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Wooster EIF, Gaynor KM, Carthey AJR, Wallach AD, Stanton LA, Ramp D, Lundgren EJ. Animal cognition and culture mediate predator-prey interactions. Trends Ecol Evol 2024; 39:52-64. [PMID: 37839906 DOI: 10.1016/j.tree.2023.09.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 09/12/2023] [Accepted: 09/19/2023] [Indexed: 10/17/2023]
Abstract
Predator-prey ecology and the study of animal cognition and culture have emerged as independent disciplines. Research combining these disciplines suggests that both animal cognition and culture can shape the outcomes of predator-prey interactions and their influence on ecosystems. We review the growing body of work that weaves animal cognition or culture into predator-prey ecology, and argue that both cognition and culture are significant but poorly understood mechanisms mediating how predators structure ecosystems. We present a framework exploring how previous experiences with the predation process creates feedback loops that alter the predation sequence. Cognitive and cultural predator-prey ecology offers ecologists new lenses through which to understand species interactions, their ecological consequences, and novel methods to conserve wildlife in a changing world.
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Affiliation(s)
- Eamonn I F Wooster
- Gulbali Institute, School of Agricultural, Environmental, and Veterinary Sciences, Charles Sturt University, Albury, NSW, Australia.
| | - Kaitlyn M Gaynor
- Departments of Zoology and Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Alexandra J R Carthey
- School of Natural Sciences, Macquarie University, Macquarie Park, NSW 2113, Australia
| | - Arian D Wallach
- School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - Lauren A Stanton
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA 94720-3114, USA
| | - Daniel Ramp
- Centre for Compassionate Conservation, TD School, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Erick J Lundgren
- School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, Brisbane, QLD, Australia; Centre for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark; Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus C, Denmark
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2
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Passoni G, Coulson T, Cagnacci F, Hudson P, Stahler DR, Smith DW, Lachish S. Investigating tritrophic interactions using bioenergetic demographic models. Ecology 2024; 105:e4197. [PMID: 37897692 DOI: 10.1002/ecy.4197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 07/27/2023] [Accepted: 09/18/2023] [Indexed: 10/30/2023]
Abstract
A central debate in ecology has been the long-running discussion on the role of apex predators in affecting the abundance and dynamics of their prey. In terrestrial systems, research has primarily relied on correlational approaches, due to the challenge of implementing robust experiments with replication and appropriate controls. A consequence of this is that we largely suffer from a lack of mechanistic understanding of the population dynamics of interacting species, which can be surprisingly complex. Mechanistic models offer an opportunity to examine the causes and consequences of some of this complexity. We present a bioenergetic mechanistic model of a tritrophic system where the primary vegetation resource follows a seasonal growth function, and the herbivore and carnivore species are modeled using two integral projection models (IPMs) with body mass as the phenotypic trait. Within each IPM, the demographic functions are structured according to bioenergetic principles, describing how animals acquire and transform resources into body mass, energy reserves, and breeding potential. We parameterize this model to reproduce the population dynamics of grass, elk, and wolves in northern Yellowstone National Park (USA) and investigate the impact of wolf reintroduction on the system. Our model generated predictions that closely matched the observed population sizes of elk and wolf in Yellowstone prior to and following wolf reintroduction. The introduction of wolves into our basal grass-elk bioenergetic model resulted in a population of 99 wolves and a reduction in elk numbers by 61% (from 14,948 to 5823) at equilibrium. In turn, vegetation biomass increased by approximately 25% in the growing season and more than threefold in the nongrowing season. The addition of wolves to the model caused the elk population to switch from being food-limited to being predator-limited and had a stabilizing effect on elk numbers across different years. Wolf predation also led to a shift in the phenotypic composition of the elk population via a small increase in elk average body mass. Our model represents a novel approach to the study of predator-prey interactions, and demonstrates that explicitly considering and linking bioenergetics, population demography and body mass phenotypes can provide novel insights into the mechanisms behind complex ecosystem processes.
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Affiliation(s)
- Gioele Passoni
- Department of Biology, University of Oxford, Oxford, UK
- Animal Ecology Unit, Research and Innovation Centre (CRI), Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Tim Coulson
- Department of Biology, University of Oxford, Oxford, UK
| | - Francesca Cagnacci
- Animal Ecology Unit, Research and Innovation Centre (CRI), Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Peter Hudson
- The Huck Institutes, Penn State University, State College, Pennsylvania, USA
| | - Daniel R Stahler
- Yellowstone Center for Resources, Yellowstone National Park, Wyoming, USA
| | - Douglas W Smith
- Yellowstone Center for Resources, Yellowstone National Park, Wyoming, USA
| | - Shelly Lachish
- Commonwealth Scientific Industrial Research Organisation (CSIRO) Environment Unit, Dutton Park, Queensland, Australia
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3
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Esattore B, Rossi AC, Bazzoni F, Riggio C, Oliveira R, Leggiero I, Ferretti F. Same place, different time, head up: Multiple antipredator responses to a recolonizing apex predator. Curr Zool 2023; 69:703-717. [PMID: 37876645 PMCID: PMC10591180 DOI: 10.1093/cz/zoac083] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 10/10/2022] [Indexed: 10/26/2023] Open
Abstract
Prey adjust their antipredator behavioral tactics to minimize the risk of an encounter with predators. Spatiotemporal responses of prey to predators have been reported, but the nature of antipredator response is not ubiquitous and it is the object of increasing interest, especially considering the recent recovery of large carnivores in Europe, and the potential for behavioral antipredator responses to elicit consequences at the ecosystem level. We have tested multiple antipredator responses by fallow deer Dama dama to wolf Canis lupus in a Mediterranean protected area recently recolonized by this apex predator. Through intensive camera trapping, we tested for temporal and spatial association between predator and prey, and we have also studied deer vigilance in forest habitats where focal observations are usually impossible. Wolf detection rates were spatially associated with those of fallow deer. Accordingly, no evidence was found for fallow deer avoiding sites with higher predator detection rates. Temporal activity patterns were significantly different between the 2 species, with the wolf being mainly nocturnal whereas fallow deer was active especially during daylight. A comparison with a preliminary study strongly suggests an increase in the diurnal activity of fallow deer along with the stabilization of wolf presence in the area. Both the rate and the duration of vigilance of female fallow deer increased with the local frequency of wolf activity. We suggest an antipredator response based on temporal-rather than spatial-avoidance, as well as increased vigilance.
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Affiliation(s)
- Bruno Esattore
- Department of Ethology, Institute of Animal Science, Přátelství 815,104 00, Uhříněves, Prague, Czech Republic
- Department of Ethology and Companion Animal Science, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Kamýcká 129, 165 00, Suchdol, Prague, Czech Republic
| | - Agnese Carlotta Rossi
- Department of Life Sciences, Research Unit of Behavioral Ecology, Ethology and Wildlife Management, University of Siena, Via Pier Andrea Mattioli 4, 53100, Siena, Italy
| | - Francesco Bazzoni
- Department of Life Sciences, Research Unit of Behavioral Ecology, Ethology and Wildlife Management, University of Siena, Via Pier Andrea Mattioli 4, 53100, Siena, Italy
| | - Chiara Riggio
- Department of Life Sciences, Research Unit of Behavioral Ecology, Ethology and Wildlife Management, University of Siena, Via Pier Andrea Mattioli 4, 53100, Siena, Italy
| | - Raquel Oliveira
- Department of Life Sciences, Research Unit of Behavioral Ecology, Ethology and Wildlife Management, University of Siena, Via Pier Andrea Mattioli 4, 53100, Siena, Italy
| | - Ivan Leggiero
- Department of Life Sciences, Research Unit of Behavioral Ecology, Ethology and Wildlife Management, University of Siena, Via Pier Andrea Mattioli 4, 53100, Siena, Italy
| | - Francesco Ferretti
- Department of Life Sciences, Research Unit of Behavioral Ecology, Ethology and Wildlife Management, University of Siena, Via Pier Andrea Mattioli 4, 53100, Siena, Italy
- NBFC, National Biodiversity Future Center, Palermo 90133, Italy
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4
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Xu C, Silliman BR, Chen J, Li X, Thomsen MS, Zhang Q, Lee J, Lefcheck JS, Daleo P, Hughes BB, Jones HP, Wang R, Wang S, Smith CS, Xi X, Altieri AH, van de Koppel J, Palmer TM, Liu L, Wu J, Li B, He Q. Herbivory limits success of vegetation restoration globally. Science 2023; 382:589-594. [PMID: 37917679 DOI: 10.1126/science.add2814] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 09/21/2023] [Indexed: 11/04/2023]
Abstract
Restoring vegetation in degraded ecosystems is an increasingly common practice for promoting biodiversity and ecological function, but successful implementation is hampered by an incomplete understanding of the processes that limit restoration success. By synthesizing terrestrial and aquatic studies globally (2594 experimental tests from 610 articles), we reveal substantial herbivore control of vegetation under restoration. Herbivores at restoration sites reduced vegetation abundance more strongly (by 89%, on average) than those at relatively undegraded sites and suppressed, rather than fostered, plant diversity. These effects were particularly pronounced in regions with higher temperatures and lower precipitation. Excluding targeted herbivores temporarily or introducing their predators improved restoration by magnitudes similar to or greater than those achieved by managing plant competition or facilitation. Thus, managing herbivory is a promising strategy for enhancing vegetation restoration efforts.
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Affiliation(s)
- Changlin Xu
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, School of Life Sciences, Fudan University, Shanghai, China
| | - Brian R Silliman
- Nicholas School of the Environment, Duke University, Beaufort, NC, USA
| | - Jianshe Chen
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, School of Life Sciences, Fudan University, Shanghai, China
| | - Xincheng Li
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, School of Life Sciences, Fudan University, Shanghai, China
| | - Mads S Thomsen
- Marine Ecology Research Group and Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Department of Bioscience, Aarhus University, Roskilde, Denmark
| | - Qun Zhang
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, School of Life Sciences, Fudan University, Shanghai, China
| | - Juhyung Lee
- Marine Science Center, Northeastern University, Nahant, MA, USA
- Department of Oceanography and Marine Research Institute, Pusan National University, Busan, Republic of Korea
| | - Jonathan S Lefcheck
- Tennenbaum Marine Observatories Network and MarineGEO Program, Smithsonian Environmental Research Center, Edgewater, MD, USA
- University of Maryland Center for Environmental Science, Cambridge, MD, USA
| | - Pedro Daleo
- Instituto de Investigaciones Marinas y Costeras (IIMyC), UNMdP, CONICETC, Mar del Plata, Argentina
| | - Brent B Hughes
- Department of Biology, Sonoma State University, Rohnert Park, CA, USA
| | - Holly P Jones
- Department of Biological Sciences and Institute for the Study of the Environment, Sustainability, and Energy, Northern Illinois University, DeKalb, IL, USA
| | - Rong Wang
- School of Ecological and Environmental Sciences, Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, East China Normal University, Shanghai, China
| | - Shaopeng Wang
- Institute of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Carter S Smith
- Nicholas School of the Environment, Duke University, Beaufort, NC, USA
| | - Xinqiang Xi
- Department of Ecology, School of Life Science, Nanjing University, Nanjing, Jiangsu, China
| | - Andrew H Altieri
- Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL, USA
| | - Johan van de Koppel
- Department of Estuarine and Delta Systems, Royal Netherlands Institute for Sea Research, Yerseke, Netherlands
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Todd M Palmer
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Lingli Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Jihua Wu
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, and College of Ecology, Lanzhou University, Lanzhou, Gansu, China
| | - Bo Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Centre for Invasion Biology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, China
| | - Qiang He
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, School of Life Sciences, Fudan University, Shanghai, China
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5
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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: 16] [Impact Index Per Article: 16.0] [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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6
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Scoleri VP, Ingram J, Johnson CN, Jones ME. Top predator restricts the niche breadth of prey: effects of assisted colonization of Tasmanian devils on a widespread omnivorous prey. Proc Biol Sci 2023; 290:20222113. [PMID: 36919429 PMCID: PMC10015323 DOI: 10.1098/rspb.2022.2113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
Few landscape-scale experiments test the effects of predators on the abundance and distribution of prey across habitat gradients. We use the assisted colonization of a top predator, the Tasmanian devil (Sarcophilus harrisii), to test the impacts of predation on the abundance, habitat use and temporal activity of a widespread prey species, the omnivorous common brushtail possum (Trichosurus vulpecula). Before introduction of devils to Maria Island, Tasmania, Australia, in 2012, possums were abundant in open grasslands as well as forests. Predation by devils caused high mortality of possums in grasslands, but individuals with access to trees had a higher survival probability. Possum abundance declined across the whole island from 2012-2016, as possums disappeared almost completely from grasslands and declined in drier forests with more open understorey. Abundance remained stable in wet forests, which are not preferred habitat for possums but provide better refuge from devils. Abundance and habitat use of possums remained unchanged at a control site on the adjacent Tasmanian mainland, where the devil population was low and stable. This study demonstrates how spatial variation in predator-caused mortality can limit both abundance and habitat breadth in generalist prey species, excluding them entirely from certain habitats.
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Affiliation(s)
- Vincent P Scoleri
- School of Natural Sciences, University of Tasmania, Sandy Bay 7005, Australia
| | - Janeane Ingram
- School of Geography, Planning and Spatial Sciences, University of Tasmania, Sandy Bay 7005, Australia
| | - Christopher N Johnson
- School of Natural Sciences, University of Tasmania, Sandy Bay 7005, Australia.,Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage, University of Tasmania, Sandy Bay 7005, Australia
| | - Menna E Jones
- School of Natural Sciences, University of Tasmania, Sandy Bay 7005, Australia
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7
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Dynamic landscapes of fear: understanding spatiotemporal risk. Trends Ecol Evol 2022; 37:911-925. [PMID: 35817684 DOI: 10.1016/j.tree.2022.06.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 06/10/2022] [Accepted: 06/14/2022] [Indexed: 02/04/2023]
Abstract
The landscape of fear (LOF) concept posits that prey navigate spatial heterogeneity in perceived predation risk, balancing risk mitigation against other activities necessary for survival and reproduction. These proactive behavioral responses to risk can affect individual fitness, population dynamics, species interactions, and coexistence. Yet, antipredator responses in free-ranging prey often contradict expectations, raising questions about the generality and scalability of the LOF framework and suggesting that a purely spatial, static LOF conceptualization may be inadequate. Here, we outline a 'dynamic' LOF framework that explicitly incorporates time to account for predictable spatiotemporal variation in risk-resource trade-offs. This integrated approach suggests novel predictions about predator effects on prey behaviors to refine understanding of the role predators play in ecological communities.
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8
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Blossey B, Hare D. Myths, Wishful Thinking, and Accountability in Predator Conservation and Management in the United States. FRONTIERS IN CONSERVATION SCIENCE 2022. [DOI: 10.3389/fcosc.2022.881483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Large predators are thought of as ecological keystone species, posterchildren of conservation campaigns, and sought-after targets of tourists and photographers. At the same time, predators kill livestock and huntable animals, and occasionally people, triggering fears and antipathy among those living alongside them. Until the 1960’s government-sponsored eradication and persecution campaigns in the United States prioritized interests of livestock producers and recreational hunters, leading to eradication of wolves and bears over much of their range. Without large predators, subsidized by changes in agricultural practices and milder winters, ungulate populations erupted, triggering negative ecological impacts, economic damage, and human health crises (such as tick-borne diseases). Shifting societal preferences have ushered in more predator-friendly, but controversial wildlife policies, from passively allowing range expansion to purposeful reintroductions (such as release of wolves in Yellowstone National Park). Attempts to restore wolves or mountain lions in the U.S. and protecting coyotes appear to enjoy strong public support, but many state wildlife agencies charged with managing wildlife, and recreational hunters continue to oppose such efforts, because they perceive predators as competitors for huntable animals. There may be compelling reasons for restoring predators or allowing them to recolonize their former ranges. But if range expansion or intentional releases of large predators do not result in ecosystem recovery, reduced deer populations, or Lyme disease reductions, conservationists who have put their reputation on the line and assured decision makers and the public of the important functional role of large predators may lose public standing and trust. Exaggerated predictions by ranchers and recreational hunters of greatly reduced ungulate populations and rampant livestock killing by large carnivores may lead to poaching and illegal killing threatening recovery of predator populations. How the return of large carnivores may affect vegetation and successional change, ungulate population size, other biota, livestock and human attitudes in different landscapes has not been appropriately assessed. Societal support and acceptance of living alongside predators as they expand their range and increase in abundance requires development and monitoring of social, ecological and economic indicators to assess how return of large predators affects human and animal and plant livelihoods.
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Donaldson JE, Holdo R, Sarakikya J, Anderson TM. Fire, grazers, and browsers interact with grass competition to determine tree establishment in an African savanna. Ecology 2022; 103:e3715. [PMID: 35388482 DOI: 10.1002/ecy.3715] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 02/10/2022] [Indexed: 11/11/2022]
Abstract
In savanna ecosystems, fire and herbivory alter the competitive relationship between trees and grasses. Mechanistically, grazing herbivores favor trees by removing grass, which reduces tree-grass competition and limits fire. Conversely, browsing herbivores consume trees and limit their recovery from fire. Herbivore feeding decisions are in turn shaped by risk-resource trade-offs that potentially determine the spatial patterns of herbivory. Identifying the dominant mechanistic pathways by which fire and herbivores control tree cover remains challenging, but is essential for understanding savanna dynamics. We used an experiment in the Serengeti ecosystem and a simple simulation driven by experimental results to address two main aims: (1) determine the importance of direct and indirect effects of grass, fire and herbivory on seedling establishment; and (2) establish whether predators determine the spatial pattern of successful seedling establishment via effects on mesoherbivore distribution. We transplanted tree seedlings into plots with a factorial combination of grass and herbivores (present/absent) across a lion kill-risk gradient in the Serengeti, burning half of the plots near the end of the experiment. Ungrazed grass limited tree seedling survival directly via competition, indirectly via fire, and by slowing seedling growth, which drove higher seedling mortality during fires. These effects restricted seedling establishment to below 18% and, in conjunction with browsing, resulted in seedling establishment dropping below 5%. In the absence of browsing and fire, grazing drove a 7.5-fold increase in seedling establishment. Lion predation risk had no observable impact on herbivore effects on seedling establishment. The severe negative effects of grass on seedling mortality suggests that regional patterns of tree cover and fire may overestimate the role of fire in limiting tree cover, with regular fires representing a proxy for the competitive effects of grass.
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Affiliation(s)
| | - Ricardo Holdo
- Odum School of Ecology, University of Georgia, Athens, GA, USA
| | | | - T Michael Anderson
- Department of Biology, Wake Forest University, Winston Salem, North Carolina, USA
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10
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Coetsee C, Wigley BJ, Sankaran M, Ratnam J, Augustine DJ. Contrasting Effects of Grazing vs Browsing Herbivores Determine Changes in Soil Fertility in an East African Savanna. Ecosystems 2022. [DOI: 10.1007/s10021-022-00748-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Chitwood MC, Baruzzi C, Lashley MA. “Ecology of fear” in ungulates: Opportunities for improving conservation. Ecol Evol 2022; 12:e8657. [PMID: 35261746 PMCID: PMC8888265 DOI: 10.1002/ece3.8657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 01/31/2022] [Accepted: 02/03/2022] [Indexed: 11/08/2022] Open
Abstract
Because ungulates are important contributors to ecosystem function, understanding the “ecology of fear” could be important to the conservation of ecosystems. Although studying ungulate ecology of fear is common, knowledge from ungulate systems is highly contested among ecologists. Here, we review the available literature on the ecology of fear in ungulates to generalize our current knowledge and how we can leverage it for conservation. Four general focus areas emerged from the 275 papers included in our literature search (and some papers were included in multiple categories): behavioral responses to predation risk (79%), physiological responses to predation risk (15%), trophic cascades resulting from ungulate responses to predation risk (20%), and manipulation of predation risk (1%). Of papers focused on behavior, 75% were about movement and habitat selection. Studies were biased toward North America (53%), tended to be focused on elk (Cervus canadensis; 29%), and were dominated by gray wolves (40%) or humans (39%) as predators of interest. Emerging literature suggests that we can utilize predation risk for conservation with top‐down (i.e., increasing predation risk) and bottom‐up (i.e., manipulating landscape characteristics to increase risk or risk perception) approaches. It is less clear whether fear‐related changes in physiology have population‐level fitness consequences or cascading effects, which could be fruitful avenues for future research. Conflicting evidence of trait‐mediated trophic cascades might be improved with better replication across systems and accounting for confounding effects of ungulate density. Improving our understanding of mechanisms modulating the nature of trophic cascades likely is most important to ensure desirable conservation outcomes. We recommend future work embrace the complexity of natural systems by attempting to link together the focal areas of study identified herein.
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Affiliation(s)
- M. Colter Chitwood
- Department of Natural Resource Ecology and Management Oklahoma State University Stillwater Oklahoma USA
| | - Carolina Baruzzi
- Department of Wildlife, Fisheries, and Aquaculture Mississippi State University Starkville Mississippi USA
- School of Forest, Fisheries, and Geomatics Sciences University of Florida Gainesville Florida USA
| | - Marcus A. Lashley
- Department of Wildlife, Fisheries, and Aquaculture Mississippi State University Starkville Mississippi USA
- Department of Wildlife Ecology and Conservation University of Florida Gainesville Florida USA
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12
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Lewis MA, Fagan WF, Auger-Méthé M, Frair J, Fryxell JM, Gros C, Gurarie E, Healy SD, Merkle JA. Learning and Animal Movement. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.681704] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Integrating diverse concepts from animal behavior, movement ecology, and machine learning, we develop an overview of the ecology of learning and animal movement. Learning-based movement is clearly relevant to ecological problems, but the subject is rooted firmly in psychology, including a distinct terminology. We contrast this psychological origin of learning with the task-oriented perspective on learning that has emerged from the field of machine learning. We review conceptual frameworks that characterize the role of learning in movement, discuss emerging trends, and summarize recent developments in the analysis of movement data. We also discuss the relative advantages of different modeling approaches for exploring the learning-movement interface. We explore in depth how individual and social modalities of learning can matter to the ecology of animal movement, and highlight how diverse kinds of field studies, ranging from translocation efforts to manipulative experiments, can provide critical insight into the learning process in animal movement.
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13
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Wells HBM, Crego RD, Opedal ØH, Khasoha LM, Alston JM, Reed CG, Weiner S, Kurukura S, Hassan AA, Namoni M, Ekadeli J, Kimuyu DM, Young TP, Kartzinel TR, Palmer TM, Pringle RM, Goheen JR. Experimental evidence that effects of megaherbivores on mesoherbivore space use are influenced by species' traits. J Anim Ecol 2021; 90:2510-2522. [PMID: 34192343 DOI: 10.1111/1365-2656.13565] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/23/2021] [Indexed: 11/27/2022]
Abstract
The extinction of 80% of megaherbivore (>1,000 kg) species towards the end of the Pleistocene altered vegetation structure, fire dynamics and nutrient cycling world-wide. Ecologists have proposed (re)introducing megaherbivores or their ecological analogues to restore lost ecosystem functions and reinforce extant but declining megaherbivore populations. However, the effects of megaherbivores on smaller herbivores are poorly understood. We used long-term exclusion experiments and multispecies hierarchical models fitted to dung counts to test (a) the effect of megaherbivores (elephant and giraffe) on the occurrence (dung presence) and use intensity (dung pile density) of mesoherbivores (2-1,000 kg), and (b) the extent to which the responses of each mesoherbivore species was predictable based on their traits (diet and shoulder height) and phylogenetic relatedness. Megaherbivores increased the predicted occurrence and use intensity of zebras but reduced the occurrence and use intensity of several other mesoherbivore species. The negative effect of megaherbivores on mesoherbivore occurrence was stronger for shorter species, regardless of diet or relatedness. Megaherbivores substantially reduced the expected total use intensity (i.e. cumulative dung density of all species) of mesoherbivores, but only minimally reduced the expected species richness (i.e. cumulative predicted occurrence probabilities of all species) of mesoherbivores (by <1 species). Simulated extirpation of megaherbivores altered use intensity by mesoherbivores, which should be considered during (re)introductions of megaherbivores or their ecological proxies. Species' traits (in this case shoulder height) may be more reliable predictors of mesoherbivores' responses to megaherbivores than phylogenetic relatedness, and may be useful for predicting responses of data-limited species.
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Affiliation(s)
- Harry B M Wells
- Lolldaiga Hills Research Programme, Nanyuki, Kenya.,Sustainability Research Institute, School of Earth and Environment, University of Leeds, Leeds, UK.,Space for Giants, Nanyuki, Kenya
| | - Ramiro D Crego
- National Zoo and Smithsonian Conservation Biology Institute, Conservation Ecology Center, Front Royal, VA, USA
| | | | - Leo M Khasoha
- Mpala Research Centre, Nanyuki, Kenya.,Program in Ecology, Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | - Jesse M Alston
- Program in Ecology, Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA.,Center for Advanced Systems Understanding (CASUS), Görlitz, Germany
| | - Courtney G Reed
- Mpala Research Centre, Nanyuki, Kenya.,Institute at Brown for Environment and Society, Brown University, Providence, RI, USA.,Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, USA
| | - Sarah Weiner
- Mpala Research Centre, Nanyuki, Kenya.,Program in Ecology, Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | | | | | | | | | - Duncan M Kimuyu
- Mpala Research Centre, Nanyuki, Kenya.,Department of Natural Resources, Karatina University, Karatina, Kenya
| | - Truman P Young
- Mpala Research Centre, Nanyuki, Kenya.,Department of Plant Sciences and Ecology Graduate Group, University of California, Davis, CA, USA
| | - Tyler R Kartzinel
- Mpala Research Centre, Nanyuki, Kenya.,Institute at Brown for Environment and Society, Brown University, Providence, RI, USA.,Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, USA
| | - Todd M Palmer
- Mpala Research Centre, Nanyuki, Kenya.,Department of Biology, University of Florida, Gainesville, FL, USA
| | - Robert M Pringle
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Jacob R Goheen
- Mpala Research Centre, Nanyuki, Kenya.,Program in Ecology, Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
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14
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Davies AB, Cromsigt JPGM, Tambling CJ, le Roux E, Vaughn N, Druce DJ, Marneweck DG, Asner GP. Environmental controls on African herbivore responses to landscapes of fear. OIKOS 2020. [DOI: 10.1111/oik.07559] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Andrew B. Davies
- Dept of Organismic and Evolutionary Biology, Harvard Univ. Cambridge MA USA
- Center for Global Discovery and Conservation Science, Arizona State Univ. Tempe AZ USA
| | - Joris P. G. M. Cromsigt
- Dept of Wildlife, Fish and Environmental Studies, Swedish Univ. of Agricultural Sciences Umeå Sweden
- Dept of Zoology, Centre for African Conservation Ecology, Nelson Mandela Univ. Port Elizabeth South Africa
| | - Craig J. Tambling
- Dept of Zoology, Centre for African Conservation Ecology, Nelson Mandela Univ. Port Elizabeth South Africa
- Dept of Zoology and Entomology, Univ. of Fort Hare Alice South Africa
| | - Elizabeth le Roux
- Dept of Zoology, Centre for African Conservation Ecology, Nelson Mandela Univ. Port Elizabeth South Africa
| | - Nicholas Vaughn
- Center for Global Discovery and Conservation Science, Arizona State Univ. Tempe AZ USA
| | - Dave J. Druce
- Ecological Advice, Ezemvelo KZN Wildlife Hluhluwe‐iMfolozi Park South Africa
- School of Life Sciences, Univ. of KwaZulu‐Natal Pietermaritzburg South Africa
| | - David G. Marneweck
- Eugène Marais Chair of Wildlife Management, Mammal Research Inst., Dept of Zoology and Entomology, Univ. of Pretoria Pretoria South Africa
- Wildlife Ecology Lab, School of Natural Resource Management, Nelson Mandela Univ. Port Elizabeth South Africa
| | - Gregory P. Asner
- Center for Global Discovery and Conservation Science, Arizona State Univ. Tempe AZ USA
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15
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Stears K, Schmitt MH, Wilmers CC, Shrader AM. Mixed-species herding levels the landscape of fear. Proc Biol Sci 2020; 287:20192555. [PMID: 32126952 DOI: 10.1098/rspb.2019.2555] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Prey anti-predator behaviours are influenced by perceived predation risk in a landscape and social information gleaned from herd mates regarding predation risk. It is well documented that high-quality social information about risk can come from heterospecific herd mates. Here, we integrate social information with the landscape of fear to quantify how these landscapes are modified by mixed-species herding. To do this, we investigated zebra vigilance in single- and mixed-species herds across different levels of predation risk (lion versus no lion), and assessed how they manage herd size and the competition-information trade-off associated with grouping behaviour. Overall, zebra performed higher vigilance in high-risk areas. However, mixed-species herding reduced vigilance levels. We estimate that zebra in single-species herds would have to feed for approximately 35 min more per day in low-risk areas and approximately 51 min more in high-risk areas to compensate for the cost of higher vigilance. Furthermore, zebra benefitted from the competition-information trade-off by increasing the number of heterospecifics while keeping the number of zebra in a herd constant. Ultimately, we show that mixed-species herding reduces the effects of predation risk, whereby zebra in mixed-species herds, under high predation risk, perform similar levels of vigilance compared with zebra in low-risk scenarios.
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Affiliation(s)
- Keenan Stears
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA.,School of Life Sciences, University of KwaZulu-Natal, Scottsville 3209, South Africa.,South African Environmental Observation Network, Ndlovu Node, Phalaborwa 1390, South Africa
| | - Melissa H Schmitt
- School of Life Sciences, University of KwaZulu-Natal, Scottsville 3209, South Africa.,South African Environmental Observation Network, Ndlovu Node, Phalaborwa 1390, South Africa.,Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064, USA
| | - Christopher C Wilmers
- Department of Environmental Studies, University of California, Santa Cruz, CA 95064, USA
| | - Adrian M Shrader
- School of Life Sciences, University of KwaZulu-Natal, Scottsville 3209, South Africa.,Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0028, South Africa
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16
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Augustine DJ, Wigley BJ, Ratnam J, Kibet S, Nyangito M, Sankaran M. Large herbivores maintain a two-phase herbaceous vegetation mosaic in a semi-arid savanna. Ecol Evol 2019; 9:12779-12788. [PMID: 31788213 PMCID: PMC6875565 DOI: 10.1002/ece3.5750] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/19/2019] [Accepted: 09/20/2019] [Indexed: 11/11/2022] Open
Abstract
Many arid and semi-arid rangelands exhibit distinct spatial patterning of vegetated and bare soil-dominated patches. The latter potentially represent a grazing-induced, degraded ecosystem state, but could also arise via mechanisms related to feedbacks between vegetation cover and soil moisture availability that are unrelated to grazing. The degree to which grazing contributes to the formation or maintenance of degraded patches has been widely discussed and modeled, but empirical studies of the role of grazing in their formation, persistence, and reversibility are limited.We report on a long-term (17 years) grazing removal experiment in a semi-arid savanna where vegetated patches composed of perennial grasses were interspersed within large (>10 m2) patches of bare soil.Short-term (3 years) grazing removal did not allow bare patches to become revegetated, whereas following long-term (17 years) grazing removal, bare soil patches were revegetated by a combination of stoloniferous grasses and tufted bunchgrasses. In the presence of grazers, stoloniferous grasses partially recolonized bare patches, but this did not lead to full recovery or to the establishment of tufted bunchgrasses.These results show that grazers alter both the balance between bare and vegetated patches, as well as the types of grasses dominating both patch types in this semiarid savanna.Synthesis: Large herbivores fundamentally shaped the composition and spatial pattern of the herbaceous layer by maintaining a two-phase herbaceous mosaic. However, bare patches within this mosaic can recover given herbivore removal over sufficiently long time scales, and hence do not represent a permanently degraded ecosystem state.
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Affiliation(s)
- David J. Augustine
- Rangeland Resources and Systems Research UnitUnited States Department of Agriculture – Agricultural Research ServiceFort CollinsCOUSA
| | - Benjamin J. Wigley
- National Centre for Biological SciencesTata Institute of Fundamental ResearchBangaloreIndia
- School of Natural Resource ManagementNelson Mandela University, George CampusGeorgeSouth Africa
| | - Jayashree Ratnam
- National Centre for Biological SciencesTata Institute of Fundamental ResearchBangaloreIndia
| | - Staline Kibet
- Department of Resource Management and Agricultural TechnologyUniversity of NairobiNairobiKenya
| | - Moses Nyangito
- Department of Resource Management and Agricultural TechnologyUniversity of NairobiNairobiKenya
| | - Mahesh Sankaran
- National Centre for Biological SciencesTata Institute of Fundamental ResearchBangaloreIndia
- School of BiologyFaculty of Biological SciencesUniversity of LeedsLeedsUK
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17
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Bubnicki JW, Churski M, Schmidt K, Diserens TA, Kuijper DPJ. Linking spatial patterns of terrestrial herbivore community structure to trophic interactions. eLife 2019; 8:e44937. [PMID: 31577225 PMCID: PMC6805123 DOI: 10.7554/elife.44937] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 09/13/2019] [Indexed: 01/05/2023] Open
Abstract
Large herbivores influence ecosystem functioning via their effects on vegetation at different spatial scales. It is often overlooked that the spatial distribution of large herbivores results from their responses to interacting top-down and bottom-up ecological gradients that create landscape-scale variation in the structure of the entire community. We studied the complexity of these cascading interactions using high-resolution camera trapping and remote sensing data in the best-preserved European lowland forest, Białowieża Forest, Poland. We showed that the variation in spatial distribution of an entire community of large herbivores is explained by species-specific responses to both environmental bottom-up and biotic top-down factors in combination with human-induced (cascading) effects. We decomposed the spatial variation in herbivore community structure and identified functionally distinct landscape-scale herbivory regimes ('herbiscapes'), which are predicted to occur in a variety of ecosystems and could be an important mechanism creating spatial variation in herbivory maintaining vegetation heterogeneity.
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Affiliation(s)
| | - Marcin Churski
- Mammal Research Institute, Polish Academy of SciencesBiałowieżaPoland
| | - Krzysztof Schmidt
- Mammal Research Institute, Polish Academy of SciencesBiałowieżaPoland
| | - Tom A Diserens
- Mammal Research Institute, Polish Academy of SciencesBiałowieżaPoland
| | - Dries PJ Kuijper
- Mammal Research Institute, Polish Academy of SciencesBiałowieżaPoland
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18
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Abstract
When herbivores avoid areas with high predation risk, the intensity of plant consumption and nutrient deposition is distributed unevenly across landscapes. Experimental work in African savanna ecosystems shows that the biggest herbivores, virtually immune to predators, smooth out these imbalances.
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Affiliation(s)
- Robert M Pringle
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA.
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19
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Food, family and female age affect reproduction and pup survival of African wild dogs. Behav Ecol Sociobiol 2019. [DOI: 10.1007/s00265-019-2676-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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20
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Stalmans ME, Massad TJ, Peel MJS, Tarnita CE, Pringle RM. War-induced collapse and asymmetric recovery of large-mammal populations in Gorongosa National Park, Mozambique. PLoS One 2019; 14:e0212864. [PMID: 30865663 PMCID: PMC6415879 DOI: 10.1371/journal.pone.0212864] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 02/11/2019] [Indexed: 11/19/2022] Open
Abstract
How do large-mammal communities reassemble after being pushed to the brink of extinction? Few data are available to answer this question, as it is rarely possible to document both the decline and recovery of wildlife populations. Here we present the first in-depth quantitative account of war-induced collapse and postwar recovery in a diverse assemblage of large herbivores. In Mozambique's Gorongosa National Park, we assembled data from 15 aerial wildlife counts conducted before (1968-1972) and after (1994-2018) the Mozambican Civil War (1977-1992). Pre-war total biomass density exceeded 9,000 kg km-2, but populations declined by >90% during the war. Since 1994, total biomass has substantially recovered, but species composition has shifted dramatically. Formerly dominant large herbivores-including elephant (Loxodonta africana), hippo (Hippopotamus amphibius), buffalo (Syncerus caffer), zebra (Equus quagga), and wildebeest (Connochaetes taurinus)-are now outnumbered by waterbuck (Kobus ellipsiprymnus) and other small to mid-sized antelopes. Waterbuck abundance has increased by an order of magnitude, with >55,000 individuals accounting for >74% of large-herbivore biomass in 2018. By contrast, elephant, hippo, and buffalo, which totaled 89% of pre-war biomass, now comprise just 23%. These trends mostly reflect natural population growth following the resumption of protection under the Gorongosa Restoration Project; reintroductions (465 animals of 7 species) accounted for a comparatively small fraction of the total numerical increase. Waterbuck are growing logistically, apparently as-yet unchecked by interspecific competition or predation (apex-carnivore abundance has been low throughout the post-war interval), suggesting a community still in flux. Most other herbivore populations have increased post-war, albeit at differing rates. Armed conflict remains a poorly understood driver of ecological change; our results demonstrate the potential for rapid post-war recovery of large-herbivore biomass, given sound protected-area management, but also suggest that restoration of community structure takes longer and may require active intervention.
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Affiliation(s)
- Marc E. Stalmans
- Department of Scientific Services, Beira, Sofala Province, Mozambique
| | - Tara J. Massad
- Department of Scientific Services, Beira, Sofala Province, Mozambique
| | - Mike J. S. Peel
- ARC-Animal Production Institute, Rangeland Ecology Group, Nelspruit, South Africa
| | - Corina E. Tarnita
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ, United States of America
| | - Robert M. Pringle
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ, United States of America
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21
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Jessop TS, Ariefiandy A, Purwandana D, Benu YJ, Hyatt M, Letnic M. Little to fear: largest lizard predator induces weak defense responses in ungulate prey. Behav Ecol 2019. [DOI: 10.1093/beheco/ary200] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Tim S Jessop
- Centre for Integrative Ecology, School of Life and Environmental Science, Deakin University, Waurn Ponds, Victoria, Australia
- Komodo Survival Program, Denpasar, Bali, Indonesia
| | | | | | | | - Matthew Hyatt
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, New South Wales, Australia
| | - Mike Letnic
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, New South Wales, Australia
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22
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Resolving a conservation dilemma: Vulnerable lions eating endangered zebras. PLoS One 2018; 13:e0201983. [PMID: 30157200 PMCID: PMC6114509 DOI: 10.1371/journal.pone.0201983] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 07/25/2018] [Indexed: 11/19/2022] Open
Abstract
When predators are removed or suppressed for generations, prey populations tend to increase and when predators are re-introduced, prey densities should fall back to pre-control levels. In cases of apparent competition where there are alternate abundant and rare prey species, rare species may decline further than expected or disappear altogether. Recently, concern about the impact of recovering predator populations on wildlife in Laikipia County, Kenya, has led to questions of whether lions (Panthera leo, IUCN Red List Vulnerable) exert top-down pressure on Grevy's zebra (Equus grevyi, IUCN Red List Endangered). We examined effects of lion predation on Plain's zebra (E. quagga, IUCN Red List Near Threatened) and Grevy's zebra populations in a 2,105 km2 area defined by lion movements. We used line transect surveys to estimate density of Grevy's (0.71/km2) and Plain's (15.9/km2) zebras, and satellite telemetry to measure movements for lions and both zebras. We tracked lions to potential feeding sites to estimate predation rates on zebras. We compared field-based estimates of predation rates on both zebras to random gas models of encounters that result in predation to ask if lions prey preferentially on Grevy's zebra at a sufficient rate to drive population declines. Lions preyed on Grevy's zebra significantly less than expected in 15 of 16 (94%) scenarios considered and lions preyed on Plain's zebras as expected or significantly less than expected in 15 of 16 scenarios. Population trend of Grevy's zebra indicates that the Kenya population may be stabilizing. Recruitment rate to the population has tripled since 2004, making it unlikely that lions are having an impact on Grevy's zebras. In Laikipia County, competitive displacement by livestock (Livestock: Grevy's zebra ratio = 864:1) and interference competition for grass with Plain's zebra (Plain's zebra:Grevy's zebra ratio = 22:1) are most likely the predominant threats to Grevy's Zebra recovery.
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23
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Miller JRB, Pitman RT, Mann GKH, Fuller AK, Balme GA. Lions and leopards coexist without spatial, temporal or demographic effects of interspecific competition. J Anim Ecol 2018; 87:1709-1726. [PMID: 30010193 DOI: 10.1111/1365-2656.12883] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 06/13/2018] [Indexed: 11/28/2022]
Abstract
Although interspecific competition plays a principal role in shaping species behaviour and demography, little is known about the population-level outcomes of competition between large carnivores, and the mechanisms that facilitate coexistence. We conducted a multilandscape analysis of two widely distributed, threatened large carnivore competitors to offer insight into coexistence strategies and assist with species-level conservation. We evaluated how interference competition affects occupancy, temporal activity and population density of a dominant competitor, the lion (Panthera leo), and its subordinate competitor, the leopard (Panthera pardus). We collected camera-trap data over 3 years in 10 study sites covering 5,070 km2 . We used multispecies occupancy modelling to assess spatial responses in varying environmental and prey conditions and competitor presence, and examined temporal overlap and the relationship between lion and leopard densities across sites and years. Results showed that both lion and leopard occupancy was independent of-rather than conditional on-their competitor's presence across all environmental covariates. Marginal occupancy probability for leopard was higher in areas with more bushy, "hideable" habitat, human (tourist) activity and topographic ruggedness, whereas lion occupancy decreased with increasing hideable habitat and increased with higher abundance of very large prey. Temporal overlap was high between carnivores, and there was no detectable relationship between species densities. Lions pose a threat to the survival of individual leopards, but they exerted no tractable influence on leopard spatial or temporal dynamics. Furthermore, lions did not appear to suppress leopard populations, suggesting that intraguild competitors can coexist in the same areas without population decline. Aligned conservation strategies that promote functioning ecosystems, rather than target individual species, are therefore advised to achieve cost- and space-effective conservation.
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Affiliation(s)
- Jennifer R B Miller
- Panthera, New York, New York.,Department of Biological Sciences, Institute for Communities and Wildlife in Africa, University of Cape Town, Cape Town, South Africa.,New York Cooperative Fish and Wildlife Research Unit, Department of Natural Resources, Cornell University, Ithaca, New York.,Department of Environmental Science, Policy, and Management, University of California-Berkeley, Berkeley, California
| | - Ross T Pitman
- Panthera, New York, New York.,Department of Biological Sciences, Institute for Communities and Wildlife in Africa, University of Cape Town, Cape Town, South Africa
| | - Gareth K H Mann
- Panthera, New York, New York.,Department of Biological Sciences, Institute for Communities and Wildlife in Africa, University of Cape Town, Cape Town, South Africa
| | - Angela K Fuller
- New York Cooperative Fish and Wildlife Research Unit, Department of Natural Resources, Cornell University, Ithaca, New York
| | - Guy A Balme
- Panthera, New York, New York.,Department of Biological Sciences, Institute for Communities and Wildlife in Africa, University of Cape Town, Cape Town, South Africa
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24
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Goheen JR, Augustine DJ, Veblen KE, Kimuyu DM, Palmer TM, Porensky LM, Pringle RM, Ratnam J, Riginos C, Sankaran M, Ford AT, Hassan AA, Jakopak R, Kartzinel TR, Kurukura S, Louthan AM, Odadi WO, Otieno TO, Wambua AM, Young HS, Young TP. Conservation lessons from large-mammal manipulations in East African savannas: the KLEE, UHURU, and GLADE experiments. Ann N Y Acad Sci 2018; 1429:31-49. [DOI: 10.1111/nyas.13848] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/03/2018] [Accepted: 04/06/2018] [Indexed: 11/26/2022]
Affiliation(s)
- Jacob R. Goheen
- Department of Zoology and Physiology; University of Wyoming; Laramie Wyoming
- Mpala Research Centre; Nanyuki Kenya
| | | | - Kari E. Veblen
- Department of Wildland Resources and Ecology Center; Utah State University; Logan Utah
| | - Duncan M. Kimuyu
- Department of Wildland Resources and Ecology Center; Utah State University; Logan Utah
- Mpala Research Centre; Nanyuki Kenya
| | - Todd M. Palmer
- Department of Biology; University of Florida; Gainesville Florida
- Mpala Research Centre; Nanyuki Kenya
| | | | - Robert M. Pringle
- Department of Ecology and Evolutionary Biology; Princeton University; Princeton New Jersey
- Mpala Research Centre; Nanyuki Kenya
| | | | | | - Mahesh Sankaran
- National Centre for Biological Sciences, TIFR; Bangalore India
- School of Biology, University of Leeds; Leeds United Kingdom
| | - Adam T. Ford
- Department of Biology; University of British Columbia; Kelowna British Columbia Canada
| | | | - Rhiannon Jakopak
- Department of Zoology and Physiology; University of Wyoming; Laramie Wyoming
| | - Tyler R. Kartzinel
- Department of Ecology and Evolutionary Biology; Brown University; Providence Rhode Island
| | | | | | - Wilfred O. Odadi
- Department of Natural Resources; Egerton University; Egerton Kenya
- Mpala Research Centre; Nanyuki Kenya
| | | | - Alois M. Wambua
- Department of Wildland Resources and Ecology Center; Utah State University; Logan Utah
- Mpala Research Centre; Nanyuki Kenya
| | - Hillary S. Young
- Department of Ecology, Evolution and Marine Biology; University of California; Santa Barbara California
| | - Truman P. Young
- Department of Plant Sciences; University of California; Davis California
- Mpala Research Centre; Nanyuki Kenya
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25
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McLaren BE, MacNearney D, Siavichay CA. Livestock and the functional habitat of vicuñas in Ecuador: a new puzzle. Ecosphere 2018. [DOI: 10.1002/ecs2.2066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Brian E. McLaren
- Lakehead University 955 Oliver Road Thunder Bay Ontario P7B 5E1 Canada
- Escuela Superior Politécnica de Chimborazo Km 1/2 Panamericana Sur Riobamba EC060155 Ecuador
| | | | - Carlos A. Siavichay
- Escuela Superior Politécnica de Chimborazo Km 1/2 Panamericana Sur Riobamba EC060155 Ecuador
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26
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Makin DF, Chamaillé-Jammes S, Shrader AM. Changes in feeding behavior and patch use by herbivores in response to the introduction of a new predator. J Mammal 2017. [DOI: 10.1093/jmammal/gyx177] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Douglas F Makin
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Simon Chamaillé-Jammes
- Centre d’Ecologie Fonctionnelle et Evolutive, UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, France
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, South Africa
| | - Adrian M Shrader
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, South Africa
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27
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Allen BL, Allen LR, Andrén H, Ballard G, Boitani L, Engeman RM, Fleming PJ, Ford AT, Haswell PM, Kowalczyk R, Linnell JD, David Mech L, Parker DM. Can we save large carnivores without losing large carnivore science? FOOD WEBS 2017. [DOI: 10.1016/j.fooweb.2017.02.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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28
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29
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Woodroffe R, Groom R, McNutt JW. Hot dogs: High ambient temperatures impact reproductive success in a tropical carnivore. J Anim Ecol 2017; 86:1329-1338. [DOI: 10.1111/1365-2656.12719] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/29/2017] [Indexed: 11/30/2022]
Affiliation(s)
| | - Rosemary Groom
- Institute of Zoology Zoological Society of London London UK
- Department of Zoology University of Johannesburg Auckland Park South Africa
- African Wildlife Conservation Fund Chishakwe Ranch Zimbabwe
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30
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Long RA, Wambua A, Goheen JR, Palmer TM, Pringle RM. Climatic variation modulates the indirect effects of large herbivores on small-mammal habitat use. J Anim Ecol 2017; 86:739-748. [PMID: 28342277 DOI: 10.1111/1365-2656.12669] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 03/07/2017] [Indexed: 11/29/2022]
Abstract
Large mammalian herbivores (LMH) strongly shape the composition and architecture of plant communities. A growing literature shows that negative direct effects of LMH on vegetation frequently propagate to suppress the abundance of smaller consumers. Indirect effects of LMH on the behaviour of these consumers, however, have received comparatively little attention despite their potential ecological significance. We sought to understand (i) how LMH indirectly shape small-mammal habitat use by altering the density and distribution of understorey plants; (ii) how these effects vary with climatic context (here, seasonality in rainfall); and (iii) the extent to which behavioural responses of small mammals are contingent upon small-mammal density. We tested the effects of a diverse LMH community on small-mammal habitat use using 4 years of spatially explicit small-mammal trapping and vegetation data from the UHURU Experiment, a replicated set of LMH exclosures in semi-arid Kenyan savanna. Small-mammal habitat use was positively associated with tree density and negatively associated with bare (unvegetated) patches in all plots and seasons. In the presence of LMH, and especially during the dry season, small mammals consistently selected tree cover and avoided bare patches. In contrast, when LMH were excluded, small mammals were weakly associated with tree cover and did not avoid bare patches as strongly. These behavioural responses of small mammals were largely unaffected by changes in small-mammal density associated with LMH exclusion. Our results show that LMH indirectly affect small-mammal behaviour, and that these effects are influenced by climate and can arise via density-independent mechanisms. This raises the possibility that anthropogenic LMH declines might interact with changing patterns of rainfall to alter small-mammal distribution and behaviour, independent of numerical responses by small mammals to these perturbations. For example, increased rainfall in East Africa (as predicted in many recent climate-model simulations) may relax constraints on small-mammal distribution where LMH are rare or absent, whereas increased aridity and/or drought frequency may tighten them.
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Affiliation(s)
- Ryan A Long
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Alois Wambua
- Mpala Research Centre, PO Box 555 Rumuruti Road, Nanyuki, Kenya
| | - Jacob R Goheen
- Mpala Research Centre, PO Box 555 Rumuruti Road, Nanyuki, Kenya.,Department of Zoology and Physiology, University of Wyoming, Laramie, WY, 82071, USA
| | - Todd M Palmer
- Mpala Research Centre, PO Box 555 Rumuruti Road, Nanyuki, Kenya.,Department of Biology, University of Florida, Gainesville, FL, 32611, USA
| | - Robert M Pringle
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA.,Mpala Research Centre, PO Box 555 Rumuruti Road, Nanyuki, Kenya
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31
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Herbivores employ a suite of antipredator behaviours to minimize risk from ambush and cursorial predators. Anim Behav 2017. [DOI: 10.1016/j.anbehav.2017.03.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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32
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Ford AT, COOKE SJ, Goheen JR, Young TP. Conserving Megafauna or Sacrificing Biodiversity? Bioscience 2017. [DOI: 10.1093/biosci/biw163] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Pringle RM, Prior KM, Palmer TM, Young TP, Goheen JR. Large herbivores promote habitat specialization and beta diversity of African savanna trees. Ecology 2016; 97:2640-2657. [DOI: 10.1002/ecy.1522] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 06/16/2016] [Accepted: 06/22/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Robert M. Pringle
- Department of Ecology and Evolutionary Biology Princeton University Princeton New Jersey 08544 USA
- Mpala Research Centre P.O. Box 555 Nanyuki 10400 Kenya
| | - Kirsten M. Prior
- Mpala Research Centre P.O. Box 555 Nanyuki 10400 Kenya
- Department of Biology University of Florida Gainesville Florida 32611 USA
- Department of Biological Sciences Binghamton University State University of New York Binghamton, New York 13920 USA
| | - Todd M. Palmer
- Mpala Research Centre P.O. Box 555 Nanyuki 10400 Kenya
- Department of Biology University of Florida Gainesville Florida 32611 USA
| | - Truman P. Young
- Mpala Research Centre P.O. Box 555 Nanyuki 10400 Kenya
- Department of Plant Sciences University of California Davis California 95616 USA
| | - Jacob R. Goheen
- Mpala Research Centre P.O. Box 555 Nanyuki 10400 Kenya
- Department of Zoology and Physiology University of Wyoming Laramie Wyoming 82070 USA
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Daskin JH, Pringle RM. Does primary productivity modulate the indirect effects of large herbivores? A global meta-analysis. J Anim Ecol 2016; 85:857-68. [PMID: 27007672 DOI: 10.1111/1365-2656.12522] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 03/11/2016] [Indexed: 12/13/2022]
Abstract
Indirect effects of large mammalian herbivores (LMH), while much less studied than those of apex predators, are increasingly recognized to exert powerful influences on communities and ecosystems. The strength of these effects is spatiotemporally variable, and several sets of authors have suggested that they are governed in part by primary productivity. However, prior theoretical and field studies have generated conflicting results and predictions, underscoring the need for a synthetic global analysis. We conducted a meta-analysis of the direction and magnitude of large mammalian herbivore-initiated indirect interactions using 67 published studies comprising 456 individual responses. We georeferenced 41 of these studies (comprising 253 responses from 33 locations on five continents) to a satellite-derived map of primary productivity. Because predator assemblages might also influence the impact of large herbivores, we conducted a similar analysis using a global map of large carnivore species richness. In general, LMH reduced the abundance of other consumer species and also tended to reduce consumer richness, although the latter effect was only marginally significant. There was a pronounced reduction in the strength of negative (i.e. suppressive, due e.g., to competition) indirect effects of LMH on consumer abundance in more productive ecosystems. In contrast, positive (facilitative) indirect effects were not significantly correlated with productivity, likely because these comprised a more heterogeneous array of mechanisms. We found no effect of carnivore species richness on herbivore-initiated indirect effect strength. Our findings help to resolve the fundamental problem of ecological contingency as it pertains to the strength of an understudied class of multitrophic interactions. Moreover, these results will aid in predicting the indirect effects of anthropogenic wildlife declines and irruptions, and how these effects might be mediated by climatically driven shifts in resource availability. To the extent that intact ungulate guilds help to suppress populations of small animals that act as agricultural pests and disease reservoirs, the negative impacts of large mammal declines on human well-being may be relatively stronger in low-productivity areas.
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Affiliation(s)
- Joshua H Daskin
- Department of Ecology and Evolutionary Biology, 106A Guyot Hall, Princeton University, Princeton, NJ, 08540, USA
| | - Robert M Pringle
- Department of Ecology and Evolutionary Biology, 106A Guyot Hall, Princeton University, Princeton, NJ, 08540, USA
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35
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Ford AT. The mechanistic pathways of trophic interactions in human-occupied landscapes. Science 2015; 350:1175. [PMID: 26785465 DOI: 10.1126/science.aad7134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Adam T Ford
- Department of Integrative Biology at the University of Guelph, Guelph, Ontario, Canada.
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Trophic Cascades by Large Carnivores: A Case for Strong Inference and Mechanism. Trends Ecol Evol 2015; 30:725-735. [PMID: 26498385 DOI: 10.1016/j.tree.2015.09.012] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 09/22/2015] [Accepted: 09/23/2015] [Indexed: 11/21/2022]
Abstract
Studies on trophic cascades involving large carnivores typically are limited by a lack of replication and control, giving rise to a spirited debate over the ecological role of these iconic species. We argue that much of this debate can be resolved by decomposing the trophic cascade hypothesis into three constituent interactions, quantifying each interaction individually, and accommodating alternative hypotheses. We advocate for a novel approach that couples the rigor characterizing foundational work on trophic cascades (i.e., from studies carried out in mesocosm and whole lake systems) with the conservation relevance of large carnivore-dominated food webs. Because of their iconic status, it is crucial that inferences about the ecological role of large carnivores rise to meet the same rigorous standards to which other studies in community ecology are held.
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