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Sivault E, Kollross J, Jorge LR, Finnie S, Diez-Méndez D, Fernandez Garzon S, Maraia H, Lenc J, Libra M, Murakami M, Nakaji T, Nakamura M, Sreekar R, Sam L, Abe T, Weiss M, Sam K. Insectivorous birds and bats outperform ants in the top-down regulation of arthropods across strata of a Japanese temperate forest. J Anim Ecol 2024. [PMID: 39045801 DOI: 10.1111/1365-2656.14146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 06/06/2024] [Indexed: 07/25/2024]
Abstract
Birds, bats and ants are recognised as significant arthropod predators. However, empirical studies reveal inconsistent trends in their relative roles in top-down control across strata. Here, we describe the differences between forest strata in the separate effects of birds, bats and ants on arthropod densities and their cascading effects on plant damage. We implemented a factorial design to exclude vertebrates and ants in both the canopy and understorey. Additionally, we separately excluded birds and bats from the understorey using diurnal and nocturnal exclosures. At the end of the experiments, we collected all arthropods and assessed herbivory damage. Arthropods responded similarly to predator exclusion across forest strata, with a density increase of 81% on trees without vertebrates and 53% without both vertebrates and ants. Additionally, bird exclusion alone led to an 89% increase in arthropod density, while bat exclusion resulted in a 63% increase. Herbivory increased by 42% when vertebrates were excluded and by 35% when both vertebrates and ants were excluded. Bird exclusion alone increased herbivory damage by 28%, while the exclusion of bats showed a detectable but non-significant increase (by 22%). In contrast, ant exclusion had no significant effect on arthropod density or herbivory damage across strata. Our results reveal that the effects of birds and bats on arthropod density and herbivory damage are similar between the forest canopy and understorey in this temperate forest. In addition, ants were not found to be significant predators in our system. Furthermore, birds, bats and ants appeared to exhibit antagonistic relationships in influencing arthropod density. These findings highlight, unprecedentedly, the equal importance of birds and bats in maintaining ecological balance across different strata of a temperate forest.
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Affiliation(s)
- Elise Sivault
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Jan Kollross
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Leonardo Re Jorge
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Sam Finnie
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - David Diez-Méndez
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Sara Fernandez Garzon
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Heveakore Maraia
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Jan Lenc
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Martin Libra
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
| | | | - Tatsuro Nakaji
- Sapporo Experimental Forest, Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Japan
| | - Masahiro Nakamura
- Tomakomai Experimental Forest, Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Japan
| | - Rachakonda Sreekar
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
- Centre for Biodiversity and Conservation Science, School of Environment, The University of Queensland, Saint Lucia, Queensland, Australia
| | - Legi Sam
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
| | - Tomokazu Abe
- Faculty of Science, Chiba University, Chiba, Japan
| | - Matthias Weiss
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Katerina Sam
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
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2
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Liu Y, Qin F, Li L, Dong X, Liu L, Yang L. The Long-Term Effects of Barren Land Afforestation on Plant Productivity, Soil Fertility, and Soil Moisture in China: A Meta-Analysis. PLANTS (BASEL, SWITZERLAND) 2024; 13:1614. [PMID: 38931046 PMCID: PMC11207343 DOI: 10.3390/plants13121614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Revised: 06/06/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024]
Abstract
As global ecological degradation intensifies, the long-term impacts of afforestation on productivity and soil fertility in barren lands have become critical in improving global ecological security and productivity. Through meta-analysis, this study integrates data from 109 barren land afforestation sites across China, aiming to comprehensively analyze the effects on plant productivity and soil fertility while identifying the key environmental drivers of these changes. We found that afforestation consistently enhances plant productivity across 60 years. However, soil fertility and moisture initially surged significantly after afforestation but gradually declined after the first decade, indicating the limited long-term benefits. Climatic factors, namely precipitation and humidity index, are crucial in enhancing plant productivity, while geographic factors, specifically lower elevations and gentler slopes, are associated with greater increases in soil fertility. Elevation and slope are two key factors that influence soil moisture after afforestation. These findings highlight the need for ongoing soil management and ecological maintenance in afforestation projects to sustain the soil fertility benefits. Our study provides a robust scientific foundation for afforestation strategies aimed at barren land restoration and offers valuable insights for policy formulation in barren land afforestation.
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Affiliation(s)
- Yanqi Liu
- College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China; (Y.L.); (L.L.); (X.D.); (L.L.)
- Tongliao Forestry and Grassland Bureau Horqin District Branch, Tongliao 028000, China
| | - Fucang Qin
- College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China; (Y.L.); (L.L.); (X.D.); (L.L.)
- Forestry and Grassland Bureau of Inner Mongolia, Hohhot 010010, China
- Key Laboratory of National Forestry and Grassland Bureau for Desert Ecosystem Protection and Rehabilitation, Hohhot 010019, China
| | - Long Li
- College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China; (Y.L.); (L.L.); (X.D.); (L.L.)
- Key Laboratory of National Forestry and Grassland Bureau for Desert Ecosystem Protection and Rehabilitation, Hohhot 010019, China
| | - Xiaoyu Dong
- College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China; (Y.L.); (L.L.); (X.D.); (L.L.)
| | - Linfu Liu
- College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China; (Y.L.); (L.L.); (X.D.); (L.L.)
| | - Liangping Yang
- Geological Survey Academy of Inner Mongolia Autonomous Region, Hohhot 010020, China;
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3
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Vázquez-González C, Castagneyrol B, Muiruri EW, Barbaro L, Abdala-Roberts L, Barsoum N, Fründ J, Glynn C, Jactel H, McShea WJ, Mereu S, Mooney KA, Morillas L, Nock CA, Paquette A, Parker JD, Parker WC, Roales J, Scherer-Lorenzen M, Schuldt A, Verheyen K, Weih M, Yang B, Koricheva J. Tree diversity enhances predation by birds but not by arthropods across climate gradients. Ecol Lett 2024; 27:e14427. [PMID: 38698677 DOI: 10.1111/ele.14427] [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: 10/06/2023] [Revised: 03/28/2024] [Accepted: 04/03/2024] [Indexed: 05/05/2024]
Abstract
Tree diversity can promote both predator abundance and diversity. However, whether this translates into increased predation and top-down control of herbivores across predator taxonomic groups and contrasting environmental conditions remains unresolved. We used a global network of tree diversity experiments (TreeDivNet) spread across three continents and three biomes to test the effects of tree species richness on predation across varying climatic conditions of temperature and precipitation. We recorded bird and arthropod predation attempts on plasticine caterpillars in monocultures and tree species mixtures. Both tree species richness and temperature increased predation by birds but not by arthropods. Furthermore, the effects of tree species richness on predation were consistent across the studied climatic gradient. Our findings provide evidence that tree diversity strengthens top-down control of insect herbivores by birds, underscoring the need to implement conservation strategies that safeguard tree diversity to sustain ecosystem services provided by natural enemies in forests.
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Affiliation(s)
- Carla Vázquez-González
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, USA
- Misión Biológica de Galicia, Consejo Superior de Investigaciones Científicas (MBG-CSIC), Pontevedra, España
| | | | - Evalyne W Muiruri
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey, UK
| | - Luc Barbaro
- Dynafor, INRAE-INPT, University of Toulouse, Castanet-Tolosan, France
| | - Luis Abdala-Roberts
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Nadia Barsoum
- Forest Research, Alice Holt Lodge, Farnham, Surrey, UK
| | - Jochen Fründ
- Biometry and Environmental System Analysis, University of Freiburg, Freiburg, Germany
- Animal Network Ecology, Department of Biology, Universität Hamburg, Hamburg, Germany
- Nature Conservation and Landscape Ecology, University of Freiburg, Freiburg, Germany
| | - Carolyn Glynn
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Hervé Jactel
- BIOGECO, University of Bordeaux, INRAE, Bordeaux, France
| | - William J McShea
- Conservation Ecology Center, Smithsonian's National Zoo and Conservation Biology Institute 1500 Remount Road, Front Royal, Virginia, USA
| | - Simone Mereu
- Institute of BioEconomy, National Research Council of Italy, Sassari, Italy
| | - Kailen A Mooney
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, USA
| | - Lourdes Morillas
- Department of Plant Biology and Ecology, University of Sevilla, C/ Professor García González s/n, Sevilla, Spain
| | - Charles A Nock
- College of Natural and Applied Sciences, Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Alain Paquette
- Center for Forest Research, Université du Québec à Montréal, Montréal, Canada
| | - John D Parker
- Smithsonian Environmental Research Center, Front Royal, Maryland, USA
| | - William C Parker
- Ontario Ministry of Natural Resources and Forestry, Sault Ste. Marie, Ontario, Canada
| | - Javier Roales
- Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Ctra, Seville, Spain
| | | | - Andreas Schuldt
- Forest Nature Conservation, University of Göttingen, Göttingen, Germany
| | - Kris Verheyen
- Forest & Nature Lab, Department of Environment, Ghent University, Melle-Gontrode, Belgium
| | - Martin Weih
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Bo Yang
- Jiangxi Key Laboratory of Plant Resources and Biodiversity, Jingdezhen University, Jingdezhen, China
| | - Julia Koricheva
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey, UK
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4
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Mitchell DJ, Beckmann C, Biro PA. Maintenance of Behavioral Variation under Predation Risk: Effects on Personality, Plasticity, and Predictability. Am Nat 2024; 203:347-361. [PMID: 38358809 DOI: 10.1086/728421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
AbstractClassic evolutionary theory predicts that predation will shift trait means and erode variance within prey species; however, several studies indicate higher behavioral trait variance and trait integration in high-predation populations. These results come predominately from field-sampled animals comparing low- and high-predation sites and thus cannot isolate the role of predation from other ecological factors, including density effects arising from higher predation. Here, we study the role of predation on behavioral trait (co)variation in experimental populations of guppies (Poecilia reticulata) living with and without a benthic ambush predator (Jaguar cichlid) to better evaluate the role of predation and where density was equalized among replicates twice per year. At 2.5 years after introduction of the predators (∼10 overlapping generations), 40 males were sampled from each of the six replicate populations and extensively assayed for activity rates, water column use, and latency to feed following disturbance. Individual variation was pronounced in both treatments, with substantial individual variation in means, temporal plasticity, and predictability (inverse residual variance). Predators had little effect on mean behavior, although there was some evidence for greater use of the upper water column in predator-exposed fish. There was greater variance among individuals in water column use in predator-exposed fish, and they habituated more quickly over time; individuals higher in the water column fed slower and had a reduced positive correlation with activity, although again this effect was time specific. Predators also affected the integration of personality and plasticity-among-individual variances in water column use increased, and those in activity decreased, through time-which was absent in controls. Our results contrast with the extensive guppy literature showing rapid evolution in trait means, demonstrating either increases or maintenance of behavioral variance under predation.
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5
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Vázquez-González C, Villa-Galaviz E, Reyes-Hernández M, Perez-Niño B, Quijano-Medina T, Parra-Tabla V, Mooney KA, Abdala-Roberts L. Temporal variation in tree diversity effects on birds and its implications for top-down control of insect herbivores in a tropical system. Oecologia 2024; 204:603-612. [PMID: 38393366 DOI: 10.1007/s00442-024-05514-1] [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: 12/14/2023] [Accepted: 01/16/2024] [Indexed: 02/25/2024]
Abstract
Tree diversity promotes predator abundance and diversity, but evidence linking these effects to increased predation pressure on herbivores remains limited. In addition, tree diversity effects on predators can vary temporally as a function of environmental variation, or due to contrasting responses by different predator types. In a multi-year study, we assessed temporal variation in tree diversity effects on bird community abundance, diversity, and predation rates as a whole and by functional group based on feeding guild (omnivores vs. insectivores) and migratory status (migrant vs. resident). To this end, we conducted bird point counts in tree monocultures and polycultures and assessed attacks on clay caterpillars four times over a 2-year period in a tree diversity experiment in Yucatan, Mexico. Tree diversity effects on the bird community varied across surveys, with positive effects on bird abundance and diversity in most but not all surveys. Tree diversity had stronger and more consistent effects on omnivorous and resident birds than on insectivorous and migratory species. Tree diversity effects on attack rates also varied temporally but patterns did not align with variation in bird abundance or diversity. Thus, while we found support for predicted increases in bird abundance, diversity, and predation pressure with tree diversity, these responses exhibited substantial variation over time and the former two were uncoupled from patterns of predation pressure, as well as contingent on bird functional traits. These results underscore the need for long-term studies measuring responses by different predator functional groups to better understand tree diversity effects on top-down control.
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Affiliation(s)
- Carla Vázquez-González
- Department of Ecology and Evolutionary Biology, University of California-Irvine, Irvine, CA, 92697, USA
- Misión Biológica de Galicia (MBG-CSIC), Apartado de Correos 28, 36080, Pontevedra, Galicia, Spain
| | - Edith Villa-Galaviz
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Apartado Postal 4-116, Itzimná, 97000, Mérida, Yucatán, Mexico
| | - Martha Reyes-Hernández
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Apartado Postal 4-116, Itzimná, 97000, Mérida, Yucatán, Mexico
| | - Biiniza Perez-Niño
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Apartado Postal 4-116, Itzimná, 97000, Mérida, Yucatán, Mexico
| | - Teresa Quijano-Medina
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Apartado Postal 4-116, Itzimná, 97000, Mérida, Yucatán, Mexico
| | - Víctor Parra-Tabla
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Apartado Postal 4-116, Itzimná, 97000, Mérida, Yucatán, Mexico
| | - Kailen A Mooney
- Department of Ecology and Evolutionary Biology, University of California-Irvine, Irvine, CA, 92697, USA
| | - Luis Abdala-Roberts
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Apartado Postal 4-116, Itzimná, 97000, Mérida, Yucatán, Mexico.
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6
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Avilés JM. The evolutionary ecology of bird-ant interactions: a pervasive but under-studied connection. Proc Biol Sci 2024; 291:20232023. [PMID: 38166423 PMCID: PMC10762437 DOI: 10.1098/rspb.2023.2023] [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: 09/08/2023] [Accepted: 12/01/2023] [Indexed: 01/04/2024] Open
Abstract
Birds and ants are among the most ubiquitous taxa co-occurring in terrestrial ecosystems, but how they mutually interact is almost unknown. Here, the main features of this neglected interaction are synthetized in a systematic literature review. Interaction with ants has been recorded in 1122 bird species (11.2% of extant species) belonging to 131 families widely distributed across the globe and the avian phylogeny. On the other hand, 47 genus of ants (14.4% of extant genus) belonging to eight subfamilies interact with birds. Interactions include competition, antagonism (either ant-bird mutual predation or parasitism) and living together commensally or mutualistically. Competition (48.9%) and antagonism (36.1%) were the most common reported interactions. The potential for engaging in commensalism and competition with ants has a phylogenetic structure in birds and was present in the birds' ancestor. Interaction is better studied in the tropics, in where the network is less dense and more nested than in temperate or arid biomes. This review demonstrates that ant-bird interactions are a pervasive phenomenon across ecological domains, playing a key role in ecosystem function. Future studies need to combine sensible experimentation within anthropogenic disturbance gradients in order to achieve a better understanding of this interaction.
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Affiliation(s)
- Jesús M. Avilés
- Departamento de Ecología Funcional y Evolutiva, EEZA-CSIC, Almería E-04120, Spain
- Unidad Asociada (CSIC-UNEX): Ecología en el Antropoceno, Badajoz E-06006, Spain
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7
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Getman-Pickering ZL, Soltis GJ, Shamash S, Gruner DS, Weiss MR, Lill JT. Periodical cicadas disrupt trophic dynamics through community-level shifts in avian foraging. Science 2023; 382:320-324. [PMID: 37856588 DOI: 10.1126/science.adi7426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 08/25/2023] [Indexed: 10/21/2023]
Abstract
Once every 13 or 17 years within eastern North American deciduous forests, billions of periodical cicadas concurrently emerge from the soil and briefly satiate a diverse array of naive consumers, offering a rare opportunity to assess the cascading impacts of an ecosystem-wide resource pulse on a complex food web. We quantified the effects of the 2021 Brood X emergence and report that more than 80 bird species opportunistically switched their foraging to include cicadas, releasing herbivorous insects from predation and essentially doubling both caterpillar densities and accumulated herbivory levels on host oak trees. These short-lived but massive emergence events help us to understand how resource pulses can rewire interaction webs and disrupt energy flows in ecosystems, with potentially long-lasting effects.
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Affiliation(s)
- Zoe L Getman-Pickering
- Department of Biological Sciences, George Washington University, Washington, DC 20052, USA
| | - Grace J Soltis
- Department of Entomology, University of Maryland, College Park, MD 20742, USA
| | - Sarah Shamash
- Department of Biological Sciences, George Washington University, Washington, DC 20052, USA
| | - Daniel S Gruner
- Department of Entomology, University of Maryland, College Park, MD 20742, USA
| | - Martha R Weiss
- Department of Biology, Georgetown University, Washington, DC 20007, USA
| | - John T Lill
- Department of Biological Sciences, George Washington University, Washington, DC 20052, USA
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8
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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: 10] [Impact Index Per Article: 10.0] [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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9
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Plant genetic diversity affects multiple trophic levels and trophic interactions. Nat Commun 2022; 13:7312. [PMID: 36437257 PMCID: PMC9701765 DOI: 10.1038/s41467-022-35087-7] [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: 05/06/2022] [Accepted: 11/17/2022] [Indexed: 11/28/2022] Open
Abstract
Intraspecific genetic diversity is an important component of biodiversity. A substantial body of evidence has demonstrated positive effects of plant genetic diversity on plant performance. However, it has remained unclear whether plant genetic diversity generally increases plant performance by reducing the pressure of plant antagonists across trophic levels for different plant life forms, ecosystems and climatic zones. Here, we analyse 4702 effect sizes reported in 413 studies that consider effects of plant genetic diversity on trophic groups and their interactions. We found that that increasing plant genetic diversity decreased the performance of plant antagonists including invertebrate herbivores, weeds, plant-feeding nematodes and plant diseases, while increasing the performance of plants and natural enemies of herbivores. Structural equation modelling indicated that plant genetic diversity increased plant performance partly by reducing plant antagonist pressure. These results reveal that plant genetic diversity often influences multiple trophic levels in ways that enhance natural pest control in managed ecosystems and consumer control of plants in natural ecosystems for sustainable plant production.
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10
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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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11
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Houska Tahadlova M, Mottl O, Jorge LR, Koane B, Novotny V, Sam K. Trophic cascades in tropical rainforests: Effects of vertebrate predator exclusion on arthropods and plants in Papua New Guinea. Biotropica 2022. [DOI: 10.1111/btp.13160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marketa Houska Tahadlova
- Laboratory of Multitrophic Interactions, Biology Centre of Czech Academy of Sciences Institute of Entomology Ceske Budejovice Czech Republic
- Faculty of Sciences University of South Bohemia Ceske Budejovice Czech Republic
| | - Ondrej Mottl
- Department of Biological Sciences and Bjerknes Centre for Climate Research University of Bergen Bergen Norway
| | - Leonardo R. Jorge
- Laboratory of Multitrophic Interactions, Biology Centre of Czech Academy of Sciences Institute of Entomology Ceske Budejovice Czech Republic
| | - Bonny Koane
- The New Guinea Binatang Research Centre Madang Papua New Guinea
| | - Vojtech Novotny
- Laboratory of Multitrophic Interactions, Biology Centre of Czech Academy of Sciences Institute of Entomology Ceske Budejovice Czech Republic
- Faculty of Sciences University of South Bohemia Ceske Budejovice Czech Republic
- The New Guinea Binatang Research Centre Madang Papua New Guinea
| | - Katerina Sam
- Laboratory of Multitrophic Interactions, Biology Centre of Czech Academy of Sciences Institute of Entomology Ceske Budejovice Czech Republic
- Faculty of Sciences University of South Bohemia Ceske Budejovice Czech Republic
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12
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Tresson P, Tixier P, Puech W, Abufera B, Wyvekens A, Carval D. Caught on camera: Field imagery reveals the unexpected importance of vertebrates for biological control of the banana weevil (Cosmopolites sordidus Col. Curculionidae). PLoS One 2022; 17:e0274223. [PMID: 36125985 PMCID: PMC9488773 DOI: 10.1371/journal.pone.0274223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 08/23/2022] [Indexed: 11/18/2022] Open
Abstract
Understanding of ecological interactions is necessary for the application of biological control. Banana is the second most produced fruit worldwide and the banana weevil (Cosmopolites sordidus) is the most important pest of banana and plantain. Its biological control remains challenging because of the robustness and cryptic behaviour of the adult and the hidden development of larval stages. Researchers therefore tend to favour conservation biological control of this pest. The commonly used methods for measuring the effects of natural enemies on the regulation of this pest focus on invertebrates and may underestimate the role of vertebrates on biological control. Using cameras, we recorded the predation of sentinel adult weevils in banana plots in La Réunion island that differed in weevil infestation levels and in animal biodiversity. To facilitate image analysis, we used background subtraction to isolate moving parts of image sequences and thus detect predators and predation events. Our cameras recorded only vertebrates as predators of adult banana weevils. The most important predator appeared to be the Asian shrew (Suncus murinus), which was responsible for 67% of the predation events. Other predators included the house mouse (Mus musculus), the oriental garden lizard (Calotes versicolor), and the guttural toad (Sclerophrys gutturalis). The exact time of predation events were determined from the images metadata. It was thus possible to identify predator foraging periods that coincided with activity of adult weevils. Our results confirm that images provide useful information for biological and ecological studies. Along with other recent studies, our results suggest that the role of vertebrates in biological control may be underestimated. Based on these results, we advocate for several management implications such as the installation of hedges, grasslands, and ponds to favour these vertebrate predators of the banana weevil, possibly also favouring other vertebrate and invertebrate natural enemies.
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Affiliation(s)
- Paul Tresson
- CIRAD, UPR GECO, Montpellier, France
- GECO, Univ Montpellier, CIRAD, Montpellier, France
- CIRAD, UPR GECO, Saint-Pierre, France
- LIRMM, Université de Montpellier, CNRS, Montpellier, France
- * E-mail:
| | - Philippe Tixier
- CIRAD, UPR GECO, Montpellier, France
- GECO, Univ Montpellier, CIRAD, Montpellier, France
| | - William Puech
- LIRMM, Université de Montpellier, CNRS, Montpellier, France
| | - Bernard Abufera
- GECO, Univ Montpellier, CIRAD, Montpellier, France
- CIRAD, UPR GECO, Saint-Pierre, France
| | - Antoine Wyvekens
- GECO, Univ Montpellier, CIRAD, Montpellier, France
- CIRAD, UPR GECO, Saint-Pierre, France
| | - Dominique Carval
- CIRAD, UPR GECO, Montpellier, France
- GECO, Univ Montpellier, CIRAD, Montpellier, France
- CIRAD, UPR GECO, Saint-Pierre, France
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13
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Khadempour L, Rivas Quijano L, terHorst CP. Prey identity affects fitness of a generalist consumer in a brown food web. Ecol Evol 2022; 12:e9207. [PMID: 36761176 PMCID: PMC9896622 DOI: 10.1002/ece3.9207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 05/11/2022] [Accepted: 07/16/2022] [Indexed: 11/11/2022] Open
Abstract
The use of ever-advancing sequencing technologies has revealed incredible biodiversity at the microbial scale, and yet we know little about the ecological interactions in these communities. For example, in the phytotelmic community found in the purple pitcher plant, Sarracenia purpurea, ecologists typically consider the bacteria as a functionally homogenous group. In this food web, bacteria decompose detritus and are consumed by protozoa that are considered generalist consumers. Here, we tested whether a generalist consumer benefits from all bacteria equally. We isolated and identified 22 strains of bacteria, belonging to six genera, from S. purpurea plants. We grew the protozoa, Tetrahymena sp. with single isolates and strain mixtures of bacteria and measured Tetrahymena fitness. We found that different bacterial strains had different effects on protozoan fitness, both in isolation and in mixture. Our results demonstrate that not accounting for the composition of prey communities may affect the predicted outcome of predator-prey interactions.
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Affiliation(s)
- Lily Khadempour
- Department of BiologyCalifornia State University, NorthridgeNorthridgeCaliforniaUSA,Present address:
Department of Earth and Environmental SciencesRutgers UniversityNewarkNew JerseyUSA
| | - Leslie Rivas Quijano
- Department of BiologyCalifornia State University, NorthridgeNorthridgeCaliforniaUSA
| | - Casey P. terHorst
- Department of BiologyCalifornia State University, NorthridgeNorthridgeCaliforniaUSA
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14
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Garfinkel MB, Fuka ME, Minor E, Whelan CJ. When a pest is not a pest: Birds indirectly increase defoliation but have no effect on yield of soybean crops. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2527. [PMID: 34994027 DOI: 10.1002/eap.2527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 08/17/2021] [Accepted: 09/13/2021] [Indexed: 06/14/2023]
Abstract
Natural habitats near agricultural systems can be sources of both ecosystem services and disservices on farms. Ecosystem disservices, those aspects of an ecosystem that have negative impacts on humans, may disproportionately affect conservation decisions made by farmers. Birds, in particular, can have complex effects on crops, ranging from positive to neutral to negative. Therefore, it is important to quantify them in a meaningful way. Birds may be more abundant on farms near natural areas and may provide ecosystem services by consuming insect pests. However, when birds consume beneficial predatory arthropods rather than pest species (intraguild predation), they can provide a disservice to the farmer if the intraguild predation decreases crop yield. We studied bird intraguild predation in Illinois (USA) at six soybean fields adjacent to grasslands that provided source habitat for bird populations. We placed cages over soybean crops, which excluded birds but allowed access to arthropods, and measured differences in leaf damage and crop yield of plants in control and exclosure plots. We also conducted point counts at each site to quantify the bird communities. We found that plants within the bird exclosures had lower levels of leaf damage by pests than those in control plots, but there was no resulting effect on crop yield. We also found that sites with higher bird abundance had higher levels of leaf damage by pests, but bird species richness was not a significant predictor of leaf damage. These results suggest that although birds may have released pests through intraguild predation, there was no net disservice when considering crop yield, the variable most important to stakeholders.
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Affiliation(s)
- Megan B Garfinkel
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Mark E Fuka
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Emily Minor
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
- Institute for Environmental Science and Policy, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Christopher J Whelan
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
- Cancer Physiology, Moffitt Cancer and Research Institute, Tampa, Florida, USA
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15
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Zhou G, Zhou X, Eldridge DJ, Han X, Song Y, Liu R, Zhou L, He Y, Du Z, Delgado‐Baquerizo M. Temperature and Rainfall Patterns Constrain the Multidimensional Rewilding of Global Forests. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2201144. [PMID: 35470591 PMCID: PMC9218649 DOI: 10.1002/advs.202201144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 03/30/2022] [Indexed: 06/14/2023]
Abstract
The long-term contribution of global forest restoration to support multiple dimensions of biodiversity and ecosystem function remains largely illusive across contrasting climates and forest types. This hampers the capacity to predict the future of forest rewilding under changing global climates. Here, 120 studies are synthesized across five continents, and it is found that forest restoration promotes multiple dimensions of biodiversity and ecosystem function such as soil fertility, plant biomass, microbial habitat, and carbon sequestration across contrasting climates and forest types. Based on global relationship between stand age and soil organic carbon stock, planting 350 million hectares of forest under the UN Bonn Challenge can sequester >30 Gt soil C in the surface 20 cm over the next century. However, these findings also indicate that predicted increases in temperature and reductions in precipitation can constrain the positive effects of forest rewilding on biodiversity and ecosystem function. Further, important tradeoffs are found in very old forests, with considerable disconnection between biodiversity and ecosystem function. Together, these findings provide evidence of the importance of the multidimensional rewilding of forests, suggesting that on-going climatic changes may dampen the expectations of the positive effects of forest restoration on biodiversity and ecosystem function.
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Affiliation(s)
- Guiyao Zhou
- Zhejiang Tiantong Forest Ecosystem National Observation and Research StationCenter for Global Change and Ecological ForecastingSchool of Ecological and Environmental SciencesEast China Normal UniversityShanghai200241China
| | - Xuhui Zhou
- Zhejiang Tiantong Forest Ecosystem National Observation and Research StationCenter for Global Change and Ecological ForecastingSchool of Ecological and Environmental SciencesEast China Normal UniversityShanghai200241China
- Northeast Asia Ecosystem Carbon Sink Research Center (NACC)Center for Ecological ResearchKey Laboratory of Sustainable Forest Ecosystem Management‐Ministry of EducationSchool of ForestryNortheast Forestry UniversityHarbin150040China
| | - David J. Eldridge
- Centre for Ecosystem ScienceSchool of BiologicalEarth and Environmental SciencesUniversity of New South WalesSydneyNew South Wales2052Australia
| | - Ximei Han
- Zhejiang Tiantong Forest Ecosystem National Observation and Research StationCenter for Global Change and Ecological ForecastingSchool of Ecological and Environmental SciencesEast China Normal UniversityShanghai200241China
| | - Yanjun Song
- Forest Ecology and Forest Management GroupWageningen University and ResearchP.O. Box 47Wageningen6700 AAthe Netherlands
| | - Ruiqiang Liu
- Northeast Asia Ecosystem Carbon Sink Research Center (NACC)Center for Ecological ResearchKey Laboratory of Sustainable Forest Ecosystem Management‐Ministry of EducationSchool of ForestryNortheast Forestry UniversityHarbin150040China
| | - Lingyan Zhou
- Zhejiang Tiantong Forest Ecosystem National Observation and Research StationCenter for Global Change and Ecological ForecastingSchool of Ecological and Environmental SciencesEast China Normal UniversityShanghai200241China
| | - Yanghui He
- Northeast Asia Ecosystem Carbon Sink Research Center (NACC)Center for Ecological ResearchKey Laboratory of Sustainable Forest Ecosystem Management‐Ministry of EducationSchool of ForestryNortheast Forestry UniversityHarbin150040China
| | - Zhenggang Du
- Northeast Asia Ecosystem Carbon Sink Research Center (NACC)Center for Ecological ResearchKey Laboratory of Sustainable Forest Ecosystem Management‐Ministry of EducationSchool of ForestryNortheast Forestry UniversityHarbin150040China
| | - Manuel Delgado‐Baquerizo
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS)CSICAv. Reina Mercedes 10SevillaE‐41012Spain
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16
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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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17
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Matsumura K, Miyatake T. Effects of individual differences in the locomotor activity of assassin bugs on predator–prey interactions. Ethology 2022. [DOI: 10.1111/eth.13272] [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)
| | - Takahisa Miyatake
- Graduate School of Environmental and Life Science Okayama University Okayama Japan
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18
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19
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Etard A, Pigot AL, Newbold T. Intensive human land uses negatively affect vertebrate functional diversity. Ecol Lett 2021; 25:330-343. [PMID: 34816566 DOI: 10.1111/ele.13926] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/25/2021] [Accepted: 10/19/2021] [Indexed: 11/29/2022]
Abstract
Land-use change is the leading driver of global biodiversity loss thus characterising its impacts on the functional structure of ecological communities is an urgent challenge. Using a database describing vertebrate assemblages in different land uses, we assess how the type and intensity of land use affect the functional diversity of vertebrates globally. We find that human land uses alter local functional structure by driving declines in functional diversity, with the strongest effects in the most disturbed land uses (intensely used urban sites, cropland and pastures), and among amphibians and birds. Both tropical and temperate areas experience important functional losses, which are only partially offset by functional gains. Tropical assemblages are more likely to show decreases in functional diversity that exceed those expected from species loss alone. Our results indicate that land-use change non-randomly reshapes the functional structure of vertebrate assemblages, raising concerns about the continuation of ecological processes sustained by vertebrates.
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Affiliation(s)
- Adrienne Etard
- Department of Genetics, Evolution and Environment, Centre for Biodiversity and Environment Research, University College London, London, UK
| | - Alex L Pigot
- Department of Genetics, Evolution and Environment, Centre for Biodiversity and Environment Research, University College London, London, UK
| | - Tim Newbold
- Department of Genetics, Evolution and Environment, Centre for Biodiversity and Environment Research, University College London, London, UK
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20
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González González C, Mora Van Cauwelaert E, Boyer D, Perfecto I, Vandermeer J, Benítez M. High-order interactions maintain or enhance structural robustness of a coffee agroecosystem network. ECOLOGICAL COMPLEXITY 2021. [DOI: 10.1016/j.ecocom.2021.100951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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21
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Sherry TW. Sensitivity of Tropical Insectivorous Birds to the Anthropocene: A Review of Multiple Mechanisms and Conservation Implications. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.662873] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Epigraph: “The house is burning. We do not need a thermometer. We need a fire hose.” (P. 102, Janzen and Hallwachs, 2019). Insectivorous birds are declining widely, and for diverse reasons. Tropical insectivorous birds, more than 60% of all tropical birds, are particularly sensitive to human disturbances including habitat loss and fragmentation, intensive agriculture and pesticide use, and climate change; and the mechanisms are incompletely understood. This review addresses multiple, complementary and sometimes synergistic explanations for tropical insectivore declines, by categorizing explanations into ultimate vs. proximate, and direct versus indirect. Ultimate explanations are diverse human Anthropocene activities and the evolutionary history of these birds. This evolutionary history, synthesized by the Biotic Challenge Hypothesis (BCH), explains tropical insectivorous birds' vulnerabilities to many proximate threats as a function of both these birds' evolutionary feeding specialization and poor dispersal capacity. These traits were favored evolutionarily by both the diversity of insectivorous clades competing intensely for prey and co-evolution with arthropods over long evolutionary time periods. More proximate, ecological threats include bottom-up forces like declining insect populations, top-down forces like meso-predator increases, plus the Anthropocene activities underlying these factors, especially habitat loss and fragmentation, agricultural intensification, and climate change. All these conditions peak in the lowland, mainland Neotropics, where insectivorous bird declines have been repeatedly documented, but also occur in other tropical locales and continents. This multiplicity of interacting evolutionary and ecological factors informs conservation implications and recommendations for tropical insectivorous birds: (1) Why they are so sensitive to global change phenomena is no longer enigmatic, (2) distinguishing ultimate versus proximate stressors matters, (3) evolutionary life-histories predispose these birds to be particularly sensitive to the Anthropocene, (4) tropical regions and continents vary with respect to these birds' ecological sensitivity, (5) biodiversity concepts need stronger incorporation of species' evolutionary histories, (6) protecting these birds will require more, larger reserves for multiple reasons, and (7) these birds have greater value than generally recognized.
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22
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Schmitt L, Greenberg R, Ibarra-Núñez G, Bichier P, Gordon CE, Perfecto I. Cascading Effects of Birds and Bats in a Shaded Coffee Agroforestry System. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2021. [DOI: 10.3389/fsufs.2021.512998] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Volant vertebrate insectivores, including birds and bats, can be important regulators of herbivores in forests and agro-ecosystems. Their effects can be realized directly through predation and indirectly via intraguild predation. This paper examines data from bird and bat exclosures in coffee farms in Chiapas, Mexico in order to determine their effect on herbivores. Arthropods were sampled in 32 exclosures (with 10 coffee plants in each) and their paired controls three times during 6 months. After 3 months, herbivore and spider abundance increased, underscoring the importance of both intertrophic predation between volant vertebrate insectivores and herbivores and intraguild predation between volant vertebrate insectivores and spiders. After 6 months, herbivore abundance increased in the exclosures, which is indicative of a direct negative effect of birds and bats on herbivores. We suggest that intraguild predation is important in this food web and that seasonality may change the relative importance of intraguild vs. intertrophic predation. Results suggest a dissipating trophic cascade and echo the growing body of evidence that finds birds and bats are regulators of herbivores in agro-ecosystems.
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23
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Wray AK, Peery MZ, Jusino MA, Kochanski JM, Banik MT, Palmer JM, Lindner DL, Gratton C. Predator preferences shape the diets of arthropodivorous bats more than quantitative local prey abundance. Mol Ecol 2020; 30:855-873. [PMID: 33301628 DOI: 10.1111/mec.15769] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 10/27/2020] [Accepted: 11/19/2020] [Indexed: 01/03/2023]
Abstract
Although most predators are generalists, the majority of studies on the association between prey availability and prey consumption have focused on specialist predators. To investigate the role of highly generalist predators in a complex food web, we measured the relationships between prey consumption and prey availability in two common arthropodivorous bats. Specifically, we used high-throughput amplicon sequencing coupled with a known mock community to characterize seasonal changes in little brown and big brown bat diets. We then linked spatiotemporal variation in prey consumption with quantitative prey availability estimated from intensive prey community sampling. We found that although quantitative prey availability fluctuated substantially over space and time, the most commonly consumed prey items were consistently detected in bat diets independently of their respective abundance. Positive relationships between prey abundance and probability of consumption were found only among prey groups that were less frequently detected in bat diets. While the probability of prey consumption was largely unrelated to abundance, the community structure of prey detected in bat diets was influenced by the local or regional abundance of prey. Observed patterns suggest that while little brown and big brown bats maintain preferences for particular prey independently of quantitative prey availability, total dietary composition may reflect some degree of opportunistic foraging. Overall, our findings suggest that generalist predators can display strong prey preferences that persist despite quantitative changes in prey availability.
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Affiliation(s)
- Amy K Wray
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, USA.,Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
| | - M Zachariah Peery
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, USA
| | - Michelle A Jusino
- Center for Forest Mycology Research, Northern Research Station, USDA Forest Service, Madison, WI, USA.,Department of Plant Pathology, University of Florida, Gainesville, FL, USA
| | - Jade M Kochanski
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
| | - Mark T Banik
- Center for Forest Mycology Research, Northern Research Station, USDA Forest Service, Madison, WI, USA
| | - Jonathan M Palmer
- Center for Forest Mycology Research, Northern Research Station, USDA Forest Service, Madison, WI, USA
| | - Daniel L Lindner
- Center for Forest Mycology Research, Northern Research Station, USDA Forest Service, Madison, WI, USA
| | - Claudio Gratton
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
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24
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Beard KH, Durham SL, Willig MR, Zimmerman JK. Lizard and frog removal increases spider abundance but does not cascade to increase herbivory. Biotropica 2020. [DOI: 10.1111/btp.12909] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Karen H. Beard
- Department of Wildland Resources and the Ecology Center Utah State University Logan UT USA
| | | | - Michael R. Willig
- Department of Ecology and Evolutionary Biology Center for Environmental Sciences and Engineering Institute of the Environment University of Connecticut Storrs CT USA
| | - Jess K. Zimmerman
- Department of Environmental Sciences University of Puerto Rico San Juan, Puerto Rico USA
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25
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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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26
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Jones MD, Crane MS, Silva IMS, Artchawakom T, Waengsothorn S, Suwanwaree P, Strine CT, Goode M. Supposed snake specialist consumes monitor lizards: diet and trophic implications of king cobra feeding ecology. Ecology 2020; 101:e03085. [PMID: 32320484 DOI: 10.1002/ecy.3085] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/25/2020] [Accepted: 04/01/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Max D Jones
- Suranaree University of Technology, 111 University Avenue, Muang, Suranaree, Nakhon Ratchasima, 30000, Thailand.,Sakaerat Environmental Research Station, 1 Moo 9 Udomsab, Wang Nam Khiao, Nakhon Wang Nam Khiao, Nakhon Ratchasima, 30370, Thailand
| | - Matt S Crane
- Suranaree University of Technology, 111 University Avenue, Muang, Suranaree, Nakhon Ratchasima, 30000, Thailand.,King Mongkut's University of Technology Thonburi, 126 Pracha Uthit Road, Bang Mot, Thung Khru, Bangkok, 10140, Thailand
| | - Inês M S Silva
- King Mongkut's University of Technology Thonburi, 126 Pracha Uthit Road, Bang Mot, Thung Khru, Bangkok, 10140, Thailand
| | - Taksin Artchawakom
- Sakaerat Environmental Research Station, 1 Moo 9 Udomsab, Wang Nam Khiao, Nakhon Wang Nam Khiao, Nakhon Ratchasima, 30370, Thailand.,Population and Community Development Association, 6 Sukhumvit Soi 12, Khlong Toei, Bangkok, 10110, Thailand
| | - Surachit Waengsothorn
- Sakaerat Environmental Research Station, 1 Moo 9 Udomsab, Wang Nam Khiao, Nakhon Wang Nam Khiao, Nakhon Ratchasima, 30370, Thailand
| | - Pongthep Suwanwaree
- Suranaree University of Technology, 111 University Avenue, Muang, Suranaree, Nakhon Ratchasima, 30000, Thailand
| | - Colin T Strine
- Suranaree University of Technology, 111 University Avenue, Muang, Suranaree, Nakhon Ratchasima, 30000, Thailand.,Sakaerat Environmental Research Station, 1 Moo 9 Udomsab, Wang Nam Khiao, Nakhon Wang Nam Khiao, Nakhon Ratchasima, 30370, Thailand
| | - Matt Goode
- University of Arizona, Tucson, Arizona, 85721, USA
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27
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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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Harrison MLK, Banks-Leite C. Edge effects on trophic cascades in tropical rainforests. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2020; 34:977-987. [PMID: 31762059 DOI: 10.1111/cobi.13438] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 10/20/2019] [Accepted: 11/08/2019] [Indexed: 06/10/2023]
Abstract
The cascading effects of biodiversity loss on ecosystem functioning of forests have become more apparent. However, how edge effects shape these processes has yet to be established. We assessed how edge effects alter arthropod populations and the strength of any resultant trophic cascades on herbivory rate in tropical forests of Brazil. We established 7 paired forest edge and interior sites. Each site had a vertebrate-exclosure, procedural (exclosure framework with open walls), and control plot (total 42 plots). Forest patches were surrounded by pasture. Understory arthropods and leaf damage were sampled every 4 weeks for 11 months. We used path analysis to determine the strength of trophic cascades in the interior and edge sites. In forest interior exclosures, abundance of predaceous and herbivorous arthropods increased by 326% and 180%, respectively, compared with control plots, and there were significant cascading effects on herbivory. Edge-dwelling invertebrates responded weakly to exclusion and there was no evidence of trophic cascade. Our results suggest that the vertebrate community at forest edges controls invertebrate densities to a lesser extent than it does in the interior. Edge areas can support vertebrate communities with a smaller contingent of insectivores. This allows arthropods to flourish and indirectly accounts for higher levels of plant damage at these sites. Increased herbivory rates may have important consequences for floristic community composition and primary productivity, as well as cascading effects on nutrient cycling. By interspersing natural forest patches with agroforests, instead of pasture, abiotic edge effects can be softened and prevented from penetrating deep into the forest. This would ensure a greater proportion of forest remains habitable for sensitive species and could help retain ecosystem functions in edge zones.
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Affiliation(s)
| | - Cristina Banks-Leite
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, U.K
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29
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Recalde FC, Breviglieri CPB, Romero GQ. Allochthonous aquatic subsidies alleviate predation pressure in terrestrial ecosystems. Ecology 2020; 101:e03074. [PMID: 32304220 DOI: 10.1002/ecy.3074] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/01/2020] [Accepted: 03/18/2020] [Indexed: 12/14/2022]
Abstract
The input of external energy and matter in recipient ecosystems can act as a bottom-up force that subsidizes consumers, with subsequent cascading effects throughout the food web. Depending on the amount of input, dietary preference, and the strength of trophic links, allochthonous resources generally play a stabilizing role on food webs. In this study, we investigated the stabilizing role of allochthonous aquatic resources on intraguild predation (IGP) and their consequences on shared prey in a terrestrial ecosystem. To this end, we manipulated the input of emergent aquatic insects (the allochthonous resources) from streams to land, and predation pressure by bats and birds (the top predators), in a multitrophic food web using an orthogonal exclusion experiment. Using stable isotope metrics, we found that bats, birds, and spiders (the mesopredators), were highly subsidized by emergent aquatic insects. Moreover, among terrestrial prey, top predators fed more on spiders than insects. As predicted, spiders were strongly affected by the presence of top predators when allochthonous resources were excluded. Consequently, in this scenario terrestrial insects were two times more abundant. Because spiders showed a higher preference for consuming aquatic resources, we suggest that nonconsumptive effects of spiders upon terrestrial insects could be mediating the strong response of those shared prey. We demonstrate that the input of allochthonous aquatic resources can play a fundamental role in stabilizing terrestrial trophic interactions and trophic cascades in riparian zones via decreasing predation pressure.
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Affiliation(s)
- Fátima C Recalde
- Programa de Pós Graduação em Ecologia, Institute of Biology, State University of Campinas - UNICAMP, Campinas, 13083-970, Brazil.,Department of Basic Sciences, Polytechnic Faculty, National University of Asunción - UNA, San Lorenzo, 2160, Paraguay
| | - Crasso P B Breviglieri
- Department of Animal Biology, Institute of Biology, State University of Campinas - UNICAMP, Campinas, 13083-970, Brazil
| | - Gustavo Q Romero
- Department of Animal Biology, Institute of Biology, State University of Campinas - UNICAMP, Campinas, 13083-970, Brazil
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30
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Sow A, Haran J, Benoit L, Galan M, Brévault T. DNA Metabarcoding as a Tool for Disentangling Food Webs in Agroecosystems. INSECTS 2020; 11:E294. [PMID: 32403224 PMCID: PMC7290477 DOI: 10.3390/insects11050294] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/03/2020] [Accepted: 05/05/2020] [Indexed: 12/26/2022]
Abstract
Better knowledge of food webs and related ecological processes is fundamental to understanding the functional role of biodiversity in ecosystems. This is particularly true for pest regulation by natural enemies in agroecosystems. However, it is generally difficult to decipher the impact of predators, as they often leave no direct evidence of their activity. Metabarcoding via high-throughput sequencing (HTS) offers new opportunities for unraveling trophic linkages between generalist predators and their prey, and ultimately identifying key ecological drivers of natural pest regulation. Here, this approach proved effective in deciphering the diet composition of key predatory arthropods (nine species.; 27 prey taxa), insectivorous birds (one species, 13 prey taxa) and bats (one species; 103 prey taxa) sampled in a millet-based agroecosystem in Senegal. Such information makes it possible to identify the diet breadth and preferences of predators (e.g., mainly moths for bats), to design a qualitative trophic network, and to identify patterns of intraguild predation across arthropod predators, insectivorous vertebrates and parasitoids. Appropriateness and limitations of the proposed molecular-based approach for assessing the diet of crop pest predators and trophic linkages are discussed.
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Affiliation(s)
- Ahmadou Sow
- Département de Biologie Animale, Faculté des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Senegal
| | - Julien Haran
- CIRAD, UMR CBGP, F-34398 Montpellier, France; (J.H.); (L.B.)
- CBGP, INRAE, CIRAD, IRD, Institut Agro, Université de Montpellier, F-34988 Montpellier, France;
| | - Laure Benoit
- CIRAD, UMR CBGP, F-34398 Montpellier, France; (J.H.); (L.B.)
- CBGP, INRAE, CIRAD, IRD, Institut Agro, Université de Montpellier, F-34988 Montpellier, France;
| | - Maxime Galan
- CBGP, INRAE, CIRAD, IRD, Institut Agro, Université de Montpellier, F-34988 Montpellier, France;
- INRA, UMR CBGP, F-34398 Montpellier, France
| | - Thierry Brévault
- CIRAD, UPR AIDA, Centre de recherche ISRA-IRD, Dakar, Senegal;
- AIDA, Univ Montpellier, CIRAD, F-34398 Montpellier, France
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31
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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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32
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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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33
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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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34
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Mayorga I, Bichier P, Philpott SM. Local and landscape drivers of bird abundance, species richness, and trait composition in urban agroecosystems. Urban Ecosyst 2020. [DOI: 10.1007/s11252-020-00934-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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35
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Abdala‐Roberts L, Puentes A, Finke DL, Marquis RJ, Montserrat M, Poelman EH, Rasmann S, Sentis A, van Dam NM, Wimp G, Mooney K, Björkman C. Tri-trophic interactions: bridging species, communities and ecosystems. Ecol Lett 2019; 22:2151-2167. [PMID: 31631502 PMCID: PMC6899832 DOI: 10.1111/ele.13392] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/18/2019] [Accepted: 09/05/2019] [Indexed: 01/12/2023]
Abstract
A vast body of research demonstrates that many ecological and evolutionary processes can only be understood from a tri-trophic viewpoint, that is, one that moves beyond the pairwise interactions of neighbouring trophic levels to consider the emergent features of interactions among multiple trophic levels. Despite its unifying potential, tri-trophic research has been fragmented, following two distinct paths. One has focused on the population biology and evolutionary ecology of simple food chains of interacting species. The other has focused on bottom-up and top-down controls over the distribution of biomass across trophic levels and other ecosystem-level variables. Here, we propose pathways to bridge these two long-standing perspectives. We argue that an expanded theory of tri-trophic interactions (TTIs) can unify our understanding of biological processes across scales and levels of organisation, ranging from species evolution and pairwise interactions to community structure and ecosystem function. To do so requires addressing how community structure and ecosystem function arise as emergent properties of component TTIs, and, in turn, how species traits and TTIs are shaped by the ecosystem processes and the abiotic environment in which they are embedded. We conclude that novel insights will come from applying tri-trophic theory systematically across all levels of biological organisation.
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Affiliation(s)
- Luis Abdala‐Roberts
- Departamento de Ecología TropicalCampus de Ciencias Biológicas y AgropecuariasUniversidad Autónoma de YucatánKm. 15.5 Carretera Mérida‐XmatkuilMX‐97000MéridaYucatánMéxico
| | - Adriana Puentes
- Department of EcologySwedish University of Agricultural SciencesBox 7044SE‐750 07UppsalaSweden
| | - Deborah L. Finke
- Division of Plant SciencesUniversity of Missouri1‐33 Agriculture BuildingUS‐65211ColumbiaMOUSA
| | - Robert J. Marquis
- Department of Biology and the Whitney R. Harris World Ecology CenterUniversity of Missouri–St. Louis1 University BoulevardUS‐63121St. LouisMOUSA
| | - Marta Montserrat
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM‐UMA‐CSIC)Consejo Superior de Investigaciones CientíficasE‐29750Algarrobo‐Costa (Málaga)Spain
| | - Erik H. Poelman
- Laboratory of EntomologyWageningen UniversityP.O. Box 166700 AAWageningenThe Netherlands
| | - Sergio Rasmann
- Institute of BiologyUniversity of NeuchâtelRue Emile‐Argand 11CH‐2000NeuchâtelSwitzerland
| | - Arnaud Sentis
- UMR RECOVERIRSTEAAix Marseille University3275 route Cézanne13182Aix‐en‐ProvenceFrance
| | - Nicole M. van Dam
- Molecular Interaction EcologyFriedrich‐Schiller‐University Jena & German Centre for Integrative Biodiversity Research (iDiv)Halle‐Jena‐LeipzigDeutscher Platz 5eDE‐04103LeipzigGermany
| | - Gina Wimp
- Department of BiologyGeorgetown University406 Reiss Science BuildingUS‐20057WashingtonDCUSA
| | - Kailen Mooney
- Department of Ecology and Evolutionary BiologyUniversity of California Irvine321 Steinhaus HallUS‐92697IrvineCAUSA
| | - Christer Björkman
- Department of EcologySwedish University of Agricultural SciencesBox 7044SE‐750 07UppsalaSweden
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Singer MS, Clark RE, Johnson ER, Lichter‐Marck IH, Mooney KA, Whitney KD. Dietary specialization is conditionally associated with increased ant predation risk in a temperate forest caterpillar community. Ecol Evol 2019; 9:12099-12112. [PMID: 31844517 PMCID: PMC6854387 DOI: 10.1002/ece3.5662] [Citation(s) in RCA: 5] [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: 10/04/2018] [Revised: 07/15/2019] [Accepted: 08/27/2019] [Indexed: 11/10/2022] Open
Abstract
The enemy-free space hypothesis (EFSH) contends that generalist predators select for dietary specialization in insect herbivores. At a community level, the EFSH predicts that dietary specialization reduces predation risk, and this pattern has been found in several studies addressing the impact of individual predator taxa or guilds. However, predation at a community level is also subject to combinatorial effects of multiple-predator types, raising the question of how so-called multiple-predator effects relate to dietary specialization in insect herbivores. Here, we test the EFSH with a field experiment quantifying ant predation risk to insect herbivores (caterpillars) with and without the combined predation effects of birds. Assessing a community of 20 caterpillar species, we use model selection in a phylogenetic comparative framework to identify the caterpillar traits that best predict the risk of ant predation. A caterpillar species' abundance, dietary specialization, and behavioral defenses were important predictors of its ant predation risk. Abundant caterpillar species had increased risk of ant predation irrespective of bird predation. Caterpillar species with broad diet breadth and behavioral responsiveness to attack had reduced ant predation risk, but these ant effects only occurred when birds also had access to the caterpillar community. These findings suggest that ant predation of caterpillar species is density- or frequency-dependent, that ants and birds may impose countervailing selection on dietary specialization within the same herbivore community, and that contingent effects of multiple predators may generate behaviorally mediated life-history trade-offs associated with herbivore diet breadth.
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Affiliation(s)
| | | | | | | | - Kailen A. Mooney
- Department of Ecology and Evolutionary BiologyUniversity of California at IrvineIrvineCAUSA
| | - Kenneth D. Whitney
- Department of Biological SciencesUniversity of New MexicoAlbuquerqueNMUSA
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37
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Fülöp D, Szita É, Gerstenbrand R, Tholt G, Samu F. Consuming alternative prey does not influence the DNA detectability half-life of pest prey in spider gut contents. PeerJ 2019; 7:e7680. [PMID: 31660259 PMCID: PMC6814063 DOI: 10.7717/peerj.7680] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 08/15/2019] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Key natural enemy-pest interactions can be mapped in agricultural food webs by analysing predator gut content for the presence of a focal pest species. For this, PCR-based approaches are the most widely used methods providing the incidence of consumption of a focal pest in field sampled predators. To interpret such data the rate of prey DNA decay in the predators' gut, described by DNA detectability half-life (t 1/2), is needed. DNA decay may depend on the presence of alternative prey in the gut of generalist predators, but this effect has not been investigated in one of the major predatory arthropod groups, spiders. METHODS In a laboratory feeding experiment, we determined t 1/2 of the key cereal pest virus vector leafhopper Psammotettix alienus in the digestive tracts of its natural enemy, the spider Tibellus oblongus. We followed the fate of prey DNA in spiders which received only the focal prey as food, or as an alternative prey treatment they also received a meal of fruit flies after leafhopper consumption. After these feeding treatments, spiders were starved for variable time intervals prior to testing for leafhopper DNA in order to establish t 1/2. RESULTS We created a PCR protocol that detects P. alienus DNA in its spider predator. The protocol was further calibrated to the digestion speed of the spider by establishing DNA decay rate. Detectability limit was reached at 14 days, where c. 10% of the animals tested positive. The calculated t 1/2 = 5 days value of P. alienus DNA did not differ statistically between the treatment groups which received only the leafhopper prey or which also received fruit fly. The PCR protocol was validated in a field with known P. alienus infestation. In this applicability trial, we showed that 12.5% of field collected spiders were positive for the leafhopper DNA. We conclude that in our model system the presence of alternative prey did not influence the t 1/2 estimate of a pest species, which makes laboratory protocols more straightforward for the calibration of future field data.
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Affiliation(s)
- Dávid Fülöp
- Department of Zoology, Plant Protection Institute, Centre for Agricultural Research, Budapest, Hungary
| | - Éva Szita
- Department of Zoology, Plant Protection Institute, Centre for Agricultural Research, Budapest, Hungary
| | - Regina Gerstenbrand
- Department of Zoology, Plant Protection Institute, Centre for Agricultural Research, Budapest, Hungary
| | - Gergely Tholt
- Department of Zoology, Plant Protection Institute, Centre for Agricultural Research, Budapest, Hungary
| | - Ferenc Samu
- Department of Zoology, Plant Protection Institute, Centre for Agricultural Research, Budapest, Hungary
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38
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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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39
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Loehle C, Scherr M, Verschuyl J. Foliage Arthropod Biomass Equations for Open Vegetation Conditions of the Pacific Coast Range. NORTHWEST SCIENCE 2019. [DOI: 10.3955/046.093.0206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Craig Loehle
- National Council for Air and Stream Improvement, Inc., 1258 Windemere Avenue, Naperville, Illinois 60564
| | - Melissa Scherr
- Oregon State University Department of Crop and Soil Science, 3017 ALS Building, Corvallis, Oregon 97331
| | - Jake Verschuyl
- National Council for Air and Stream Improvement, Inc., PO Box 1259, Anacortes, Washington 98221
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Nell CS, Mooney KA. Plant structural complexity mediates trade‐off in direct and indirect plant defense by birds. Ecology 2019; 100:e02853. [DOI: 10.1002/ecy.2853] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 07/19/2019] [Accepted: 07/22/2019] [Indexed: 02/04/2023]
Affiliation(s)
- Colleen S. Nell
- Department of Ecology & Evolutionary Biology UC Irvine 321 Steinhaus Hall Irvine California 92697 USA
| | - Kailen A. Mooney
- Department of Ecology & Evolutionary Biology UC Irvine 321 Steinhaus Hall Irvine California 92697 USA
- Center for Environmental Biology UC Irvine Irvine California 92697 USA
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Štrobl M, Saska P, Seidl M, Kocian M, Tajovský K, Řezáč M, Skuhrovec J, Marhoul P, Zbuzek B, Jakubec P, Knapp M, Kadlec T. Impact of an invasive tree on arthropod assemblages in woodlots isolated within an intensive agricultural landscape. DIVERS DISTRIB 2019. [DOI: 10.1111/ddi.12981] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Martin Štrobl
- Department of Ecology, Faculty of Environmental Sciences Czech University of Life Sciences Prague Praha – Suchdol Czech Republic
| | - Pavel Saska
- Department of Ecology, Faculty of Environmental Sciences Czech University of Life Sciences Prague Praha – Suchdol Czech Republic
- Crop Research Institute Prague 6 – Ruzyně Czech Republic
| | - Miroslav Seidl
- Department of Ecology, Faculty of Environmental Sciences Czech University of Life Sciences Prague Praha – Suchdol Czech Republic
| | - Matúš Kocian
- Department of Ecology, Faculty of Environmental Sciences Czech University of Life Sciences Prague Praha – Suchdol Czech Republic
| | - Karel Tajovský
- Institute of Soil Biology Biology Centre of the Czech Academy of Sciences České Budějovice Czech Republic
| | - Milan Řezáč
- Crop Research Institute Prague 6 – Ruzyně Czech Republic
| | - Jiří Skuhrovec
- Crop Research Institute Prague 6 – Ruzyně Czech Republic
| | | | - Bořivoj Zbuzek
- Crop Research Institute Prague 6 – Ruzyně Czech Republic
| | - Pavel Jakubec
- Department of Ecology, Faculty of Environmental Sciences Czech University of Life Sciences Prague Praha – Suchdol Czech Republic
| | - Michal Knapp
- Department of Ecology, Faculty of Environmental Sciences Czech University of Life Sciences Prague Praha – Suchdol Czech Republic
| | - Tomáš Kadlec
- Department of Ecology, Faculty of Environmental Sciences Czech University of Life Sciences Prague Praha – Suchdol Czech Republic
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Koemel NA, Barnes CL, Wilder SM. Metabolic and behavioral responses of predators to prey nutrient content. JOURNAL OF INSECT PHYSIOLOGY 2019; 116:25-31. [PMID: 31009622 DOI: 10.1016/j.jinsphys.2019.04.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 04/12/2019] [Accepted: 04/18/2019] [Indexed: 06/09/2023]
Abstract
Predators feed on a diversity of prey that can vary widely in nutrient content. While prey nutrient content is known to have important consequences for life history traits, less is known about how it affects physiology and behavior. The purpose of this study was to test how diet affected the physiology and behavior of the wolf spider Hogna carolinensis. We hypothesized that higher protein intake would result in a lower metabolic rate due to less energy intake. Further, we also expected the high protein group to exhibit increased activity levels and aggression in an attempt to increase energy intake. Spiders were maintained on three different treatment diets in order to simulate prey with differing macronutrient composition: high protein, intermediate, and high lipid. Spider respiration was measured to quantify the baseline metabolic rate (SMR), digestive metabolic rate (SDA), and active metabolic rate (AMR). We found no significant effect of diet on metabolic rates. However, the SDA coefficient (i.e. digestive cost relative to prey content) was higher in the high protein group, meaning that this group metabolized a greater portion of their prey during digestion and had a lower net energy intake from prey. In our behavioral assays, spiders in the high protein group were significantly more active and attacked prey more quickly in their first trial. Our results demonstrate that diet had relatively little effect on predator metabolism but more of an effect on behavior. These findings suggest that diet regulation should be analyzed by studying multiple responses together, including metabolism and behavior, to gain a more comprehensive understanding of the effects of diet on organism performance and fitness.
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Affiliation(s)
- Nicholas A Koemel
- Department of Integrative Biology, Oklahoma State University, 501 Life Science West, Stillwater, OK 74075, USA
| | - Cody L Barnes
- Department of Integrative Biology, Oklahoma State University, 501 Life Science West, Stillwater, OK 74075, USA
| | - Shawn M Wilder
- Department of Integrative Biology, Oklahoma State University, 501 Life Science West, Stillwater, OK 74075, USA.
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Wilder SM, Barnes CL, Hawlena D. Predicting Predator Nutrient Intake From Prey Body Contents. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00042] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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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: 13] [Impact Index Per Article: 2.6] [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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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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Nell CS, Abdala-Roberts L, Parra-Tabla V, Mooney KA. Tropical tree diversity mediates foraging and predatory effects of insectivorous birds. Proc Biol Sci 2018; 285:rspb.2018.1842. [PMID: 30404881 DOI: 10.1098/rspb.2018.1842] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 10/17/2018] [Indexed: 11/12/2022] Open
Abstract
Biodiversity affects the structure of ecological communities, but little is known about the interactive effects of diversity across multiple trophic levels. We used a large-scale forest diversity experiment to investigate the effects of tropical tree species richness on insectivorous birds, and the subsequent indirect effect on predation rates by birds. Diverse plots (four tree species) had higher bird abundance (61%), phylogenetic diversity (61%), and functional diversity (55%) than predicted based on single-species monocultures, which corresponded to higher attack rates on artificial caterpillars (65%). Tree diversity effects on attack rate were driven by complementarity among tree species, with increases in attack rate observed on all tree species in polycultures. Attack rates on artificial caterpillars were higher in plots with higher bird abundance and diversity, but the indirect effect of tree species richness was mediated by bird diversity, providing evidence that diversity can interact across trophic levels with consequences tied to ecosystem services and function.
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Affiliation(s)
- Colleen S Nell
- Department of Ecology and Evolutionary Biology, University of California, 92697 Irvine, CA, USA
| | - Luis Abdala-Roberts
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, 97000 Mérida, Yucatan, Mexico
| | - Victor Parra-Tabla
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, 97000 Mérida, Yucatan, Mexico
| | - Kailen A Mooney
- Department of Ecology and Evolutionary Biology, University of California, 92697 Irvine, CA, USA
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Parratt SR, Laine A. Pathogen dynamics under both bottom-up host resistance and top-down hyperparasite attack. J Appl Ecol 2018; 55:2976-2985. [PMID: 30449900 PMCID: PMC6220889 DOI: 10.1111/1365-2664.13185] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/19/2018] [Indexed: 02/04/2023]
Abstract
The relative importance of bottom-up versus top-down control of population dynamics has been the focus of much debate. In infectious disease biology, research is typically focused on the bottom-up process of host resistance, wherein the direction of control flows from the lower to the higher trophic level to impact on pathogen population size and epidemiology. However, the importance of top-down control by a pathogen's natural enemies has been mostly overlooked.Here, we explore the effects of, and interaction between, host genotype (i.e., genetic susceptibility to pathogen infection) and infection by a hyperparasitic fungus, Ampelomyces spp., on the establishment and early epidemic growth and transmission of a powdery mildew plant pathogen (Podosphaera plantaginis). We used a semi-natural field experiment to contrast the impacts of hyperparasite infection, host-plant resistance and spatial structure to reveal the key factors that determine pathogen spread. We then used a laboratory-based inoculation approach to test whether the field experiment results hold across multiple pathogen-host genetic combinations and to explore hyperparasite effects on the pathogen's later life-history stages.We found that hyperparasite infection had a negligible effect on within-host infection development and between-host spread of the pathogen during the onset of epidemics. In contrast, host-plant resistance was the major determinant of whether plants became infected, and host genotype and proximity to an infection source determined infection severity.Our laboratory study showed that, while the interaction between host and pathogen genotypes was the key determinant of infection outcome, hyperparasitism did, on average, reduce the severity of infection. Moreover, hyperparasite infection negatively influenced the production of the pathogen's overwintering structures. Synthesis and applications. Our results suggest that bottom-up host resistance affects pathogen spread, but top-down control of powdery mildew pathogens is likely more effective against later life-history stages. Further, while hyperparasitism in this system can reduce early pathogen growth under stable laboratory conditions, this effect is not detectable in a semi-natural environment. Considering the effects of hyperparasites at multiple points in pathogen's life history will be important when considering hyperparasite-derived biocontrol measures in other natural and agricultural systems.
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Affiliation(s)
- Steven R. Parratt
- Research Centre for Ecological ChangeUniversity of HelsinkiHelsinkiFinland
| | - Anna‐Liisa Laine
- Research Centre for Ecological ChangeUniversity of HelsinkiHelsinkiFinland
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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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Hite JL, Hughey MC, Warkentin KM, Vonesh JR. Cross‐ecosystem effects of terrestrial predators link treefrogs, zooplankton, and aquatic primary production. Ecosphere 2018. [DOI: 10.1002/ecs2.2377] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Jessica L. Hite
- Department of Biology Virginia Commonwealth University Richmond Virginia 23284 USA
| | - Myra C. Hughey
- Department of Biology Boston University Boston Massachusetts 02215 USA
| | - Karen M. Warkentin
- Department of Biology Boston University Boston Massachusetts 02215 USA
- Smithsonian Tropical Research Institute Apartado Postal 0843–03092 Panamá Panamá
| | - James R. Vonesh
- Department of Biology Virginia Commonwealth University Richmond Virginia 23284 USA
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50
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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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