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Yoshida T, Choh Y. Leaf trichome-mediated predator effects on the distribution of herbivorous mites within a kidney bean plant. EXPERIMENTAL & APPLIED ACAROLOGY 2024; 93:155-167. [PMID: 38600348 DOI: 10.1007/s10493-024-00915-6] [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: 09/08/2023] [Accepted: 03/26/2024] [Indexed: 04/12/2024]
Abstract
Some predators prefer to settle on leaf patches with microstructures (e.g., trichomes and domatia), leaving traces on the patches. Herbivorous arthropods, in turn, select leaf patches in response to these traces left by predators. It remains unclear whether traces of predators on leaf patches affect the distribution of herbivorous prey within plants through plant microstructure. Therefore, we examined the distribution of herbivorous mite (Tetranychus urticae) and predatory mite (Phytoseiulus persimilis) by investigating their oviposition pattern. We used a kidney bean plant (Phaseolus vulgaris) with two expanded primary leaves and the first trifoliate leaf, focusing on leaf trichomes as the microstructure. The density of trichomes was higher on the first trifoliate leaf than on the primary leaves and on the abaxial surface of the leaves than on the adaxial surface. Adult female P. persimilis laid more eggs on the first trifoliate leaf to the primary leaves. Although adult female T. urticae preferred to oviposit on the abaxial surface of primary leaves, previous exposure of plants to predators diminished this preference. The altered egg distribution would be a response to the traces of P. persimilis rather than eggs of P. persimilis. Our findings indicate that T. urticae reproduces on leaf patches with traces of predators without altering their oviposition preference. Given that the presence of predator traces is known to reduce the reproduction of T. urticae, it may have a substantial effect on the population of T. urticae in the next generations on kidney bean plants.
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Affiliation(s)
- Tatsuya Yoshida
- Laboratory of Applied Entomology, Department of Horticulture, Chiba University, 648, Matsudo, Chiba, 271-8510, Japan
| | - Yasuyuki Choh
- Laboratory of Applied Entomology, Department of Horticulture, Chiba University, 648, Matsudo, Chiba, 271-8510, Japan.
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2
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Nuijten RJM, Katzner TE, Allen AM, Bijleveld AI, Boorsma T, Börger L, Cagnacci F, Hart T, Henley MA, Herren RM, Kok EMA, Maree B, Nebe B, Shohami D, Vogel SM, Walker P, Heitkönig IMA, Milner‐Gulland EJ. Priorities for translating goodwill between movement ecologists and conservation practitioners into effective collaboration. CONSERVATION SCIENCE AND PRACTICE 2022. [DOI: 10.1111/csp2.12870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Rascha J. M. Nuijten
- Interdisciplinary Centre for Conservation Science, Department of Biology University of Oxford Oxford United Kingdom
- Wildlife Ecology and Conservation Wageningen University and Research Wageningen The Netherlands
| | - Todd E. Katzner
- U.S. Geological Survey Forest and Rangeland Ecosystem Science Center Boise Idaho USA
| | - Andrew M. Allen
- Department of Animal Ecology Netherlands Institute of Ecology (NIOO‐KNAW) Wageningen The Netherlands
- Department of Animal Ecology and Physiology Radboud University Nijmegen The Netherlands
| | - Allert I. Bijleveld
- Department of Coastal Systems NIOZ Royal Netherlands Institute for Sea Research Den Burg The Netherlands
| | - Tjalle Boorsma
- Asociación Civil Armonía Santa Cruz de la Sierra Bolivia
| | - Luca Börger
- Department of Biosciences Swansea University Swansea UK
| | - Francesca Cagnacci
- Animal Ecology Unit, Research and Innovation Centre Fondazione Edmund Mach San Michele all'Adige Italy
| | - Tom Hart
- Department of Zoology University of Oxford Oxford UK
| | - Michelle A. Henley
- Applied Behavioural Ecology and Environmental Research Unit University of South Africa Pretoria South Africa
- Elephants Alive Limpopo South Africa
| | | | - Eva M. A. Kok
- Department of Coastal Systems NIOZ Royal Netherlands Institute for Sea Research Den Burg The Netherlands
| | | | | | - David Shohami
- Movement Ecology Lab, Department of Ecology, Evolution and Behavior, Faculty of Science The Hebrew University of Jerusalem Jerusalem Israel
| | - Susanne Marieke Vogel
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology Aarhus University Aarhus C Denmark
- Section for Ecoinformatics and Biodiversity, Department of Biology Aarhus University Aarhus C Denmark
| | | | - Ignas M. A. Heitkönig
- Wildlife Ecology and Conservation Wageningen University and Research Wageningen The Netherlands
| | - E. J. Milner‐Gulland
- Interdisciplinary Centre for Conservation Science, Department of Biology University of Oxford Oxford United Kingdom
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3
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Nielsen ME, Papaj DR. Why study plasticity in multiple traits? New hypotheses for how phenotypically plastic traits interact during development and selection. Evolution 2022; 76:858-869. [PMID: 35274745 PMCID: PMC9313899 DOI: 10.1111/evo.14464] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 12/12/2021] [Accepted: 12/29/2021] [Indexed: 01/21/2023]
Abstract
Organisms can often respond adaptively to a change in their environment through phenotypic plasticity in multiple traits, a phenomenon termed as multivariate plasticity. These different plastic responses could interact and affect each other's development as well as selection on each other, but the causes and consequences of these interactions have received relatively little attention. Here, we propose a new conceptual framework for understanding how different plastic responses can affect each other's development and why organisms should have multiple plastic responses. A plastic change in one trait could alter the phenotype of a second plastic trait by changing either the cue received by the organism (cue-mediated effect) or the response to that cue (response-mediated effect). Multivariate plasticity could benefit the organism either because the plastic responses work better when expressed together (synergy) or because each response is more effective under different environmental circumstances (complementarity). We illustrate these hypotheses with case studies, focusing on interactions between behavior and morphology, plastic traits that differ in their reversibility. Future empirical and theoretical research should investigate the consequences of these interactions for additional factors important for the evolution of plasticity, such as the limits and costs of plasticity.
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Affiliation(s)
- Matthew E. Nielsen
- Department of Ecology and Evolutionary BiologyUniversity of ArizonaTucsonArizona85721,Zoology DepartmentStockholm UniversityStockholm11419Sweden
| | - Daniel R. Papaj
- Department of Ecology and Evolutionary BiologyUniversity of ArizonaTucsonArizona85721
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4
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Gupte PR, Beardsworth CE, Spiegel O, Lourie E, Toledo S, Nathan R, Bijleveld AI. A guide to pre-processing high-throughput animal tracking data. J Anim Ecol 2021; 91:287-307. [PMID: 34657296 PMCID: PMC9299236 DOI: 10.1111/1365-2656.13610] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 10/14/2021] [Indexed: 11/29/2022]
Abstract
Modern, high‐throughput animal tracking increasingly yields ‘big data’ at very fine temporal scales. At these scales, location error can exceed the animal's step size, leading to mis‐estimation of behaviours inferred from movement. ‘Cleaning’ the data to reduce location errors is one of the main ways to deal with position uncertainty. Although data cleaning is widely recommended, inclusive, uniform guidance on this crucial step, and on how to organise the cleaning of massive datasets, is relatively scarce. A pipeline for cleaning massive high‐throughput datasets must balance ease of use and computationally efficiency, in which location errors are rejected while preserving valid animal movements. Another useful feature of a pre‐processing pipeline is efficiently segmenting and clustering location data for statistical methods while also being scalable to large datasets and robust to imperfect sampling. Manual methods being prohibitively time‐consuming, and to boost reproducibility, pre‐processing pipelines must be automated. We provide guidance on building pipelines for pre‐processing high‐throughput animal tracking data to prepare it for subsequent analyses. We apply our proposed pipeline to simulated movement data with location errors, and also show how large volumes of cleaned data can be transformed into biologically meaningful ‘residence patches’, for exploratory inference on animal space use. We use tracking data from the Wadden Sea ATLAS system (WATLAS) to show how pre‐processing improves its quality, and to verify the usefulness of the residence patch method. Finally, with tracks from Egyptian fruit bats Rousettus aegyptiacus, we demonstrate the pre‐processing pipeline and residence patch method in a fully worked out example. To help with fast implementation of standardised methods, we developed the R package atlastools, which we also introduce here. Our pre‐processing pipeline and atlastools can be used with any high‐throughput animal movement data in which the high data‐volume combined with knowledge of the tracked individuals' movement capacity can be used to reduce location errors. atlastools is easy to use for beginners while providing a template for further development. The common use of simple yet robust pre‐processing steps promotes standardised methods in the field of movement ecology and leads to better inferences from data.
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Affiliation(s)
- Pratik Rajan Gupte
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.,Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, The Netherlands
| | - Christine E Beardsworth
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, The Netherlands
| | - Orr Spiegel
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.,Minerva Center for Movement Ecology, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Emmanuel Lourie
- Minerva Center for Movement Ecology, The Hebrew University of Jerusalem, Jerusalem, Israel.,Movement Ecology Lab, Department of Ecology, Evolution, and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Sivan Toledo
- Minerva Center for Movement Ecology, The Hebrew University of Jerusalem, Jerusalem, Israel.,Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv, Israel
| | - Ran Nathan
- Minerva Center for Movement Ecology, The Hebrew University of Jerusalem, Jerusalem, Israel.,Movement Ecology Lab, Department of Ecology, Evolution, and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Allert I Bijleveld
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, The Netherlands
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5
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Beardsworth CE, Whiteside MA, Laker PR, Nathan R, Orchan Y, Toledo S, van Horik JO, Madden JR. Is habitat selection in the wild shaped by individual-level cognitive biases in orientation strategy? Ecol Lett 2021; 24:751-760. [PMID: 33616308 DOI: 10.1111/ele.13694] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 10/26/2020] [Accepted: 12/16/2020] [Indexed: 11/29/2022]
Abstract
Cognitive biases for encoding spatial information (orientation strategies) in relation to self (egocentric) or landmarks (allocentric) differ between species or populations according to the habitats they occupy. Whether biases in orientation strategy determine early habitat selection or if individuals adapt their biases following experience is unknown. We determined orientation strategies of pheasants, Phasianus colchicus, using a dual-strategy maze with an allocentric probe trial, before releasing them (n = 20) into a novel landscape, where we monitored their movement and habitat selection. In general, pheasants selected for woodland over non-woodland habitat, but allocentric-biased individuals exhibited weaker avoidance of non-woodland habitat, where we expected allocentric navigation to be more effective. Sex did not influence selection but was associated with speed and directional persistence in non-woodland habitat. Our results suggest that an individual's habitat selection is associated with inherent cognitive bias in early life, but it is not yet clear what advantages this may offer.
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Affiliation(s)
- Christine E Beardsworth
- Centre for Research in Animal Behaviour, Psychology, University of Exeter, Exeter, EX4 4QG, UK
| | - Mark A Whiteside
- Centre for Research in Animal Behaviour, Psychology, University of Exeter, Exeter, EX4 4QG, UK
| | - Philippa R Laker
- Centre for Research in Animal Behaviour, Psychology, University of Exeter, Exeter, EX4 4QG, UK
| | - Ran Nathan
- Movement Ecology Laboratory, Department of Ecology, Evolution and Behaviour, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Yotam Orchan
- Movement Ecology Laboratory, Department of Ecology, Evolution and Behaviour, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Sivan Toledo
- Blavatnik School of Computer Science, Tel-Aviv University, Tel Aviv, 67798, Israel
| | - Jayden O van Horik
- Centre for Research in Animal Behaviour, Psychology, University of Exeter, Exeter, EX4 4QG, UK
| | - Joah R Madden
- Centre for Research in Animal Behaviour, Psychology, University of Exeter, Exeter, EX4 4QG, UK
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6
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Börger L, Bijleveld AI, Fayet AL, Machovsky-Capuska GE, Patrick SC, Street GM, Vander Wal E. Biologging Special Feature. J Anim Ecol 2020; 89:6-15. [PMID: 32091640 DOI: 10.1111/1365-2656.13163] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Luca Börger
- Department of Biosciences, College of Science, Swansea University, Swansea, UK
| | - Allert I Bijleveld
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, Den Burg, The Netherlands
| | | | | | - Samantha C Patrick
- School of Environmental Sciences, University of Liverpool, Liverpool, UK
| | - Garrett M Street
- Department of Wildlife, Fisheries, and Aquaculture, Mississippi State University, Mississippi State, MS, USA
| | - Eric Vander Wal
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, Canada
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7
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Shafer MW, Vega G, Rothfus K, Flikkema P. UAV wildlife radiotelemetry: System and methods of localization. Methods Ecol Evol 2019. [DOI: 10.1111/2041-210x.13261] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael W. Shafer
- Department of Mechanical Engineering Northern Arizona University Flagstaff Arizona
| | - Gabriel Vega
- Department of Mechanical Engineering Northern Arizona University Flagstaff Arizona
| | - Kellan Rothfus
- Department of Mechanical Engineering Northern Arizona University Flagstaff Arizona
| | - Paul Flikkema
- School of Informatics, Computing, and Cyber Systems Northern Arizona University Flagstaff Arizona
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8
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Kok EMA, Burant JB, Dekinga A, Manche P, Saintonge D, Piersma T, Mathot KJ. Within-Individual Canalization Contributes to Age-Related Increases in Trait Repeatability: A Longitudinal Experiment in Red Knots. Am Nat 2019; 194:455-469. [DOI: 10.1086/704593] [Citation(s) in RCA: 13] [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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9
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Chan Y, Tibbitts TL, Lok T, Hassell CJ, Peng H, Ma Z, Zhang Z, Piersma T. Filling knowledge gaps in a threatened shorebird flyway through satellite tracking. J Appl Ecol 2019. [DOI: 10.1111/1365-2664.13474] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ying‐Chi Chan
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen Groningen the Netherlands
- Department of Coastal Systems NIOZ Royal Netherlands Institute for Sea Research, Utrecht University Den Burg the Netherlands
| | | | - Tamar Lok
- Department of Coastal Systems NIOZ Royal Netherlands Institute for Sea Research, Utrecht University Den Burg the Netherlands
| | | | - He‐Bo Peng
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen Groningen the Netherlands
- Department of Coastal Systems NIOZ Royal Netherlands Institute for Sea Research, Utrecht University Den Burg the Netherlands
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Coastal Ecosystems Research Station of the Yangtze River Estuary, Fudan University Shanghai China
| | - Zhijun Ma
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Coastal Ecosystems Research Station of the Yangtze River Estuary, Fudan University Shanghai China
| | - Zhengwang Zhang
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Beijing Normal University Beijing China
| | - Theunis Piersma
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen Groningen the Netherlands
- Department of Coastal Systems NIOZ Royal Netherlands Institute for Sea Research, Utrecht University Den Burg the Netherlands
- Global Flyway Network Broome WA Australia
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10
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Oudman T, Piersma T, Ahmedou Salem MV, Feis ME, Dekinga A, Holthuijsen S, ten Horn J, van Gils JA, Bijleveld AI. Resource landscapes explain contrasting patterns of aggregation and site fidelity by red knots at two wintering sites. MOVEMENT ECOLOGY 2018; 6:24. [PMID: 30598823 PMCID: PMC6300905 DOI: 10.1186/s40462-018-0142-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 11/14/2018] [Indexed: 06/01/2023]
Abstract
BACKGROUND Space use strategies by foraging animals are often considered to be species-specific. However, similarity between conspecific strategies may also result from similar resource environments. Here, we revisit classic predictions of the relationships between the resource distribution and foragers' space use by tracking free-living foragers of a single species in two contrasting resource landscapes. At two main non-breeding areas along the East-Atlantic flyway (Wadden Sea, The Netherlands and Banc d'Arguin, Mauritania), we mapped prey distributions and derived resource landscapes in terms of the predicted intake rate of red knots (Calidris canutus), migratory molluscivore shorebirds. We tracked the foraging paths of 13 and 38 individual red knots at intervals of 1 s over two and five weeks in the Wadden Sea and at Banc d'Arguin, respectively. Mediated by competition for resources, we expected aggregation to be strong and site fidelity weak in an environment with large resource patches. The opposite was expected for small resource patches, but only if local resource abundances were high. RESULTS Compared with Banc d'Arguin, resource patches in the Wadden Sea were larger and the maximum local resource abundance was higher. However, because of constraints set by digestive capacity, the average potential intake rates by red knots were similar at the two study sites. Space-use patterns differed as predicted from these differences in resource landscapes. Whereas foraging red knots in the Wadden Sea roamed the mudflats in high aggregation without site fidelity (i.e. grouping nomads), at Banc d'Arguin they showed less aggregation but were strongly site-faithful (i.e. solitary residents). CONCLUSION The space use pattern of red knots in the two study areas showed diametrically opposite patterns. These differences could be explained from the distribution of resources in the two areas. Our findings imply that intraspecific similarities in space use patterns represent responses to similar resource environments rather than species-specificity. To predict how environmental change affects space use, we need to understand the degree to which space-use strategies result from developmental plasticity and behavioural flexibility. This requires not only tracking foragers throughout their development, but also tracking their environment in sufficient spatial and temporal detail.
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Affiliation(s)
- Thomas Oudman
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, P.O. Box 59, 1790 AB Den Burg, Texel The Netherlands
- Centre for Biological Diversity, School of Biology, University of St Andrews, Fife, KY16 9TF UK
| | - Theunis Piersma
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, P.O. Box 59, 1790 AB Den Burg, Texel The Netherlands
- Rudi Drent 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
| | - Mohamed V. Ahmedou Salem
- EBIOME Ecobiologie Marine et Environnement, Département de Biologie, L’université de Nouakchott Al-Aasriya, BP. 880 Nouakchott, Mauritania
| | - Marieke E. Feis
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, P.O. Box 59, 1790 AB Den Burg, Texel The Netherlands
- Present Address: Sorbonne Université, CNRS, Station Biologique de Roscoff, Laboratoire Adaptation et Diversité en Milieu Marin, UMR 7144, CS90074, 29688 Roscoff Cedex, France
| | - Anne Dekinga
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, P.O. Box 59, 1790 AB Den Burg, Texel The Netherlands
| | - Sander Holthuijsen
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, P.O. Box 59, 1790 AB Den Burg, Texel The Netherlands
| | - Job ten Horn
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, P.O. Box 59, 1790 AB Den Burg, Texel The Netherlands
| | - Jan A. van Gils
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, P.O. Box 59, 1790 AB Den Burg, Texel The Netherlands
| | - Allert I. Bijleveld
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, P.O. Box 59, 1790 AB Den Burg, Texel The Netherlands
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11
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Presence-absence of marine macrozoobenthos does not generally predict abundance and biomass. Sci Rep 2018; 8:3039. [PMID: 29445105 PMCID: PMC5813040 DOI: 10.1038/s41598-018-21285-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 02/02/2018] [Indexed: 01/18/2023] Open
Abstract
Many monitoring programmes of species abundance and biomass increasingly face financial pressures. Occupancy is often easier and cheaper to measure than abundance or biomass. We, therefore, explored whether measuring occupancy is a viable alternative to measuring abundance and biomass. Abundance- or biomass-occupancy relationships were studied for sixteen macrozoobenthos species collected across the entire Dutch Wadden Sea in eight consecutive summers. Because the form and strength of these relationships are scale-dependent, the analysis was completed at different spatiotemporal scales. Large differences in intercept and slope of abundance- or biomass-occupancy relationships were found. Abundance, not biomass, was generally positively correlated with occupancy. Only at the largest scale, seven species showed reasonably strong abundance-occupancy relationships with large coefficients of determination and small differences in observed and predicted values (RMSE). Otherwise, and at all the other scales, intraspecific abundance and biomass relationships were poor. Our results showed that there is no generic relationship between a species' abundance or biomass and its occupancy. We discuss how ecological differences between species could cause such large variation in these relationships. Future technologies might allow estimating a species' abundance or biomass directly from eDNA sampling data, but for now, we need to rely on traditional sampling technology.
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12
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Mezzalira JC, Bonnet OJF, Carvalho PCDF, Fonseca L, Bremm C, Mezzalira CC, Laca EA. Mechanisms and implications of a type IV functional response for short-term intake rate of dry matter in large mammalian herbivores. J Anim Ecol 2017; 86:1159-1168. [PMID: 28542901 DOI: 10.1111/1365-2656.12698] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 05/08/2017] [Indexed: 11/27/2022]
Abstract
The functional response (i.e. the relationship between consumers' intake rate and resource density) is central in plant-herbivore interactions. Its shape and the biological processes leading to it have significant implications for both foraging theory and ecology of grazing systems. A type IV functional response (i.e. dome-shaped relationship) of short-term intake rate of dry matter (intake while grazing) has rarely been reported for large herbivores and the conditions that can lead to it are poorly understood. We report a type IV functional response observed in heifers grazing monocultures of Cynodon sp. and Avena strigosa. The mechanisms and consequences of this type of functional response for grazed system dynamics are discussed. Intake rate was higher at intermediate than at short or tall sward heights in both grass species. The type IV functional response resulted from changes in bite mass instead of a longer time needed to encounter and process bites. Thus, the decrease of intake rate of dry matter in tall swards is not explained by a shift from process 3 (potential bites are concentrated and apparent) to process 2 (potential bites are apparent but dispersed, Spalinger & Hobbs 1992). Bite mass was smaller in tall than in intermediate swards due to a reduction of bite volume possibly caused by the greater proportion of stem and sheath acting as a physical barrier to bite formation. It is generally accepted that potential bites are abundant and apparent in most grassland and meadow systems, as they were in the present experiments. Therefore, a type IV response of intake rate not directly related to digestive constraints may determine the dynamics of intake and defoliation under a much larger set of conditions than previously thought. These results have implications for foraging theory and stability of grazing systems. For example, if animals prefer patches of intermediate stature that yield the highest intake rate, grazing should lead to the widely observed bimodal distribution of plant mass per unit area, even when tall patches are not of significantly lower digestive quality than the pasture average.
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Affiliation(s)
- Jean C Mezzalira
- Grazing Ecology Research Group, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Olivier J F Bonnet
- Grazing Ecology Research Group, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Department of Ecology, Zoology and Genetics, Institute of Biology, Federal University of Pelotas, Pelotas, Brazil
| | - Paulo C de F Carvalho
- Grazing Ecology Research Group, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Lidiane Fonseca
- Grazing Ecology Research Group, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Carolina Bremm
- Grazing Ecology Research Group, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Carlos C Mezzalira
- Federal Technological University of Paraná (UTFPR), Dois Vizinhos, Brazil
| | - Emilio A Laca
- Department of Plant and Environmental Sciences, University of California, Davis, CA, USA
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13
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Oudman T, Bijleveld AI, Kavelaars MM, Dekinga A, Cluderay J, Piersma T, van Gils JA. Diet preferences as the cause of individual differences rather than the consequence. J Anim Ecol 2016; 85:1378-88. [PMID: 27306138 DOI: 10.1111/1365-2656.12549] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 05/06/2016] [Indexed: 11/28/2022]
Abstract
Behavioural variation within a species is usually explained as the consequence of individual variation in physiology. However, new evidence suggests that the arrow of causality may well be in the reverse direction: behaviours such as diet preferences cause the differences in physiological and morphological traits. Recently, diet preferences were proposed to underlie consistent differences in digestive organ mass and movement patterns (patch residence times) in red knots (Calidris canutus islandica). Red knots are molluscivorous and migrant shorebirds for which the size of the muscular stomach (gizzard) is critical for the food processing rate. In this study, red knots (C. c. canutus, n = 46) were caught at Banc d'Arguin, an intertidal flat ecosystem in Mauritania, and released with radio-tags after the measurement of gizzard mass. Using a novel tracking system (time-of-arrival), patch residence times were measured over a period of three weeks. Whether or not gizzard mass determined patch residence times was tested experimentally by offering 12 of the 46 tagged red knots soft diets prior to release; this reduced an individual's gizzard mass by 20-60%. To validate whether the observed range of patch residence times would be expected from individual diet preferences, we simulated patch residence times as a function of diet preferences via a simple departure rule. Consistent with previous empirical studies, patch residence times in the field were positively correlated with gizzard mass. The slope of this correlation, as well as the observed range of patch residence times, was in accordance with the simulated values. The 12 birds with reduced gizzard masses did not decrease patch residence times in response to the reduction in gizzard mass. These findings suggest that diet preferences can indeed cause the observed among-individual variation in gizzard mass and patch residence times. We discuss how early diet experiences can have cascading effects on the individual expression of both behavioural and physiomorphic traits. This emphasizes that to understand the ecological consequences of individual differences, knowledge of the environment during development is required.
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Affiliation(s)
- Thomas Oudman
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems and Utrecht University, Texel, The Netherlands
| | - Allert I Bijleveld
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems and Utrecht University, Texel, The Netherlands
| | - Marwa M Kavelaars
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems and Utrecht University, Texel, The Netherlands
| | - Anne Dekinga
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems and Utrecht University, Texel, The Netherlands
| | - John Cluderay
- NIOZ Royal Netherlands Institute for Sea Research, National Marine Facilities and Utrecht University, Texel, The Netherlands
| | - Theunis Piersma
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems and Utrecht University, Texel, The Netherlands.,Chair in Global Flyway Ecology, Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, The Netherlands
| | - Jan A van Gils
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems and Utrecht University, Texel, The Netherlands
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