1
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Finnie S, Butterill P, Novotny V, Redmond C, Jorge LR, Abe T, Lamarre GPA, Maicher V, Sam K. Vertical stratification and defensive traits of caterpillars against parasitoids in a lowland tropical forest in Cameroon. Oecologia 2024; 204:915-930. [PMID: 38613574 PMCID: PMC11062930 DOI: 10.1007/s00442-024-05542-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 03/12/2024] [Indexed: 04/15/2024]
Abstract
Insect herbivores and their parasitoids play a crucial role in terrestrial trophic interactions in tropical forests. These interactions occur across the entire vertical gradient of the forest. This study compares how caterpillar communities, and their parasitism rates, vary across vertical strata and between caterpillar defensive strategies in a semi deciduous tropical forest in Nditam, Cameroon. Within a 0.1 ha plot, all trees with a diameter at breast height (DBH) ≥ 5 cm were felled and systematically searched for caterpillars. We divided the entire vertical gradient of the forest into eight, five-metre strata. All caterpillars were assigned to a stratum based on their collection height, reared, identified, and classified into one of three defensive traits: aposematic, cryptic and shelter-building. Caterpillar species richness and diversity showed a midstory peak, whereas density followed the opposite pattern, decreasing in the midstory and then increasing towards the highest strata. This trend was driven by some highly dense shelter-building caterpillars in the upper canopy. Specialisation indices indicated decreasing levels of caterpillar generality with increasing height, a midstory peak in vulnerability, and increasing connectance towards the upper canopy, although the latter was likely driven by decreasing network size. Both aposematic and shelter-building caterpillars had significantly higher parasitism rates than cryptic caterpillars. Our results highlight nuanced changes in caterpillar communities across forest strata and provide evidence that defences strategies are important indicators of parasitism rates in caterpillars and that both aposematic and shelter-building caterpillars could be considered a "safe haven" for parasitoids.
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Affiliation(s)
- Sam Finnie
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic.
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic.
| | - Philip Butterill
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Vojtech Novotny
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Conor Redmond
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Leonardo Ré Jorge
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Tomokazu Abe
- Department of Biology, Faculty of Science, Chiba University, Chiba, 263-8522, Japan
| | - Greg P A Lamarre
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic
- Smithsonian Tropical Research Institute, Apartado, Balboa, 0843-03092, Ancon, Panama
| | - Vincent Maicher
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
- The Nature Conservancy (TNC), Libreville, Gabon
| | - Katerina Sam
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
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2
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Eichenwald AJ, Fefferman NH, Reed JM. Potential extinction cascades in a desert ecosystem: Linking food web interactions to community viability. Ecol Evol 2024; 14:e10930. [PMID: 38362165 PMCID: PMC10867880 DOI: 10.1002/ece3.10930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 11/27/2023] [Accepted: 12/05/2023] [Indexed: 02/17/2024] Open
Abstract
Desert communities are threatened with species loss due to climate change, and their resistance to such losses is unknown. We constructed a food web of the Mojave Desert terrestrial community (300 nodes, 4080 edges) to empirically examine the potential cascading effects of bird extinctions on this desert network, compared to losses of mammals and lizards. We focused on birds because they are already disappearing from the Mojave, and their relative thermal vulnerabilities are known. We quantified bottom-up secondary extinctions and evaluated the relative resistance of the community to losses of each vertebrate group. The impact of random bird species loss was relatively low compared to the consequences of mammal (causing the greatest number of cascading losses) or reptile loss, and birds were relatively less likely to be in trophic positions that could drive top-down effects in apparent competition and tri-tropic cascade motifs. An avian extinction cascade with year-long resident birds caused more secondary extinctions than the cascade involving all bird species for randomized ordered extinctions. Notably, we also found that relatively high interconnectivity among avian species has formed a subweb, enhancing network resistance to bird losses.
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Affiliation(s)
| | - Nina H. Fefferman
- Department of Ecology and Evolutionary BiologyUniversity of TennesseeKnoxvilleTennesseeUSA
| | - J. Michael Reed
- Department of BiologyTufts UniversityMedfordMassachusettsUSA
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3
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Beilke EA, O'Keefe JM. Bats reduce insect density and defoliation in temperate forests: An exclusion experiment. Ecology 2023; 104:e3903. [PMID: 36310413 PMCID: PMC10078224 DOI: 10.1002/ecy.3903] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/29/2022] [Accepted: 09/13/2022] [Indexed: 02/03/2023]
Abstract
Bats suppress insect populations in agricultural ecosystems, yet the question of whether bats initiate trophic cascades in forests is mainly unexplored. We used a field experiment to test the hypothesis that insectivorous bats reduce defoliation through the top-down suppression of forest-defoliating insects. We excluded bats from 20 large, subcanopy forest plots (opened daily to allow birds access), each paired with an experimental control plot, during three summers between 2018 and 2020 in the central hardwood region of the United States. We monitored leaf area changes and insect density for nine to 10 oak or hickory seedlings per plot. Insect density was three times greater on seedlings in bat-excluded versus control plots. Additionally, seedling defoliation was five times greater with bats excluded, and bats' impact on defoliation was three times greater for oaks than for hickories. We show that insectivorous bats drive top-down trophic cascades, play an integral role in forest ecosystems, and may ultimately influence forest health, structure, and composition. This work demonstrates insectivorous bats' ecological and economic value and the importance of conserving this highly imperiled group of predators.
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Affiliation(s)
- Elizabeth A. Beilke
- Department of Natural Resources and Environmental SciencesUniversity of Illinois at Urbana‐ChampaignUrbanaIllinoisUSA
- Center for Bat Research, Outreach, and ConservationIndiana State UniversityTerre HauteIndianaUSA
| | - Joy M. O'Keefe
- Department of Natural Resources and Environmental SciencesUniversity of Illinois at Urbana‐ChampaignUrbanaIllinoisUSA
- Center for Bat Research, Outreach, and ConservationIndiana State UniversityTerre HauteIndianaUSA
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4
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Forde AJ, Feller IC, Parker JD, Gruner DS. Insectivorous birds reduce herbivory but do not increase mangrove growth across productivity zones. Ecology 2022; 103:e3768. [PMID: 35608609 PMCID: PMC9786852 DOI: 10.1002/ecy.3768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 02/24/2022] [Accepted: 04/19/2022] [Indexed: 12/30/2022]
Abstract
Top-down effects of predators and bottom-up effects of resources are important drivers of community structure and function in a wide array of ecosystems. Fertilization experiments impose variation in resource availability that can mediate the strength of predator impacts, but the prevalence of such interactions across natural productivity gradients is less clear. We studied the joint impacts of top-down and bottom-up factors in a tropical mangrove forest system, leveraging fine-grained patchiness in resource availability and primary productivity on coastal cays of Belize. We excluded birds from canopies of red mangrove (Rhizophoraceae: Rhizophora mangle) for 13 months in zones of phosphorus-limited, stunted dwarf mangroves, and in adjacent zones of vigorous mangroves that receive detrital subsidies. Birds decreased total arthropod densities by 62%, herbivore densities more than fivefold, and reduced rates of leaf and bud herbivory by 45% and 52%, respectively. Despite similar arthropod densities across both zones of productivity, leaf and bud damage were 2.0 and 4.3 times greater in productive stands. Detrital subsidies strongly impacted a suite of plant traits in productive stands, potentially making leaves more nutritious and vulnerable to damage. Despite consistently strong impacts on herbivory, we did not detect top-down forcing that impacted mangrove growth, which was similar with and without birds. Our results indicated that both top-down and bottom-up forces drive arthropod community dynamics, but attenuation at the plant-herbivore interface weakens top-down control by avian insectivores.
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Affiliation(s)
| | - Ilka C. Feller
- Smithsonian Environmental Research CenterEdgewaterMarylandUSA
| | - John D. Parker
- Smithsonian Environmental Research CenterEdgewaterMarylandUSA
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5
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Gómez-González S, Paniw M, Blanco-Pastor JL, García-Cervigón AI, Godoy O, Herrera JM, Lara A, Miranda A, Ojeda F, Ochoa-Hueso R. Moving towards the ecological intensification of tree plantations. TRENDS IN PLANT SCIENCE 2022; 27:637-645. [PMID: 35039247 DOI: 10.1016/j.tplants.2021.12.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 11/19/2021] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
Abstract
The growing demand for timber and the boom in massive tree-planting programs could mean the spreading of mismanaged tree plantations worldwide. Here, we apply the concept of ecological intensification to forestry systems as a viable biodiversity-focused strategy that could be critical to develop productive, yet sustainable, tree plantations. Tree plantations can be highly productive if tree species are properly combined to complement their ecological functions. Simultaneously considering soil biodiversity and animal-mediated biocontrol will be critical to minimize the reliance on external inputs. Integrating genetic, functional, and demographic diversity across heterogeneous landscapes should improve resilience under climate change. Designing ecologically intensified plantations will mean breaking the timber productivity versus conservation dichotomy and assuring the maintenance of key ecosystem services at safe levels.
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Affiliation(s)
- Susana Gómez-González
- Departamento de Biología-IVAGRO, Universidad de Cádiz, Campus Río San Pedro, 11510 Puerto Real, Spain; Center for Climate and Resilience Research (CR)2, Blanco Encalada 2002, 8370449 Santiago, Chile; Center for Fire and Socioecological Systems (FireSES), Universidad Austral de Chile, Campus Isla Teja, 5090000 Valdivia, Chile.
| | - Maria Paniw
- Department of Conservation Biology and Global Change, Estación Biológica de Doñana (EBD-CSIC), Avenida Americo Vespucio 26, 41092 Sevilla, Spain
| | - José Luis Blanco-Pastor
- Department of Plant Biology and Ecology, University of Seville, Avenida Reina Mercedes 6, 41012 Seville, Spain
| | - Ana I García-Cervigón
- Biodiversity and Conservation Area, Rey Juan Carlos University, c/ Tulipán s/n, 28933 Móstoles, Spain
| | - Oscar Godoy
- Instituto Universitario de Investigación Marina (INMAR), Departamento de Biología, Universidad de Cádiz, Campus Río San Pedro, 11510 Puerto Real, Spain
| | - José M Herrera
- Mediterranean Institute for Agriculture, Environment and Development and University of Évora, Casa Cordovil, 2nd Floor, R. Dom Augusto Eduardo Nunes 7, 7000 - 651 Évora, Portugal
| | - Antonio Lara
- Center for Climate and Resilience Research (CR)2, Blanco Encalada 2002, 8370449 Santiago, Chile; Instituto de Conservación, Biodiversidad y Territorio, Universidad Austral de Chile, Campus Isla Teja, 5090000 Valdivia, Chile; Fundación Centro de los Bosques Nativos Forecos, Valdivia, Chile
| | - Alejandro Miranda
- Center for Climate and Resilience Research (CR)2, Blanco Encalada 2002, 8370449 Santiago, Chile; Laboratorio de Ecología del Paisaje y Conservación, Departamento de Ciencias Forestales, Universidad de La Frontera, P.O. Box 54-D, 4780000 Temuco, Chile
| | - Fernando Ojeda
- Departamento de Biología-IVAGRO, Universidad de Cádiz, Campus Río San Pedro, 11510 Puerto Real, Spain
| | - Raúl Ochoa-Hueso
- Departamento de Biología-IVAGRO, Universidad de Cádiz, Campus Río San Pedro, 11510 Puerto Real, Spain; Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB, Wageningen, The Netherlands
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6
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Rossi LC, Berenguer E, Lees AC, Barlow J, Ferreira J, França FM, Tavares P, Pizo MA. Predation on artificial caterpillars following understorey fires in human‐modified Amazonian forests. Biotropica 2022. [DOI: 10.1111/btp.13097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Liana Chesini Rossi
- Departamento de Biodiversidade Instituto de Biociências Universidade Estadual Paulista (UNESP) Rio Claro Brazil
- Division of Biology and Conservation Ecology Department of Natural Sciences Manchester Metropolitan University Manchester UK
| | - Erika Berenguer
- Environmental Change Institute School of Geography and the Environment University of Oxford Oxford UK
- Lancaster Environment Centre Lancaster University Lancaster UK
| | - Alexander Charles Lees
- Division of Biology and Conservation Ecology Department of Natural Sciences Manchester Metropolitan University Manchester UK
- Cornell Lab of Ornithology Cornell University Ithaca USA
| | - Jos Barlow
- Lancaster Environment Centre Lancaster University Lancaster UK
- Setor de Ecologia e Conservação Universidade Federal de Lavras Lavras MG Brazil
| | - Joice Ferreira
- Embrapa Amazônia Oriental Belém PA Brazil
- Programa de Pós‐Graduação em Ecologia (PPGECO) e Programa de Pós‐Graduação em Ciências Ambientais (PPGCA) Universidade Federal do Pará Belém PA Brazil
| | | | - Paulo Tavares
- Programa de Pós‐Graduação em Ecologia (PPGECO) e Programa de Pós‐Graduação em Ciências Ambientais (PPGCA) Universidade Federal do Pará Belém PA Brazil
| | - Marco Aurélio Pizo
- Departamento de Biodiversidade Instituto de Biociências Universidade Estadual Paulista (UNESP) Rio Claro Brazil
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7
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Szefer P, Molem K, Sau A, Novotny V. Weak effects of birds, bats, and ants on their arthropod prey on pioneering tropical forest gap vegetation. Ecology 2022; 103:e3690. [PMID: 35322403 DOI: 10.1002/ecy.3690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/18/2021] [Accepted: 01/18/2022] [Indexed: 11/11/2022]
Abstract
The relative roles of plants competing for resources versus top-down control of vegetation by herbivores, in turn impacted by predators, during early stages of tropical forest succession remain poorly understood. Here we examine the impact of insectivorous birds, bats and ants exclusion on arthropods communities on replicated 5x5 m of pioneering early successional vegetation plots in lowland tropical forest gaps in Papua New Guinea. In plots from which focal taxa of predators were excluded we observed increased biomass of herbivorous and predatory arthropods, and increased density, and decreased diversity of herbivorous insects. However, changes in the biomass of plants, herbivores and arthropod predators were positively correlated or uncorrelated between these three trophic levels and also between individual arthropod orders. Arthropod abundance and biomass correlated strongly with the plant biomass irrespective of the arthropods' trophic position - a signal of bottom-up control. Patterns in herbivore specialization confirm lack of a strong top-down control and were largely unaffected by the exclusion of insectivorous birds, bats and ants. No changes of plant-herbivore interaction networks were detected except for decrease in modularity of the exclosure plots. Our results suggest weak top-down control of herbivores, limited compensation between arthropod and vertebrate predators, and limited intra-guild predation by birds, bats and ants. Possible explanations are strong bottom-up control, a low activity of the higher order predators, especially birds, possibly also bats, in gaps, and continuous influx of herbivores from surrounding mature forest matrix.
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Affiliation(s)
- Piotr Szefer
- Faculty of Science, University of South Bohemia, Branišovská 1645/31a, České Budějovice, Czech Republic.,Biology Centre, Institute of Entomology, Czech Academy of Sciences, Branišovská 31, České Budějovice, Czech Republic
| | - Kenneth Molem
- New Guinea Binatang Research Centre, PO Box 604, Madang 511, Papua New Guinea
| | - Austin Sau
- New Guinea Binatang Research Centre, PO Box 604, Madang 511, Papua New Guinea
| | - Vojtech Novotny
- Faculty of Science, University of South Bohemia, Branišovská 1645/31a, České Budějovice, Czech Republic.,Biology Centre, Institute of Entomology, Czech Academy of Sciences, Branišovská 31, České Budějovice, Czech Republic
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8
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Stewart PS, Voskamp A, Santini L, Biber MF, Devenish AJM, Hof C, Willis SG, Tobias JA. Global impacts of climate change on avian functional diversity. Ecol Lett 2022; 25:673-685. [PMID: 35199917 DOI: 10.1111/ele.13830] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 05/18/2021] [Accepted: 05/18/2021] [Indexed: 01/03/2023]
Abstract
Climate change is predicted to drive geographical range shifts, leading to fluctuations in species richness (SR) worldwide. However, the effect of these changes on functional diversity (FD) remains unclear, in part because comprehensive species-level trait data are generally lacking at global scales. Here, we use morphometric and ecological traits for 8268 bird species to estimate the impact of climate change on avian FD. We show that future bird assemblages are likely to undergo substantial shifts in trait structure, with a magnitude of change greater than predicted from SR alone, and a direction of change varying according to geographical location and trophic guild. For example, our models predict that FD of insect predators will increase at higher latitudes with concurrent losses at mid-latitudes, whereas FD of seed dispersing birds will fluctuate across the tropics. Our findings highlight the potential for climate change to drive continental-scale shifts in avian FD with implications for ecosystem function and resilience.
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Affiliation(s)
- Peter S Stewart
- Department of Biosciences, Durham University, Durham, UK.,Department of Life Sciences, Imperial College London, Ascot, UK
| | - Alke Voskamp
- Department of Biosciences, Durham University, Durham, UK.,Senckenberg Biodiversity and Climate Research Centre (BiK-F), Frankfurt, Germany
| | - Luca Santini
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University of Rome, Rome, Italy.,National Research Council, Institute of Research on Terrestrial Ecosystems (CNR-IRET), Monterotondo (Rome), Italy
| | - Matthias F Biber
- Senckenberg Biodiversity and Climate Research Centre (BiK-F), Frankfurt, Germany.,Terrestrial Ecology Research Group, Technical University of Munich, Freising, Germany
| | | | - Christian Hof
- Senckenberg Biodiversity and Climate Research Centre (BiK-F), Frankfurt, Germany.,Terrestrial Ecology Research Group, Technical University of Munich, Freising, Germany
| | | | - Joseph A Tobias
- Department of Life Sciences, Imperial College London, Ascot, UK
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9
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Potapov AM, Beaulieu F, Birkhofer K, Bluhm SL, Degtyarev MI, Devetter M, Goncharov AA, Gongalsky KB, Klarner B, Korobushkin DI, Liebke DF, Maraun M, Mc Donnell RJ, Pollierer MM, Schaefer I, Shrubovych J, Semenyuk II, Sendra A, Tuma J, Tůmová M, Vassilieva AB, Chen T, Geisen S, Schmidt O, Tiunov AV, Scheu S. Feeding habits and multifunctional classification of soil‐associated consumers from protists to vertebrates. Biol Rev Camb Philos Soc 2022; 97:1057-1117. [DOI: 10.1111/brv.12832] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/31/2021] [Accepted: 01/05/2022] [Indexed: 12/17/2022]
Affiliation(s)
- Anton M. Potapov
- J.F. Blumenbach Institute of Zoology and Anthropology University of Göttingen Untere Karspüle 2 37073 Göttingen Germany
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences Leninsky Prospect 33 119071 Moscow Russia
| | - Frédéric Beaulieu
- Canadian National Collection of Insects, Arachnids and Nematodes, Agriculture and Agri‐Food Canada Ottawa ON K1A 0C6 Canada
| | - Klaus Birkhofer
- Department of Ecology Brandenburg University of Technology Karl‐Wachsmann‐Allee 6 03046 Cottbus Germany
| | - Sarah L. Bluhm
- J.F. Blumenbach Institute of Zoology and Anthropology University of Göttingen Untere Karspüle 2 37073 Göttingen Germany
| | - Maxim I. Degtyarev
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences Leninsky Prospect 33 119071 Moscow Russia
| | - Miloslav Devetter
- Biology Centre of the Czech Academy of Sciences, Institute of Soil Biology Na Sádkách 702/7 37005 České Budějovice Czech Republic
| | - Anton A. Goncharov
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences Leninsky Prospect 33 119071 Moscow Russia
| | - Konstantin B. Gongalsky
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences Leninsky Prospect 33 119071 Moscow Russia
| | - Bernhard Klarner
- J.F. Blumenbach Institute of Zoology and Anthropology University of Göttingen Untere Karspüle 2 37073 Göttingen Germany
| | - Daniil I. Korobushkin
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences Leninsky Prospect 33 119071 Moscow Russia
| | - Dana F. Liebke
- J.F. Blumenbach Institute of Zoology and Anthropology University of Göttingen Untere Karspüle 2 37073 Göttingen Germany
| | - Mark Maraun
- J.F. Blumenbach Institute of Zoology and Anthropology University of Göttingen Untere Karspüle 2 37073 Göttingen Germany
| | - Rory J. Mc Donnell
- Department of Crop and Soil Science Oregon State University Corvallis OR 97331 U.S.A
| | - Melanie M. Pollierer
- J.F. Blumenbach Institute of Zoology and Anthropology University of Göttingen Untere Karspüle 2 37073 Göttingen Germany
| | - Ina Schaefer
- J.F. Blumenbach Institute of Zoology and Anthropology University of Göttingen Untere Karspüle 2 37073 Göttingen Germany
| | - Julia Shrubovych
- Biology Centre of the Czech Academy of Sciences, Institute of Soil Biology Na Sádkách 702/7 37005 České Budějovice Czech Republic
- Institute of Systematics and Evolution of Animals PAS Slawkowska 17 Pl 31‐016 Krakow Poland
- State Museum Natural History of NAS of Ukraine Teatralna 18 79008 Lviv Ukraine
| | - Irina I. Semenyuk
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences Leninsky Prospect 33 119071 Moscow Russia
- Joint Russian‐Vietnamese Tropical Center №3 Street 3 Thang 2, Q10 Ho Chi Minh City Vietnam
| | - Alberto Sendra
- Colecciones Entomológicas Torres‐Sala, Servei de Patrimoni Històric, Ajuntament de València València Spain
- Departament de Didàctica de les Cièncias Experimentals i Socials, Facultat de Magisteri Universitat de València València Spain
| | - Jiri Tuma
- Biology Centre of the Czech Academy of Sciences, Institute of Soil Biology Na Sádkách 702/7 37005 České Budějovice Czech Republic
- Biology Centre CAS, Institute of Entomology Branisovska 1160/31 370 05 Ceske Budejovice Czech Republic
| | - Michala Tůmová
- Biology Centre of the Czech Academy of Sciences, Institute of Soil Biology Na Sádkách 702/7 37005 České Budějovice Czech Republic
| | - Anna B. Vassilieva
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences Leninsky Prospect 33 119071 Moscow Russia
| | - Ting‐Wen Chen
- Biology Centre of the Czech Academy of Sciences, Institute of Soil Biology Na Sádkách 702/7 37005 České Budějovice Czech Republic
| | - Stefan Geisen
- Department of Nematology Wageningen University & Research 6700ES Wageningen The Netherlands
| | - Olaf Schmidt
- UCD School of Agriculture and Food Science University College Dublin Belfield Dublin 4 Ireland
| | - Alexei V. Tiunov
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences Leninsky Prospect 33 119071 Moscow Russia
| | - Stefan Scheu
- J.F. Blumenbach Institute of Zoology and Anthropology University of Göttingen Untere Karspüle 2 37073 Göttingen Germany
- Centre of Biodiversity and Sustainable Land Use Büsgenweg 1 37077 Göttingen Germany
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10
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Serée L, Gardarin A, Crouzet O, Barbottin A, Valantin‐Morison M, Chiron F. Exploring multitrophic interactions in oilseed rape fields reveals the prevailing role of Carabidae. Ecol Evol 2021; 11:15377-15388. [PMID: 34765184 PMCID: PMC8571632 DOI: 10.1002/ece3.8229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/20/2021] [Accepted: 09/30/2021] [Indexed: 11/06/2022] Open
Abstract
In cropped fields, birds are often at the highest position in the food chain, feeding on pest arthropods and their intermediate predators in a process known as intraguild predation. The net effects of bird predation on phytophagous insect populations (feeding on plants) are difficult to predict without comprehensively describing prey-predator communities and their complex interplay. We sampled bird and arthropod communities in 30 oilseed rape fields in the spring of 2019 and 2020 in France. To assess the top-down control of arthropods by birds, we used a vertebrate exclusion experiment. Using a taxonomic and functional trait-based approach, we determined the direct and indirect influences of birds on arthropod predators and phytophagous insect populations in arable crops. We observed a negative relationship between the abundance of Carabidae and phytophagous insects but not with the other predator group suggesting the key role of Carabidae on phytophagous insects in agroecosystem. We found no statistical evidence of intraguild predation from birds toward intermediate predators. Despite the lack of overall effect of predator functional diversity on their prey, we highlighted the negative relationship between the functional complementarity (through functional evenness) of Carabidae and the abundance of phytophagous insects. This result suggests that functional complementarity between Carabidae species could help to reduce phytophagous insect populations. We analyzed the effect of agricultural practices on these multitrophic interactions, showing that pesticide intensity only had detrimental effects on Carabidae abundance, while the frequency of tillage did not affect the studied communities. Complementary indices used to depict communities are helpful to better understand the mechanisms underlying trophic relationships.
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Affiliation(s)
- Lola Serée
- AgronomieINRAEAgroParisTechUniversité Paris‐SaclayThiverval‐GrignonFrance
- Ecologie Systématique EvolutionUniversité Paris‐SaclayCNRSAgroParisTechOrsayFrance
| | - Antoine Gardarin
- AgronomieINRAEAgroParisTechUniversité Paris‐SaclayThiverval‐GrignonFrance
| | | | - Aude Barbottin
- SADAPTINRAEAgroParisTechUniversité Paris‐SaclayThiverval‐GrignonFrance
| | | | - François Chiron
- Ecologie Systématique EvolutionUniversité Paris‐SaclayCNRSAgroParisTechOrsayFrance
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11
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Amo L, Saavedra I. Attraction to Smelly Food in Birds: Insectivorous Birds Discriminate between the Pheromones of Their Prey and Those of Non-Prey Insects. BIOLOGY 2021; 10:1010. [PMID: 34681109 PMCID: PMC8533543 DOI: 10.3390/biology10101010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/28/2021] [Accepted: 10/04/2021] [Indexed: 11/16/2022]
Abstract
Natural selection has favored the evolution of different capabilities that allow animals to obtain food-e.g., the development of senses for improving prey/food detection. Among these senses, chemical sense is possibly the most ancient mechanism used by organisms for environmental assessment. Comparative studies suggest the prime role of foraging ecology in the evolution of the olfactory apparatus of vertebrates, including birds. Here, we review empirical studies that have shown birds' abilities to detect prey/food via olfaction and report the results of a study aiming to analyze the specificity of eavesdropping on prey pheromones in insectivorous birds. In a field study, we placed artificial larvae and a dispenser with one of three treatments-prey (Operopthera brumata) pheromones, non-prey (Rhynchophorus ferrugineus) pheromones, or a control unscented dispenser-on the branches of Pyrenean oak trees (Quercus pyrenaica). We then measured the predation rate of birds on artificial larvae. Our results show that more trees had larvae with signs of avian predation when they contained a prey pheromone dispenser than when they contained a non-prey pheromone dispenser or an unscented dispenser. Our results indicate that insectivorous birds can discriminate between the pheromones emitted by their prey and those emitted by non-prey insects and that they only exhibit attraction to prey pheromones. These results highlight the potential use of insectivorous birds in the biological control of insect pests.
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Affiliation(s)
- Luisa Amo
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), C/José Gutiérrez Abascal, 2, E-28006 Madrid, Spain;
- Area of Biodiversity and Conservation, Universidad Rey Juan Carlos, c/Tulipán s/n., E-28933 Madrid, Spain
| | - Irene Saavedra
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), C/José Gutiérrez Abascal, 2, E-28006 Madrid, Spain;
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12
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Ning Z, Chen C, Xie T, Zhu Z, Wang Q, Cui B, Bai J. Can the native faunal communities be restored from removal of invasive plants in coastal ecosystems? A global meta-analysis. GLOBAL CHANGE BIOLOGY 2021; 27:4644-4656. [PMID: 34170600 DOI: 10.1111/gcb.15765] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 06/09/2021] [Indexed: 06/13/2023]
Abstract
Coastal ecosystems worldwide are being threatened by invasive plants in the context of global changes. However, how invasive plants influence native faunal communities and whether native faunal communities can recover following the invader removals/controls across global coastal ecosystems are still poorly understood. Here, we present the first global meta-analysis to quantify the impacts of Spartina species invasions on coastal faunal communities and further to evaluate the outcomes of Spartina species removals on faunal community recovery based on 74 independent studies. We found that invasive Spartina species generally decreased the biodiversity (e.g., species richness), but increased coastal faunal abundance (e.g., individual number) and fitness (e.g., biomass), though the effect on abundance was insignificant. The pattern of influence was strongly dependent on habitat types, faunal taxa, trophic levels, and feeding types. Specifically, Spartina species invasion of mudflats caused greater impacts than invasion of vegetated habitats. Insects and birds at higher trophic levels were strongly affected by invasive Spartina, indicating that invasive plant effects can cascade upward along the food chain. Additionally, impacts of Spartina invasions were more obvious on food specialists such as herbivores and carnivores. Furthermore, our analyses revealed that invader removals were overall beneficial for native faunal communities to recover from the displacement caused by Spartina invasions, but this recovery process depended on specific removal measure and time. For example, the long-term waterlogging had strong negative impacts on faunal recovery, so it should not be encouraged. Our findings suggest that invasive plants could have contrasting effects on functional responses of native faunal communities. Although invasive plant removals could restore native faunal communities, future functional restorations of invaded ecosystems should take the legacy effects of invasive species on native communities into account. These findings provide insightful implications for future scientific controls of invasive species and ecosystem restoration under intensifying global changes.
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Affiliation(s)
- Zhonghua Ning
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing, China
- Yellow River Estuary Wetland Ecosystem Observation and Research Station, Ministry of Education, Shandong, China
| | - Cong Chen
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing, China
- Research and Development Center for Watershed Environmental Eco-Engineering, Advanced Institute of Natural Science, Beijing Normal University at Zhuhai, Guangdong, China
| | - Tian Xie
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing, China
- Yellow River Estuary Wetland Ecosystem Observation and Research Station, Ministry of Education, Shandong, China
| | - Zhenchang Zhu
- Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangdong, China
| | - Qing Wang
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing, China
- Research and Development Center for Watershed Environmental Eco-Engineering, Advanced Institute of Natural Science, Beijing Normal University at Zhuhai, Guangdong, China
| | - Baoshan Cui
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing, China
- Yellow River Estuary Wetland Ecosystem Observation and Research Station, Ministry of Education, Shandong, China
| | - Junhong Bai
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing, China
- Yellow River Estuary Wetland Ecosystem Observation and Research Station, Ministry of Education, Shandong, China
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13
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Cuny MAC, Bourne ME, Dicke M, Poelman EH. The enemy of my enemy is not always my friend: Negative effects of carnivorous arthropods on plants. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13884] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
| | - Mitchel E. Bourne
- Laboratory of Entomology Wageningen University Wageningen The Netherlands
| | - Marcel Dicke
- Laboratory of Entomology Wageningen University Wageningen The Netherlands
| | - Erik H. Poelman
- Laboratory of Entomology Wageningen University Wageningen The Netherlands
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14
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Stüber M, Tack AJM, Zewdie B, Mendesil E, Shimales T, Ayalew B, Nemomissa S, Sjögren J, Vesterinen E, Wezel A, Hylander K. Multi-scale mosaics in top-down pest control by ants from natural coffee forests to plantations. Ecology 2021; 102:e03376. [PMID: 33937985 DOI: 10.1002/ecy.3376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 03/16/2021] [Indexed: 11/09/2022]
Abstract
While top-down control plays an important role in shaping both natural and agricultural food webs, we lack insights into how top-down control effects vary across spatial scales. We used a multi-scale survey of top-down control of coffee pests and diseases by arboreal ants to examine if colony location creates a small-scale mosaic in top-down control around trees and if the strength of that control varies between sites at the landscape scale. We investigated pest and disease levels on coffee shrubs at different distances from shade trees with and without a Crematogaster spp. ant colony in 59 sites along a coffee management intensity gradient in southwestern Ethiopia. Within sites, ants significantly suppressed herbivory and coffee leaf rust at distances less than 10 m from nesting trees. Top-down control varied between sites, with stronger top-down control of free-feeding herbivory near ant colonies at sites with lower management intensity and stronger top-down control of a skeletonizer at sites with higher canopy cover. We conclude that the strength of top-down control by ants is highly heterogeneous across spatial scales, as a consequence of the biology of the predator at the small scale and herbivore density or changes in herbivore-ant interactions at the landscape scale.
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Affiliation(s)
- Moritz Stüber
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, 106 91, Sweden.,Agroecology and Environment Research Unit, ISARA-Lyon, Lyon, 69007, France.,Center for Organic Farming, University of Hohenheim, Stuttgart, 70599, Germany
| | - Ayco J M Tack
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, 106 91, Sweden
| | - Beyene Zewdie
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, 106 91, Sweden
| | - Esayas Mendesil
- Department of Horticulture & Plant Sciences, College of Agriculture and Veterinary Medicine, Jimma University, P.O. Box 307, Jimma, Ethiopia
| | - Tamiru Shimales
- Jimma Agricultural Research Center, P.O. Box 192, Jimma, Ethiopia
| | - Biruk Ayalew
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, 106 91, Sweden
| | - Sileshi Nemomissa
- Department of Plant Biology and Biodiversity Management, College of Natural Sciences, Addis Ababa University, P.O. Box 3434, Addis Ababa, Ethiopia
| | - Jörgen Sjögren
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, 106 91, Sweden.,Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences (SLU), Umeå, SE-901 83, Sweden
| | - Eero Vesterinen
- Department of Biology, University of Turku, Turku, Finland.,Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Alexander Wezel
- Agroecology and Environment Research Unit, ISARA-Lyon, Lyon, 69007, France
| | - Kristoffer Hylander
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, 106 91, Sweden
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15
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Morii Y, Kitazawa M, Squires TE, Watanabe M, Watanabe Y, Saito T, Yamazaki D, Uchida A, Machida Y. A complete dietary review of Japanese birds with special focus on molluscs. Sci Data 2021; 8:19. [PMID: 33473131 PMCID: PMC7817678 DOI: 10.1038/s41597-021-00800-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 12/04/2020] [Indexed: 11/09/2022] Open
Abstract
Birds often hold important positions in the food webs of ecosystems. As a result, interactions between birds and their prey have attracted attention not only in ecology, but also in fields like agriculture and conservation. Avian food resources are well researched in Japan, however there is no database critically reviewing molluscs as a food resource for birds. Here, we present a new database reviewing dietary information for all Japanese bird species. In addition to addressing general diet categories and specific food habits for each bird, we include detailed data on the molluscan prey observed for all species that consume them. The information within this database was collected through intense literary review to provide a complete look at bird species historically present around the country. We also include new information on snail species found in the upper digestive tract of harvested wild birds. This database is publicly available in the Zenodo repository. The information should aid research around the Japanese archipelago, especially projects involving birds or molluscs.
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Affiliation(s)
- Yuta Morii
- The Hakubi Project, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ward, Kyoto, 6068501, Japan.
- Laboratory of Animal Ecology, Department of Zoology, Graduate School of Science, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ward, Kyoto, 6068502, Japan.
| | - Munehiro Kitazawa
- Graduate School of Agriculture, Hokkaido University, Nishi 9, Kita 9, Kita-ward, Sapporo, Hokkaido, 0608589, Japan
| | - Theodore E Squires
- Kenkyu Services, 12511 84th Ave NE, Kirkland, WA, 98034, United States of America
| | | | | | - Takumi Saito
- Department of Biology, Faculty of Science, Toho University, Miyama 2-2-1, Funabashi, Chiba, 2748510, Japan
| | - Daishi Yamazaki
- Center for Northeast Asian Studies, Tohoku University, 41 Kawauchi, Aoba-ward, Sendai, Miyagi, 9808576, Japan
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16
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Schooler SL, Johnson MD, Njoroge P, Bean WT. Shade trees preserve avian insectivore biodiversity on coffee farms in a warming climate. Ecol Evol 2020; 10:12960-12972. [PMID: 33304508 PMCID: PMC7713971 DOI: 10.1002/ece3.6879] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/02/2020] [Accepted: 09/16/2020] [Indexed: 11/10/2022] Open
Abstract
AIM Coffee is an important export for many developing countries, with a global annual trade value of $100 billion, but it is threatened by a warming climate. Shade trees may mitigate the effects of climate change through temperature regulation that can aid in coffee growth, slow pest reproduction, and sustain avian insectivore diversity. The impact of shade on bird diversity and microclimate on coffee farms has been studied extensively in the Neotropics, but there is a dearth of research in the Paleotropics. LOCATION East Africa. METHODS We created current and future regional Maxent models for avian insectivores in East Africa using Worldclim temperature data and observations from the Global Biodiversity Information Database. We then adjusted current and future bioclimatic layers based on mean differences in temperature between shade and sun coffee farms and projected the models using these adjusted layers to predict the impact of shade tree removal on climatic suitability for avian insectivores. RESULTS Existing Worldclim temperature layers more closely matched temperatures under shade trees than temperatures in the open. Removal of shade trees, through warmer temperatures alone, would result in reduction of avian insectivore species by over 25%, a loss equivalent to 50 years of climate change under the most optimistic emissions scenario. Under the most extreme climate scenario and removal of shade trees, insectivore richness is projected to decline from a mean of 38 to fewer than 8 avian insectivore species. MAIN CONCLUSIONS We found that shade trees on coffee farms already provide important cooler microclimates for avian insectivores. Future temperatures will become a regionally limiting factor for bird distribution in East Africa, which could negatively impact control of coffee pests, but the effect of climate change can be potentially mediated through planting and maintaining shade trees on coffee farms.
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Affiliation(s)
- Sarah L. Schooler
- Wildlife DepartmentHumboldt State UniversityArcataCAUSA
- Department of Environmental and Forest BiologyState University of New York School of Environmental Science and ForestrySyracuseNYUSA
| | | | - Peter Njoroge
- Ornithology SectionNational Museums of KenyaNairobiKenya
| | - William T. Bean
- Wildlife DepartmentHumboldt State UniversityArcataCAUSA
- Biology DepartmentCalifornia Polytechnic State University – San Luis ObispoSan Luis ObispoCAUSA
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17
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Chan AA, Banks-Leite C. Habitat modification mediates the strength of trophic cascades on oak trees. Perspect Ecol Conserv 2020. [DOI: 10.1016/j.pecon.2020.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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18
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Mäntylä E, Kipper S, Hilker M. Insectivorous birds can see and smell systemically herbivore-induced pines. Ecol Evol 2020; 10:9358-9370. [PMID: 32953066 PMCID: PMC7487227 DOI: 10.1002/ece3.6622] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/25/2020] [Accepted: 07/08/2020] [Indexed: 11/10/2022] Open
Abstract
Several studies have shown that insectivorous birds are attracted to herbivore-damaged trees even when they cannot see or smell the actual herbivores or their feces. However, it often remained an open question whether birds are attracted by herbivore-induced changes in leaf odor or in leaf light reflectance or by both types of changes. Our study addressed this question by investigating the response of great tits (Parus major) and blue tits (Cyanistes caeruleus) to Scots pine (Pinus sylvestris) damaged by pine sawfly larvae (Diprion pini). We released the birds individually to a study booth, where they were simultaneously offered a systemically herbivore-induced and a noninfested control pine branch. In the first experiment, the birds could see the branches, but could not smell them, because each branch was kept inside a transparent, airtight cylinder. In the second experiment, the birds could smell the branches, but could not see them, because each branch was placed inside a nontransparent cylinder with a mesh lid. The results show that the birds were more attracted to the herbivore-induced branch in both experiments. Hence, either type of the tested cues, the herbivore-induced visual plant cue alone as well as the olfactory cues per se, is attractive to the birds.
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Affiliation(s)
- Elina Mäntylä
- Applied Zoology/Animal EcologyInstitute of BiologyFreie Universität BerlinBerlinGermany
- Institute of EntomologyBiology Centre of the Czech Academy of SciencesČeské BudĕjoviceCzech Republic
- Faculty of ScienceUniversity of South BohemiaČeské BudĕjoviceCzech Republic
- Section of EcologyDepartment of BiologyUniversity of TurkuTurkuFinland
| | - Silke Kipper
- Animal BehaviourInstitute of BiologyFreie Universität BerlinBerlinGermany
- Technische Universität MünchenFreisingGermany
| | - Monika Hilker
- Applied Zoology/Animal EcologyInstitute of BiologyFreie Universität BerlinBerlinGermany
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19
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Olimpi EM, Garcia K, Gonthier DJ, De Master KT, Echeverri A, Kremen C, Sciligo AR, Snyder WE, Wilson-Rankin EE, Karp DS. Shifts in species interactions and farming contexts mediate net effects of birds in agroecosystems. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2020; 30:e02115. [PMID: 32145709 DOI: 10.1002/eap.2115] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 01/07/2020] [Accepted: 01/29/2020] [Indexed: 06/10/2023]
Abstract
Some birds are viewed as pests and vectors of foodborne pathogens in farmlands, yet birds also benefit growers by consuming pests. While many growers seek to prevent birds from accessing their farms, few studies have attempted to quantify the net effects of bird services and disservices, let alone how net effects shift across farm management strategies. We quantified the net effect of birds on crop production across 20 California strawberry (Fragaria × ananassa) farms that varied in local management practices and landscape context. We surveyed farms for berry damage and bird droppings (as potential sources of pathogens) and implemented a large-scale exclusion experiment to quantify the impact of birds on production. We found that birds had only a slightly negative overall impact on strawberry production, reducing economic value by 3.6%. Direct bird damage and intraguild predation contributed equally to this net effect, underscoring the importance of indirect trophic interactions that may be less apparent to growers. In simple landscapes (e.g., low proportions of surrounding seminatural habitat), birds provided pest control in the interiors of farm fields, and costs from bird damage to crops peaked at field edges. In complex landscapes (e.g., high proportions of seminatural habitat), birds were more likely to disrupt pest control by feeding as intraguild predators. Nonetheless, seminatural habitat dampened bird services and disservices, and our models predicted that removing habitat around farm fields would increase costs from bird damage to crops by up to 76%. Fecal contamination of crops was extremely rare (0.01%). However, both fecal contamination and bird damage did increase on farms with higher densities of fencing and wires, where birds often perch. Our results demonstrate that maintaining seminatural habitat around farms may enhance bird diversity and mitigate bird damage without increasing food safety risks. We also show that the net effects of birds depend on farming context and vary in complex ways in relation to locations within a farm, local farm attributes, and the surrounding landscape. This context-specific variation must be considered in order to optimize the management of wild birds in agroecosystems.
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Affiliation(s)
- E M Olimpi
- Department of Wildlife, Fish, and Conservation Biology, University of California, 1088 Academic Surge, 455 Crocker Lane, Davis, California, 95616, USA
| | - K Garcia
- Department of Entomology, University of Kentucky, Lexington, Kentucky, 40546, USA
| | - D J Gonthier
- Department of Entomology, University of Kentucky, Lexington, Kentucky, 40546, USA
| | - K T De Master
- Environmental Science, Policy, and Management, University of California, Mulford Hall, 130 Hilgard Way, Berkeley, California, 94720, USA
| | - A Echeverri
- Institute for Resources, Environment and Sustainability, University of British Columbia, Vancouver Campus, AERL Building, 429-2202 Main Mall, Vancouver, British Columbia, V6T 1Z4, Canada
| | - C Kremen
- Environmental Science, Policy, and Management, University of California, Mulford Hall, 130 Hilgard Way, Berkeley, California, 94720, USA
- Institute for Resources, Environment and Sustainability, University of British Columbia, Vancouver Campus, AERL Building, 429-2202 Main Mall, Vancouver, British Columbia, V6T 1Z4, Canada
- Biodiversity Research Centre, Department of Zoology, University of British Columbia, 2212 Main Mall, Vancouver, British Columbia, V6T 1Z4, Canada
| | - A R Sciligo
- Environmental Science, Policy, and Management, University of California, Mulford Hall, 130 Hilgard Way, Berkeley, California, 94720, USA
| | - W E Snyder
- Department of Entomology, Washington State University, PO Box 646382, Pullman, Washington, 99164, USA
| | - E E Wilson-Rankin
- Department of Entomology, University of California, 165 Entomology Bldg., Citrus Drive, Riverside, California, 92521, USA
| | - D S Karp
- Department of Wildlife, Fish, and Conservation Biology, University of California, 1088 Academic Surge, 455 Crocker Lane, Davis, California, 95616, USA
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20
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Harris SH, Kormann UG, Stokely TD, Verschuyl J, Kroll AJ, Betts MG. Do birds help trees grow? An experimental study of the effects of land-use intensification on avian trophic cascades. Ecology 2020; 101:e03018. [PMID: 32078157 DOI: 10.1002/ecy.3018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 12/26/2019] [Accepted: 01/24/2020] [Indexed: 11/09/2022]
Abstract
By regulating populations of herbivores, predators can indirectly influence plant production. However, the factors influencing the strength of this type of trophic cascade are still unclear. We hypothesized that changes to plant community structure would affect the number of avian predators, thereby mediating cascade strength. Using a 4-yr, blocked, split-plot experiment, we independently manipulated both predators (birds) and plants in an early seral managed forest system in western Oregon, USA, and measured abundance across three trophic levels. We applied herbicides, as a surrogate for land-use intensification, to recently clear-cut stands to establish an experimental gradient in plant abundance and species richness, and excluded birds using 28, 225 m2 exclosures. In total, we counted and identified 94,738 arthropods of 141 families in paired control and bird exclosure plots. On average, insectivorous birds reduced arthropod abundance by 16% and plant damage by 14%, and some well-known pests (e.g., Adelges cooleyi) of crop trees (mostly Pseudotsuga menziesii) in our system were reduced by as much as 30%. However, this effect did not translate into a trophic cascade that increased crop-tree growth in the presence of birds. We experimentally reduced plant abundance and diversity by 67% and 55%, respectively, in the most intensive herbicide treatment in relation to untreated controls, but reduced vegetative resources did not change the strength of the direct effect of birds on arthropods or the indirect effect of birds on plants.
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Affiliation(s)
- Scott H Harris
- Department of Forest Ecosystems & Society, Forest Biodiversity Research Network, Oregon State University, Corvallis, Oregon, 97331, USA
| | - Urs G Kormann
- Swiss Ornithological Institute, Seerose 1, CH-6204, Sempach, Switzerland
| | - Thomas D Stokely
- Department of Forest Ecosystems & Society, Forest Biodiversity Research Network, Oregon State University, Corvallis, Oregon, 97331, USA
| | - Jake Verschuyl
- National Council for Air & Stream Improvement, Anacortes, Washington, 98221, USA
| | - Andrew J Kroll
- Weyerhaeuser, 785 N 42nd Street, Springfield, Oregon, 97478, USA
| | - Matthew G Betts
- Department of Forest Ecosystems & Society, Forest Biodiversity Research Network, Oregon State University, Corvallis, Oregon, 97331, USA
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21
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Zvereva EL, Paolucci LN, Kozlov MV. Top-down factors contribute to differences in insect herbivory between saplings and mature trees in boreal and tropical forests. Oecologia 2020; 193:167-176. [PMID: 32314043 PMCID: PMC7235072 DOI: 10.1007/s00442-020-04659-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 04/15/2020] [Indexed: 11/26/2022]
Abstract
Ontogenetic changes in herbivory are generally not consistent with ontogenetic changes in defensive traits of woody plants. This inconsistency suggests that other factors may affect ontogenetic trajectories in herbivory. We tested the hypothesis that top-down factors contribute to differences in foliar losses to insects between juvenile and mature trees in tropical and boreal forests. We used artificial caterpillars made of modelling clay to compare predation rates between saplings and mature trees of two common forest species, Siparuna guianensis in Brazil (tropical site) and Betula pubescens in Finland (boreal site). Leaf area losses to chewing insects in saplings were 2.5-fold higher than in mature trees in both species. Physical plant defences (measured as specific leaf area, SLA) did not differ between saplings and mature trees in the boreal forest, whereas in the tropical forest, SLA was greater in saplings than in mature trees. Attack rates on the model prey by birds were higher in the boreal forest, whereas attack rates by arthropod predators were higher in the tropical forest. Overall, predation rates on model prey were consistently higher on mature trees than on saplings at both sites, but in the boreal site, this pattern was primarily driven by birds, whereas in the tropical site, it was primarily driven by arthropod predators. We conclude that the effect of predation on herbivorous insects may considerably contribute to ontogenetic differences in herbivory, but the relative roles of different predatory groups and of top-down and bottom-up factors may vary between environments.
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Affiliation(s)
- Elena L Zvereva
- Department of Biology, University of Turku, 20014, Turku, Finland.
| | - Lucas N Paolucci
- Setor de Ecologia E Conservação, Departamento de Biologia, Universidade Federal de Lavras, Lavras, CEP: 37200-000, Brazil
- Departamento de Biologia Geral, Universidade Federal de Viçosa, Campus Universitário, Viçosa, MG, CEP: 36570-900, Brazil
| | - Mikhail V Kozlov
- Department of Biology, University of Turku, 20014, Turku, Finland
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22
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Kaunisto KM, Roslin T, Forbes MR, Morrill A, Sääksjärvi IE, Puisto AIE, Lilley TM, Vesterinen EJ. Threats from the air: Damselfly predation on diverse prey taxa. J Anim Ecol 2020; 89:1365-1374. [PMID: 32124439 DOI: 10.1111/1365-2656.13184] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 11/19/2019] [Indexed: 12/21/2022]
Abstract
To understand the diversity and strength of predation in natural communities, researchers must quantify the total amount of prey species in the diet of predators. Metabarcoding approaches have allowed widespread characterization of predator diets with high taxonomic resolution. To determine the wider impacts of predators, researchers should combine DNA techniques with estimates of population size of predators using mark-release-recapture (MRR) methods, and with accurate metrics of food consumption by individuals. Herein, we estimate the scale of predation exerted by four damselfly species on diverse prey taxa within a well-defined 12-ha study area, resolving the prey species of individual damselflies, to what extent the diets of predatory species overlap, and which fraction of the main prey populations are consumed. We identify the taxonomic composition of diets using DNA metabarcoding and quantify damselfly population sizes by MRR. We also use predator-specific estimates of consumption rates, and independent data on prey emergence rates to estimate the collective predation pressure summed over all prey taxa and specific to their main prey (non-biting midges or chironomids) of the four damselfly species. The four damselfly species collectively consumed a prey mass equivalent to roughly 870 (95% CL 410-1,800) g, over 2 months. Each individual consumed 29%-66% (95% CL 9.4-123) of its body weight during its relatively short life span (2.1-4.7 days; 95% CL 0.74-7.9) in the focal population. This predation pressure was widely distributed across the local invertebrate prey community, including 4 classes, 19 orders and c. 140 genera. Different predator species showed extensive overlap in diets, with an average of 30% of prey shared by at least two predator species. Of the available prey individuals in the widely consumed family Chironomidae, only a relatively small proportion (0.76%; 95% CL 0.35%-1.61%) were consumed. Our synthesis of population sizes, per-capita consumption rates and taxonomic distribution of diets identifies damselflies as a comparatively minor predator group of aerial insects. As the next step, we should add estimates of predation by larger odonate species, and experimental removal of odonates, thereby establishing the full impact of odonate predation on prey communities.
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Affiliation(s)
- Kari M Kaunisto
- Zoological Museum, Biodiversity Unit, University of Turku, Turku, Finland
| | - Tomas Roslin
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland
| | - Mark R Forbes
- Department of Biology, Carleton University, Ottawa, ON, Canada
| | - Andre Morrill
- Department of Biology, Carleton University, Ottawa, ON, Canada
| | - Ilari E Sääksjärvi
- Zoological Museum, Biodiversity Unit, University of Turku, Turku, Finland
| | - Anna I E Puisto
- Zoological Museum, Biodiversity Unit, University of Turku, Turku, Finland.,Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland
| | - Thomas M Lilley
- Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - Eero J Vesterinen
- Zoological Museum, Biodiversity Unit, University of Turku, Turku, Finland.,Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland
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23
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Zverev V, Zvereva EL, Kozlov MV. Bird predation does not explain spatial variation in insect herbivory in a forest–tundra ecotone. Polar Biol 2020. [DOI: 10.1007/s00300-020-02633-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AbstractThe contribution of bird predation to the spatial variations in insect herbivory remains imperfectly understood, especially in Arctic ecosystems. We experimentally tested the hypothesis that the differences in insect herbivory between tundra and forest biomes, and between plant life-forms in these biomes, are associated with differences in the intensity of bird predation on defoliating insects. We observed substantial variation in herbivory (0% to 20% of foliage lost) among nine forest, mountain tundra, and lowland tundra sites in the Kola Peninsula (northwestern Russia) and among five woody plant species, but we found no consistent differences in herbivory between biomes and between plant life-forms. Bird attacks on artificial caterpillars were tenfold more frequent in forest than in tundra, while bird exclusion effects on herbivory did not differ between biomes, and the intensities of bird predation measured by these two methods were not correlated. Bird exclusion led to increases in insect herbivory, and this effect was significant in trees and tall shrubs but was not significant in dwarf shrubs in either forest or tundra sites. Bird predation, as measured in bird exclusion experiments, increased with an increase in the level of foliar damage inflicted by insects in forests but not in tundra habitats. We conclude that bird predation generally decreases plant losses to insects in both forest and tundra habitats, but birds are unlikely to shape the spatial patterns of plant losses to insects in Arctic ecosystems.
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24
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Otieno NE, Jacobs SM, Pryke JS. Maize‐field complexity and farming system influence insectivorous birds’ contribution to arthropod herbivore regulation. Biotropica 2019. [DOI: 10.1111/btp.12701] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nickson E. Otieno
- Zoology Department National Museums of Kenya Nairobi Kenya
- Department of Conservation Ecology and Entomology Stellenbosch University, Matieland Stellenbosch South Africa
| | - Shayne M. Jacobs
- Department of Conservation Ecology and Entomology Stellenbosch University, Matieland Stellenbosch South Africa
| | - James S. Pryke
- Department of Conservation Ecology and Entomology Stellenbosch University, Matieland Stellenbosch South Africa
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25
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Gardner CJ, Bicknell JE, Baldwin-Cantello W, Struebig MJ, Davies ZG. Quantifying the impacts of defaunation on natural forest regeneration in a global meta-analysis. Nat Commun 2019; 10:4590. [PMID: 31611554 PMCID: PMC6791894 DOI: 10.1038/s41467-019-12539-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 09/11/2019] [Indexed: 12/02/2022] Open
Abstract
Intact forests provide diverse and irreplaceable ecosystem services that are critical to human well-being, such as carbon storage to mitigate climate change. However, the ecosystem functions that underpin these services are highly dependent on the woody vegetation-animal interactions occurring within forests. While vertebrate defaunation is of growing policy concern, the effects of vertebrate loss on natural forest regeneration have yet to be quantified globally. Here we conduct a meta-analysis to assess the direction and magnitude of defaunation impacts on forests. We demonstrate that real-world defaunation caused by hunting and habitat fragmentation leads to reduced forest regeneration, although manipulation experiments provide contrasting findings. The extirpation of primates and birds cause the greatest declines in forest regeneration, emphasising their key role in maintaining carbon stores, and the need for national and international climate change and conservation strategies to protect forests from defaunation fronts as well as deforestation fronts. The defaunation of vertebrates may disrupt forest functioning through the loss of plant-animal interactions, but impacts on forests remain unquantified. Here the authors show that seed dispersal is a key interaction and defaunation of primates and birds negatively impacts forest regeneration.
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Affiliation(s)
- Charlie J Gardner
- Durrell Institute of Conservation and Ecology (DICE), School of Anthropology and Conservation, University of Kent, Canterbury, Kent, CT2 7NR, UK.
| | - Jake E Bicknell
- Durrell Institute of Conservation and Ecology (DICE), School of Anthropology and Conservation, University of Kent, Canterbury, Kent, CT2 7NR, UK
| | | | - Matthew J Struebig
- Durrell Institute of Conservation and Ecology (DICE), School of Anthropology and Conservation, University of Kent, Canterbury, Kent, CT2 7NR, UK
| | - Zoe G Davies
- Durrell Institute of Conservation and Ecology (DICE), School of Anthropology and Conservation, University of Kent, Canterbury, Kent, CT2 7NR, UK
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26
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Mrazova A, Sam K, Amo L. What do we know about birds' use of plant volatile cues in tritrophic interactions? CURRENT OPINION IN INSECT SCIENCE 2019; 32:131-136. [PMID: 31113625 DOI: 10.1016/j.cois.2019.02.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 02/04/2019] [Accepted: 02/11/2019] [Indexed: 06/09/2023]
Abstract
The first study showing that birds can smell herbivore-induced plant volatiles was published ten years ago. Since then, only 12 studies have been published, showing contradictory results. This review evaluates the role of birds in relation to the crying for help hypothesis and their use of olfactory cues. In accordance with the methodologies used in previous studies, we herein provide a summary of experimental approaches and describe the advantages and disadvantages of experiments conducted in nature versus aviaries. Moreover, we recommend experimental methodologies which lead to a deeper knowledge of the topic, including reflection on the induction of plant defenses and adaptations of birds. Finally, we propose some interesting questions for future research to direct further studies towards a thorough and accurate description of birds' roles in tritrophic interactions.
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Affiliation(s)
- Anna Mrazova
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branisovska 1160/31, 37005 Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic.
| | - Katerina Sam
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branisovska 1160/31, 37005 Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic
| | - Luisa Amo
- Department of Evolutionary Ecology, Museo Nacional de Ciencias Naturales (CSIC), C/ José Gutiérrez Abascal 2, 28006 Madrid, Spain
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27
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Godschalx AL, Rodríguez-Castañeda G, Rasmann S. Contribution of different predator guilds to tritrophic interactions along ecological clines. CURRENT OPINION IN INSECT SCIENCE 2019; 32:104-109. [PMID: 31113621 DOI: 10.1016/j.cois.2019.01.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/19/2018] [Accepted: 01/07/2019] [Indexed: 06/09/2023]
Abstract
The strengths of interactions between plants, herbivores, and predators are predicted to relax with elevation. Despite the fundamental role predators play in tritrophic interactions, high-resolution experimental evidence describing predation across habitat gradients is still scarce in the literature and varies by predator. With this opinion paper, we look at how tritrophic strength of systems including different vertebrate and invertebrate predator guilds changes with elevation. Specifically, we focus on how birds, ants, parasitoids, and nematodes exert top-down pressure as predators and propose ways, in which each group could be better understood through elevational gradient studies. We hope to enrich future perspectives for disentangling the different biotic and abiotic factors underlying predator-mediated trophic interactions in a diversity of habitats.
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Affiliation(s)
- Adrienne L Godschalx
- Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland
| | | | - Sergio Rasmann
- Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland.
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28
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Rubene D, Leidefors M, Ninkovic V, Eggers S, Low M. Disentangling olfactory and visual information used by field foraging birds. Ecol Evol 2019; 9:545-552. [PMID: 30680135 PMCID: PMC6341975 DOI: 10.1002/ece3.4773] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 10/23/2018] [Accepted: 11/01/2018] [Indexed: 11/22/2022] Open
Abstract
Foraging strategies of birds can influence trophic plant-insect networks with impacts on primary plant production. Recent experiments show that some forest insectivorous birds can use herbivore-induced plant volatiles (HIPVs) to locate herbivore-infested trees, but it is unclear how birds combine or prioritize visual and olfactory information when making foraging decisions. Here, we investigated attraction of ground-foraging birds to HIPVs and visible prey in short vegetation on farmland in a series of foraging choice experiments. Birds showed an initial preference for HIPVs when visual information was the same for all choice options (i.e., one experimental setup had all options with visible prey, another setup with hidden prey). However, if the alternatives within an experimental setup included visible prey (without HIPV) in competition with HIPV-only, then birds preferred the visual option over HIPVs. Our results show that olfactory cues can play an important role in birds' foraging choices when visual information contains little variation; however, visual cues are preferred when variation is present. This suggests certain aspects of bird foraging decisions in agricultural habitats are mediated by olfactory interaction mechanisms between birds and plants. We also found that birds from variety of dietary food guilds were attracted to HIPVs; hence, the ability of birds to use plant cues is probably more general than previously thought, and may influence the biological pest control potential of birds on farmland.
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Affiliation(s)
- Diana Rubene
- Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
- Present address:
Department of Crop Production EcologySwedish University of Agricultural SciencesUppsalaSweden
| | - Malin Leidefors
- Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
| | - Velemir Ninkovic
- Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
| | - Sönke Eggers
- Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
| | - Matthew Low
- Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
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29
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Boevé JL, Nyman T, Shinohara A, Schmidt S. Endogenous toxins and the coupling of gregariousness to conspicuousness in Argidae and Pergidae sawflies. Sci Rep 2018; 8:17636. [PMID: 30518939 PMCID: PMC6281571 DOI: 10.1038/s41598-018-35925-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 11/12/2018] [Indexed: 11/25/2022] Open
Abstract
Phytophagous insects tend to be either cryptic and solitary, or brightly colored and gregarious, as a defense against vertebrate predators. Here, we tested whether potent defensive chemicals produced de novo by larvae of Argidae and Pergidae sawflies have influenced the evolutionary relationship between larval appearance and levels of gregariousness. Phylogeny-based correlation analyses indicated only a weak trend for solitary species to be cryptic, and for gregarious ones to be conspicuous. Numerous Argidae were cryptic-solitary or conspicuous-gregarious, whereas most Pergidae were conspicuous-gregarious. Both families also included not truly gregarious but aggregated species, i.e. with individuals more evenly distributed on the host plant. By considering two specific morphological traits, predominant body coloration and contrasting spots on body, each one was (weakly) associated with appearance but none with gregariousness, which reflects the functional relevance of appearance as a whole. Furthermore, Argidae can display alternate appearances during successive larval instars. Finally, an independent contrasts test showed no obvious correlation between two major toxic peptides. Our results point towards diversely combined patterns of linked ecological traits in these insects. By assuming that warning coloration is more warranted against vertebrate than invertebrate predators, we suggest that the occurrence itself of toxins allowed this diversity via differing predator guilds and environmental factors, to which these insects were confronted during evolution.
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Affiliation(s)
- Jean-Luc Boevé
- OD Taxonomy and Phylogeny, Royal Belgian Institute of Natural Sciences, Rue Vautier 29, B-1000, Brussels, Belgium.
| | - Tommi Nyman
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, FI-80101, Joensuu, Finland
- Department of Ecosystems in the Barents Region, Norwegian Institute of Bioeconomy Research, Svanhovd Research Station, NO-9925, Svanvik, Norway
| | - Akihiko Shinohara
- Department of Zoology, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba-shi, Ibaraki, 305-0005, Japan
| | - Stefan Schmidt
- SNSB - Zoologische Staatssammlung München, Münchhausenstr. 21, 81247, Munich, Germany
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30
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Mäntylä E, Kleier S, Lindstedt C, Kipper S, Hilker M. Insectivorous Birds Are Attracted by Plant Traits Induced by Insect Egg Deposition. J Chem Ecol 2018; 44:1127-1138. [PMID: 30417204 DOI: 10.1007/s10886-018-1034-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/03/2018] [Accepted: 10/08/2018] [Indexed: 01/26/2023]
Abstract
Insectivorous birds feed upon all developmental stages of herbivorous insects, including insect eggs if larvae and adults are unavailable. Insect egg deposition on plants can induce plant traits that are subsequently exploited by egg parasitoids searching for hosts. However, it is unknown whether avian predators can also use egg-induced plant changes for prey localization. Here, we studied whether great tits (Parus major) and blue tits (Cyanistes caeruleus) are attracted by traits of the Scots pine (Pinus sylvestris) induced by pine sawfly (Diprion pini) egg deposition. We chose this plant - insect system because sawfly egg deposition on pine needles is known to locally and systemically induce a change in pine volatile organic compounds (VOCs), and tits are known to prey upon sawfly eggs. In dual choice laboratory experiments, we simultaneously offered the birds an egg-free control branch and a systemically egg-induced branch. Significantly more birds visited the egg-induced branch first. We confirmed by GC-MS analyses that systemically egg-induced branches released more (E)-β-farnesene compared to control branches. Spectrophotometric analyses showed that control branches reflected more light than egg-induced branches throughout the avian visual range. Although a discrimination threshold model for blue tits suggests that the birds are poor at discriminating this visual difference, the role of visual stimuli in attracting the birds to egg-induced pines cannot be discounted. Our study shows, for the first time, that egg-induced odorous and/or visual plant traits can help birds to locate insect eggs without smelling or seeing those eggs.
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Affiliation(s)
- Elina Mäntylä
- Applied Zoology/Animal Ecology, Institute of Biology, Freie Universität Berlin, Haderslebener Str. 9, DE-12163, Berlin, Germany. .,Institute of Entomology, Biology Centre of the Czech Academy of Sciences, Branišovská 31, CZ-37005, České Budějovice, Czech Republic.
| | - Sven Kleier
- Applied Zoology/Animal Ecology, Institute of Biology, Freie Universität Berlin, Haderslebener Str. 9, DE-12163, Berlin, Germany
| | - Carita Lindstedt
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental Sciences, University of Jyväskylä, P.O. Box 35, FI-40014, Jyväskylä, Finland
| | - Silke Kipper
- Animal Behaviour, Institute of Biology, Freie Universität Berlin, Takustr. 6, DE-14195, Berlin, Germany.,Chair of Zoology, Technische Universität München, Liesel-Beckmann-Str. 4, DE-85350, Freising, Germany
| | - Monika Hilker
- Applied Zoology/Animal Ecology, Institute of Biology, Freie Universität Berlin, Haderslebener Str. 9, DE-12163, Berlin, Germany
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31
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Landscape-level bird loss increases the prevalence of honeydew-producing insects and non-native ants. Oecologia 2018; 188:1263-1272. [PMID: 30367244 PMCID: PMC6244808 DOI: 10.1007/s00442-018-4273-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 10/15/2018] [Indexed: 11/30/2022]
Abstract
Bird exclusion experiments consistently show that birds exhibit strong top-down control of arthropods, including ants and the honeydew-producing insects (HPIs) that they tend. However, it remains unclear whether the results of these small-scale bird exclosure experiments can be extrapolated to larger spatial scales. In this study, we use a natural bird removal experiment to compare the prevalence of ants and HPIs between Guam, an island whose bird community has been extirpated since the 1980s due to the introduction of the brown tree snake, and two nearby islands (Rota and Saipan) that have more intact bird assemblages. Consistent with smaller-scale bird exclosure experiments, we show that (1) forest trees from Guam are significantly more likely to host HPIs than trees from Saipan and (2) ants are nearly four times as abundant on Guam than on both Saipan and Rota. The prevalence of HPIs varied slightly based on tree species identity, although these effects were not as strong as island-level effects associated with bird loss. Ant community composition differed between Guam and the other two islands. These results corroborate past observational studies showing increased spider densities on Guam and suggest that trophic changes associated with landscape-level bird extirpation may also involve alterations in the abundance of ants and HPIs. This study also provides a clear example of the strong indirect effects that invasive species can have on natural food webs.
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32
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Godoy-Güinao J, Díaz IA, Celis-Diez JL. Confirmation of arboreal habits in Dromiciops gliroides
: a key role in Chilean Temperate Rainforests. Ecosphere 2018. [DOI: 10.1002/ecs2.2424] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Javier Godoy-Güinao
- Laboratorio de Biodiversidad y Ecología del Dosel; Instituto de Conservación; Biodiversidad y Territorio; Universidad Austral de Chile; Casilla 567, Valdivia Chile
- Fundación Mar Adentro; Av. El Golf 99, of. 901 Santiago Chile
| | - Iván A. Díaz
- Laboratorio de Biodiversidad y Ecología del Dosel; Instituto de Conservación; Biodiversidad y Territorio; Universidad Austral de Chile; Casilla 567, Valdivia Chile
- Fundación Mar Adentro; Av. El Golf 99, of. 901 Santiago Chile
| | - Juan L. Celis-Diez
- Escuela de Agronomía; Pontificia Universidad Católica de Valparaíso; Quillota Chile
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33
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Pejchar L, Clough Y, Ekroos J, Nicholas KA, Olsson O, Ram D, Tschumi M, Smith HG. Net Effects of Birds in Agroecosystems. Bioscience 2018. [DOI: 10.1093/biosci/biy104] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Liba Pejchar
- Associate professor of conservation biology at Colorado State University, in Fort Collins
| | - Yann Clough
- Professor of environmental sciences at Lund University, in Lund, Sweden
| | - Johan Ekroos
- Research scientist at the Centre for Environmental and Climate Research, at Lund University, in Lund, Sweden
| | - Kimberly A Nicholas
- Associate professor of sustainability science at the Lund University Centre for Sustainability Studies, in Lund, Sweden
| | - Ola Olsson
- Associate professor and the head of the Biodiversity Unit, Department of Biology at Lund University
| | - Dafne Ram
- Department of Biology at Lund University
| | | | - Henrik G Smith
- Professor of animal ecology and director of the Centre for Environmental and Climate Research at Lund University
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34
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Tschumi M, Ekroos J, Hjort C, Smith HG, Birkhofer K. Rodents, not birds, dominate predation-related ecosystem services and disservices in vertebrate communities of agricultural landscapes. Oecologia 2018; 188:863-873. [PMID: 30187116 PMCID: PMC6208704 DOI: 10.1007/s00442-018-4242-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/03/2018] [Indexed: 11/25/2022]
Abstract
To understand the relationship between conservation measures and agricultural yields, we need to know the contributions of organisms to both ecosystem services and disservices. We studied the activity and contribution of birds and mammals to intermediate ecosystem services (predation of weed seeds or invertebrate pests) and disservices (predation of crop seeds or beneficial invertebrates) in southern Sweden between June and November 2016. We measured seed and invertebrate predation rates using trays placed in front of 32 wildlife cameras in 16 cereal fields with a local habitat contrast (8 fields adjacent to another crop field and 8 fields adjacent to a semi-natural grassland) and along a landscape heterogeneity gradient (amount of semi-natural grassland). Both activity and predation were dominated by small mammals (mainly rodents), yet only a few species contributed to predation services and disservices according to camera records. Small mammal activity and predation varied considerably over time. Small mammal activity was significantly higher at trays with crop seeds or beneficial invertebrate prey compared to trays with pest prey, and crop seed predation by small mammals was significantly higher than weed seed predation. In contrast, bird activity and predation did not differ significantly between resource types, but varied over time depending on the habitat contrast. Predation of animal prey by birds was highest after cereal harvest, independent of habitat contrast. Our study highlights that birds and in particular rodents provide important intermediate ecosystem services, but also disservices, which fluctuate strongly in intensity over time.
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Affiliation(s)
- Matthias Tschumi
- Department of Biology, Lund University, Lund, Sweden.
- Ecology Department, Swiss Ornithological Institute, Sempach, Switzerland.
| | - Johan Ekroos
- Centre for Environmental and Climate Research, Lund University, Lund, Sweden
| | - Cecilia Hjort
- Department of Biology, Lund University, Lund, Sweden
| | - Henrik G Smith
- Department of Biology, Lund University, Lund, Sweden
- Centre for Environmental and Climate Research, Lund University, Lund, Sweden
| | - Klaus Birkhofer
- Department of Biology, Lund University, Lund, Sweden
- Department of Ecology, Brandenburg University of Technology, Cottbus, Germany
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35
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Gunnarsson B, Wallin J, Klingberg J. Predation by avian insectivores on caterpillars is linked to leaf damage on oak (Quercus robur). Oecologia 2018; 188:733-741. [PMID: 30116876 PMCID: PMC6208694 DOI: 10.1007/s00442-018-4234-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 07/23/2018] [Indexed: 11/04/2022]
Abstract
Birds that are foraging in tree canopies can cause a substantial decrease in arthropod numbers. Trees may benefit from avian insectivores attacking insect herbivores. In a field study, we tested whether the intensity of bird predation on caterpillars is linked quantitatively to leaf damage caused by insect herbivores, a hypothesized relationship that previously was poorly investigated. Artificial caterpillars were placed in the lower part of oak trees (Quercus robur) in urban and suburban sites across the city of Gothenburg, Sweden. Two days later, we recorded the survival: the pooled predation rate was 11.5% (5.7% day−1). Mean predation rate per tree was 10.4%. Mean leaf damage, i.e. leaf area eaten by insect herbivores, per tree was 5.7% but there was large variation between trees. We found a significant negative relationship between survival probability of caterpillars and leaf damage in an analysis using a mixed model logistic regression. This suggests that caterpillars are at high risk of bird attacks in trees with a high degree of leaf damage and avian insectivores may increase the foraging effort in the foliage of such oak trees. Our findings concerning the quantitative relationship between the predator–prey interactions and plant damage suggested tentatively that the survival probability of caterpillars decreases rapidly at 15–20% leaf damage in lower part of oak canopies. Furthermore, our findings add credence to the idea of using artificial caterpillars as a means to obtain standardized comparisons of predation rates in various habitats.
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Affiliation(s)
- Bengt Gunnarsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, 405 30, Göteborg, Sweden.
| | - Jonas Wallin
- Department of Statistics, Lund University, Lund, Sweden
| | - Jenny Klingberg
- Gothenburg Botanical Garden, Gothenburg Global Biodiversity Centre, Göteborg, Sweden
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Redlich S, Martin EA, Wende B, Steffan-Dewenter I. Landscape heterogeneity rather than crop diversity mediates bird diversity in agricultural landscapes. PLoS One 2018; 13:e0200438. [PMID: 30067851 PMCID: PMC6070203 DOI: 10.1371/journal.pone.0200438] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 06/26/2018] [Indexed: 01/10/2023] Open
Abstract
Crop diversification has been proposed as farm management tool that could mitigate the externalities of conventional farming while reducing productivity-biodiversity trade-offs. Yet evidence for the acclaimed biodiversity benefits of landscape-level crop diversity is ambiguous. Effects may strongly depend on spatial scale and the level of landscape heterogeneity (e.g. overall habitat diversity). At the same time, contrasting within-taxon responses obscure benefits to specific functional groups (i.e. species with shared characteristics or requirements) if studied at the community level. The objectives of this study were to 1) disentangle the relative effects of crop diversity and landscape heterogeneity on avian species richness across five spatial scales ranging from 250 to 3000 m radii around focal winter wheat fields; and 2) assess whether functional groups (feeding guild, conservation status, habitat preference, nesting behaviour) determine the strength and direction of responses to crop diversity and landscape heterogeneity. In central Germany, 14 landscapes were selected along independent gradients of crop diversity (annual arable crops) and landscape heterogeneity. Bird species richness in each landscape was estimated using four point counts throughout the breeding season. We found no effects of landscape-level crop diversity on bird richness and functional groups. Instead, landscape heterogeneity was strongly associated with increased total bird richness across all spatial scales. In particular, insect-feeding and non-farmland birds were favoured in heterogeneous landscapes, as were species not classified as endangered or vulnerable on the regional Red List. Crop-nesting farmland birds, however, were less species-rich in these landscapes. Accordingly, crop diversification may be less suitable for conserving avian diversity and associated ecosystem services (e.g. biological pest control), although confounding interactions with management intensity need yet to be confirmed. In contrast, enhancement of landscape heterogeneity by increasing perennial habitat diversity, reducing field sizes and the amount of cropland has the potential to benefit overall bird richness. Specialist farmland birds, however, may require more targeted management approaches.
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Affiliation(s)
- Sarah Redlich
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
- * E-mail:
| | - Emily A. Martin
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Beate Wende
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Ingolf Steffan-Dewenter
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
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Zhang J, Qian H, Girardello M, Pellissier V, Nielsen SE, Svenning JC. Trophic interactions among vertebrate guilds and plants shape global patterns in species diversity. Proc Biol Sci 2018; 285:20180949. [PMID: 30051871 PMCID: PMC6083253 DOI: 10.1098/rspb.2018.0949] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 06/29/2018] [Indexed: 11/12/2022] Open
Abstract
Trophic interactions play critical roles in structuring biotic communities. Understanding variation in trophic interactions among systems provides important insights into biodiversity maintenance and conservation. However, the relative importance of bottom-up versus top-down trophic processes for broad-scale patterns in biodiversity is poorly understood. Here, we used global datasets on species richness of vascular plants, mammals and breeding birds to evaluate the role of trophic interactions in shaping large-scale diversity patterns. Specifically, we used non-recursive structural equation models to test for top-down and bottom-up forcing of global species diversity patterns among plants and trophic guilds of mammals and birds (carnivores, invertivores and herbivores), while accounting for extrinsic environmental drivers. The results show that trophic linkages emerged as being more important to explaining species richness than extrinsic environmental drivers. In particular, there were strong, positive top-down interactions between mammal herbivores and plants, and moderate to strong bottom-up and/or top-down interactions between herbivores/invertivores and carnivores. Estimated trophic interactions for separate biogeographical regions were consistent with global patterns. Our findings demonstrate that, after accounting for environmental drivers, large-scale species richness patterns in plant and vertebrate taxa consistently support trophic interactions playing a major role in shaping global patterns in biodiversity. Furthermore, these results suggest that top-down forces often play strong complementary roles relative to bottom-up drivers in structuring biodiversity patterns across trophic levels. These findings underscore the importance of integrating trophic forcing mechanisms into studies of biodiversity patterns.
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Affiliation(s)
- Jian Zhang
- Tiantong National Station for Forest Ecosystem Research & Center for Global Change and Ecological Forecasting, School of Ecological and Environmental Science, East China Normal University, Shanghai 200241, People's Republic of China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, People's Republic of China
- Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Hong Qian
- Research and Collections Center, Illinois State Museum, 1011 East Ash Street, Springfield, IL 62703, USA
| | - Marco Girardello
- Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Vincent Pellissier
- Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Scott E Nielsen
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada T6G 2H1
| | - Jens-Christian Svenning
- Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Aarhus University, 8000 Aarhus C, Denmark
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38
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Nyffeler M, Şekercioğlu ÇH, Whelan CJ. Insectivorous birds consume an estimated 400-500 million tons of prey annually. THE SCIENCE OF NATURE - NATURWISSENSCHAFTEN 2018; 105:47. [PMID: 29987431 PMCID: PMC6061143 DOI: 10.1007/s00114-018-1571-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 06/08/2018] [Accepted: 06/11/2018] [Indexed: 11/20/2022]
Abstract
In this paper, we present an estimate of the predation impact of the global population of insectivorous birds based on 103 (for the most part) published studies of prey consumption (kg ha-1 season-1) of insectivorous birds in seven biome types. By extrapolation-taking into account the global land cover of the various biomes-an estimate of the annual prey consumption of the world's insectivorous birds was obtained. We estimate the prey biomass consumed by the world's insectivorous birds to be somewhere between 400 and 500 million metric tons year-1, but most likely at the lower end of this range (corresponding to an energy consumption of ≈ 2.7 × 1018 J year-1 or ≈ 0.15% of the global terrestrial net primary production). Birds in forests account for > 70% of the global annual prey consumption of insectivorous birds (≥ 300 million tons year-1), whereas birds in other biomes (savannas and grasslands, croplands, deserts, and Arctic tundra) are less significant contributors (≥ 100 million tons year-1). Especially during the breeding season, when adult birds feed their nestlings protein-rich prey, large numbers of herbivorous insects (i.e., primarily in the orders Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, and Orthoptera) supplemented by spiders are captured. The estimates presented in this paper emphasize the ecological and economic importance of insectivorous birds in suppressing potentially harmful insect pests on a global scale-especially in forested areas.
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Affiliation(s)
- Martin Nyffeler
- Section of Conservation Biology, Department of Environmental Sciences, University of Basel, CH-4056, Basel, Switzerland.
| | - Çağan H Şekercioğlu
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA
- College of Sciences, Koç University, Rumelifeneri, Istanbul, Sariyer, Turkey
| | - Christopher J Whelan
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, 60607, USA
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Bosc C, Roets F, Hui C, Pauw A. Interactions among predators and plant specificity protect herbivores from top predators. Ecology 2018; 99:1602-1609. [PMID: 29727477 DOI: 10.1002/ecy.2377] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/21/2018] [Accepted: 04/05/2018] [Indexed: 11/10/2022]
Abstract
The worldwide loss of top predators from natural and agricultural systems has heightened the need to understand how important they are in controlling herbivore abundance. The effect of top predators on herbivore species is likely to depend on (1) the importance of the consumption of intermediate predators by top predators (intra-guild predation; IGP), but also on (2) plant specificity by herbivores, because specialists may defend themselves better (enemy-free space; EFS). Insectivorous birds, as top predators, are generally known to effectively control herbivorous insects, despite also consuming intermediate predators such as spiders, but how this effect varies among herbivore species in relation to the cascading effects of IGP and EFS is not known. To explore this, we excluded birds from natural fynbos vegetation in South Africa using large netted cages and recorded changes in abundance relative to control plots for 199 plant-dwelling intermediate predator and 341 herbivore morpho-species that varied in their estimated plant specificity. We found a strong negative effect of birds on the total abundance of all intermediate predators, with especially clear effects on spiders (strong IGP). In contrast with previous studies, which document a negative effect of birds on herbivores, we found an overall neutral effect of birds on herbivore abundance, but the effect varied among species: some species were negatively affected by birds, suggesting that they were mainly consumed by birds, whereas others, likely released from spiders by IGP, were positively affected. Some species were also effectively neutrally affected by birds. These tended to be more specialized to plants compared to the other species, which may imply that some plant specialists benefited from protection provided by EFS from both birds and spiders. These results suggest that the response of herbivore species to top predators may depend on cascading effects of interactions among predators and on their degree of plant specificity.
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Affiliation(s)
- Christopher Bosc
- Department of Botany and Zoology, Stellenbosch University, Matieland, 7602, South Africa
| | - Francois Roets
- Department of Conservation Ecology and Entomology, Stellenbosch University, Matieland, 7602, South Africa
| | - Cang Hui
- Centre for Invasion Biology, Department of Mathematical Sciences, Stellenbosch University, Matieland, 7602, South Africa
| | - Anton Pauw
- Department of Botany and Zoology, Stellenbosch University, Matieland, 7602, South Africa
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40
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The effects of overwintering and habitat type on body condition and locomotion of the wolf spider Pardosa alacris. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2018. [DOI: 10.1016/j.actao.2018.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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41
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Bagchi R, Brown LM, Elphick CS, Wagner DL, Singer MS. Anthropogenic fragmentation of landscapes: mechanisms for eroding the specificity of plant-herbivore interactions. Oecologia 2018; 187:521-533. [PMID: 29560512 DOI: 10.1007/s00442-018-4115-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 03/11/2018] [Indexed: 11/26/2022]
Abstract
Reduced ecological specialization is an emerging, general pattern of ecological networks in fragmented landscapes. In plant-herbivore interactions, reductions in dietary specialization of herbivore communities are consistently associated with fragmented landscapes, but the causes remain poorly understood. We propose several hypothetical bottom-up and top-down mechanisms that may reduce the specificity of plant-herbivore interactions. These include empirically plausible applications and extensions of theory based on reduced habitat patch size and isolation (considered jointly), and habitat edge effects. Bottom-up effects in small, isolated habitat patches may limit availability of suitable hostplants, a constraint that increases with dietary specialization. Poor hostplant quality due to inbreeding in such fragments may especially disadvantage dietary specialist herbivores even when their hostplants are present. Size and isolation of habitat patches may change patterns of predation of herbivores, but whether such putative changes are associated with herbivore dietary specialization should depend on the mobility, size, and diet breadth of predators. Bottom-up edge effects may favor dietary generalist herbivores, yet top-down edge effects may favor dietary specialists owing to reduced predation. An increasingly supported edge effect is trophic ricochets generated by large grazers/browsers, which remove key hostplant species of specialist herbivores. We present empirical evidence that greater deer browsing in small forest fragments disproportionately reduces specialist abundances in lepidopteran assemblages in northeastern USA. Despite indirect evidence for these mechanisms, they have received scant direct testing with experimental approaches at a landscape scale. Identifying their relative contributions to reduced specificity of plant-herbivore interactions in fragmented landscapes is an important research goal.
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Affiliation(s)
- Robert Bagchi
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Road Unit 3043, Storrs, CT, 06260-3043, USA.
| | - Leone M Brown
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Road Unit 3043, Storrs, CT, 06260-3043, USA
| | - Chris S Elphick
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Road Unit 3043, Storrs, CT, 06260-3043, USA
| | - David L Wagner
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Road Unit 3043, Storrs, CT, 06260-3043, USA
| | - Michael S Singer
- Department of Biology, Wesleyan University, Middletown, CT, 06459, USA
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42
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Saavedra I, Amo L. Insectivorous birds eavesdrop on the pheromones of their prey. PLoS One 2018; 13:e0190415. [PMID: 29414994 PMCID: PMC5802436 DOI: 10.1371/journal.pone.0190415] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Accepted: 12/14/2017] [Indexed: 12/23/2022] Open
Abstract
Chemical cues play a fundamental role in mate attraction and mate choice. Lepidopteran females, such as the winter moth (Operophtera brumata), emit pheromones to attract males in the reproductive period. However, these chemical cues could also be eavesdropped by predators. To our knowledge, no studies have examined whether birds can detect pheromones of their prey. O. brumata adults are part of the winter diet of some insectivorous tit species, such as the great tit (Parus major) and blue tit (Cyanistes caeruleus). We performed a field experiment aimed to disentangle whether insectivorous birds can exploit the pheromones emitted by their prey for prey location. We placed artificial larvae and a dispenser on branches of Pyrenean oak trees (Quercus pyrenaica). In half of the trees we placed an O. brumata pheromone dispenser and in the other half we placed a control dispenser. We measured the predation rate of birds on artificial larvae. Our results show that more trees had larvae with signs of avian predation when they contained an O. brumata pheromone than when they contained a control dispenser. Furthermore, the proportion of artificial larvae with signs of avian predation was greater in trees that contained the pheromone than in control trees. Our results indicate that insectivorous birds can exploit the pheromones emitted by moth females to attract males, as a method of prey detection. These results highlight the potential use of insectivorous birds in the biological control of insect pests.
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Affiliation(s)
- Irene Saavedra
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), C/ José Gutiérrez Abascal, Madrid, Spain
- * E-mail:
| | - Luisa Amo
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), C/ José Gutiérrez Abascal, Madrid, Spain
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43
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Manning P, Beynon SA, Lewis OT. Quantifying immediate and delayed effects of anthelmintic exposure on ecosystem functioning supported by a common dung beetle species. PLoS One 2017; 12:e0182730. [PMID: 28800623 PMCID: PMC5553719 DOI: 10.1371/journal.pone.0182730] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/24/2017] [Indexed: 11/18/2022] Open
Abstract
Dung beetles (Coleoptera: Scarabaeoidea) support numerous ecosystem functions in livestock-grazed pastures. Exposure to veterinary anthelmintic residues in livestock dung can have lethal and sublethal effects on dung beetles, and can reduce rates of dung removal, but the immediate and longer-term consequences for other dung beetle mediated functions have rarely been studied. We investigated the consequences of anthelmintic exposure on survival of the dung beetle Aphodius fossor and its delivery of four ecosystems functions that underpin pasture production: dung removal, soil fauna feeding activity, primary productivity, and reduction of soil compaction. We tested whether anthelmintic exposure had immediate or delayed effects on these functions individually and simultaneously (i.e., ecosystem multifunctionality). We found no evidence that ivermectin residues had a lethal effect on adult beetles. For dung removal, we found a significant interaction between the timing of exposure and functioning: while dung removal was impaired by concurrent exposure to high levels of ivermectin, functioning was unaffected when beetles that had been exposed previously to the same concentration of anthelmintic later interacted with untreated dung. Other ecosystem functions were not affected significantly by anthelmintic exposure, and there was no evidence to suggest any persistent impact of anthelmintic exposure on ecosystem multifunctionality. While anthelmintic residues remain a significant threat to dung beetle populations, for adult beetles, we found no evidence that residues have detrimental consequences for ecosystem functioning beyond the immediate point of exposure.
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Affiliation(s)
- Paul Manning
- Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada
- University of Oxford, Department of Zoology, Oxford, United Kingdom
- Dr Beynon’s Bug Farm, Lower Harglodd Farm, St. David’s, Pembrokeshire, United Kingdom
- * E-mail:
| | - Sarah A. Beynon
- University of Oxford, Department of Zoology, Oxford, United Kingdom
- Dr Beynon’s Bug Farm, Lower Harglodd Farm, St. David’s, Pembrokeshire, United Kingdom
| | - Owen T. Lewis
- University of Oxford, Department of Zoology, Oxford, United Kingdom
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44
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Benkman CW. The Natural History of the South Hills Crossbill in Relation to Its Impending Extinction. Am Nat 2016; 188:589-601. [PMID: 27860509 DOI: 10.1086/688904] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Increasingly, the species that we discover will be uncommon, area restricted, and vulnerable to extinction. I describe the natural history of a newly discovered seed-eating finch from the Rocky Mountain region, the South Hills crossbill (Loxia curvirostra complex). It relies on seeds in the closed cones of the fire-adapted Rocky Mountain lodgepole pine (Pinus contorta latifolia) and is found only in the higher elevations of two small mountain ranges in southern Idaho. Here crossbills and pine are engaged in a coevolutionary arms race. Although most of the seeds remain secured within the cones for decades until the heat of a stand-replacing fire causes the cone scales to separate, seeds become accessible to crossbills slowly as cones weather and gaps form between some of the scales. However, hot days (≥32°C), especially four or more hot days, seem to mimic the effect of fire, apparently causing the immediate release of a fraction of the seeds. Such events caused a 20% annual decline in crossbills that lasted up to 4 years and an 80% decline in the population between 2003 and 2011. This is an example of a novel trophic mismatch between a consumer and its resource caused by a shift in the phenology of the resource arising from climate change. Not only do these phenological shifts have the potential to cause seed consumers to decline, these shifts are also likely to cause reduced recruitment of the plants. The South Hills crossbill is especially vulnerable and will likely go extinct this century before lodgepole pine is extirpated from the South Hills.
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Barbaro L, Rusch A, Muiruri EW, Gravellier B, Thiery D, Castagneyrol B. Avian pest control in vineyards is driven by interactions between bird functional diversity and landscape heterogeneity. J Appl Ecol 2016. [DOI: 10.1111/1365-2664.12740] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Luc Barbaro
- Biogeco; INRA; Univ. Bordeaux; F-33610 Cestas France
- Dynafor; INPT; EI Purpan; INRA; Univ. Toulouse; F-31320 Auzeville France
| | - Adrien Rusch
- SAVE; Bordeaux Sciences Agro; INRA; F-33140 Villenave d'Ornon France
| | - Evalyne W. Muiruri
- School of Biological Sciences; Royal Holloway University of London; Egham Surrey TW20 0EX UK
| | | | - Denis Thiery
- SAVE; Bordeaux Sciences Agro; INRA; F-33140 Villenave d'Ornon France
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Crisol-Martínez E, Moreno-Moyano LT, Wormington KR, Brown PH, Stanley D. Using Next-Generation Sequencing to Contrast the Diet and Explore Pest-Reduction Services of Sympatric Bird Species in Macadamia Orchards in Australia. PLoS One 2016; 11:e0150159. [PMID: 26930484 PMCID: PMC4773005 DOI: 10.1371/journal.pone.0150159] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 02/10/2016] [Indexed: 01/30/2023] Open
Abstract
Worldwide, avian communities inhabiting agro-ecosystems are threatened as a consequence of agricultural intensification. Unravelling their ecological role is essential to focus conservation efforts. Dietary analysis can elucidate bird-insect interactions and expose avian pest-reduction services, thus supporting avian conservation. In this study, we used next-generation sequencing to analyse the dietary arthropod contents of 11 sympatric bird species foraging in macadamia orchards in eastern Australia. Across all species and based on arthropod DNA sequence similarities ≥98% with records in the Barcode of Life Database, 257 operational taxonomy units were assigned to 8 orders, 40 families, 90 genera and 89 species. These taxa included 15 insect pests, 5 of which were macadamia pests. Among the latter group, Nezara viridula (Pentatomidae; green vegetable bug), considered a major pest, was present in 23% of all faecal samples collected. Results also showed that resource partitioning in this system is low, as most bird species shared large proportion of their diets by feeding primarily on lepidopteran, dipteran and arachnids. Dietary composition differed between some species, most likely because of differences in foraging behaviour. Overall, this study reached a level of taxonomic resolution never achieved before in the studied species, thus contributing to a significant improvement in the avian ecological knowledge. Our results showed that bird communities prey upon economically important pests in macadamia orchards. This study set a precedent by exploring avian pest-reduction services using next-generation sequencing, which could contribute to the conservation of avian communities and their natural habitats in agricultural systems.
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Affiliation(s)
- Eduardo Crisol-Martínez
- School of Medical and Applied Sciences, Central Queensland University, Rockhampton, Queensland, Australia
| | | | - Kevin R. Wormington
- School of Medical and Applied Sciences, Central Queensland University, Rockhampton, Queensland, Australia
| | - Philip H. Brown
- School of Medical and Applied Sciences, Central Queensland University, Rockhampton, Queensland, Australia
- Institute for Future Farming Systems, Central Queensland University, Rockhampton, Queensland, Australia
| | - Dragana Stanley
- School of Medical and Applied Sciences, Central Queensland University, Rockhampton, Queensland, Australia
- Institute for Future Farming Systems, Central Queensland University, Rockhampton, Queensland, Australia
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47
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Oehm J, Thalinger B, Mayr H, Traugott M. Maximizing dietary information retrievable from carcasses of Great Cormorants Phalacrocorax carbo using a combined morphological and molecular analytical approach. THE IBIS 2016; 158:51-60. [PMID: 26877544 PMCID: PMC4739555 DOI: 10.1111/ibi.12337] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 11/03/2015] [Indexed: 05/11/2023]
Abstract
Avian carcasses can provide important information on the trophic ecology of birds. Usually, the number of carcasses available for examination is limited and therefore it is important to gain as much dietary information per specimen as possible. In piscivorous birds and raptors, the stomach has been the primary source of dietary information, whereas the gut (intestine) has so far been neglected as it usually contains only a few morphologically identifiable hard parts of prey. Molecular approaches have the potential to retrieve dietary information from the gut, although this has not yet been verified. As well as identifying the prey, it is important to estimate any secondary predation to avoid food web errors in dietary analyses. The assignment of accidentally consumed prey is notoriously difficult regardless of the prey identification approach used. In the present study, morphological and molecular analyses were, for the first time, combined to maximize the dietary information retrievable from the complete digestive tract of Great Cormorants Phalacrocorax carbo sinensis. Moreover, a novel approach based on predator-prey size ratios was applied to these piscivorous birds to minimize the number of samples that might contain secondarily predated prey. The stomach contents of the examined birds were found to provide the most dietary information when morphological and molecular analyses were used in combination. However, compared with the morphological approach, the molecular analysis increased the number of fish species detected by 39%. The molecular approach also permitted the identification of fish DNA in the Cormorant guts. Predator-prey size ratios derived from morphological analysis of fish hard parts can reduce the incidence of potential confounding influence of secondarily predated prey by 80%. Our findings demonstrate that a combination of morphological and molecular approaches maximizes the trophic information retrievable from bird carcasses.
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Affiliation(s)
- Johannes Oehm
- Institute of Ecology University of Innsbruck Technikerstraße 25 6020 Innsbruck Austria
| | - Bettina Thalinger
- Institute of Ecology University of Innsbruck Technikerstraße 25 6020 Innsbruck Austria
| | - Hannes Mayr
- Institute of Ecology University of Innsbruck Technikerstraße 25 6020 Innsbruck Austria
| | - Michael Traugott
- Institute of Ecology University of Innsbruck Technikerstraße 25 6020 Innsbruck Austria
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48
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Abstract
Arthropod herbivory induces the emission of plant volatiles that can be used by natural enemies of the herbivores to find their prey. Recently it has been shown that insectivorous birds also use these volatiles to locate their prey. Results of a previous study showed that birds with experience in foraging for caterpillars in trees were able to discriminate between caterpillar-infested and uninfested trees, even in the absence of caterpillars or their damage on leaves. Here, we tested whether the attraction to caterpillar-infested trees is exhibited in birds naïve with respect to finding caterpillars on trees. Results show that naïve great tits (Parus major) were not attracted to infested trees, when they could not see the larvae or their feeding damage. Naïve birds cannot discriminate between caterpillar-infested and uninfested trees. Therefore, the attraction to caterpillar-infested trees does not seem to be innate in great tits, and may be acquired through learning.
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Affiliation(s)
- Luisa Amo
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands
- Department of Evolutionary Ecology, Museo Nacional de Ciencias Naturales (CSIC), C/ José Gutiérrez Abascal 2, 28006 Madrid, Spain
| | - Marcel Dicke
- Laboratory of Entomology, Wageningen University, P.O. Box 16, 6700 AA Wageningen, The Netherlands
| | - Marcel E. Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands
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49
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Koski TM, Laaksonen T, Mäntylä E, Ruuskanen S, Li T, Girón-Calva PS, Huttunen L, Blande JD, Holopainen JK, Klemola T. Do Insectivorous Birds use Volatile Organic Compounds from Plants as Olfactory Foraging Cues? Three Experimental Tests. Ethology 2015. [DOI: 10.1111/eth.12426] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Toni Laaksonen
- Section of Ecology; Department of Biology; University of Turku; Turku Finland
| | - Elina Mäntylä
- Section of Ecology; Department of Biology; University of Turku; Turku Finland
| | - Suvi Ruuskanen
- Section of Ecology; Department of Biology; University of Turku; Turku Finland
| | - Tao Li
- Department of Environmental Science; University of Eastern Finland; Kuopio Finland
| | | | - Liisa Huttunen
- Section of Ecology; Department of Biology; University of Turku; Turku Finland
| | - James D. Blande
- Department of Environmental Science; University of Eastern Finland; Kuopio Finland
| | - Jarmo K. Holopainen
- Department of Environmental Science; University of Eastern Finland; Kuopio Finland
| | - Tero Klemola
- Section of Ecology; Department of Biology; University of Turku; Turku Finland
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Wu PC, Shaner PJL. Trophic cascade effects of avian predation on a willow in an urban wetland. Oecologia 2015; 180:293-303. [PMID: 26391382 DOI: 10.1007/s00442-015-3448-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 09/01/2015] [Indexed: 10/23/2022]
Abstract
Trophic cascades play a crucial role in ecosystem functioning. In this study, we tested the effects of avian predation on willows (Salix warburgii) and associated arthropods in an urban wetland. We excluded birds by netting around willow branches for 20 months from September-November 2010 to June 2012. We compared the leaf count, leaf area, leaf biomass, bud count, catkin (flower) count and herbivory from pairs of bird-exclusion and no-exclusion branches on 11 trees. Simultaneously, we compared herbivorous and predatory arthropod abundances associated with bird-exclusion and no-exclusion branches. Another nine trees were used as reference branches to assess whether the bird exclusion impacted other branches of the same trees (i.e., no-exclusion branches). Bird exclusion resulted in increased herbivory 1 year after the treatment, followed by a reduced leaf count, leaf area, leaf biomass, bud count and catkin count in the second year. The bird-exclusion branches exhibited greater spider abundance than the no-exclusion branches. However, herbivorous arthropod abundances were similar between the branch types. The reference branches had similar values in all plant traits and for all arthropod abundances to those of the no-exclusion branches. This study demonstrated the branch-level effects of trophic cascades on willows via the exclusion of birds and a resulting reduction in herbivory. However, whether and how the arthropods mediate such effects require further investigation. This study adds to the limited empirical data demonstrating the effects of trophic cascades on plant reproduction. Our findings highlight the importance of bird conservation in urban wetlands.
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Affiliation(s)
- Pei-Chen Wu
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingzhou Road, Taipei, Taiwan
| | - Pei-Jen L Shaner
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingzhou Road, Taipei, Taiwan.
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