Fratercula arctica), razorbill (Alca torda), common murre (Uria aalge), and black-legged kittiwake (Rissa tridactyla). Although there was overlap at foraging hotspots, all species differentiated in either diet (prey species, size and number) or foraging range. Whereas puffins and razorbills consumed multiple smaller prey items that were readily available closer to the colony, murres selected larger more diverse prey that were accessible due to their deeper diving capability. Kittiwakes compensated for their surface foraging by having a large foraging range, including foraging largely at a specific distant hotspot. These foraging habitat specialisations may alleviate high interspecific competition allowing for their coexistence, providing insight on multispecies colonial living.
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Colominas-Ciuró R, Santos M, Coria N, Barbosa A. Sex-specific foraging strategies of Adélie penguins (Pygoscelis adeliae): Females forage further and on more krill than males in the Antarctic Peninsula. Polar Biol 2018. [DOI: 10.1007/s00300-018-2395-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Elliott KH, Linnebjerg JF, Burke C, Gaston AJ, Mosbech A, Frederiksen M, Merkel F. Variation in Growth Drives the Duration of Parental Care: A Test of Ydenberg's Model. Am Nat 2017; 189:526-538. [PMID: 28410026 DOI: 10.1086/691097] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The duration of parental care in animals varies widely, from none to lifelong. Such variation is typically thought to represent a trade-off between growth and safety. Seabirds show wide variation in the age at which offspring leave the nest, making them ideal to test the idea that a trade-off between high energy gain at sea and high safety at the nest drives variation in departure age (Ydenberg's model). To directly test the model assumptions, we attached time-depth recorders to murre parents (fathers [which do all parental care at sea] and mothers; [Formula: see text] of each). Except for the initial mortality experienced by chicks departing from the colony, the mortality rate at sea was similar to the mortality rate at the colony. However, energy gained by the chick per day was ∼2.1 times as high at sea compared with at the colony because the father spent more time foraging, since he no longer needed to spend time commuting to and from the colony. Compared with the mother, the father spent ∼2.6 times as much time diving per day and dived in lower-quality foraging patches. We provide a simple model for optimal departure date based on only (1) the difference in growth rate at sea relative to the colony and (2) the assumption that transition mortality from one life-history stage to the other is size dependent. Apparently, large variation in the duration of parental care can arise simply as a result of variation in energy gain without any trade-off with safety.
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Physiological constraints and dive behavior scale in tandem with body mass in auks: A comparative analysis. Comp Biochem Physiol A Mol Integr Physiol 2016; 196:54-60. [PMID: 26952335 DOI: 10.1016/j.cbpa.2016.02.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 02/29/2016] [Accepted: 02/29/2016] [Indexed: 11/22/2022]
Abstract
Many behavioral processes scale with body mass (M) because underlying physiological constraints, such as metabolism, scale with M. A classic example is the maximum duration of dives by breath-hold divers, which scales with M0.25, as predicted from the ratio of oxygen stores (M1.0) to diving oxygen consumption rate (M0.75) - assuming classic scaling relationships for those physiological processes. However, maximum dive duration in some groups of birds does not have a 0.25 scaling exponent. We re-examined the allometric scaling of maximum dive duration in auks to test whether the discrepancy was due to poor data (earlier analyses included data from many different sources possibly leading to bias), phylogeny (earlier analyses did not account for phylogenetic inertia) or physiology (earlier analyses did not analyze physiological parameters alongside behavioral parameters). When we included only data derived from electronic recorders and after accounting for phylogeny, the equation for maximum dive duration was proportional to M0.33. At the same time, myoglobin concentration in small breath-hold divers was proportional to M0.36, implying that muscle oxygen stores were proportional to M1.36, but diving oxygen consumption rate in wing-propelled divers was only proportional to M0.79. Thus, the 99% confidence interval included the exponent of 0.57 predicted from the observed relationships between oxygen stores and consumption rates. In conclusion, auks are not exceptions to the hypothesis that a trade-off between oxygen stores and oxygen utilization drives variation in maximum dive duration. Rather, the scaling exponent for maximum dive duration is higher than expected due to the higher than expected scaling of muscle oxygen stores to body mass.
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Chimienti M, Cornulier T, Owen E, Bolton M, Davies IM, Travis JMJ, Scott BE. The use of an unsupervised learning approach for characterizing latent behaviors in accelerometer data. Ecol Evol 2016; 6:727-41. [PMID: 26865961 PMCID: PMC4739568 DOI: 10.1002/ece3.1914] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 11/30/2015] [Accepted: 12/01/2015] [Indexed: 11/11/2022] Open
Abstract
The recent increase in data accuracy from high resolution accelerometers offers substantial potential for improved understanding and prediction of animal movements. However, current approaches used for analysing these multivariable datasets typically require existing knowledge of the behaviors of the animals to inform the behavioral classification process. These methods are thus not well‐suited for the many cases where limited knowledge of the different behaviors performed exist. Here, we introduce the use of an unsupervised learning algorithm. To illustrate the method's capability we analyse data collected using a combination of GPS and Accelerometers on two seabird species: razorbills (Alca torda) and common guillemots (Uria aalge). We applied the unsupervised learning algorithm Expectation Maximization to characterize latent behavioral states both above and below water at both individual and group level. The application of this flexible approach yielded significant new insights into the foraging strategies of the two study species, both above and below the surface of the water. In addition to general behavioral modes such as flying, floating, as well as descending and ascending phases within the water column, this approach allowed an exploration of previously unstudied and important behaviors such as searching and prey chasing/capture events. We propose that this unsupervised learning approach provides an ideal tool for the systematic analysis of such complex multivariable movement data that are increasingly being obtained with accelerometer tags across species. In particular, we recommend its application in cases where we have limited current knowledge of the behaviors performed and existing supervised learning approaches may have limited utility.
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Affiliation(s)
- Marianna Chimienti
- School of Biological Sciences University of Aberdeen Tillydrone Avenue Aberdeen AB24 2TZ UK; Marine Scotland Science Scottish Government Marine Laboratory PO Box 101375 Victoria Road Aberdeen AB11 9DB UK
| | - Thomas Cornulier
- School of Biological Sciences University of Aberdeen Tillydrone Avenue Aberdeen AB24 2TZ UK
| | - Ellie Owen
- RSPB Centre for Conservation Science North Scotland Office Etive House, Beechwood Park Inverness IV2 6AL UK
| | - Mark Bolton
- RSPB Centre for Conservation Science The Lodge Sandy Bedfordshire SG19 2DL UK
| | - Ian M Davies
- Marine Scotland Science Scottish Government Marine Laboratory PO Box 101 375 Victoria Road Aberdeen AB11 9DB UK
| | - Justin M J Travis
- School of Biological Sciences University of Aberdeen Tillydrone Avenue Aberdeen AB24 2TZ UK
| | - Beth E Scott
- School of Biological Sciences University of Aberdeen Tillydrone Avenue Aberdeen AB24 2TZ UK
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Burke CM, Montevecchi WA, Regular PM. Seasonal Variation in Parental Care Drives Sex-Specific Foraging by a Monomorphic Seabird. PLoS One 2015; 10:e0141190. [PMID: 26575646 PMCID: PMC4648532 DOI: 10.1371/journal.pone.0141190] [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: 06/11/2015] [Accepted: 10/05/2015] [Indexed: 11/19/2022] Open
Abstract
Evidence of sex-specific foraging in monomorphic seabirds is increasing though the underlying mechanisms remain poorly understood. We investigate differential parental care as a mechanism for sex-specific foraging in monomorphic Common Murres (Uria aalge), where the male parent alone provisions the chick after colony departure. Using a combination of geolocation-immersion loggers and stable isotopes, we assess two hypotheses: the reproductive role specialization hypothesis and the energetic constraint hypothesis. We compare the foraging behavior of females (n = 15) and males (n = 9) during bi-parental at the colony, post-fledging male-only parental care and winter when parental care is absent. As predicted by the reproductive role specialization hypothesis, we found evidence of sex-specific foraging during post-fledging only, the stage with the greatest divergence in parental care roles. Single-parenting males spent almost twice as much time diving per day and foraged at lower quality prey patches relative to independent females. This implies a potential energetic constraint for males during the estimated 62.8 ± 8.9 days of offspring dependence at sea. Contrary to the predictions of the energetic constraint hypothesis, we found no evidence of sex-specific foraging during biparental care, suggesting that male parents did not forage for their own benefit before colony departure in anticipation of post-fledging energy constraints. We hypothesize that unpredictable prey conditions at Newfoundland colonies in recent years may limit male parental ability to allocate additional time and energy to self-feeding during biparental care, without compromising chick survival. Our findings support differential parental care as a mechanism for sex-specific foraging in monomorphic murres, and highlight the need to consider ecological context in the interpretation of sex-specific foraging behavior.
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Affiliation(s)
- Chantelle M. Burke
- Cognitive and Behavioural Ecology Program, Psychology Department, Memorial University, St. John’s, Newfoundland and Labrador, Canada
- * E-mail:
| | - William A. Montevecchi
- Cognitive and Behavioural Ecology Program, Psychology Department, Memorial University, St. John’s, Newfoundland and Labrador, Canada
| | - Paul M. Regular
- Cognitive and Behavioural Ecology Program, Psychology Department, Memorial University, St. John’s, Newfoundland and Labrador, Canada
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10
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Orben RA, Paredes R, Roby DD, Irons DB, Shaffer SA. Body size affects individual winter foraging strategies of thick-billed murres in the Bering Sea. J Anim Ecol 2015; 84:1589-99. [DOI: 10.1111/1365-2656.12410] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 06/05/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Rachael A. Orben
- Department of Ocean Sciences; University of California Santa Cruz; Long Marine Lab; 100 Shaffer Road Santa Cruz CA 95060 USA
- Department of Fisheries and Wildlife; Hatfield Marine Science Center; Oregon State University; Newport OR 97365 USA
| | - Rosana Paredes
- Department of Fisheries and Wildlife; Oregon State University; 104 Nash Hall Corvallis OR 97331-3803 USA
| | - Daniel D. Roby
- U.S. Geological Survey-Oregon Cooperative Fish and Wildlife Research Unit; Oregon State University; 104 Nash Hall Corvallis OR 97331-3803 USA
| | - David B. Irons
- U.S. Fish and Wildlife Service; 1011 East Tudor Road, MS 341 Anchorage AK 99503 USA
| | - Scott A. Shaffer
- Department of Biological Sciences; San Jose State University; One Washington Square San Jose CA 95192-0100 USA
- Long Marine Lab; Institute of Marine Sciences; University of California Santa Cruz; Santa Cruz CA 95060 USA
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11
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Young RC, Kitaysky AS, Barger CP, Dorresteijn I, Ito M, Watanuki Y. Telomere length is a strong predictor of foraging behavior in a long-lived seabird. Ecosphere 2015. [DOI: 10.1890/es14-00345.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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12
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Elliott KH, Chivers LS, Bessey L, Gaston AJ, Hatch SA, Kato A, Osborne O, Ropert-Coudert Y, Speakman JR, Hare JF. Windscapes shape seabird instantaneous energy costs but adult behavior buffers impact on offspring. MOVEMENT ECOLOGY 2014; 2:17. [PMID: 26019870 PMCID: PMC4445632 DOI: 10.1186/s40462-014-0017-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Accepted: 07/25/2014] [Indexed: 05/08/2023]
Abstract
BACKGROUND Windscapes affect energy costs for flying animals, but animals can adjust their behavior to accommodate wind-induced energy costs. Theory predicts that flying animals should decrease air speed to compensate for increased tailwind speed and increase air speed to compensate for increased crosswind speed. In addition, animals are expected to vary their foraging effort in time and space to maximize energy efficiency across variable windscapes. RESULTS We examined the influence of wind on seabird (thick-billed murre Uria lomvia and black-legged kittiwake Rissa tridactyla) foraging behavior. Airspeed and mechanical flight costs (dynamic body acceleration and wing beat frequency) increased with headwind speed during commuting flights. As predicted, birds adjusted their airspeed to compensate for crosswinds and to reduce the effect of a headwind, but they could not completely compensate for the latter. As we were able to account for the effect of sampling frequency and wind speed, we accurately estimated commuting flight speed with no wind as 16.6 ms(?1) (murres) and 10.6 ms(?1) (kittiwakes). High winds decreased delivery rates of schooling fish (murres), energy (murres) and food (kittiwakes) but did not impact daily energy expenditure or chick growth rates. During high winds, murres switched from feeding their offspring with schooling fish, which required substantial above-water searching, to amphipods, which required less above-water searching. CONCLUSIONS Adults buffered the adverse effect of high winds on chick growth rates by switching to other food sources during windy days or increasing food delivery rates when weather improved.
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Affiliation(s)
- Kyle Hamish Elliott
- Department of Biological Sciences, University of Manitoba, Winnipeg R3T 2N2, Manitoba, Canada
| | | | - Lauren Bessey
- Department of Biological Sciences, University of Manitoba, Winnipeg R3T 2N2, Manitoba, Canada
| | - Anthony J Gaston
- Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa K1A 0H3, Ontario, Canada
| | - Scott A Hatch
- Institute for Seabird Research and Conservation, Anchorage, AK, USA
| | - Akiko Kato
- Université de Strasbourg, IPHC, 23 rue Becquerel, Strasbourg 67087, France
- CNRS, UMR7178, Strasbourg 67087, France
| | - Orla Osborne
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Yan Ropert-Coudert
- Université de Strasbourg, IPHC, 23 rue Becquerel, Strasbourg 67087, France
- CNRS, UMR7178, Strasbourg 67087, France
| | - John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
- State Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 1 West Beichen Road, Chaoyang, Beijing, CN-100101, PR China
| | - James F Hare
- Department of Biological Sciences, University of Manitoba, Winnipeg R3T 2N2, Manitoba, Canada
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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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Thaxter CB, Daunt F, Grémillet D, Harris MP, Benvenuti S, Watanuki Y, Hamer KC, Wanless S. Modelling the effects of prey size and distribution on prey capture rates of two sympatric marine predators. PLoS One 2013; 8:e79915. [PMID: 24260318 PMCID: PMC3829866 DOI: 10.1371/journal.pone.0079915] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 09/27/2013] [Indexed: 11/19/2022] Open
Abstract
Understanding how prey capture rates are influenced by feeding ecology and environmental conditions is fundamental to assessing anthropogenic impacts on marine higher predators. We compared how prey capture rates varied in relation to prey size, prey patch distribution and prey density for two species of alcid, common guillemot (Uria aalge) and razorbill (Alca torda) during the chick-rearing period. We developed a Monte Carlo approach parameterised with foraging behaviour from bird-borne data loggers, observations of prey fed to chicks, and adult diet from water-offloading, to construct a bio-energetics model. Our primary goal was to estimate prey capture rates, and a secondary aim was to test responses to a set of biologically plausible environmental scenarios. Estimated prey capture rates were 1.5±0.8 items per dive (0.8±0.4 and 1.1±0.6 items per minute foraging and underwater, respectively) for guillemots and 3.7±2.4 items per dive (4.9±3.1 and 7.3±4.0 items per minute foraging and underwater, respectively) for razorbills. Based on species' ecology, diet and flight costs, we predicted that razorbills would be more sensitive to decreases in 0-group sandeel (Ammodytes marinus) length (prediction 1), but guillemots would be more sensitive to prey patches that were more widely spaced (prediction 2), and lower in prey density (prediction 3). Estimated prey capture rates increased non-linearly as 0-group sandeel length declined, with the slope being steeper in razorbills, supporting prediction 1. When prey patches were more dispersed, estimated daily energy expenditure increased by a factor of 3.0 for guillemots and 2.3 for razorbills, suggesting guillemots were more sensitive to patchier prey, supporting prediction 2. However, both species responded similarly to reduced prey density (guillemot expenditure increased by 1.7; razorbill by 1.6), thus not supporting prediction 3. This bio-energetics approach complements other foraging models in predicting likely impacts of environmental change on marine higher predators dependent on species-specific foraging ecologies.
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Affiliation(s)
- Chris B. Thaxter
- School of Biology, University of Leeds, Leeds, United Kingdom
- Centre for Ecology & Hydrology, Bush Estate, Penuick, Midlothian, United Kingdom
- * E-mail:
| | - Francis Daunt
- Centre for Ecology & Hydrology, Bush Estate, Penuick, Midlothian, United Kingdom
| | - David Grémillet
- Centre d'Ecologie Fonctionnelle et Evolutive, UMR 5175 du CNRS, Montpellier, France
- Percy FitzPatrick Institute, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa
| | - Mike P. Harris
- Centre for Ecology & Hydrology, Bush Estate, Penuick, Midlothian, United Kingdom
| | | | - Yutaka Watanuki
- Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido, Japan
| | - Keith C. Hamer
- School of Biology, University of Leeds, Leeds, United Kingdom
| | - Sarah Wanless
- Centre for Ecology & Hydrology, Bush Estate, Penuick, Midlothian, United Kingdom
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15
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Ratcliffe N, Takahashi A, O'Sullivan C, Adlard S, Trathan PN, Harris MP, Wanless S. The roles of sex, mass and individual specialisation in partitioning foraging-depth niches of a pursuit-diving predator. PLoS One 2013; 8:e79107. [PMID: 24205368 PMCID: PMC3804524 DOI: 10.1371/journal.pone.0079107] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 09/18/2013] [Indexed: 11/30/2022] Open
Abstract
Intra-specific foraging niche partitioning can arise due to gender differences or individual specialisation in behaviour or prey selection. These may in turn be related to sexual size dimorphism or individual variation in body size through allometry. These variables are often inter-related and challenging to separate statistically. We present a case study in which the effects of sex, body mass and individual specialisation on the dive depths of the South Georgia shag on Bird Island, South Georgia are investigated simultaneously using a linear mixed model. The nested random effects of trip within individual explained a highly significant amount of the variance. The effects of sex and body mass were both significant independently but could not be separated statistically owing to them being strongly interrelated. Variance components analysis revealed that 45.5% of the variation occurred among individuals, 22.6% among trips and 31.8% among Dives, while R2 approximations showed gender explained 31.4% and body mass 55.9% of the variation among individuals. Male dive depths were more variable than those of females at the levels of individual, trip and dive. The effect of body mass on individual dive depths was only marginally significant within sexes. The percentage of individual variation in dive depths explained by mass was trivial in males (0.8%) but substantial in females (24.1%), suggesting that differences in dive depths among males was largely due to them adopting different behavioural strategies whereas in females allometry played an additional role. Niche partitioning in the study population therefore appears to be achieved through the interactive effects of individual specialisation and gender upon vertical foraging patch selection, and has the potential to interact in complex ways with other axes of the niche hypervolume such as foraging locations, timing of foraging and diet.
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Kristensen DL, Erikstad KE, Reiertsen TK, Moum T, Barrett RT, Jenni-Eiermann S. Are female offspring from a single-egg seabird more costly to raise? Behav Ecol 2012. [DOI: 10.1093/beheco/ars144] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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Quintana F, Wilson R, Dell'Arciprete P, Shepard E, Laich AG. Women from Venus, men from Mars: inter-sex foraging differences in the imperial cormorant Phalacrocorax atriceps a colonial seabird. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2010.18387.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Thaxter CB, Wanless S, Daunt F, Harris MP, Benvenuti S, Watanuki Y, Grémillet D, Hamer KC. Influence of wing loading on the trade-off between pursuit-diving and flight in common guillemots and razorbills. ACTA ACUST UNITED AC 2010; 213:1018-25. [PMID: 20228337 DOI: 10.1242/jeb.037390] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Species of bird that use their wings for underwater propulsion are thought to face evolutionary trade-offs between flight and diving, leading to the prediction that species with different wing areas relative to body mass (i.e. different wing loadings) also differ in the relative importance of flight and diving activity during foraging trips. We tested this hypothesis for two similarly sized species of Alcidae (common guillemots and razorbills) by using bird-borne devices to examine three-dimensional foraging behaviour at a single colony. Guillemots have 30% higher wing loading than razorbills and, in keeping with this difference, razorbills spent twice as long in flight as a proportion of trip duration whereas guillemots spent twice as long in diving activity. Razorbills made a large number of short, relatively shallow dives and spent little time in the bottom phase of the dive whereas guillemots made fewer dives but frequently attained depths suggesting that they were near the seabed (ca. 35-70 m). The bottom phase of dives by guillemots was relatively long, indicating that they spent considerable time searching for and pursuing prey. Guillemots also spent a greater proportion of each dive bout underwater and had faster rates of descent, indicating that they were more adept at maximising time for pursuit and capture of prey. These differences in foraging behaviour may partly reflect guillemots feeding their chicks single large prey obtained near the bottom and razorbills feeding their chicks multiple prey from the water column. Nonetheless, our data support the notion that interspecific differences in wing loadings of auks reflect an evolutionary trade-off between aerial and underwater locomotion.
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Affiliation(s)
- C B Thaxter
- Institute of Integrative and Comparative Biology, University of Leeds, Leeds, LS2 9JT, UK.
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Elliott KH, Gaston AJ, Crump D. Sex-specific behavior by a monomorphic seabird represents risk partitioning. Behav Ecol 2010. [DOI: 10.1093/beheco/arq076] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Hamish Elliott K, Bull RD, Gaston AJ, Davoren GK. Underwater and above-water search patterns of an Arctic seabird: reduced searching at small spatiotemporal scales. Behav Ecol Sociobiol 2009. [DOI: 10.1007/s00265-009-0801-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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