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Nafus MG, Gray LN. Quantifying the importance of ontogeny and prey type in modeling top-down and bottom-up effects of an ectothermic predator. Sci Rep 2024; 14:21601. [PMID: 39285164 PMCID: PMC11405723 DOI: 10.1038/s41598-024-61761-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 05/09/2024] [Indexed: 09/19/2024] Open
Abstract
Dietary decisions by predators can affect prey abundance and overall food web dynamics. Many predators do not forage on the same prey at the same frequency throughout their lives. Ontogenetic shifts in prey preference are not, however, often accounted for when modeling food web relationships, despite growing literature that suggests that stage specific dietary relationships may be an important consideration when modeling trophic interactions. We investigated the importance of considering size-structure of a predator population with ontogenetic diet shifts in evaluating relationships with prey response using a manipulative experiment with the brown treesnake (Boiga irregularis) in Guam. After removing ~ 40% of the snake population via toxic mammal carrion, we measured the strength of the relationship between snake density and the response of two types of prey (lizards and mammals). We evaluated these relationships based on total population size or division of the population into stage specific size categories based on diet preference predictions. We hypothesized that the density of juvenile snakes would correlate more strongly with lizard detections, while adult snakes would better correlate to rodent detections. We also measured reproductive output following changes in rates of prey detection. As expected by known ontogenetic shifts in dietary preference, explicit stage-based models better predicted shifts in rates of observed prey items than did total predator density for both lizards and mammals. Additionally, rodent detections were predictive of one reproductive pulse from snakes, while lizard detections were not predictive or correlated. Our findings support that consideration of predatory species stage-based dietary preference can be meaningful for understanding food web dynamics, particularly when a predator has a broad diet or one that changes through time.
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Affiliation(s)
- Melia G Nafus
- U.S. Geological Survey, Pacific Island Ecosystems Research Center, Hawai'i Volcanoes National Park, Hawai'i, USA.
| | - Levi N Gray
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, USA.
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2
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Yang X, Deng Y, Qin J, Luo K, Kang B, He X, Yan Y. Dietary Shifts in the Adaptation to Changing Marine Resources: Insights from a Decadal Study on Greater Lizardfish ( Saurida tumbil) in the Beibu Gulf, South China Sea. Animals (Basel) 2024; 14:798. [PMID: 38473183 DOI: 10.3390/ani14050798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/24/2024] [Accepted: 02/29/2024] [Indexed: 03/14/2024] Open
Abstract
Understanding dietary behavior during the individual development of marine predators and its temporal variations elucidates how species adapt to changes in marine resources. This is crucial for predicting marine predators' habitat selection and the natural population's responses to environmental changes. The authors conducted a comparative analysis of dietary shift strategies and trophic level variations in Greater lizardfish (Saurida tumbil) in the Beibu Gulf during two distinct periods (2010 and 2020) using stomach content and stable isotope analysis methods. Possible driving factors for these changes were also explored. Changes in the fishery community structure and the decline in the abundance of primary prey resources have led the S. tumbil population to diversify their prey species, utilize alternative resources, and expand their foraging space. However, the species' foraging strategy, characterized by chasing and preying on schooling and pelagic prey, promoted stability in their feeding behavior across spatial and temporal scales. The main prey items remained demersal and pelagic fish species, followed by cephalopods and crustaceans. Similar to other generalist fish species, ontogenetic dietary shifts (ODSs) indicated a partial transition towards larger prey items. However, the timing and magnitude of the ODSs varied between the two periods, reflecting life-history variations and adaptive adjustments to environmental changes. In comparison to 2010, the population's mean body length (BL) increased in 2020, and the proportion of the population feeding on pelagic-neritic prey significantly increased. However, the δ15N values were lower, indicating that the shift in the ecological niche of preferred prey from demersal to pelagic-neritic was the primary cause of the decrease in trophic levels. In the future, we will conduct further quantitative research integrating the spatiotemporal data of both predators and prey to clarify the relationships between marine predators' feeding behavior, trophic levels, and changes in prey community structure.
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Affiliation(s)
- Xiaodong Yang
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
| | - Yujian Deng
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
| | - Jiao Qin
- Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524000, China
| | - Konglan Luo
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
| | - Bin Kang
- Fisheries College, Ocean University of China, Qingdao 266003, China
| | - Xiongbo He
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
- Guangdong Provincial Engineering and Technology Research Center of Far Sea Fisheries Management and Fishing of South China Sea, Guangdong Ocean University, Zhanjiang 524088, China
| | - Yunrong Yan
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
- Guangdong Provincial Engineering and Technology Research Center of Far Sea Fisheries Management and Fishing of South China Sea, Guangdong Ocean University, Zhanjiang 524088, China
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Stallings CD, Nelson JA, Peebles EB, Ellis G, Goddard EA, Jue NK, Mickle A, Tzadik OE, Koenig CC. Trophic ontogeny of a generalist predator is conserved across space. Oecologia 2023; 201:721-732. [PMID: 36843229 DOI: 10.1007/s00442-023-05337-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 02/12/2023] [Indexed: 02/28/2023]
Abstract
Consumers can influence ecological patterns and processes through their trophic roles and contributions to the flow of energy through ecosystems. However, the diet and associated trophic roles of consumers commonly change during ontogeny. Despite the prevalence of ontogenetic variation in trophic roles of most animals, we lack an understanding of whether they change consistently across local populations and broad geographic gradients. We examined how the diet and trophic position of a generalist marine predator varied with ontogeny across seven broadly separated locations (~ 750 km). We observed a high degree of heterogeneity in prey consumed without evidence of spatial structuring in this variability. However, compound-specific isotope analysis of amino acids revealed remarkably consistent patterns of increasing trophic position through ontogeny across local populations, suggesting that the roles of this generalist predator scaled with its body size across space. Given the high degree of diet heterogeneity we observed, this finding suggests that even though the dietary patterns differed, the underlying food web architecture transcended variation in prey species across locations for this generalist consumer. Our research addresses a gap in empirical field work regarding the interplay between stage-structured populations and food webs, and suggests ontogenetic changes in trophic position can be consistent in generalist consumers.
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Affiliation(s)
| | - James A Nelson
- Department of Biology, University of Louisiana Lafayette, Lafayette, LA, USA
| | - Ernst B Peebles
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | - Gregory Ellis
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
- Johns Hopkins All Children's Hospital, St Petersburg, FL, USA
| | - Ethan A Goddard
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | - Nathaniel K Jue
- Department of Biology and Chemistry, California State University, Monterey Bay, Seaside, CA, USA
| | - Alejandra Mickle
- Department of Biology, Florida State University, Tallahassee, FL, USA
- Office of Habitat Conservation-Restoration Center, NOAA Fisheries, Silver Spring, MD, USA
| | - Orian E Tzadik
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
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4
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Toscano BJ, Figel AS, Rudolf VHW. Ontogenetic development underlies population response to mortality. OIKOS 2021. [DOI: 10.1111/oik.07796] [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)
- Benjamin J. Toscano
- Dept of Biology, Trinity College Hartford CT USA
- BioSciences, Rice Univ. Houston TX USA
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6
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Sánchez-Hernández J, Nunn AD, Adams CE, Amundsen PA. Causes and consequences of ontogenetic dietary shifts: a global synthesis using fish models. Biol Rev Camb Philos Soc 2018; 94:539-554. [DOI: 10.1111/brv.12468] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 08/24/2018] [Accepted: 08/30/2018] [Indexed: 02/01/2023]
Affiliation(s)
- Javier Sánchez-Hernández
- Departamento de Zooloxía, Xenética e Antropoloxía Física, Facultade de Bioloxía; Universidade de Santiago de Compostela; Campus Vida s/n, 15782, Santiago de Compostela Spain
| | - Andy D. Nunn
- Hull International Fisheries Institute, School of Environmental Sciences; University of Hull; Hull, HU6 7RX UK
| | - Colin E. Adams
- Scottish Centre for Ecology and the Natural Environment, Institute of Biodiversity; Animal Health and Comparative Medicine, University of Glasgow; Rowardennan, Glasgow, G63 0AW UK
| | - Per-Arne Amundsen
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics; UiT The Arctic University of Norway; N-9037, Tromsø Norway
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7
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Losapio G, Pugnaire FI, O'Brien MJ, Schöb C. Plant life history stage and nurse age change the development of ecological networks in an arid ecosystem. OIKOS 2018. [DOI: 10.1111/oik.05199] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gianalberto Losapio
- Dep. of Evolutionary Biology and Environmental Studies; Univ. of Zurich; Winterthurerstrasse 190 CH-8057 Zurich Switzerland
- Swiss Federal Inst. of Technology, ETH Zurich; Dept of Environmental Systems Science, Inst. of Agricultural Sciences; Zurich Switzerland
| | - Francisco I. Pugnaire
- Estación Experimental de Zonas Áridas; Consejo Superior de Investigaciones Científicas, La Cañada; Almería Spain
| | - Michael J. O'Brien
- Estación Experimental de Zonas Áridas; Consejo Superior de Investigaciones Científicas, La Cañada; Almería Spain
| | - Christian Schöb
- Dep. of Evolutionary Biology and Environmental Studies; Univ. of Zurich; Winterthurerstrasse 190 CH-8057 Zurich Switzerland
- Swiss Federal Inst. of Technology, ETH Zurich; Dept of Environmental Systems Science, Inst. of Agricultural Sciences; Zurich Switzerland
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8
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Robust permanence for ecological equations with internal and external feedbacks. J Math Biol 2017; 77:79-105. [PMID: 29075847 PMCID: PMC5949143 DOI: 10.1007/s00285-017-1187-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 08/26/2017] [Indexed: 11/25/2022]
Abstract
Species experience both internal feedbacks with endogenous factors such as trait evolution and external feedbacks with exogenous factors such as weather. These feedbacks can play an important role in determining whether populations persist or communities of species coexist. To provide a general mathematical framework for studying these effects, we develop a theorem for coexistence for ecological models accounting for internal and external feedbacks. Specifically, we use average Lyapunov functions and Morse decompositions to develop sufficient and necessary conditions for robust permanence, a form of coexistence robust to large perturbations of the population densities and small structural perturbations of the models. We illustrate how our results can be applied to verify permanence in non-autonomous models, structured population models, including those with frequency-dependent feedbacks, and models of eco-evolutionary dynamics. In these applications, we discuss how our results relate to previous results for models with particular types of feedbacks.
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9
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Griffiths JR, Kadin M, Nascimento FJA, Tamelander T, Törnroos A, Bonaglia S, Bonsdorff E, Brüchert V, Gårdmark A, Järnström M, Kotta J, Lindegren M, Nordström MC, Norkko A, Olsson J, Weigel B, Žydelis R, Blenckner T, Niiranen S, Winder M. The importance of benthic-pelagic coupling for marine ecosystem functioning in a changing world. GLOBAL CHANGE BIOLOGY 2017; 23:2179-2196. [PMID: 28132408 DOI: 10.1111/gcb.13642] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 12/22/2016] [Accepted: 01/06/2017] [Indexed: 05/12/2023]
Abstract
Benthic-pelagic coupling is manifested as the exchange of energy, mass, or nutrients between benthic and pelagic habitats. It plays a prominent role in aquatic ecosystems, and it is crucial to functions from nutrient cycling to energy transfer in food webs. Coastal and estuarine ecosystem structure and function are strongly affected by anthropogenic pressures; however, there are large gaps in our understanding of the responses of inorganic nutrient and organic matter fluxes between benthic habitats and the water column. We illustrate the varied nature of physical and biological benthic-pelagic coupling processes and their potential sensitivity to three anthropogenic pressures - climate change, nutrient loading, and fishing - using the Baltic Sea as a case study and summarize current knowledge on the exchange of inorganic nutrients and organic material between habitats. Traditionally measured benthic-pelagic coupling processes (e.g., nutrient exchange and sedimentation of organic material) are to some extent quantifiable, but the magnitude and variability of biological processes are rarely assessed, preventing quantitative comparisons. Changing oxygen conditions will continue to have widespread effects on the processes that govern inorganic and organic matter exchange among habitats while climate change and nutrient load reductions may have large effects on organic matter sedimentation. Many biological processes (predation, bioturbation) are expected to be sensitive to anthropogenic drivers, but the outcomes for ecosystem function are largely unknown. We emphasize how improved empirical and experimental understanding of benthic-pelagic coupling processes and their variability are necessary to inform models that can quantify the feedbacks among processes and ecosystem responses to a changing world.
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Affiliation(s)
- Jennifer R Griffiths
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691, Stockholm, Sweden
| | - Martina Kadin
- Stockholm Resilience Centre, Stockholm University, 10691, Stockholm, Sweden
| | - Francisco J A Nascimento
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691, Stockholm, Sweden
| | - Tobias Tamelander
- Tvärminne Zoological Station, University of Helsinki, J.A. Palméns väg 260, 10900, Hangö, Finland
| | - Anna Törnroos
- Environmental and Marine Biology, Åbo Akademi University, FI-20500, Turku, Finland
- Centre for Ocean Life, National Institute of Aquatic Resources, Technical University of Denmark, Kavalergården 6, 2920, Charlottenlund, Denmark
| | - Stefano Bonaglia
- Department of Geological Sciences, Stockholm University, 10691, Stockholm, Sweden
- Department of Geology, Lund University, 22362, Lund, Sweden
| | - Erik Bonsdorff
- Environmental and Marine Biology, Åbo Akademi University, FI-20500, Turku, Finland
| | - Volker Brüchert
- Department of Geological Sciences, Stockholm University, 10691, Stockholm, Sweden
| | - Anna Gårdmark
- Department of Aquatic Resources, Swedish University of Agricultural Sciences, Skolgatan 6, 74242, Öregrund, Sweden
| | - Marie Järnström
- Environmental and Marine Biology, Åbo Akademi University, FI-20500, Turku, Finland
| | - Jonne Kotta
- Estonian Marine Institute, University of Tartu, Mäealuse 14, 12618, Tallinn, Estonia
| | - Martin Lindegren
- Centre for Ocean Life, National Institute of Aquatic Resources, Technical University of Denmark, Kavalergården 6, 2920, Charlottenlund, Denmark
| | - Marie C Nordström
- Environmental and Marine Biology, Åbo Akademi University, FI-20500, Turku, Finland
| | - Alf Norkko
- Tvärminne Zoological Station, University of Helsinki, J.A. Palméns väg 260, 10900, Hangö, Finland
- Baltic Sea Centre, Stockholm University, Stockholm, 106 91, Sweden
| | - Jens Olsson
- Department of Aquatic Resources, Swedish University of Agricultural Sciences, Skolgatan 6, 74242, Öregrund, Sweden
| | - Benjamin Weigel
- Environmental and Marine Biology, Åbo Akademi University, FI-20500, Turku, Finland
| | | | - Thorsten Blenckner
- Stockholm Resilience Centre, Stockholm University, 10691, Stockholm, Sweden
| | - Susa Niiranen
- Stockholm Resilience Centre, Stockholm University, 10691, Stockholm, Sweden
| | - Monika Winder
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691, Stockholm, Sweden
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10
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Fields WR, Grant EHC, Lowe WH. Detecting spatial ontogenetic niche shifts in complex dendritic ecological networks. Ecosphere 2017. [DOI: 10.1002/ecs2.1662] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- William R. Fields
- U.S. Geological Survey Patuxent Wildlife Research Center S.O. Conte Anadromous Fish Research Center Turners Falls Massachusetts 01376 USA
| | - Evan H. Campbell Grant
- U.S. Geological Survey Patuxent Wildlife Research Center S.O. Conte Anadromous Fish Research Center Turners Falls Massachusetts 01376 USA
| | - Winsor H. Lowe
- Division of Biological Sciences University of Montana Missoula Montana 59812 USA
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11
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Approximation of a physiologically structured population model with seasonal reproduction by a stage-structured biomass model. THEOR ECOL-NETH 2017; 10:73-90. [PMID: 32226567 PMCID: PMC7089643 DOI: 10.1007/s12080-016-0309-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 08/09/2016] [Indexed: 12/02/2022]
Abstract
Seasonal reproduction causes, due to the periodic inflow of young small individuals in the population, seasonal fluctuations in population size distributions. Seasonal reproduction furthermore implies that the energetic body condition of reproducing individuals varies over time. Through these mechanisms, seasonal reproduction likely affects population and community dynamics. While seasonal reproduction is often incorporated in population models using discrete time equations, these are not suitable for size-structured populations in which individuals grow continuously between reproductive events. Size-structured population models that consider seasonal reproduction, an explicit growing season and individual-level energetic processes exist in the form of physiologically structured population models. However, modeling large species ensembles with these models is virtually impossible. In this study, we therefore develop a simpler model framework by approximating a cohort-based size-structured population model with seasonal reproduction to a stage-structured biomass model of four ODEs. The model translates individual-level assumptions about food ingestion, bioenergetics, growth, investment in reproduction, storage of reproductive energy, and seasonal reproduction in stage-based processes at the population level. Numerical analysis of the two models shows similar values for the average biomass of juveniles, adults, and resource unless large-amplitude cycles with a single cohort dominating the population occur. The model framework can be extended by adding species or multiple juvenile and/or adult stages. This opens up possibilities to investigate population dynamics of interacting species while incorporating ontogenetic development and complex life histories in combination with seasonal reproduction.
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12
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Sánchez-Hernández J, Eloranta AP, Finstad AG, Amundsen PA. Community structure affects trophic ontogeny in a predatory fish. Ecol Evol 2016; 7:358-367. [PMID: 28070298 PMCID: PMC5214065 DOI: 10.1002/ece3.2600] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 10/13/2016] [Accepted: 10/22/2016] [Indexed: 11/11/2022] Open
Abstract
While most studies have focused on the timing and nature of ontogenetic niche shifts, information is scarce about the effects of community structure on trophic ontogeny of top predators. We investigated how community structure affects ontogenetic niche shifts (i.e., relationships between body length, trophic position, and individual dietary specialization) of a predatory fish, brown trout (Salmo trutta). We used stable isotope and stomach content analyses to test how functional characteristics of lake fish community compositions (competition and prey availability) modulate niche shifts in terms of (i) piscivorous behavior, (ii) trophic position, and (iii) individual dietary specialization. Northern Scandinavian freshwater fish communities were used as a study system, including nine subarctic lakes with contrasting fish community configurations: (i) trout‐only systems, (ii) two‐species systems (brown trout and Arctic charr [Salvelinus alpinus] coexisting), and (iii) three‐species systems (brown trout, Arctic charr, and three‐spined sticklebacks [Gasterosteus aculeatus] coexisting). We expected that the presence of profitable small prey (stickleback) and mixed competitor–prey fish species (charr) supports early piscivory and high individual dietary specialization among trout in multispecies communities, whereas minor ontogenetic shifts were expected in trout‐only systems. From logistic regression models, the presence of a suitable prey fish species (stickleback) emerged as the principal variable determining the size at ontogenetic niche shifts. Generalized additive mixed models indicated that fish community structure shaped ontogenetic niche shifts in trout, with the strongest positive relationships between body length, trophic position, and individual dietary specialization being observed in three‐species communities. Our findings revealed that the presence of a small‐sized prey fish species (stickleback) rather than a mixed competitor–prey fish species (charr) was an important factor affecting the ontogenetic niche‐shift processes of trout. The study demonstrates that community structure may modulate the ontogenetic diet trajectories of and individual niche specialization within a top predator.
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Affiliation(s)
- Javier Sánchez-Hernández
- Department of Zoology, Genetics and Physical Anthropology University of Santiago de Compostela Santiago de Compostela Spain; Department of Arctic and Marine Biology UiT The Arctic University of Norway Tromsø Norway; Department of Natural History NTNU University Museum Trondheim Norway
| | - Antti P Eloranta
- Aquatic Ecology Department Norwegian Institute for Nature Research (NINA)Trondheim Norway; Department of Biological and Environmental Sciences University of Jyväskylä Jyväskylä Finland
| | - Anders G Finstad
- Department of Natural History NTNU University Museum Trondheim Norway; Aquatic Ecology Department Norwegian Institute for Nature Research (NINA)Trondheim Norway
| | - Per-Arne Amundsen
- Department of Arctic and Marine Biology UiT The Arctic University of Norway Tromsø Norway
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13
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Barabás G, D'Andrea R. The effect of intraspecific variation and heritability on community pattern and robustness. Ecol Lett 2016; 19:977-86. [PMID: 27335262 DOI: 10.1111/ele.12636] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 04/25/2016] [Accepted: 05/10/2016] [Indexed: 02/05/2023]
Abstract
Intraspecific trait variation is widespread in nature, yet its effects on community dynamics are not well understood. Here we explore the consequences of intraspecific trait variation for coexistence in two- and multispecies competitive communities. For two species, the likelihood of coexistence is in general reduced by intraspecific variation, except when the species have almost equal trait means but different trait variances, such that one is a generalist and the other a specialist consumer. In multispecies communities, the only strong effect of non-heritable intraspecific variation is to reduce expected species richness. However, when intraspecific variation is heritable, allowing for the possibility of trait evolution, communities are much more resilient against environmental disturbance and exhibit far more predictable trait patterns. Our results are robust to varying model parameters and relaxing model assumptions.
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Affiliation(s)
- György Barabás
- Department of Ecology & Evolution, University of Chicago, Chicago, IL, USA
| | - Rafael D'Andrea
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
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14
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Alternative stable states in a stage-structured consumer-resource biomass model with niche shift and seasonal reproduction. Theor Popul Biol 2015; 103:60-70. [PMID: 25963630 DOI: 10.1016/j.tpb.2015.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 04/27/2015] [Accepted: 04/30/2015] [Indexed: 11/22/2022]
Abstract
We formulate and analyze a stage-structured consumer-resource biomass model, in which consumers reproduce in a pulsed event at the beginning of a growing season and furthermore go through a niche shift during their life history. We show that the resulting semi-discrete model can exhibit two stable states that can be characterized as a development-controlled state and a reproduction-controlled state. Varying resource availabilities and varying the extent of the niche shift determines whether juveniles or adults are more limited by their resource(s) and can lead to switches between the alternative stable states. Furthermore, we quantify the persistence of the consumer population and the occurrence of the two alternative stable states as a function of resource availabilities and extent of the niche shift. All the results show that irrespective of the type of reproduction of the consumers (continuous or seasonal), the stage-structured model will exhibit alternative stable states as long as development of the juvenile stage and reproduction of the adult stage are both resource-dependent.
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