1
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Abraham JO, Lin B, Miller AE, Henry LP, Demmel MY, Warungu R, Mwangi M, Lobura PM, Pallares LF, Ayroles JF, Pringle RM, Rubenstein DI. Determinants of microbiome composition: Insights from free-ranging hybrid zebras (Equus quagga × grevyi). Mol Ecol 2024; 33:e17370. [PMID: 38682799 DOI: 10.1111/mec.17370] [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] [Revised: 04/12/2024] [Accepted: 04/17/2024] [Indexed: 05/01/2024]
Abstract
The composition of mammalian gut microbiomes is highly conserved within species, yet the mechanisms by which microbiome composition is transmitted and maintained within lineages of wild animals remain unclear. Mutually compatible hypotheses exist, including that microbiome fidelity results from inherited dietary habits, shared environmental exposure, morphophysiological filtering and/or maternal effects. Interspecific hybrids are a promising system in which to interrogate the determinants of microbiome composition because hybrids can decouple traits and processes that are otherwise co-inherited in their parent species. We used a population of free-living hybrid zebras (Equus quagga × grevyi) in Kenya to evaluate the roles of these four mechanisms in regulating microbiome composition. We analysed faecal DNA for both the trnL-P6 and the 16S rRNA V4 region to characterize the diets and microbiomes of the hybrid zebra and of their parent species, plains zebra (E. quagga) and Grevy's zebra (E. grevyi). We found that both diet and microbiome composition clustered by species, and that hybrid diets and microbiomes were largely nested within those of the maternal species, plains zebra. Hybrid microbiomes were less variable than those of either parent species where they co-occurred. Diet and microbiome composition were strongly correlated, although the strength of this correlation varied between species. These patterns are most consistent with the maternal-effects hypothesis, somewhat consistent with the diet hypothesis, and largely inconsistent with the environmental-sourcing and morphophysiological-filtering hypotheses. Maternal transmittance likely operates in conjunction with inherited feeding habits to conserve microbiome composition within species.
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Affiliation(s)
- Joel O Abraham
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Bing Lin
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
- School of Public and International Affairs, Princeton University, Princeton, New Jersey, USA
| | - Audrey E Miller
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Lucas P Henry
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
- Department of Biology, New York University, New York City, New York, USA
| | - Margaret Y Demmel
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
- Section of Ecology, Behavior and Evolution, University of California San Diego, San Diego, California, USA
| | | | | | | | - Luisa F Pallares
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, USA
- Friedrich Miescher Laboratory, Max Planck Society, Tübingen, Germany
| | - Julien F Ayroles
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, USA
| | - Robert M Pringle
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Daniel I Rubenstein
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
- Mpala Research Conservancy, Laikipia County, Kenya
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2
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Svenning JC, Buitenwerf R, Le Roux E. Trophic rewilding as a restoration approach under emerging novel biosphere conditions. Curr Biol 2024; 34:R435-R451. [PMID: 38714176 DOI: 10.1016/j.cub.2024.02.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2024]
Abstract
Rewilding is a restoration approach that aims to promote self-regulating complex ecosystems by restoring non-human ecological processes while reducing human control and pressures. Rewilding is forward-looking in that it aims to enhance functionality for biodiversity, accepting and indeed promoting the dynamic nature of ecosystems, rather than fixating on static composition or structure. Rewilding is thus especially relevant in our epoch of increasingly novel biosphere conditions, driven by strong human-induced global change. Here, we explore this hypothesis in the context of trophic rewilding - the restoration of trophic complexity mediated by wild, large-bodied animals, known as 'megafauna'. This focus reflects the strong ecological impacts of large-bodied animals, their widespread loss during the last 50,000 years and their high diversity and ubiquity in the preceding 50 million years. Restoring abundant, diverse, wild-living megafauna is expected to promote vegetation heterogeneity, seed dispersal, nutrient cycling and biotic microhabitats. These are fundamental drivers of biodiversity and ecosystem function and are likely to gain importance for maintaining a biodiverse biosphere under increasingly novel ecological conditions. Non-native megafauna species may contribute to these effects as ecological surrogates of extinct species or by promoting ecological functionality within novel assemblages. Trophic rewilding has strong upscaling potential via population growth and expansion of wild fauna. It is likely to facilitate biotic adaptation to changing climatic conditions and resilience to ecosystem collapse, and to curb some negative impacts of globalization, notably the dominance of invasive alien plants. Finally, we discuss the complexities of realizing the biodiversity benefits that trophic rewilding offers under novel biosphere conditions in a heavily populated world.
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Affiliation(s)
- Jens-Christian Svenning
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO), Department of Biology, Aarhus University, Ny Munkegade 114, DK-8000 Aarhus C, Denmark.
| | - Robert Buitenwerf
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO), Department of Biology, Aarhus University, Ny Munkegade 114, DK-8000 Aarhus C, Denmark
| | - Elizabeth Le Roux
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO), Department of Biology, Aarhus University, Ny Munkegade 114, DK-8000 Aarhus C, Denmark; Department of Zoology and Entomology, Faculty of Natural and Agricultural Sciences, Mammal Research Institute, University of Pretoria, Pretoria 0028, South Africa
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3
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Mata JC, Davison CW, Frøslev TG, Buitenwerf R, Svenning JC. Resource partitioning in a novel herbivore assemblage in South America. J Anim Ecol 2024; 93:606-618. [PMID: 38414265 DOI: 10.1111/1365-2656.14069] [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: 10/20/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024]
Abstract
Human-induced species declines and extinctions have led to the downsizing of large-herbivore assemblages, with implications for many ecosystem processes. Active reintroduction of extirpated large herbivores or their functional equivalents may help to reverse this trend and restore diverse ecosystems and their processes. However, it is unclear whether resource competition between native and non-native herbivores could threaten restoration initiatives, or to what extent (re)introduced species may influence local vegetation dynamics. To answer these questions, we investigated the diets of a novel South American herbivore assemblage that includes resident native species, reintroduced native species and introduced non-native species. We examined plant composition, diet breadth and the overlap between species to describe the local herbivory profile and the potential for resource competition. Using DNA metabarcoding on faecal samples (n = 465), we analysed the diets of the herbivore assemblage in the Rincón del Socorro rewilding area of Iberá National Park, Argentina. We compared the species richness of faecal samples, the occurrence of plant families/growth forms and the compositional similarity of samples (inter- and intraspecifically). Our results indicate species-level taxonomic partitioning of plant resources by herbivores in this system. Differences in sample richness, composition and diet breadth reflected a diverse range of herbivory strategies, from grazers (capybara) to mixed feeders/browsers (brocket deer, lowland tapir). Differences in diet compositional similarity (Jaccard) revealed strong taxonomic resource partitioning. The two herbivores with the most similar diets (Pampas deer and brocket deer) still differed by more than 80%. Furthermore, all but one species (axis deer) had more similar diet composition intraspecifically than compared to the others. Overall, we found little evidence for resource competition between herbivore species. Instead, recently reintroduced native species and historically introduced non-natives are likely expanding the range of herbivory dynamics in the ecosystem. Further research will be needed to determine the full ecological impacts of these (re)introduced herbivores. In conclusion, we show clear differences in diet breadth and composition among native, reintroduced and non-native herbivore species that may be key to promoting resource partitioning, species coexistence and the restoration of ecological function.
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Affiliation(s)
- Julia C Mata
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus C, Denmark
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO), Department of Biology, Aarhus University, Aarhus C, Denmark
| | - Charles W Davison
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus C, Denmark
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO), Department of Biology, Aarhus University, Aarhus C, Denmark
| | | | - Robert Buitenwerf
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus C, Denmark
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO), Department of Biology, Aarhus University, Aarhus C, Denmark
| | - Jens-Christian Svenning
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus C, Denmark
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO), Department of Biology, Aarhus University, Aarhus C, Denmark
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4
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da Silva LP, Mata VA, Lopes PB, Pinho CJ, Chaves C, Correia E, Pinto J, Heleno RH, Timoteo S, Beja P. Dietary metabarcoding reveals the simplification of bird-pest interaction networks across a gradient of agricultural cover. Mol Ecol 2024; 33:e17324. [PMID: 38506491 DOI: 10.1111/mec.17324] [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: 02/28/2024] [Accepted: 03/12/2024] [Indexed: 03/21/2024]
Abstract
Agriculture is vital for supporting human populations, but its intensification often leads to landscape homogenization and a decline in non-provisioning ecosystem services. Ecological intensification and multifunctional landscapes are suggested as nature-based alternatives to intensive agriculture, using ecological processes like natural pest regulation to maximize food production. Birds are recognized for their role in increasing crop yields by consuming invertebrate pests in several agroecosystems. However, the understanding of how bird species, their traits and agricultural land cover influence the structure of bird-pest interactions remains limited. We sampled bird-pest interactions monthly for 1 year, at four sites within a multifunctional landscape, following a gradient of increasing agricultural land cover. We analysed 2583 droppings of 55 bird species with DNA metabarcoding and detected 225 pest species in 1139 samples of 42 bird species. As expected, bird-pest interactions were highly variable across bird species. Dietary pest richness was lower in the fully agricultural site, while predation frequency remained consistent across the agricultural land cover gradient. Network analysis revealed a reduction in the complexity of bird-pest interactions as agricultural coverage increased. Bird species abundance affected the bird's contribution to the network structure more than any of the bird traits analysed (weight, phenology, invertebrate frequency in diet and foraging strata), with more common birds being more important to network structure. Overall, our results show that increasing agricultural land cover increases the homogenization of bird-pest interactions. This shows the importance of maintaining natural patches within agricultural landscapes for biodiversity conservation and enhanced biocontrol.
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Affiliation(s)
- Luis P da Silva
- CIBIO, Centro de Investigação Em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
| | - Vanessa A Mata
- CIBIO, Centro de Investigação Em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
| | - Pedro B Lopes
- CIBIO, Centro de Investigação Em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
| | - Catarina J Pinho
- CIBIO, Centro de Investigação Em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Porto, Portugal
| | - Catia Chaves
- CIBIO, Centro de Investigação Em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
| | - Edna Correia
- Departamento de Biologia Animal, Centro de Estudos Do Ambiente e Do Mar, Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal
| | - Joana Pinto
- CIBIO, Centro de Investigação Em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
| | - Ruben H Heleno
- Department of Life Sciences, Centre for Functional Ecology, Associate Laboratory TERRA, University of Coimbra, Coimbra, Portugal
| | - Sergio Timoteo
- Department of Life Sciences, Centre for Functional Ecology, Associate Laboratory TERRA, University of Coimbra, Coimbra, Portugal
| | - Pedro Beja
- CIBIO, Centro de Investigação Em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
- CIBIO, Centro de Investigação Em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Institute of Agronomy, University of Lisbon, Lisbon, Portugal
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5
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Harvey Sky N, Britnell J, Antwis R, Kartzinel T, Rubenstein D, Toye P, Karani B, Njeru R, Hinchcliffe D, Gaymer J, Mutisya S, Shultz S. Linking diet switching to reproductive performance across populations of two critically endangered mammalian herbivores. Commun Biol 2024; 7:333. [PMID: 38491117 PMCID: PMC10943211 DOI: 10.1038/s42003-024-05983-3] [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: 07/11/2023] [Accepted: 02/27/2024] [Indexed: 03/18/2024] Open
Abstract
Optimal foraging theory predicts that animals maximise energy intake by consuming the most valuable foods available. When resources are limited, they may include lower-quality fallback foods in their diets. As seasonal herbivore diet switching is understudied, we evaluate its extent and effects across three Kenyan reserves each for Critically Endangered eastern black rhino (Diceros bicornis michaeli) and Grevy's zebra (Equus grevyi), and its associations with habitat quality, microbiome variation, and reproductive performance. Black rhino diet breadth increases with vegetation productivity (NDVI), whereas zebra diet breadth peaks at intermediate NDVI. Black rhino diets associated with higher vegetation productivity have less acacia (Fabaceae: Vachellia and Senegalia spp.) and more grass suggesting that acacia are fallback foods, upending conventional assumptions. Larger dietary shifts are associated with longer calving intervals. Grevy's zebra diets in high rainfall areas are consistently grass-dominated, whereas in arid areas they primarily consume legumes during low vegetation productivity periods. Whilst microbiome composition between individuals is affected by the environment, and diet composition in black rhino, seasonal dietary shifts do not drive commensurate microbiome shifts. Documenting diet shifts across ecological gradients can increase the effectiveness of conservation by informing habitat suitability models and improving understanding of responses to resource limitation.
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Affiliation(s)
- Nick Harvey Sky
- Department of Earth and Environmental Sciences, University of Manchester, Manchester, M13 9NT, UK.
- North of England Zoological Society, Chester Zoo, Upton-by-Chester, CH2 1LH, UK.
| | - Jake Britnell
- Department of Earth and Environmental Sciences, University of Manchester, Manchester, M13 9NT, UK
- North of England Zoological Society, Chester Zoo, Upton-by-Chester, CH2 1LH, UK
| | - Rachael Antwis
- School of Environment and Life Sciences, University of Salford, Salford, M5 4WX, UK
| | - Tyler Kartzinel
- Department of Ecology, Evolution, and Organismal Biology, Brown University, 85 Waterman Street, Providence, RI, 02912, USA
- Institute at Brown for Environment and Society, Brown University, 85 Waterman Street, Providence, RI, 02912, USA
| | - Daniel Rubenstein
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544-2016, USA
| | - Phil Toye
- International Livestock Research Institute and Centre for Tropical Livestock Genetics and Health, Nairobi, P.O. Box 30709-00100, Kenya
| | - Benedict Karani
- International Livestock Research Institute and Centre for Tropical Livestock Genetics and Health, Nairobi, P.O. Box 30709-00100, Kenya
| | - Regina Njeru
- International Livestock Research Institute and Centre for Tropical Livestock Genetics and Health, Nairobi, P.O. Box 30709-00100, Kenya
| | - Danielle Hinchcliffe
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | | | | | - Susanne Shultz
- Department of Earth and Environmental Sciences, University of Manchester, Manchester, M13 9NT, UK
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6
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Zhu D, Liu Y, Gong L, Si M, Wang Q, Feng J, Jiang T. The Consumption and Diversity Variation Responses of Agricultural Pests and Their Dietary Niche Differentiation in Insectivorous Bats. Animals (Basel) 2024; 14:815. [PMID: 38473199 DOI: 10.3390/ani14050815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/21/2024] [Accepted: 03/05/2024] [Indexed: 03/14/2024] Open
Abstract
Insectivorous bats are generalist predators and can flexibly respond to fluctuations in the distribution and abundance of insect prey. To better understand the effects of bats on arthropod pests, the types of pests eaten by bats and the response of bats to insect prey need to be determined. In this study, we performed DNA metabarcoding to examine prey composition and pest diversity in the diets of four insectivorous species of bats (Hipposideros armiger, Taphozous melanopogon, Aselliscus stoliczkanus, and Miniopterus fuliginosus). We evaluated the correlation between bat activity and insect resources and assessed dietary niche similarity and niche breadth among species and factors that influence prey consumption in bats. We found that the diets of these bats included arthropods from 23 orders and 200 families, dominated by Lepidoptera, Coleoptera, and Diptera. The proportion of agricultural pests in the diet of each of the four species of bats exceeded 40% and comprised 713 agricultural pests, including those that caused severe economic losses. Bats responded to the availability of insects. For example, a higher abundance of insects, especially Lepidoptera, and a higher insect diversity led to an increase in the duration of bat activity. In areas with more abundant insects, the number of bat passes also increased. The dietary composition, diversity, and niches differed among species and were particularly significant between H. armiger and T. melanopogon; the dietary niche width was the greatest in A. stoliczkanus and the narrowest in H. armiger. The diet of bats was correlated with their morphological and echolocation traits. Larger bats preyed more on insects in the order Coleoptera, whereas the proportion of bats consuming insects in the order Lepidoptera increased as the body size decreased. Bats that emitted echolocation calls with a high peak frequency and duration preyed more on insects in the order Mantodea. Our results suggest that dietary niche differentiation promotes the coexistence of different bat species and increases the ability of bats to consume insect prey and agricultural pests. Our findings provide greater insights into the role of bats that prey on agricultural pests and highlight the importance of combining bat conservation with integrated pest management.
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Affiliation(s)
- Dan Zhu
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
- Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Yingying Liu
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
- Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Lixin Gong
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
- Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Man Si
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
- Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Qiuya Wang
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
- Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
- College of Life Science, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, China
| | - Jiang Feng
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
- Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
- College of Life Science, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, China
| | - Tinglei Jiang
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
- Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
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7
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Anderson TM, Hepler SA, Holdo RM, Donaldson JE, Erhardt RJ, Hopcraft JGC, Hutchinson MC, Huebner SE, Morrison TA, Muday J, Munuo IN, Palmer MS, Pansu J, Pringle RM, Sketch R, Packer C. Interplay of competition and facilitation in grazing succession by migrant Serengeti herbivores. Science 2024; 383:782-788. [PMID: 38359113 DOI: 10.1126/science.adg0744] [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: 11/30/2022] [Accepted: 01/10/2024] [Indexed: 02/17/2024]
Abstract
Competition, facilitation, and predation offer alternative explanations for successional patterns of migratory herbivores. However, these interactions are difficult to measure, leaving uncertainty about the mechanisms underlying body-size-dependent grazing-and even whether succession occurs at all. We used data from an 8-year camera-trap survey, GPS-collared herbivores, and fecal DNA metabarcoding to analyze the timing, arrival order, and interactions among migratory grazers in Serengeti National Park. Temporal grazing succession is characterized by a "push-pull" dynamic: Competitive grazing nudges zebra ahead of co-migrating wildebeest, whereas grass consumption by these large-bodied migrants attracts trailing, small-bodied gazelle that benefit from facilitation. "Natural experiments" involving intense wildfires and rainfall respectively disrupted and strengthened these effects. Our results highlight a balance between facilitative and competitive forces in co-regulating large-scale ungulate migrations.
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Affiliation(s)
- T Michael Anderson
- Department of Biology, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Staci A Hepler
- Department of Statistical Sciences, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Ricardo M Holdo
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
| | - Jason E Donaldson
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
| | - Robert J Erhardt
- Department of Statistical Sciences, Wake Forest University, Winston-Salem, NC 27109, USA
| | - J Grant C Hopcraft
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow G61 1QH, UK
| | - Matthew C Hutchinson
- Department of Life & Environmental Sciences, University of California Merced, Merced, CA 95343, USA
| | - Sarah E Huebner
- Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN 55108, USA
| | - Thomas A Morrison
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow G61 1QH, UK
| | - Jeffry Muday
- Department of Biology, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Issack N Munuo
- Serengeti Wildlife Research Centre, 2113 Lemara, Arusha, TZ
| | - Meredith S Palmer
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - Johan Pansu
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - Robert M Pringle
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - Robert Sketch
- Department of Statistical Sciences, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Craig Packer
- Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN 55108, USA
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8
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Abraham JO, Rowan J, O'Brien K, Sokolowski KG, Faith JT. Environmental context shapes the relationship between grass consumption and body size in African herbivore communities. Ecol Evol 2024; 14:e11050. [PMID: 38362169 PMCID: PMC10867881 DOI: 10.1002/ece3.11050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 01/24/2024] [Accepted: 02/05/2024] [Indexed: 02/17/2024] Open
Abstract
Though herbivore grass dependence has been shown to increase with body size across herbivore species, it is unclear whether this relationship holds at the community level. Here we evaluate whether grass consumption scales positively with body size within African large mammalian herbivore communities and how this relationship varies with environmental context. We used stable carbon isotope and community occurrence data to investigate how grass dependence scales with body size within 23 savanna herbivore communities throughout eastern and central Africa. We found that dietary grass fraction increased with body size for the majority of herbivore communities considered, especially when complete community data were available. However, the slope of this relationship varied, and rainfall seasonality and elephant presence were key drivers of the variation-grass dependence increased less strongly with body size where rainfall was more seasonal and where elephants were present. We found also that the dependence of the herbivore community as a whole on grass peaked at intermediate woody cover. Intraspecific diet variation contributed to these community-level patterns: common hippopotamus (Hippopotamus amphibius) and giraffe (Giraffa camelopardalis) ate less grass where rainfall was more seasonal, whereas Cape buffalo (Syncerus caffer) and savanna elephant (Loxodonta africana) grass consumption were parabolically related to woody cover. Our results indicate that general rules appear to govern herbivore community assembly, though some aspects of herbivore foraging behavior depend upon local environmental context.
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Affiliation(s)
- Joel O. Abraham
- Department of Ecology and Evolutionary BiologyPrinceton UniversityPrincetonNew JerseyUSA
| | - John Rowan
- Department of AnthropologyUniversity at AlbanyAlbanyNew YorkUSA
| | - Kaedan O'Brien
- Department of AnthropologyUniversity of UtahSalt Lake CityUtahUSA
- Natural History Museum of UtahUniversity of UtahSalt Lake CityUtahUSA
| | - Kathryn G. Sokolowski
- Department of AnthropologyUniversity of UtahSalt Lake CityUtahUSA
- Natural History Museum of UtahUniversity of UtahSalt Lake CityUtahUSA
| | - J. Tyler Faith
- Department of AnthropologyUniversity of UtahSalt Lake CityUtahUSA
- Natural History Museum of UtahUniversity of UtahSalt Lake CityUtahUSA
- Origins CentreUniversity of the WitwatersrandJohannesburgSouth Africa
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9
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Rioux È, Cabrol J, Lesage V. Long-term evolution of the structure of the St. Lawrence (Canada) marine ecosystem in the context of climate change and anthropogenic activities: An isotopic perceptive. Ecol Evol 2023; 13:e10740. [PMID: 38034343 PMCID: PMC10684986 DOI: 10.1002/ece3.10740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 10/31/2023] [Accepted: 11/03/2023] [Indexed: 12/02/2023] Open
Abstract
Documenting long-term changes in the trophic structure of food webs and how species respond to these changes is essential to forecast their vulnerability and resilience to environmental stressors. Over the past decades, the St. Lawrence marine ecosystem (Canada) has experienced major changes in its physical, chemical, and biological conditions from overfishing, acoustic and chemical pollution, climate change, and the increased abundance of some top predators. These changes have likely affected the trophodynamics of the ecosystem, and are suspected to have deleterious effects on endangered species of mammals and other components of the ecosystem, such as blue whales (Balaenoptera musculus), fin whales (B. physalus), and beluga (Delphinapterus leucas). This study examined the trophic structure of the St. Lawrence marine ecosystem, including the isotopic niche of various species, over two periods of contrasting pressures from anthropogenic and climatic stressors (1995-2003 vs. 2019-2021). Stable isotope ratios were measured in 1240 samples of 21 species of marine invertebrates, fishes, and mammals sampled during both periods. A significant change in the isotopic value and niche position between periods is observed in most of the sampled species. While the direction of change and effect size were not uniform among species, these changes confirmed that substantial modifications in community structure have occurred over time. Niche overlap decreased considerably among some of the pelagic and demersal fishes, and among whale species during the most recent period. Combined with a concomitant reduction in niche breadth in several species, these observations suggested that resource sharing was limited among these species. This study highlighted some degree of dietary plasticity in several species, and a long-term change in the trophic structure of the St. Lawrence marine ecosystem, with likely effects on diet composition and energetics of several populations, including endangered species.
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Affiliation(s)
- Ève Rioux
- Fisheries and Oceans CanadaMaurice Lamontagne InstituteMont‐JoliQuébecCanada
| | - Jory Cabrol
- Fisheries and Oceans CanadaMaurice Lamontagne InstituteMont‐JoliQuébecCanada
| | - Véronique Lesage
- Fisheries and Oceans CanadaMaurice Lamontagne InstituteMont‐JoliQuébecCanada
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10
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Walker RH, Hutchinson MC, Becker JA, Daskin JH, Gaynor KM, Palmer MS, Gonçalves DD, Stalmans ME, Denlinger J, Bouley P, Angela M, Paulo A, Potter AB, Arumoogum N, Parrini F, Marshal JP, Pringle RM, Long RA. Trait-based sensitivity of large mammals to a catastrophic tropical cyclone. Nature 2023; 623:757-764. [PMID: 37968390 DOI: 10.1038/s41586-023-06722-0] [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: 11/15/2022] [Accepted: 10/06/2023] [Indexed: 11/17/2023]
Abstract
Extreme weather events perturb ecosystems and increasingly threaten biodiversity1. Ecologists emphasize the need to forecast and mitigate the impacts of these events, which requires knowledge of how risk is distributed among species and environments. However, the scale and unpredictability of extreme events complicate risk assessment1-4-especially for large animals (megafauna), which are ecologically important and disproportionately threatened but are wide-ranging and difficult to monitor5. Traits such as body size, dispersal ability and habitat affiliation are hypothesized to determine the vulnerability of animals to natural hazards1,6,7. Yet it has rarely been possible to test these hypotheses or, more generally, to link the short-term and long-term ecological effects of weather-related disturbance8,9. Here we show how large herbivores and carnivores in Mozambique responded to Intense Tropical Cyclone Idai, the deadliest storm on record in Africa, across scales ranging from individual decisions in the hours after landfall to changes in community composition nearly 2 years later. Animals responded behaviourally to rising floodwaters by moving upslope and shifting their diets. Body size and habitat association independently predicted population-level impacts: five of the smallest and most lowland-affiliated herbivore species declined by an average of 28% in the 20 months after landfall, while four of the largest and most upland-affiliated species increased by an average of 26%. We attribute the sensitivity of small-bodied species to their limited mobility and physiological constraints, which restricted their ability to avoid the flood and endure subsequent reductions in the quantity and quality of food. Our results identify general traits that govern animal responses to severe weather, which may help to inform wildlife conservation in a volatile climate.
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Affiliation(s)
- Reena H Walker
- Department of Fish and Wildlife Sciences, University of Idaho, Moscow, ID, USA
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Matthew C Hutchinson
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Department of Life and Environmental Sciences, University of California Merced, Merced, CA, USA
| | - Justine A Becker
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Department of Ecology, Montana State University, Bozeman, MT, USA
| | - Joshua H Daskin
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
- Archbold Biological Station, Venus, FL, USA
| | - Kaitlyn M Gaynor
- Departments of Zoology and Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Meredith S Palmer
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Dominique D Gonçalves
- Department of Scientific Services, Gorongosa National Park, Sofala, Mozambique
- Durrell Institute of Conservation and Ecology, University of Kent, Canterbury, UK
| | - Marc E Stalmans
- Department of Scientific Services, Gorongosa National Park, Sofala, Mozambique
| | - Jason Denlinger
- Department of Scientific Services, Gorongosa National Park, Sofala, Mozambique
| | - Paola Bouley
- Department of Conservation, Gorongosa National Park, Sofala, Mozambique
- Associação Azul Moçambique, Maputo, Mozambique
| | - Mercia Angela
- Department of Conservation, Gorongosa National Park, Sofala, Mozambique
| | - Antonio Paulo
- Department of Conservation, Gorongosa National Park, Sofala, Mozambique
| | - Arjun B Potter
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Wake Forest University, Winston-Salem, NC, USA
| | - Nikhail Arumoogum
- Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Francesca Parrini
- Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Jason P Marshal
- Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Robert M Pringle
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA.
| | - Ryan A Long
- Department of Fish and Wildlife Sciences, University of Idaho, Moscow, ID, USA.
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11
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Mungi NA, Jhala YV, Qureshi Q, le Roux E, Svenning JC. Megaherbivores provide biotic resistance against alien plant dominance. Nat Ecol Evol 2023; 7:1645-1653. [PMID: 37652995 DOI: 10.1038/s41559-023-02181-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 07/26/2023] [Indexed: 09/02/2023]
Abstract
While human-driven biological invasions are rapidly spreading, finding scalable and effective control methods poses an unresolved challenge. Here, we assess whether megaherbivores-herbivores reaching ≥1,000 kg of body mass-offer a nature-based solution to plant invasions. Invasive plants are generally adapted to maximize vegetative growth. Megaherbivores, with broad dietary tolerances, could remove large biomass of established plants, facilitating new plant growth. We used a massive dataset obtained from 26,838 camera stations and 158,979 vegetation plots to assess the relationships between megaherbivores, native plants and alien plants across India (~121,330 km2). We found a positive relationship between megaherbivore abundance and native plant richness and abundance, and a concomitant reduction in alien plant abundance. This relationship was strongest in protected areas with midproductive ecosystem and high megaherbivore density but it was lost in areas where thicket-forming alien plants predominated (>40% cover). By incorporating the role of ecosystem productivity, plants traits and densities of megaherbivores on megaherbivore-vegetation relationships, our study highlights a function of megaherbivores in controlling alien plant proliferation and facilitating diverse native plants in invaded ecosystems. The study shows great potential for megafauna-based trophic rewilding as a nature-based solution to counteract dominance of plant invasions.
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Affiliation(s)
- Ninad Avinash Mungi
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) & Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark.
- Wildlife Institute of India, Dehradun, India.
| | | | | | - Elizabeth le Roux
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) & Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
| | - Jens-Christian Svenning
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) & Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
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12
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Fletcher RJ, O'Brien A, Hall TF, Jones M, Potash AD, Kruger L, Simelane P, Roques K, Monadjem A, McCleery RA. Frightened of giants: fear responses to elephants approach that of predators. Biol Lett 2023; 19:20230202. [PMID: 37817576 PMCID: PMC10565413 DOI: 10.1098/rsbl.2023.0202] [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: 05/07/2023] [Accepted: 09/15/2023] [Indexed: 10/12/2023] Open
Abstract
Animals are faced with a variety of dangers or threats, which are increasing in frequency with ongoing environmental change. While our understanding of fearfulness of such dangers is growing in the context of predation and parasitism risk, the extent to which non-trophic, interspecific dangers elicit fear in animals remains less appreciated. We provide an experimental test for fear responses of savannah ungulates to a dominant and aggressive megaherbivore, the African bush elephant (Loxodonta africana), and contrast responses to an apex predator known to elicit fear in this system. Using an automated behavioural response system, we contrast vigilance and run responses of ungulates to elephant, leopard (Panthera pardus), and control (red-chested cuckoo Cuculus solitarius) vocalizations. Overall, we find that ungulates responded to elephant calls, both in terms of an increase in run and vigilance responses relative to controls. The magnitude of most behavioural responses (four of six considered) to elephant vocalizations were not significantly different than responses to leopards. These results suggest that megaherbivores can elicit strong non-trophic fear responses by ungulates and call to broaden frameworks on fear to consider dominant species, such as megaherbivores, as key modifiers of fear-induced interactions.
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Affiliation(s)
- Robert J. Fletcher
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | - Amanda O'Brien
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | - Timothy F. Hall
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Maggie Jones
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | - Alex D. Potash
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | | | - Phumlile Simelane
- All Out Africa, Savannah Research Centre, Mbuluzi Game Reserve, Lubombo, Eswatini
| | - Kim Roques
- All Out Africa, Savannah Research Centre, Mbuluzi Game Reserve, Lubombo, Eswatini
| | - Ara Monadjem
- Department of Biological Sciences, University of Eswatini, Kwaluseni, Eswatini
- Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Pretoria, South Africa
| | - Robert A. McCleery
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
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13
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Gill BA, Wittemyer G, Cerling TE, Musili PM, Kartzinel TR. Foraging history of individual elephants using DNA metabarcoding. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230337. [PMID: 37416829 PMCID: PMC10320352 DOI: 10.1098/rsos.230337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 06/07/2023] [Indexed: 07/08/2023]
Abstract
Individual animals should adjust diets according to food availability. We used DNA metabarcoding to construct individual-level dietary timeseries for elephants from two family groups in Kenya varying in habitat use, social position and reproductive status. We detected at least 367 dietary plant taxa, with up to 137 unique plant sequences in one fecal sample. Results matched well-established trends: elephants tended to eat more grass when it rained and other plants when dry. Nested within these switches from 'grazing' to 'browsing' strategies, dietary DNA revealed seasonal shifts in food richness, composition and overlap between individuals. Elephants of both families converged on relatively cohesive diets in dry seasons but varied in their maintenance of cohesion during wet seasons. Dietary cohesion throughout the timeseries of the subdominant 'Artists' family was stronger and more consistently positive compared to the dominant 'Royals' family. The greater degree of individuality within the dominant family's timeseries could reflect more divergent nutritional requirements associated with calf dependency and/or priority access to preferred habitats. Whereas theory predicts that individuals should specialize on different foods under resource scarcity, our data suggest family bonds may promote cohesion and foster the emergence of diverse feeding cultures reflecting links between social behaviour and nutrition.
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Affiliation(s)
- Brian A. Gill
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, RI 02912, USA
- Institute at Brown for Environment and Society, Brown University, Providence, RI 02912, USA
| | - George Wittemyer
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523, USA
- Save the Elephants, Nairobi, Kenya
| | - Thure E. Cerling
- Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112, USA
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA
| | - Paul M. Musili
- Botany Department, East African Herbarium, National Museums of Kenya, Nairobi, Kenya
| | - Tyler R. Kartzinel
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, RI 02912, USA
- Institute at Brown for Environment and Society, Brown University, Providence, RI 02912, USA
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14
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Pringle RM, Abraham JO, Anderson TM, Coverdale TC, Davies AB, Dutton CL, Gaylard A, Goheen JR, Holdo RM, Hutchinson MC, Kimuyu DM, Long RA, Subalusky AL, Veldhuis MP. Impacts of large herbivores on terrestrial ecosystems. Curr Biol 2023; 33:R584-R610. [PMID: 37279691 DOI: 10.1016/j.cub.2023.04.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Large herbivores play unique ecological roles and are disproportionately imperiled by human activity. As many wild populations dwindle towards extinction, and as interest grows in restoring lost biodiversity, research on large herbivores and their ecological impacts has intensified. Yet, results are often conflicting or contingent on local conditions, and new findings have challenged conventional wisdom, making it hard to discern general principles. Here, we review what is known about the ecosystem impacts of large herbivores globally, identify key uncertainties, and suggest priorities to guide research. Many findings are generalizable across ecosystems: large herbivores consistently exert top-down control of plant demography, species composition, and biomass, thereby suppressing fires and the abundance of smaller animals. Other general patterns do not have clearly defined impacts: large herbivores respond to predation risk but the strength of trophic cascades is variable; large herbivores move vast quantities of seeds and nutrients but with poorly understood effects on vegetation and biogeochemistry. Questions of the greatest relevance for conservation and management are among the least certain, including effects on carbon storage and other ecosystem functions and the ability to predict outcomes of extinctions and reintroductions. A unifying theme is the role of body size in regulating ecological impact. Small herbivores cannot fully substitute for large ones, and large-herbivore species are not functionally redundant - losing any, especially the largest, will alter net impact, helping to explain why livestock are poor surrogates for wild species. We advocate leveraging a broad spectrum of techniques to mechanistically explain how large-herbivore traits and environmental context interactively govern the ecological impacts of these animals.
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Affiliation(s)
- Robert M Pringle
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA.
| | - Joel O Abraham
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - T Michael Anderson
- Department of Biology, Wake Forest University, Winston Salem, NC 27109, USA
| | - Tyler C Coverdale
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Andrew B Davies
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | | | | | - Jacob R Goheen
- Department of Zoology & Physiology, University of Wyoming, Laramie, WY 82072, USA
| | - Ricardo M Holdo
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
| | - Matthew C Hutchinson
- Department of Life & Environmental Sciences, University of California Merced, Merced, CA 95343, USA
| | - Duncan M Kimuyu
- Department of Natural Resources, Karatina University, Karatina, Kenya
| | - Ryan A Long
- Department of Fish and Wildlife Sciences, University of Idaho, Moscow, ID 83844, USA
| | - Amanda L Subalusky
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Michiel P Veldhuis
- Institute of Environmental Sciences, Leiden University, 2333 CC Leiden, The Netherlands
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15
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Phillips EM, Pringle RM. Ecology: How mesopredators run with the big dogs. Curr Biol 2023; 33:R197-R199. [PMID: 36917945 DOI: 10.1016/j.cub.2023.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
Food webs are indispensable maps of community organization, but most are crudely drawn - an inconvenient truth that ecologists must confront. A new DNA metabarcoding study quantifies predator-prey interactions and ecological-network structure with long-overdue precision, supplying insight into how large and small carnivores coexist.
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Affiliation(s)
- Erin M Phillips
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - Robert M Pringle
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA.
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16
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Valdovinos FS, Hale KRS, Dritz S, Glaum PR, McCann KS, Simon SM, Thébault E, Wetzel WC, Wootton KL, Yeakel JD. A bioenergetic framework for aboveground terrestrial food webs. Trends Ecol Evol 2023; 38:301-312. [PMID: 36437144 DOI: 10.1016/j.tree.2022.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/10/2022] [Accepted: 11/04/2022] [Indexed: 11/26/2022]
Abstract
Bioenergetic approaches have been greatly influential for understanding community functioning and stability and predicting effects of environmental changes on biodiversity. These approaches use allometric relationships to establish species' trophic interactions and consumption rates and have been successfully applied to aquatic ecosystems. Terrestrial ecosystems, where body mass is less predictive of plant-consumer interactions, present inherent challenges that these models have yet to meet. Here, we discuss the processes governing terrestrial plant-consumer interactions and develop a bioenergetic framework integrating those processes. Our framework integrates bioenergetics specific to terrestrial plants and their consumers within a food web approach while also considering mutualistic interactions. Such a framework is poised to advance our understanding of terrestrial food webs and to predict their responses to environmental changes.
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Affiliation(s)
- Fernanda S Valdovinos
- Department of Environmental Science and Policy, University of California, Davis, Davis, CA, USA.
| | - Kayla R S Hale
- Department of Environmental Science and Policy, University of California, Davis, Davis, CA, USA; Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Sabine Dritz
- Department of Environmental Science and Policy, University of California, Davis, Davis, CA, USA
| | - Paul R Glaum
- Department of Environmental Science and Policy, University of California, Davis, Davis, CA, USA
| | - Kevin S McCann
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - Sophia M Simon
- Department of Environmental Science and Policy, University of California, Davis, Davis, CA, USA
| | - Elisa Thébault
- Sorbonne Université, UPEC, Université Paris Cité, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris, Paris, France
| | - William C Wetzel
- Department of Integrative Biology, Michigan State University, East Lansing, MI, USA; Department of Entomology, Michigan State University, East Lansing, MI, USA
| | - Kate L Wootton
- BioFrontiers Institute at the University of Colorado, Boulder, CO, USA
| | - Justin D Yeakel
- Department of Life & Environmental Sciences, University of California, Merced, CA, USA
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17
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Lu Q, Cheng C, Xiao L, Li J, Li X, Zhao X, Lu Z, Zhao J, Yao M. Food webs reveal coexistence mechanisms and community organization in carnivores. Curr Biol 2023; 33:647-659.e5. [PMID: 36669497 DOI: 10.1016/j.cub.2022.12.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/11/2022] [Accepted: 12/20/2022] [Indexed: 01/20/2023]
Abstract
Globally, massive carnivore guild extirpations have led to trophic downgrading and compromised ecosystem services. However, the complexity of multi-carnivore food webs complicates accurate identification of species interactions and community organization. Here, we used fecal DNA metabarcoding to investigate three communities that together encompass eight large- and meso-carnivore species and their 44 prey taxa of the Qinghai-Tibet Plateau (QTP), one of the last places on Earth that still harbors intact carnivore assemblages. Quantitative food-web analyses revealed pronounced interspecific variations in the carnivores' prey compositions and dietary partitioning both between and within guilds. Additionally, body masses of the carnivores and their prey exhibited consistent hump-shaped correlations across communities. Overall, differences in prey diversity, size category, and proportional utilization among the carnivore species result in trophic niche segregation that likely promotes carnivore coexistence in the harsh QTP environment. Network structure analyses detected significant modularity in all food webs but nestedness in only one. Furthermore, network characterization identified pikas (Ochotona spp.), bharal (Pseudois nayaur), and domestic yak (Bos grunniens) as potential keystone prey across the areas. Our results paint a holistic and detailed picture of the QTP carnivore assemblages' trophic networks and demonstrate that the combined use of the molecular dietary approach and network analysis can generate structural insights into carnivore coexistence and can identify functionally important species in complex communities. Such knowledge can help safeguard carnivore guild integrity and enhance community resilience to environmental perturbations in the sensitive QTP ecosystems.
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Affiliation(s)
- Qi Lu
- School of Life Sciences, Peking University, Beijing 100871, China; Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Chen Cheng
- Center for Nature and Society, School of Life Sciences, Peking University, Beijing 100871, China; Shan Shui Conservation Center, Beijing 100871, China
| | - Lingyun Xiao
- School of Life Sciences, Peking University, Beijing 100871, China; Department of Health and Environmental Sciences, Xi'an Jiaotong Liverpool University, Suzhou, Jiangsu 215123, China
| | - Juan Li
- School of Life Sciences, Peking University, Beijing 100871, China; Department of Health and Environmental Sciences, Xi'an Jiaotong Liverpool University, Suzhou, Jiangsu 215123, China
| | - Xueyang Li
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Xiang Zhao
- Shan Shui Conservation Center, Beijing 100871, China
| | - Zhi Lu
- School of Life Sciences, Peking University, Beijing 100871, China; Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China; Center for Nature and Society, School of Life Sciences, Peking University, Beijing 100871, China; Shan Shui Conservation Center, Beijing 100871, China
| | - Jindong Zhao
- School of Life Sciences, Peking University, Beijing 100871, China; Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Meng Yao
- School of Life Sciences, Peking University, Beijing 100871, China; Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
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18
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Wolves, otters, ungulates, and a promising path for ecology. Proc Natl Acad Sci U S A 2023; 120:e2221817120. [PMID: 36745786 PMCID: PMC9963706 DOI: 10.1073/pnas.2221817120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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19
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Walker RH, Hutchinson MC, Potter AB, Becker JA, Long RA, Pringle RM. Mechanisms of individual variation in large herbivore diets: Roles of spatial heterogeneity and state-dependent foraging. Ecology 2023; 104:e3921. [PMID: 36415899 PMCID: PMC10078531 DOI: 10.1002/ecy.3921] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 10/05/2022] [Accepted: 10/06/2022] [Indexed: 11/24/2022]
Abstract
Many populations of consumers consist of relatively specialized individuals that eat only a subset of the foods consumed by the population at large. Although the ecological significance of individual-level diet variation is recognized, such variation is difficult to document, and its underlying mechanisms are poorly understood. Optimal foraging theory provides a useful framework for predicting how individuals might select different diets, positing that animals balance the "opportunity cost" of stopping to eat an available food item against the cost of searching for something more nutritious; diet composition should be contingent on the distribution of food, and individual foragers should be more selective when they have greater energy reserves to invest in searching for high-quality foods. We tested these predicted mechanisms of individual niche differentiation by quantifying environmental (resource heterogeneity) and organismal (nutritional condition) determinants of diet in a widespread browsing antelope (bushbuck, Tragelaphus sylvaticus) in an African floodplain-savanna ecosystem. We quantified individuals' realized dietary niches (taxonomic richness and composition) using DNA metabarcoding of fecal samples collected repeatedly from 15 GPS-collared animals (range 6-14 samples per individual, median 12). Bushbuck diets were structured by spatial heterogeneity and constrained by individual condition. We observed significant individual-level partitioning of food plants by bushbuck both within and between two adjacent habitat types (floodplain and woodland). Individuals with home ranges that were closer together and/or had similar vegetation structure (measured using LiDAR) ate more similar diets, supporting the prediction that heterogeneous resource distribution promotes individual differentiation. Individuals in good nutritional condition had significantly narrower diets (fewer plant taxa), searched their home ranges more intensively (intensity-of-use index), and had higher-quality diets (percent digestible protein) than those in poor condition, supporting the prediction that animals with greater endogenous reserves have narrower realized niches because they can invest more time in searching for nutritious foods. Our results support predictions from optimal foraging theory about the energetic basis of individual-level dietary variation and provide a potentially generalizable framework for understanding how individuals' realized niche width is governed by animal behavior and physiology in heterogeneous landscapes.
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Affiliation(s)
- Reena H Walker
- Department of Fish and Wildlife Sciences, University of Idaho, Moscow, Idaho, USA
| | - Matthew C Hutchinson
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Arjun B Potter
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Justine A Becker
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA.,Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, USA
| | - Ryan A Long
- Department of Fish and Wildlife Sciences, University of Idaho, Moscow, Idaho, USA
| | - Robert M Pringle
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
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20
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