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Hedh L, Dänhardt J, Hedenström A. Evolution of leapfrog migration: A test of competition-based hypotheses. Ecology 2024; 105:e4379. [PMID: 39056159 DOI: 10.1002/ecy.4379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 01/19/2024] [Accepted: 04/13/2024] [Indexed: 07/28/2024]
Abstract
Leapfrog migration is a common migration pattern in birds where the breeding and wintering latitudes between populations are in reversed latitudinal sequence. Competition for wintering and breeding sites has been suggested to be an ultimate factor, and several competitor-based hypotheses have been proposed to explain this pattern. If wintering sites close to the breeding sites are favored, competitive exclusion could force subdominant individuals to winter further away. Competitive exclusion could be mediated either through body size or by prior occupancy. The alternative "spring predictability" hypothesis assumes competition for sufficiently close wintering areas, allowing the birds to use autocorrelated weather cues to optimally time spring migration departure. To test predictions and assumptions of these hypotheses, we combined morphometrics, migration, and weather data from four populations of common ringed plover breeding along a latitudinal (56-68° N) and climatic gradient (temperate to Arctic). Critical for our evaluation was that two populations were breeding on the same latitude in subarctic Sweden with the same distance to the closest potential wintering site, but differed in breeding phenology, and wintered in West Africa and Europe, respectively. Thus, while breeding on the same latitude, their winter distribution overlapped with that of an Arctic and temperate population. Body size was largest within the temperate population, but there was no size difference between the two subarctic populations. Populations wintering in Europe arrived there before populations wintering in Africa. The largest variation in the arrival of meteorological spring occurred at the temperate breeding site, while there was almost no difference among the other sites. In general, temperatures at the northernmost wintering area correlated well with each breeding site prior to breeding site-specific spring arrival. Based on these observations, we conclude that competitive exclusion through body-size-related dominance cannot explain leapfrog migration. Furthermore, the assumptions on which the "spring predictability" hypothesis is based did not match the observed wintering ranges either. However, we could not reject the hypothesis that competitive exclusion mediated by prior occupancy in the wintering area could lead to leapfrog migration, and therefore, this hypothesis should be retained as working hypothesis for further work.
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Affiliation(s)
- Linus Hedh
- Department of Biology, Ecology Building, Lund University, Lund, Sweden
| | - Juliana Dänhardt
- Centre for Environmental and Climate Science, Lund University, Lund, Sweden
| | - Anders Hedenström
- Department of Biology, Ecology Building, Lund University, Lund, Sweden
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2
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Functional and Compositional Changes in the Fecal Microbiome of a Shorebird during Migratory Stopover. mSystems 2023; 8:e0112822. [PMID: 36786579 PMCID: PMC10134852 DOI: 10.1128/msystems.01128-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
Shorebirds migrate long distances twice annually, which requires intense physiological and morphological adaptations, including the ability to rapidly gain weight via fat deposition at stopover locations. The role of the microbiome in weight gain in avian hosts is unresolved, but there is substantial evidence to support the hypothesis that the microbiome is involved with host weight from mammalian microbiome literature. Here, we collected 100 fecal samples of Ruddy Turnstones to investigate microbiome composition and function during stopover weight gain in Delaware Bay, USA. Using 16S rRNA sequencing on 90 of these samples and metatranscriptomic sequencing on 22, we show that taxonomic composition of the microbiome shifts during weight gain, as do functional aspects of the metatranscriptome. We identified 10 genes that are associated with weight class, and polyunsaturated fatty acid biosynthesis in the microbiota is significantly increasing as birds gain weight. Our results support that the microbiome is a dynamic feature of host biology that interacts with both the host and the environment and may be involved in the rapid weight gain of shorebirds. IMPORTANCE Many animals migrate long distances annually, and these journeys require intense physiological and morphological adaptations. One such adaptation in shorebirds is the ability to rapidly gain weight at stopover locations in the middle of their migrations. The role of the microbiome in weight gain in birds is unresolved but is likely to play a role. Here, we collected 100 fecal samples from Ruddy Turnstones to investigate microbiome composition (who is there) and function (what they are doing) during stopover weight gain in Delaware Bay, USA. Using multiple molecular methods, we show that both taxonomic composition and function of the microbiome shifts during weight gain. We identified 10 genes that are associated with weight class, and polyunsaturated fatty acid biosynthesis in the microbiota is significantly increasing as birds gain weight. Our results support that the microbiome is a dynamic feature of host biology that interacts with both the host and the environment and may be involved in the rapid weight gain of shorebirds.
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3
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Masero JA, Abad-Gómez JM, Gutiérrez JS, Santiago-Quesada F, Senner NR, Sánchez-Guzmán JM, Piersma T, Schroeder J, Amat JA, Villegas A. Wetland salinity induces sex-dependent carry-over effects on the individual performance of a long-distance migrant. Sci Rep 2017; 7:6867. [PMID: 28761120 PMCID: PMC5537338 DOI: 10.1038/s41598-017-07258-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 06/26/2017] [Indexed: 01/09/2023] Open
Abstract
Salinization is having a major impact on wetlands and its biota worldwide. Specifically, many migratory animals that rely on wetlands are increasingly exposed to elevated salinity on their nonbreeding grounds. Experimental evidence suggests that physiological challenges associated with increasing salinity may disrupt self-maintenance processes in these species. Nonetheless, the potential role of salinity as a driver of ecological carry-over effects remains unstudied. Here, we investigated the extent to which the use of saline wetlands during winter - inferred from feather stable isotope values - induces residual effects that carry over and influence physiological traits relevant to fitness in black-tailed godwits Limosa limosa limosa on their northward migration. Overwintering males and females were segregated by wetland salinity in West Africa, with females mostly occupying freshwater wetlands. The use of these wetlands along a gradient of salinities was associated with differences in immune responsiveness to phytohaemagglutinin and sized-corrected body mass in godwits staging in southern Europe during northward migration - 3,000 km from the nonbreeding grounds - but in males only. These findings provide a window onto the processes by which wetland salinity can induce carry-over effects and can help predict how migratory species should respond to future climate-induced increases in salinity.
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Affiliation(s)
- José A Masero
- Conservation Biology Research Group, Department of Anatomy, Cell Biology and Zoology, Faculty of Sciences, University of Extremadura, 06006, Badajoz, Spain.
| | - José M Abad-Gómez
- Conservation Biology Research Group, Department of Anatomy, Cell Biology and Zoology, Faculty of Sciences, University of Extremadura, 06006, Badajoz, Spain
| | - Jorge S Gutiérrez
- Conservation Biology Research Group, Department of Anatomy, Cell Biology and Zoology, Faculty of Sciences, University of Extremadura, 06006, Badajoz, Spain.,NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems and Utrecht University, PO Box 59, 1790 AB, Den Burg, Texel, The Netherlands
| | - Francisco Santiago-Quesada
- Conservation Biology Research Group, Department of Anatomy, Cell Biology and Zoology, Faculty of Sciences, University of Extremadura, 06006, Badajoz, Spain
| | - Nathan R Senner
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, PO Box 11103, 9700 CC, Groningen, The Netherlands.,Division of Biological Sciences, University of Montana, 32 Campus Drive, Missoula, Montana, 59802, USA
| | - Juan M Sánchez-Guzmán
- Conservation Biology Research Group, Department of Anatomy, Cell Biology and Zoology, Faculty of Sciences, University of Extremadura, 06006, Badajoz, Spain
| | - Theunis Piersma
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems and Utrecht University, PO Box 59, 1790 AB, Den Burg, Texel, The Netherlands.,Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, PO Box 11103, 9700 CC, Groningen, The Netherlands
| | - Julia Schroeder
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, PO Box 11103, 9700 CC, Groningen, The Netherlands.,Imperial College London, Department of Life Sciences, Silwood Park Campus, London, United Kingdom
| | - Juan A Amat
- Department of Wetland Ecology, Doñana Biological Station (EBD-CSIC), 41092, Seville, Spain
| | - Auxiliadora Villegas
- Conservation Biology Research Group, Department of Anatomy, Cell Biology and Zoology, Faculty of Sciences, University of Extremadura, 06006, Badajoz, Spain
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4
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van den Hout PJ, Piersma T, ten Horn J, Spaans B, Lok T. Individual shifts toward safety explain age-related foraging distribution in a gregarious shorebird. Behav Ecol 2016. [DOI: 10.1093/beheco/arw173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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5
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van Gils JA, Lisovski S, Lok T, Meissner W, Ożarowska A, de Fouw J, Rakhimberdiev E, Soloviev MY, Piersma T, Klaassen M. Body shrinkage due to Arctic warming reduces red knot fitness in tropical wintering range. Science 2016; 352:819-21. [PMID: 27174985 DOI: 10.1126/science.aad6351] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 04/05/2016] [Indexed: 01/18/2023]
Abstract
Reductions in body size are increasingly being identified as a response to climate warming. Here we present evidence for a case of such body shrinkage, potentially due to malnutrition in early life. We show that an avian long-distance migrant (red knot, Calidris canutus canutus), which is experiencing globally unrivaled warming rates at its high-Arctic breeding grounds, produces smaller offspring with shorter bills during summers with early snowmelt. This has consequences half a world away at their tropical wintering grounds, where shorter-billed individuals have reduced survival rates. This is associated with these molluscivores eating fewer deeply buried bivalve prey and more shallowly buried seagrass rhizomes. We suggest that seasonal migrants can experience reduced fitness at one end of their range as a result of a changing climate at the other end.
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Affiliation(s)
- Jan A van Gils
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, and Utrecht University, Post Office Box 59, 1790 AB Den Burg (Texel), Netherlands
| | - Simeon Lisovski
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds Campus, Victoria 3217, Australia
| | - Tamar Lok
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Post Office Box 11103, 9700 CC Groningen, Netherlands. Centre d'Ecologie Fonctionnelle et Evolutive, Unité Mixte de Recherche 5175, Campus Centre National de la Recherche Scientifique, 1919 Route de Mende, 34293 Montpellier Cedex 5, France
| | - Włodzimierz Meissner
- Avian Ecophysiology Unit, Department of Vertebrate Ecology and Zoology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland
| | - Agnieszka Ożarowska
- Avian Ecophysiology Unit, Department of Vertebrate Ecology and Zoology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland
| | - Jimmy de Fouw
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, and Utrecht University, Post Office Box 59, 1790 AB Den Burg (Texel), Netherlands
| | - Eldar Rakhimberdiev
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, and Utrecht University, Post Office Box 59, 1790 AB Den Burg (Texel), Netherlands. Department of Vertebrate Zoology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Mikhail Y Soloviev
- Department of Vertebrate Zoology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Theunis Piersma
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, and Utrecht University, Post Office Box 59, 1790 AB Den Burg (Texel), Netherlands. Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Post Office Box 11103, 9700 CC Groningen, Netherlands
| | - Marcel Klaassen
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds Campus, Victoria 3217, Australia
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6
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Piersma T, Lok T, Chen Y, Hassell CJ, Yang HY, Boyle A, Slaymaker M, Chan YC, Melville DS, Zhang ZW, Ma Z. Simultaneous declines in summer survival of three shorebird species signals a flyway at risk. J Appl Ecol 2016. [DOI: 10.1111/1365-2664.12582] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Theunis Piersma
- Chair in Global Flyway Ecology, Conservation Ecology Group; Groningen Institute for Evolutionary Life Sciences (GELIFES); University of Groningen; PO Box 11103 9700 CC Groningen The Netherlands
- Department of Marine Ecology; NIOZ Royal Netherlands Institute for Sea Research; PO Box 59 1790 AB Den Burg Texel The Netherlands
| | - Tamar Lok
- Chair in Global Flyway Ecology, Conservation Ecology Group; Groningen Institute for Evolutionary Life Sciences (GELIFES); University of Groningen; PO Box 11103 9700 CC Groningen The Netherlands
- Department of Marine Ecology; NIOZ Royal Netherlands Institute for Sea Research; PO Box 59 1790 AB Den Burg Texel The Netherlands
- Centre d'Ecologie Fonctionnelle et Evolutive; UMR 5175; Montpellier France
| | - Ying Chen
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering; Institute of Biodiversity Science; Fudan University; Shanghai 200433 China
| | - Chris J. Hassell
- Chair in Global Flyway Ecology, Conservation Ecology Group; Groningen Institute for Evolutionary Life Sciences (GELIFES); University of Groningen; PO Box 11103 9700 CC Groningen The Netherlands
- Global Flyway Network; PO Box 3089 Broome WA 6725 Australia
| | - Hong-Yan Yang
- Chair in Global Flyway Ecology, Conservation Ecology Group; Groningen Institute for Evolutionary Life Sciences (GELIFES); University of Groningen; PO Box 11103 9700 CC Groningen The Netherlands
- Department of Marine Ecology; NIOZ Royal Netherlands Institute for Sea Research; PO Box 59 1790 AB Den Burg Texel The Netherlands
- Key Laboratory for Biodiversity Science and Ecological Engineering; Beijing Normal University; Beijing 100875 China
- College of Nature Conservation; Beijing Forestry University; Beijing 100083 China
| | - Adrian Boyle
- Chair in Global Flyway Ecology, Conservation Ecology Group; Groningen Institute for Evolutionary Life Sciences (GELIFES); University of Groningen; PO Box 11103 9700 CC Groningen The Netherlands
- Global Flyway Network; PO Box 3089 Broome WA 6725 Australia
| | - Matt Slaymaker
- Chair in Global Flyway Ecology, Conservation Ecology Group; Groningen Institute for Evolutionary Life Sciences (GELIFES); University of Groningen; PO Box 11103 9700 CC Groningen The Netherlands
- Global Flyway Network; PO Box 3089 Broome WA 6725 Australia
| | - Ying-Chi Chan
- Chair in Global Flyway Ecology, Conservation Ecology Group; Groningen Institute for Evolutionary Life Sciences (GELIFES); University of Groningen; PO Box 11103 9700 CC Groningen The Netherlands
- Department of Marine Ecology; NIOZ Royal Netherlands Institute for Sea Research; PO Box 59 1790 AB Den Burg Texel The Netherlands
| | - David S. Melville
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering; Institute of Biodiversity Science; Fudan University; Shanghai 200433 China
- 1261 Dovedale Road RD 2 Wakefield Nelson 7096 New Zealand
| | - Zheng-Wang Zhang
- Key Laboratory for Biodiversity Science and Ecological Engineering; Beijing Normal University; Beijing 100875 China
| | - Zhijun Ma
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering; Institute of Biodiversity Science; Fudan University; Shanghai 200433 China
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7
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van Gils JA, Ahmedou Salem MV. Validating the Incorporation of 13C and 15N in a Shorebird That Consumes an Isotopically Distinct Chemosymbiotic Bivalve. PLoS One 2015; 10:e0140221. [PMID: 26458005 PMCID: PMC4601768 DOI: 10.1371/journal.pone.0140221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 09/23/2015] [Indexed: 11/18/2022] Open
Abstract
The wealth of field studies using stable isotopes to make inferences about animal diets require controlled validation experiments to make proper interpretations. Despite several pleas in the literature for such experiments, validation studies are still lagging behind, notably in consumers dwelling in chemosynthesis-based ecosystems. In this paper we present such a validation experiment for the incorporation of 13C and 15N in the blood plasma of a medium-sized shorebird, the red knot (Calidris canutus canutus), consuming a chemosymbiotic lucinid bivalve (Loripes lucinalis). Because this bivalve forms a symbiosis with chemoautotrophic sulphide-oxidizing bacteria living inside its gill, the bivalve is isotopically distinct from 'normal' bivalves whose food has a photosynthetic basis. Here we experimentally tested the hypothesis that isotope discrimination and incorporation dynamics are different when consuming such chemosynthesis-based prey. The experiment showed that neither the isotopic discrimination factor, nor isotopic turnover time, differed between birds consuming the chemosymbiotic lucinid and a control group consuming a photosynthesis-based bivalve. This was true for 13C as well as for 15N. However, in both groups the 15N discrimination factor was much higher than expected, which probably had to do with the birds losing body mass over the course of the experiment.
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Affiliation(s)
- Jan A. van Gils
- NIOZ Royal Netherlands Institute for Sea Research, 1790 AB Den Burg, The Netherlands
- * E-mail:
| | - Mohamed Vall Ahmedou Salem
- EBIOME Ecobiologie Marine et Environnement, Département de Biologie, Université des Sciences, de Technologie et de Médecine, B.P. 880, Nouakchott, Mauritania
- Laboratoire de Biologie Appliquée et Pathologie, Département de Biologie, Faculté des Science, B.P. 2121, Tetouan, Morocco
- Parc National du Banc d’Arguin, B.P. 5355, Nouakchott, Mauritania
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8
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Oudman T, Hin V, Dekinga A, van Gils JA. The Effect of Digestive Capacity on the Intake Rate of Toxic and Non-Toxic Prey in an Ecological Context. PLoS One 2015; 10:e0136144. [PMID: 26287951 PMCID: PMC4543589 DOI: 10.1371/journal.pone.0136144] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 07/30/2015] [Indexed: 11/18/2022] Open
Abstract
Digestive capacity often limits food intake rate in animals. Many species can flexibly adjust digestive organ mass, enabling them to increase intake rate in times of increased energy requirement and/or scarcity of high-quality prey. However, some prey species are defended by secondary compounds, thereby forcing a toxin limitation on the forager’s intake rate, a constraint that potentially cannot be alleviated by enlarging digestive capacity. Hence, physiological flexibility may have a differential effect on intake of different prey types, and consequently on dietary preferences. We tested this effect in red knots (Calidris canutus canutus), medium-sized migratory shorebirds that feed on hard-shelled, usually mollusc, prey. Because they ingest their prey whole and crush the shell in their gizzard, the intake rate of red knots is generally constrained by digestive capacity. However, one of their main prey, the bivalve Loripes lucinalis, imposes a toxin constraint due to its symbiosis with sulphide-oxidizing bacteria. We manipulated gizzard sizes of red knots through prolonged exposure to hard-shelled or soft foods. We then measured maximum intake rates of toxic Loripes versus a non-toxic bivalve, Dosinia isocardia. We found that intake of Dosinia exponentially increased with gizzard mass, confirming earlier results with non-toxic prey, whereas intake of Loripes was independent of gizzard mass. Using linear programming, we show that this leads to markedly different expected diet preferences in red knots that try to maximize energy intake rate with a small versus a large gizzard. Intra- and inter-individual variation in digestive capacity is found in many animal species. Hence, the here proposed functional link with individual differences in foraging decisions may be general. We emphasize the potential relevance of individual variation in physiology when studying trophic interactions.
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Affiliation(s)
- Thomas Oudman
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands
- * E-mail:
| | - Vincent Hin
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands
| | - Anne Dekinga
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands
| | - Jan A. van Gils
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands
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9
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How salinity and temperature combine to affect physiological state and performance in red knots with contrasting non-breeding environments. Oecologia 2015; 178:1077-91. [DOI: 10.1007/s00442-015-3308-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Accepted: 03/25/2015] [Indexed: 10/23/2022]
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10
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van Gils JA, van der Geest M, De Meulenaer B, Gillis H, Piersma T, Folmer EO. Moving on with foraging theory: incorporating movement decisions into the functional response of a gregarious shorebird. J Anim Ecol 2014; 84:554-64. [PMID: 25283546 DOI: 10.1111/1365-2656.12301] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 09/26/2014] [Indexed: 11/29/2022]
Abstract
Models relating intake rate to food abundance and competitor density (generalized functional response models) can predict forager distributions and movements between patches, but we lack understanding of how distributions and small-scale movements by the foragers themselves affect intake rates. Using a state-of-the-art approach based on continuous-time Markov chain dynamics, we add realism to classic functional response models by acknowledging that the chances to encounter food and competitors are influenced by movement decisions, and, vice versa, that movement decisions are influenced by these encounters. We used a multi-state modelling framework to construct a stochastic functional response model in which foragers alternate between three behavioural states: searching, handling and moving. Using behavioural observations on a molluscivore migrant shorebird (red knot, Calidris canutus canutus), at its main wintering area (Banc d'Arguin, Mauritania), we estimated transition rates between foraging states as a function of conspecific densities and densities of the two main bivalve prey. Intake rate decreased with conspecific density. This interference effect was not due to decreased searching efficiency, but resulted from time lost to avoidance movements. Red knots showed a strong functional response to one prey (Dosinia isocardia), but a weak response to the other prey (Loripes lucinalis). This corroborates predictions from a recently developed optimal diet model that accounts for the mildly toxic effects due to consuming Loripes. Using model averaging across the most plausible multi-state models, the fully parameterized functional response model was then used to predict intake rate for an independent data set on habitat choice by red knot. Comparison of the sites selected by red knots with random sampling sites showed that the birds fed at sites with higher than average Loripes and Dosinia densities, that is sites for which we predicted higher than average intake rates. We discuss the limitations of Holling's classic functional response model which ignores movement and the limitations of contemporary movement ecological theory that ignores consumer-resource interactions. With the rapid advancement of technologies to track movements of individual foragers at fine spatial scales, the time is ripe to integrate descriptive tracking studies with stochastic movement-based functional response models.
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Affiliation(s)
- Jan A van Gils
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790, AB Den Burg, Texel, The Netherlands
| | - Matthijs van der Geest
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790, AB Den Burg, Texel, The Netherlands.,Chair in Global Flyway Ecology, Animal Ecology Group, Centre for Ecological and Evolutionary Studies (CEES), University of Groningen, PO Box 11103, 9700, CC Groningen, the Netherlands
| | - Brecht De Meulenaer
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790, AB Den Burg, Texel, The Netherlands
| | - Hanneke Gillis
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790, AB Den Burg, Texel, The Netherlands
| | - Theunis Piersma
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790, AB Den Burg, Texel, The Netherlands.,Chair in Global Flyway Ecology, Animal Ecology Group, Centre for Ecological and Evolutionary Studies (CEES), University of Groningen, PO Box 11103, 9700, CC Groningen, the Netherlands
| | - Eelke O Folmer
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790, AB Den Burg, Texel, The Netherlands
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11
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Oudman T, Onrust J, de Fouw J, Spaans B, Piersma T, van Gils JA. Digestive Capacity and Toxicity Cause Mixed Diets in Red Knots That Maximize Energy Intake Rate. Am Nat 2014; 183:650-9. [DOI: 10.1086/675759] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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12
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van den Hout PJ, van Gils JA, Robin F, van der Geest M, Dekinga A, Piersma T. Interference from adults forces young red knots to forage for longer and in dangerous places. Anim Behav 2014. [DOI: 10.1016/j.anbehav.2013.11.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Rosier RL, Langkilde T. Early Activity Rates do not Predict Growth and Future Body Size of Juvenile Eastern Fence Lizards, Sceloporus undulatus. Ethology 2013. [DOI: 10.1111/eth.12101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Renee L. Rosier
- Department of Biology; Pennsylvania State University; University Park; PA; USA
| | - Tracy Langkilde
- Department of Biology; Pennsylvania State University; University Park; PA; USA
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14
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van Gils JA, van der Geest M, Leyrer J, Oudman T, Lok T, Onrust J, de Fouw J, van der Heide T, van den Hout PJ, Spaans B, Dekinga A, Brugge M, Piersma T. Toxin constraint explains diet choice, survival and population dynamics in a molluscivore shorebird. Proc Biol Sci 2013; 280:20130861. [PMID: 23740782 PMCID: PMC3774237 DOI: 10.1098/rspb.2013.0861] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Recent insights suggest that predators should include (mildly) toxic prey when non-toxic food is scarce. However, the assumption that toxic prey is energetically as profitable as non-toxic prey misses the possibility that non-toxic prey have other ways to avoid being eaten, such as the formation of an indigestible armature. In that case, predators face a trade-off between avoiding toxins and minimizing indigestible ballast intake. Here, we report on the trophic interactions between a shorebird (red knot, Calidris canutus canutus) and its two main bivalve prey, one being mildly toxic but easily digestible, and the other being non-toxic but harder to digest. A novel toxin-based optimal diet model is developed and tested against an existing one that ignores toxin constraints on the basis of data on prey abundance, diet choice, local survival and numbers of red knots at Banc d'Arguin (Mauritania) over 8 years. Observed diet and annual survival rates closely fit the predictions of the toxin-based model, with survival and population size being highest in years when the non-toxic prey is abundant. In the 6 of 8 years when the non-toxic prey is not abundant enough to satisfy the energy requirements, red knots must rely on the toxic alternative.
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Affiliation(s)
- Jan A van Gils
- Department of Marine Ecology, Royal Netherlands Institute for Sea Research (NIOZ), PO Box 59, 1790 AB Den Burg (Texel), The Netherlands.
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Lok T, Overdijk O, Piersma T. Migration Tendency Delays Distributional Response to Differential Survival Prospects along a Flyway. Am Nat 2013; 181:520-31. [DOI: 10.1086/669679] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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