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Donohue JG, Piiroinen PT, Kane A. Predicted short-term mesoscavenger release gives way to apex-scavenger dominance. J Anim Ecol 2024. [PMID: 39300743 DOI: 10.1111/1365-2656.14180] [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: 01/10/2024] [Accepted: 08/09/2024] [Indexed: 09/22/2024]
Abstract
Vultures play a crucial role in scavenging communities as apex scavengers. Scavenging communities in turn are a key component of terrestrial ecosystems, ensuring that dead biomass is removed quickly and efficiently. Anthropogenic disturbances, particularly mass poisonings, have caused crashes in vulture populations in Africa and Asia. We ask if vultures can re-establish themselves in a scavenging community from a point of near extirpation. To allow for maximum knowledge transfer across ecosystems, we focus on an ecosystem that is otherwise considered pristine. We chose Kruger National Park (KNP), a well-documented African scavenging community, as our focal ecosystem and parameterised a mathematical model of scavenging-community dynamics using field data from the park. We predicted the upper limit of vulture population size in an ecosystem like KNP. We then analysed vultures' path to recovery, using this empirically parameterised scavenging-community model. We used perturbation methods to determine how parameter values that may be specific to KNP influence our predictions. Comparisons of predicted vulture carrying capacity with recent population estimates suggest that the cumulative effect of human activities on vulture abundance is larger than previously believed. Our analysis shows that vulture populations can reach their carrying capacity approximately five decades after a poisoning event that would almost extirpate the population. Over shorter time scales, we predict a decade of enhanced mammal abundance (i.e. mesoscavenger release) before the mammals are excluded from the scavenging community. In our study system, jackals and hyenas are the mammalian groups predicted to benefit from the absence of vultures. However, neither group removes biomass as efficiently as vultures and animal carcasses are predicted to accumulate in the ecosystem while the vulture population recovers. In our framework, the carrying capacity for vulture populations is determined by carcass availability. As evidence for an alternative regulating factor is lacking, we conclude that present-day vulture population densities are orders of magnitude below their upper limits. Our results therefore suggest that with a recovery plan in place, the long-term prospects for vulture species and the associated ecosystems are positive.
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Affiliation(s)
- J G Donohue
- MACSI, Department of Mathematics and Statistics, University of Limerick, Limerick, Ireland
| | - P T Piiroinen
- Division of Dynamics, Department of Mechanics and Maritime Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - A Kane
- UCD School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
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2
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Newsome T, Cairncross R, Cunningham CX, Spencer EE, Barton PS, Ripple WJ, Wirsing AJ. Scavenging with invasive species. Biol Rev Camb Philos Soc 2024; 99:562-581. [PMID: 38148253 DOI: 10.1111/brv.13035] [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: 05/02/2023] [Revised: 11/19/2023] [Accepted: 11/22/2023] [Indexed: 12/28/2023]
Abstract
Carrion acts as a hotspot of animal activity within many ecosystems globally, attracting scavengers that rely on this food source. However, many scavengers are invasive species whose impacts on scavenging food webs and ecosystem processes linked to decomposition are poorly understood. Here, we use Australia as a case study to review the extent of scavenging by invasive species that have colonised the continent since European settlement, identify the factors that influence their use of carcasses, and highlight the lesser-known ecological effects of invasive scavengers. From 44 published studies we identified six invasive species from 48 vertebrates and four main groups of arthropods (beetles, flies, ants and wasps) that scavenge. Invasive red foxes (Vulpes vulpes), domestic dogs (Canis familiaris), feral pigs (Sus scrofa), black rats (Rattus rattus) and feral cats (Felis catus) were ranked as highly common vertebrate scavengers. Invasive European wasps (Vespula germanica) are also common scavengers where they occur. We found that the diversity of native vertebrate scavengers is lower when the proportion of invasive scavengers is higher. We highlight that the presence of large (apex) native vertebrate scavengers can decrease rates of scavenging by invasive species, but that invasive scavengers can monopolise carcass resources, outcompete native scavengers, predate other species around carcass resources and even facilitate invasion meltdowns that affect other species and ecological processes including altered decomposition rates and nutrient cycling. Such effects are likely to be widespread where invasive scavengers occur and suggest a need to determine whether excessive or readily available carcass loads are facilitating or exacerbating the impacts of invasive species on ecosystems globally.
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Affiliation(s)
- Thomas Newsome
- School of Life and Environmental Science, University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Rhys Cairncross
- School of Life and Environmental Science, University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Calum X Cunningham
- School of Environmental and Forest Sciences, University of Washington, College of the Environment, Box 352100, Seattle, WA, 98195-2100, USA
| | - Emma E Spencer
- School of Life and Environmental Science, University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Philip S Barton
- School of Life and Environmental Science, Deakin University, Geelong, Victoria, 3216, Australia
| | - William J Ripple
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331, USA
| | - Aaron J Wirsing
- School of Environmental and Forest Sciences, University of Washington, College of the Environment, Box 352100, Seattle, WA, 98195-2100, USA
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3
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Tobajas J, Oliva‐Vidal P, Piqué J, Afonso‐Jordana I, García‐Ferré D, Moreno‐Opo R, Margalida A. Scavenging patterns of generalist predators in forested areas: The potential implications of increase in carrion availability on a threatened capercaillie population. Anim Conserv 2021. [DOI: 10.1111/acv.12735] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jorge Tobajas
- Instituto de Investigación en Recursos Cinegéticos (IREC) CSIC‐UCLM‐JCCM Ciudad Real Spain
| | - Pilar Oliva‐Vidal
- Instituto de Investigación en Recursos Cinegéticos (IREC) CSIC‐UCLM‐JCCM Ciudad Real Spain
- Department of Animal Science Faculty of Life Sciences and Engineering University of Lleida Lleida Spain
| | | | | | | | - Rubén Moreno‐Opo
- Ministerio para la Transición Ecológica y el Reto Demográfico. Pza. San Juan de la Cruz s/n Madrid Spain
| | - Antoni Margalida
- Instituto de Investigación en Recursos Cinegéticos (IREC) CSIC‐UCLM‐JCCM Ciudad Real Spain
- Department of Animal Science Faculty of Life Sciences and Engineering University of Lleida Lleida Spain
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4
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Spencer EE, Dickman CR, Greenville A, Crowther MS, Kutt A, Newsome TM. Carcasses attract invasive species and increase artificial nest predation in a desert environment. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01588] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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5
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Mellard JP, Hamel S, Henden J, Ims RA, Stien A, Yoccoz N. Effect of scavenging on predation in a food web. Ecol Evol 2021; 11:6742-6765. [PMID: 34141254 PMCID: PMC8207452 DOI: 10.1002/ece3.7525] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 02/28/2021] [Accepted: 03/17/2021] [Indexed: 11/06/2022] Open
Abstract
Scavenging can have important consequences for food web dynamics, for example, it may support additional consumer species and affect predation on live prey. Still, few food web models include scavenging. We develop a dynamic model that includes two facultative scavenger species, which we refer to as the predator or scavenger species according to their natural scavenging propensity, as well as live prey, and a carrion pool to show ramifications of scavenging for predation in simple food webs. Our modeling suggests that the presence of scavengers can both increase and decrease predator kill rates and overall predation in model food webs and the impact varies (in magnitude and direction) with context. In particular, we explore the impact of the amount of dynamics (exploitative competition) allowed in the predator, scavenger, and prey populations as well as the direction and magnitude of interference competition between predators and scavengers. One fundamental prediction is that scavengers most likely increase predator kill rates, especially if there are exploitative feedback effects on the prey or carrion resources like is normally observed in natural systems. Scavengers only have minimal effects on predator kill rate when predator, scavenger, and prey abundances are kept constant by management. In such controlled systems, interference competition can greatly affect the interactions in contrast to more natural systems, with an increase in interference competition leading to a decrease in predator kill rate. Our study adds to studies that show that the presence of predators affects scavenger behavior, vital rates, and food web structure, by showing that scavengers impact predator kill rates through multiple mechanisms, and therefore indicating that scavenging and predation patterns are tightly intertwined. We provide a road map to the different theoretical outcomes and their support from different empirical studies on vertebrate guilds to provide guidance in wildlife management.
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Affiliation(s)
- Jarad P. Mellard
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
| | - Sandra Hamel
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
- Département de biologieUniversité LavalQuébecCanada
| | - John‐André Henden
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
| | - Rolf A. Ims
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
| | - Audun Stien
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
| | - Nigel Yoccoz
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
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6
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Newsome TM, Barton B, Buck JC, DeBruyn J, Spencer E, Ripple WJ, Barton PS. Monitoring the dead as an ecosystem indicator. Ecol Evol 2021; 11:5844-5856. [PMID: 34141188 PMCID: PMC8207411 DOI: 10.1002/ece3.7542] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/17/2021] [Accepted: 03/23/2021] [Indexed: 12/21/2022] Open
Abstract
Dead animal biomass (carrion) is present in all terrestrial ecosystems, and its consumption, decomposition, and dispersal can have measurable effects on vertebrates, invertebrates, microbes, parasites, plants, and soil. But despite the number of studies examining the influence of carrion on food webs, there has been no attempt to identify how general ecological processes around carrion might be used as an ecosystem indicator. We suggest that knowledge of scavenging and decomposition rates, scavenger diversity, abundance, and behavior around carrion, along with assessments of vegetation, soil, microbe, and parasite presence, can be used individually or in combination to understand food web dynamics. Monitoring carrion could also assist comparisons of ecosystem processes among terrestrial landscapes and biomes. Although there is outstanding research needed to fully integrate carrion ecology and monitoring into ecosystem management, we see great potential in using carrion as an ecosystem indicator of an intact and functional food web.
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Affiliation(s)
- Thomas M. Newsome
- School of Life and Environmental SciencesThe University of SydneySydneyNSWAustralia
| | - Brandon Barton
- Department of Biological SciencesMississippi State UniversityMississippi StateMSUSA
| | - Julia C. Buck
- Biology and Marine BiologyUniversity of North Carolina WilmingtonWilmingtonNCUSA
| | - Jennifer DeBruyn
- Biosystems Engineering and Soil ScienceUniversity of TennesseeKnoxvilleTNUSA
| | - Emma Spencer
- School of Life and Environmental SciencesThe University of SydneySydneyNSWAustralia
| | - William J. Ripple
- Department of Forest Ecosystems and SocietyOregon State UniversityCorvallisORUSA
| | - Philip S. Barton
- School of ScienceFederation University AustraliaMt HelenVICAustralia
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7
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Couch CE, Wise BL, Scurlock BM, Rogerson JD, Fuda RK, Cole EK, Szcodronski KE, Sepulveda AJ, Hutchins PR, Cross PC. Effects of supplemental feeding on the fecal bacterial communities of Rocky Mountain elk in the Greater Yellowstone Ecosystem. PLoS One 2021; 16:e0249521. [PMID: 33831062 PMCID: PMC8031386 DOI: 10.1371/journal.pone.0249521] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 03/19/2021] [Indexed: 12/27/2022] Open
Abstract
Supplemental feeding of wildlife is a common practice often undertaken for recreational or management purposes, but it may have unintended consequences for animal health. Understanding cryptic effects of diet supplementation on the gut microbiomes of wild mammals is important to inform conservation and management strategies. Multiple laboratory studies have demonstrated the importance of the gut microbiome for extracting and synthesizing nutrients, modulating host immunity, and many other vital host functions, but these relationships can be disrupted by dietary perturbation. The well-described interplay between diet, the microbiome, and host health in laboratory and human systems highlights the need to understand the consequences of supplemental feeding on the microbiomes of free-ranging animal populations. This study describes changes to the gut microbiomes of wild elk under different supplemental feeding regimes. We demonstrated significant cross-sectional variation between elk at different feeding locations and identified several relatively low-abundance bacterial genera that differed between fed versus unfed groups. In addition, we followed four of these populations through mid-season changes in supplemental feeding regimes and demonstrated a significant shift in microbiome composition in a single population that changed from natural forage to supplementation with alfalfa pellets. Some of the taxonomic shifts in this population mirrored changes associated with ruminal acidosis in domestic livestock. We discerned no significant changes in the population that shifted from natural forage to hay supplementation, or in the populations that changed from one type of hay to another. Our results suggest that supplementation with alfalfa pellets alters the native gut microbiome of elk, with potential implications for population health.
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Affiliation(s)
- Claire E. Couch
- Department of Fisheries & Wildlife, Oregon State University, Corvallis, Oregon, United States of America
| | - Benjamin L. Wise
- Wyoming Game & Fish Department, Jackson, Wyoming, United States of America
| | | | - Jared D. Rogerson
- Wyoming Game & Fish Department, Pinedale, Wyoming, United States of America
| | - Rebecca K. Fuda
- Oregon Department of Fish & Wildlife, Prineville, Oregon, United States of America
| | - Eric K. Cole
- U.S. Fish & Wildlife Service, National Elk Refuge, Jackson, Wyoming, United States of America
| | - Kimberly E. Szcodronski
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Bozeman, Montana, United States of America
| | - Adam J. Sepulveda
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Bozeman, Montana, United States of America
| | - Patrick R. Hutchins
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Bozeman, Montana, United States of America
| | - Paul C. Cross
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Bozeman, Montana, United States of America
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8
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Handler KS, Subalusky AL, Kendall CJ, Dutton CL, Rosi EJ, Post DM. Temporal resource partitioning of wildebeest carcasses by scavengers after riverine mass mortality events. Ecosphere 2021. [DOI: 10.1002/ecs2.3326] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Katherine S. Handler
- Department of Ecology and Evolutionary Biology Yale University New Haven Connecticut06511USA
| | - Amanda L. Subalusky
- Department of Ecology and Evolutionary Biology Yale University New Haven Connecticut06511USA
- Department of Biology University of Florida Gainesville Florida32611USA
| | - Corinne J. Kendall
- North Carolina Zoo Asheboro North Carolina27205USA
- North Carolina State University Raleigh North Carolina27607USA
| | - Christopher L. Dutton
- Department of Ecology and Evolutionary Biology Yale University New Haven Connecticut06511USA
- Department of Biology University of Florida Gainesville Florida32611USA
| | - Emma J. Rosi
- Cary Institute of Ecosystem Studies Millbrook New York12545USA
| | - David M. Post
- Department of Ecology and Evolutionary Biology Yale University New Haven Connecticut06511USA
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9
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The Role of Carrion in the Landscapes of Fear and Disgust: A Review and Prospects. DIVERSITY 2021. [DOI: 10.3390/d13010028] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Animal behavior is greatly shaped by the ‘landscape of fear’, induced by predation risk, and the equivalent ‘landscape of disgust’, induced by parasitism or infection risk. However, the role that carrion may play in these landscapes of peril has been largely overlooked. Here, we aim to emphasize that animal carcasses likely represent ubiquitous hotspots for both predation and infection risk, thus being an outstanding paradigm of how predation and parasitism pressures can concur in space and time. By conducting a literature review, we highlight the manifold inter- and intra-specific interactions linked to carrion via predation and parasitism risks, which may affect not only scavengers, but also non-scavengers. However, we identified major knowledge gaps, as reviewed articles were highly biased towards fear, terrestrial environments, vertebrates, and behavioral responses. Based on the reviewed literature, we provide a conceptual framework on the main fear- and disgust-based interaction pathways associated with carrion resources. This framework may be used to formulate predictions about how the landscape of fear and disgust around carcasses might influence animals’ individual behavior and ecological processes, from population to ecosystem functioning. We encourage ecologists, evolutionary biologists, epidemiologists, forensic scientists, and conservation biologists to explore the promising research avenues associated with the scary and disgusting facets of carrion. Acknowledging the multiple trophic and non-trophic interactions among dead and live animals, including both herbivores and carnivores, will notably improve our understanding of the overlapping pressures that shape the landscape of fear and disgust.
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10
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Marinković S, Hribšek I, Tatalović N, Skorić S. A long-term population study of the Eurasian griffon (Gyps fulvus) in Serbia before and following the establishment of a supplementary feeding program. ETHOL ECOL EVOL 2020. [DOI: 10.1080/03949370.2020.1844302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Saša Marinković
- Department of Ecology, Institute for Biological Research “Siniša Stanković”, National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
- The Birds of Prey Protection Foundation, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia
| | - Irena Hribšek
- The Birds of Prey Protection Foundation, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia
| | | | - Stefan Skorić
- The Birds of Prey Protection Foundation, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia
- Department of Physiology, Institute for Biological Research “Siniša Stanković”, National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
- Department of Biology and Inland Waters Protection, Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia
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11
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Brink CW, Santangeli A, Amar A, Wolter K, Tate G, Krüger S, Tucker AS, Thomson RL. Perceptions of vulture supplementary feeding site managers and potential hidden risks to avian scavengers. CONSERVATION SCIENCE AND PRACTICE 2020. [DOI: 10.1111/csp2.237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Christiaan W. Brink
- FitzPatrick Institute of African Ornithology, DST‐NRF Centre of Excellence, Department of Biological SciencesUniversity of Cape Town Cape Town South Africa
| | - Andrea Santangeli
- FitzPatrick Institute of African Ornithology, DST‐NRF Centre of Excellence, Department of Biological SciencesUniversity of Cape Town Cape Town South Africa
- The Helsinki Lab of Ornithology, Finnish Museum of Natural HistoryUniversity of Helsinki Helsinki Finland
| | - Arjun Amar
- FitzPatrick Institute of African Ornithology, DST‐NRF Centre of Excellence, Department of Biological SciencesUniversity of Cape Town Cape Town South Africa
| | | | - Gareth Tate
- Birds of Prey ProgrammeEndangered Wildlife Trust Modderfontein South Africa
| | - Sonja Krüger
- Ezemvelo KwaZulu‐Natal Wildlife Cascades South Africa
| | | | - Robert L. Thomson
- FitzPatrick Institute of African Ornithology, DST‐NRF Centre of Excellence, Department of Biological SciencesUniversity of Cape Town Cape Town South Africa
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12
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Ferrière C, Zuël N, Ewen JG, Jones CG, Tatayah V, Canessa S. Assessing the risks of changing ongoing management of endangered species. Anim Conserv 2020. [DOI: 10.1111/acv.12602] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- C. Ferrière
- Mauritian Wildlife Foundation Vacoas Mauritius
- Ebony Forest Reserve Chamarel Chamarel Mauritius
| | - N. Zuël
- Mauritian Wildlife Foundation Vacoas Mauritius
- Ebony Forest Reserve Chamarel Chamarel Mauritius
| | - J. G. Ewen
- Institute of Zoology Zoological Society of London London UK
| | - C. G. Jones
- Mauritian Wildlife Foundation Vacoas Mauritius
- Durrell Wildlife Conservation Trust St Helier UK
| | - V. Tatayah
- Mauritian Wildlife Foundation Vacoas Mauritius
| | - S. Canessa
- Institute of Zoology Zoological Society of London London UK
- Wildlife Health Ghent Department of Pathology, Bacteriology and Avian Diseases Faculty of Veterinary Medicine Ghent University Merelbeke Belgium
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13
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Frank SC, Blaalid R, Mayer M, Zedrosser A, Steyaert SMJG. Fear the reaper: ungulate carcasses may generate an ephemeral landscape of fear for rodents. ROYAL SOCIETY OPEN SCIENCE 2020; 7:191644. [PMID: 32742677 PMCID: PMC7353961 DOI: 10.1098/rsos.191644] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 05/03/2020] [Indexed: 06/11/2023]
Abstract
Animal carcasses provide an ephemeral pulse of nutrients for scavengers that use them. Carcass sites can increase species interactions and/or ephemeral, localized landscapes of fear for prey within the vicinity. Few studies have applied the landscape of fear to carcasses. Here, we use a mass die-off of reindeer caused by lightning in Norway to test whether rodents avoided larger scavengers (e.g. corvids and fox). We used the presence and abundance of faeces as a proxy for carcass use over the course of 2 years and found that rodents showed the strongest avoidance towards changes in raven abundance (β = -0.469, s.e. = 0.231, p-value = 0.0429), but not fox, presumably due to greater predation risk imposed by large droves of raven. Moreover, the emergence of rodent occurrence within the carcass area corresponded well with the disappearance of raven during the second year of the study. We suggest that carcasses have the potential to shape the landscape of fear for prey, but that the overall effects of carcasses on individual fitness and populations of species ultimately depend on the carcass regime, e.g. carcass size, count, and areal extent, frequency and the scavenger guild. We discuss conservation implications and how carcass provisioning and landscapes of fear could be potentially used to manage populations and ecosystems, but that there is a gap in understanding that must first be bridged.
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Affiliation(s)
- S. C. Frank
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, 3800 Bø i Telemark, Norway
| | - R. Blaalid
- Norwegian Institute for Nature Research, Thormøhlensgate 55, 5006 Bergen
| | - M. Mayer
- Department of Bioscience, Aarhus University, 8410 Rønde, Denmark
| | - A. Zedrosser
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, 3800 Bø i Telemark, Norway
- Department of Integrative Biology, Institute of Wildlife Biology and Game Management, University of Natural Resources and Applied Life Sciences, Vienna, Austria
| | - S. M. J. G. Steyaert
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, 3800 Bø i Telemark, Norway
- Faculty of Biosciences and Aquaculture, Nord University, 7711 Steinkjer, Norway
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14
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van Klink R, van Laar-Wiersma J, Vorst O, Smit C. Rewilding with large herbivores: Positive direct and delayed effects of carrion on plant and arthropod communities. PLoS One 2020; 15:e0226946. [PMID: 31967995 PMCID: PMC6975527 DOI: 10.1371/journal.pone.0226946] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 12/09/2019] [Indexed: 12/22/2022] Open
Abstract
Carrion of large animals is an extremely nutrient rich, ephemeral resource that is essential for many species, but is scarce in the anthropogenic Western-European landscape due to legislative restrictions. Rewilding, a novel conservation strategy that aims at restoring natural processes with minimal human intervention, is increasing in popularity and could lead to increased carrion availability in the landscape. It is therefore important to understand the effects of carrion on biodiversity. We investigated the direct and delayed (five months) effects of red deer (Cervus elaphus) carcasses on plants and arthropods in the Oostvaardersplassen, the Netherlands, one of the oldest rewilding sites in Europe. Specifically, we tested whether carrion has a positive direct effect on the abundances and diversity of various arthropod functional groups, as well as a delayed effect on the vegetation and arthropods through the increased nutrient availability. During the active decomposition stage in spring, we, not surprisingly, observed higher abundances of carrion associated species (scavengers and their specialized predators) at the carrion sites than at control sites without carrion, but no higher abundances of predators or detritivores. In late summer, after near-complete decomposition, plant biomass was five times higher, and nutritional plant quality (C:N ratio) was higher at the carrion sites than at the control sites. Arthropod abundance and diversity were also manifold higher, owing to higher numbers of herbivorous and predatory species. Regression analysis showed that abundances of herbivores and detritivores were positively related to plant biomass, and predator abundances were positively related to abundances of herbivores and detritivores, suggesting bottom-up effects propagating through the food chain. Our results show that even in a naturally nutrient-rich ecosystem like the Oostvaardersplassen, carrion can have strong positive effects on local plant biomass and nutritional quality and arthropod abundances, lasting the whole growing season. We found evidence that these effects were first directly caused by the presence of carrion, and later by the enhanced nutrient availability in the soil. This highlights the importance of the indirect pathways by which carrion can structure arthropod communities.
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Affiliation(s)
- Roel van Klink
- Groningen Institute for Evolutionary Life Sciences (GELIFES), Conservation Ecology Group, University of Groningen, Groningen, The Netherlands
- * E-mail:
| | - Jitske van Laar-Wiersma
- Groningen Institute for Evolutionary Life Sciences (GELIFES), Conservation Ecology Group, University of Groningen, Groningen, The Netherlands
| | - Oscar Vorst
- Independent Researcher, Utrecht, The Netherlands
| | - Christian Smit
- Groningen Institute for Evolutionary Life Sciences (GELIFES), Conservation Ecology Group, University of Groningen, Groningen, The Netherlands
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15
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Brink CW, Santangeli A, Amar A, Wolter K, Tate G, Krüger S, Tucker AS, Thomson RL. Quantifying the spatial distribution and trends of supplementary feeding sites in South Africa and their potential contribution to vulture energetic requirements. Anim Conserv 2020. [DOI: 10.1111/acv.12561] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- C. W. Brink
- FitzPatrick Institute of African Ornithology DST‐NRF Centre of Excellence University of Cape Town Cape Town South Africa
| | - A. Santangeli
- FitzPatrick Institute of African Ornithology DST‐NRF Centre of Excellence University of Cape Town Cape Town South Africa
- The Helsinki Lab of Ornithology Finnish Museum of Natural History University of Helsinki Helsinki Finland
| | - A. Amar
- FitzPatrick Institute of African Ornithology DST‐NRF Centre of Excellence University of Cape Town Cape Town South Africa
| | | | - G. Tate
- Birds of Prey Programme Endangered Wildlife Trust Modderfontein South Africa
| | - S. Krüger
- Ezemvelo KwaZulu‐Natal Wildlife Cascades South Africa
| | | | - R. L. Thomson
- FitzPatrick Institute of African Ornithology DST‐NRF Centre of Excellence University of Cape Town Cape Town South Africa
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16
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Coates SE, Wright BW, Carlisle JD. Long‐billed curlew nest site selection and success in the Intermountain West. J Wildl Manage 2019. [DOI: 10.1002/jwmg.21661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Stephanie E. Coates
- Intermountain Bird Observatory, Department of Biological Sciences, Boise State University1910 University Drive Boise ID 83725 USA
| | - Benjamin W. Wright
- Intermountain Bird Observatory, Department of Biological Sciences, Boise State University1910 University Drive Boise ID 83725 USA
| | - Jay D. Carlisle
- Intermountain Bird Observatory, Department of Biological Sciences, Boise State University1910 University Drive Boise ID 83725 USA
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17
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Fležar U, Costa B, Bordjan D, Jerina K, Krofel M. Free food for everyone: artificial feeding of brown bears provides food for many non-target species. EUR J WILDLIFE RES 2018. [DOI: 10.1007/s10344-018-1237-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Cunningham CX, Johnson CN, Barmuta LA, Hollings T, Woehler EJ, Jones ME. Top carnivore decline has cascading effects on scavengers and carrion persistence. Proc Biol Sci 2018; 285:rspb.2018.1582. [PMID: 30487308 DOI: 10.1098/rspb.2018.1582] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 11/05/2018] [Indexed: 01/24/2023] Open
Abstract
Top carnivores have suffered widespread global declines, with well-documented effects on mesopredators and herbivores. We know less about how carnivores affect ecosystems through scavenging. Tasmania's top carnivore, the Tasmanian devil (Sarcophilus harrisii), has suffered severe disease-induced population declines, providing a natural experiment on the role of scavenging in structuring communities. Using remote cameras and experimentally placed carcasses, we show that mesopredators consume more carrion in areas where devils have declined. Carcass consumption by the two native mesopredators was best predicted by competition for carrion, whereas consumption by the invasive mesopredator, the feral cat (Felis catus), was better predicted by the landscape-level abundance of devils, suggesting a relaxed landscape of fear where devils are suppressed. Reduced discovery of carcasses by devils was balanced by the increased discovery by mesopredators. Nonetheless, carcasses persisted approximately 2.6-fold longer where devils have declined, highlighting their importance for rapid carrion removal. The major beneficiary of increased carrion availability was the forest raven (Corvus tasmanicus). Population trends of ravens increased 2.2-fold from 1998 to 2017, the period of devil decline, but this increase occurred Tasmania-wide, making the cause unclear. This case study provides a little-studied potential mechanism for mesopredator release, with broad relevance to the vast areas of the world that have suffered carnivore declines.
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Affiliation(s)
- Calum X Cunningham
- School of Natural Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Christopher N Johnson
- School of Natural Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia.,Australian Research Council Centre for Australian Biodiversity and Heritage, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Leon A Barmuta
- School of Natural Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Tracey Hollings
- Department of Environment, Land, Water and Planning, Arthur Rylah Institute for Environmental Research, Heidelberg, Victoria 3084, Australia.,Centre of Excellence for Biosecurity Risk Analysis, School of Biosciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Eric J Woehler
- Birdlife Tasmania, GPO Box 68, Hobart, Tasmania, Australia
| | - Menna E Jones
- School of Natural Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia
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20
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Steinbeiser C, Wawrzynowski C, Ramos X, Olson Z. Scavenging and the ecology of fear: do animal carcasses create islands of risk on the landscape? CAN J ZOOL 2018. [DOI: 10.1139/cjz-2016-0268] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many vertebrate scavengers function as predators in ecosystems, suggesting that the presence of scavengers and occurrence of predator effects may be intertwined near carcasses. We tested for risk effects near a series of experimentally placed carcasses by measuring small-mammal foraging in a before–after control–impact design. Validation efforts revealed low levels of food loss from stations due to human error and invertebrate foraging, and habituation to stations occurred after 2 weeks. Increased perceived predation risk by small mammals relative to controls occurred in three of seven trials. The effect was observed across tested carcass types (beaver, Castor canadensis Kuhl, 1820; white-tailed deer, Odocoileus virginianus (Zimmermann, 1780)) and seasons (summer and fall). However, small mammals also increased foraging relative to controls in two of seven trials, and foraging reached a ceiling in two other trials that prevented inference on a response. Taken together, our results suggest that scavenger recruitment to carcasses can in some instances create islands of risk for prey on the landscape, but the effect is not likely to be universal. Where small-mammal foraging does decrease, further work will be necessary to determine if risk effects cascade to adjacent trophic levels through enhanced seed and seedling survival.
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Affiliation(s)
- C.M. Steinbeiser
- University of New England, Department of Psychology, 11 Hills Beach Road, Biddeford, ME 04005, USA
- University of New England, Department of Psychology, 11 Hills Beach Road, Biddeford, ME 04005, USA
| | - C.A. Wawrzynowski
- University of New England, Department of Psychology, 11 Hills Beach Road, Biddeford, ME 04005, USA
- University of New England, Department of Psychology, 11 Hills Beach Road, Biddeford, ME 04005, USA
| | - X. Ramos
- University of New England, Department of Psychology, 11 Hills Beach Road, Biddeford, ME 04005, USA
- University of New England, Department of Psychology, 11 Hills Beach Road, Biddeford, ME 04005, USA
| | - Z.H. Olson
- University of New England, Department of Psychology, 11 Hills Beach Road, Biddeford, ME 04005, USA
- University of New England, Department of Psychology, 11 Hills Beach Road, Biddeford, ME 04005, USA
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21
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Turner KL, Abernethy EF, Conner LM, Rhodes OE, Beasley JC. Abiotic and biotic factors modulate carrion fate and vertebrate scavenging communities. Ecology 2017. [DOI: 10.1002/ecy.1930] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Kelsey L. Turner
- Warnell School of Forestry and Natural Resources University of Georgia Savannah River Ecology Laboratory P.O. Box Drawer E Aiken South Carolina 29802 USA
- University of Georgia Savannah River Ecology Laboratory P.O. Box Drawer E Aiken South Carolina 29802 USA
| | - Erin F. Abernethy
- Odum School of Ecology University of Georgia Savannah River Ecology Laboratory P.O. Box Drawer E Aiken South Carolina 29802 USA
- University of Georgia Savannah River Ecology Laboratory P.O. Box Drawer E Aiken South Carolina 29802 USA
| | - L. Mike Conner
- Joseph W. Jones Ecological Research Center 3988 Jones Center Drive Newton Georgia 39870 USA
| | - Olin E. Rhodes
- Warnell School of Forestry and Natural Resources University of Georgia Savannah River Ecology Laboratory P.O. Box Drawer E Aiken South Carolina 29802 USA
- University of Georgia Savannah River Ecology Laboratory P.O. Box Drawer E Aiken South Carolina 29802 USA
| | - James C. Beasley
- Warnell School of Forestry and Natural Resources University of Georgia Savannah River Ecology Laboratory P.O. Box Drawer E Aiken South Carolina 29802 USA
- University of Georgia Savannah River Ecology Laboratory P.O. Box Drawer E Aiken South Carolina 29802 USA
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22
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Morales-Reyes Z, Sánchez-Zapata JA, Sebastián-González E, Botella F, Carrete M, Moleón M. Scavenging efficiency and red fox abundance in Mediterranean mountains with and without vultures. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2017. [DOI: 10.1016/j.actao.2016.12.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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23
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Becker DJ, Hall RJ. Heterogeneity in patch quality buffers metapopulations from pathogen impacts. THEOR ECOL-NETH 2015. [DOI: 10.1007/s12080-015-0284-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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24
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Moreno-Opo R, Trujillano A, Margalida A. Optimization of supplementary feeding programs for European vultures depends on environmental and management factors. Ecosphere 2015. [DOI: 10.1890/es15-00009.1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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25
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Ewen JG, Walker L, Canessa S, Groombridge JJ. Improving supplementary feeding in species conservation. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2015; 29:341-349. [PMID: 25354808 PMCID: PMC4405093 DOI: 10.1111/cobi.12410] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 07/10/2014] [Indexed: 06/04/2023]
Abstract
Supplementary feeding is often a knee-jerk reaction to population declines, and its application is not critically evaluated, leading to polarized views among managers on its usefulness. Here, we advocate a more strategic approach to supplementary feeding so that the choice to use it is clearly justified over, or in combination with, other management actions and the predicted consequences are then critically assessed following implementation. We propose combining methods from a set of specialist disciplines that will allow critical evaluation of the need, benefit, and risks of food supplementation. Through the use of nutritional ecology, population ecology, and structured decision making, conservation managers can make better choices about what and how to feed by estimating consequences on population recovery across a range of possible actions. This structured approach also informs targeted monitoring and more clearly allows supplementary feeding to be integrated in recovery plans and reduces the risk of inefficient decisions. In New Zealand, managers of the endangered Hihi (Notiomystis cincta) often rely on supplementary feeding to support reintroduced populations. On Kapiti island the reintroduced Hihi population has responded well to food supplementation, but the logistics of providing an increasing demand recently outstretched management capacity. To decide whether and how the feeding regime should be revised, managers used a structured decision making approach informed by population responses to alternative feeding regimes. The decision was made to reduce the spatial distribution of feeders and invest saved time in increasing volume of food delivered into a smaller core area. The approach used allowed a transparent and defendable management decision in regard to supplementary feeding, reflecting the multiple objectives of managers and their priorities.
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Affiliation(s)
- John G Ewen
- Institute of Zoology, Zoological Society of London, Regents Park, NW1 4RY, London, United Kingdom.
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26
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Don’t think local! Scale in conservation, parochialism, dogmatic bureaucracy and the implementing of the European Directives. J Nat Conserv 2015. [DOI: 10.1016/j.jnc.2015.01.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Steyaert SM, Kindberg J, Jerina K, Krofel M, Stergar M, Swenson JE, Zedrosser A. Behavioral correlates of supplementary feeding of wildlife: Can general conclusions be drawn? Basic Appl Ecol 2014. [DOI: 10.1016/j.baae.2014.10.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Fielding D, Newey S, van der Wal R, Irvine RJ. Carcass provisioning to support scavengers: evaluating a controversial nature conservation practice. AMBIO 2014; 43:810-819. [PMID: 24366570 PMCID: PMC4165841 DOI: 10.1007/s13280-013-0469-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Revised: 10/09/2013] [Accepted: 11/11/2013] [Indexed: 05/29/2023]
Abstract
A number of scavenger species have suffered population declines across Europe. In attempts to reverse their decline, some land and wildlife managers have adopted the practice of leaving or placing out carcasses of wild or domestic herbivores to provide a source of carrion. However, this can be a controversial practice, with as yet unclear outcomes for many target species and the ecosystems they are part of. Here we bring out the key aspects of this increasingly common conservation practice illustrated using three contrasting cases studies. We show that the provision of carcasses is often motivated by a desire to benefit charismatic species or to facilitate nutrient cycling throughout an ecosystem. Evidence for the effectiveness of this practice in achieving these objectives, however, is mostly lacking, with ecologists studying "easier" species groups such as beetles and therefore not providing relevant insights. Moreover, conflicts between environmental policies that carcass provisioning is aimed at and other social and economic objectives do occur but these projects are often designed without taking into account this broader context. We conclude that expecting carcasses to simply be "good for biodiversity" may be too naïve a view. A greater knowledge of the impact of carcass provisioning and placement on ecosystems and society at large is required before it can become a more effective conservation tool at a wider scale.
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Affiliation(s)
- Debbie Fielding
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK,
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29
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Yarnell RW, Phipps WL, Dell S, MacTavish LM, Scott DM. Evidence that vulture restaurants increase the local abundance of mammalian carnivores in South Africa. Afr J Ecol 2014. [DOI: 10.1111/aje.12178] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Richard W. Yarnell
- School of Animal Rural and Environmental Sciences; Nottingham Trent University; Brackenhurst Campus Southwell NG25 0QF U.K
| | - William Louis Phipps
- School of Animal Rural and Environmental Sciences; Nottingham Trent University; Brackenhurst Campus Southwell NG25 0QF U.K
| | - Steve Dell
- Pilanesberg National Park; North West Parks and Tourism Board; Mogwase South Africa
| | | | - Dawn M. Scott
- Biology and Biomedical Sciences Division; University of Brighton; Huxley Building Lewes Road Brighton BN2 4GJ U.K
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30
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Rees JD, Webb JK, Crowther MS, Letnic M. Carrion subsidies provided by fishermen increase predation of beach-nesting bird nests by facultative scavengers. Anim Conserv 2014. [DOI: 10.1111/acv.12133] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J. D. Rees
- School of Biological Sciences; University of Sydney; Sydney NSW Australia
- Centre for Ecosystem Science, School of Biological Sciences; University of New South Wales; Sydney NSW Australia
| | - J. K. Webb
- School of Environmental Sciences; University of Technology Sydney; Sydney NSW Australia
| | - M. S. Crowther
- School of Biological Sciences; University of Sydney; Sydney NSW Australia
| | - M. Letnic
- Centre for Ecosystem Science, School of Biological Sciences; University of New South Wales; Sydney NSW Australia
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31
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Moleón M, Sánchez-Zapata JA, Selva N, Donázar JA, Owen-Smith N. Inter-specific interactions linking predation and scavenging in terrestrial vertebrate assemblages. Biol Rev Camb Philos Soc 2014; 89:1042-54. [PMID: 24602047 DOI: 10.1111/brv.12097] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 01/30/2014] [Accepted: 02/07/2014] [Indexed: 11/29/2022]
Abstract
Predation and scavenging have been classically understood as independent processes, with predator-prey interactions and scavenger-carrion relationships occurring separately. However, the mere recognition that most predators also scavenge at variable rates, which has been traditionally ignored in food-web and community ecology, leads to a number of emergent interaction routes linking predation and scavenging. The general goal of this review is to draw attention to the main inter-specific interactions connecting predators (particularly, large mammalian carnivores), their live prey (mainly ungulates), vultures and carrion production in terrestrial assemblages of vertebrates. Overall, we report an intricate network of both direct (competition, facilitation) and indirect (hyperpredation, hypopredation) processes, and provide a conceptual framework for the future development of this promising topic in ecological, evolutionary and biodiversity conservation research. The classic view that scavenging does not affect the population dynamics of consumed organisms is questioned, as multiple indirect top-down effects emerge when considering carrion and its facultative consumption by predators as fundamental and dynamic components of food webs. Stimulating although challenging research opportunities arise from the study of the interactions among living and detrital or non-living resource pools in food webs.
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Affiliation(s)
- Marcos Moleón
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Wits, 2050, Johannesburg, South Africa; Departamento de Biología Aplicada, Universidad Miguel Hernández, Ctra. Beniel Km 3.2, 03312, Orihuela, Alicante, Spain
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32
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Selva N, Berezowska-Cnota T, Elguero-Claramunt I. Unforeseen effects of supplementary feeding: ungulate baiting sites as hotspots for ground-nest predation. PLoS One 2014; 9:e90740. [PMID: 24599216 PMCID: PMC3944607 DOI: 10.1371/journal.pone.0090740] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 02/05/2014] [Indexed: 11/18/2022] Open
Abstract
Despite the ubiquity and magnitude of food provision to wildlife, our understanding of its ecological effects and conservation implications is very limited. Supplementary feeding of ungulates, still one of the main paradigms of game management in Europe, occurs in natural areas on an enormous scale. We investigated the indirect effects of this practice on nest predation risk in the Polish Eastern Carpathians (Bieszczady Mountains). We hypothesized that the predators attracted to ungulate baiting sites would also forage for alternative prey nearby, increasing the nest predation risk for ground-nesting birds in the vicinity. We conducted a paired experiment by placing artificial nests (N=120) in feeding and control sites (N=12) at different distances from the ungulate feeding site. We also documented the use of three ungulate feeding sites by potential nest predators with automatic cameras. The proportion of depredated nests was 30% higher in the vicinity of feeding sites than at control sites (65%± 31.5 vs 35%± 32.1). The probability of a nest being depredated significantly increased with time and at shorter distances from the feeding site. We predicted that the area within 1-km distance from the feeding site would have a high risk (>0.5) of nest predation. We recorded 13 species of potential ground-nest predators at ungulate baiting sites. Most frequent were Eurasian jays Garrulus glandarius, mice and voles Muroidea, ravens Corvus corax, brown bears Ursus arctos, and wild boar Sus scrofa. Nest predators made most use of supplementary feeding sites (82% pictures with predators vs 8% with ungulates, the target group). Our study alerts of the impacts of ungulate feeding on alternative prey; this is of special concern when affecting protected species. We urge for a sensible management of ungulate feeding, which considers potential indirect effects on other species and the spatial and temporal components of food provision.
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Affiliation(s)
- Nuria Selva
- Institute of Nature Conservation, Polish Academy of Sciences, Mickiewicza, Kraków
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García-Heras MS, Cortés-Avizanda A, Donázar JA. Who are we feeding? Asymmetric individual use of surplus food resources in an insular population of the endangered Egyptian vulture Neophron percnopterus. PLoS One 2013; 8:e80523. [PMID: 24244695 PMCID: PMC3823625 DOI: 10.1371/journal.pone.0080523] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 10/15/2013] [Indexed: 11/21/2022] Open
Abstract
Supplementary feeding stations, or “vulture restaurants”, are common conservation management tools. While a number of studies have investigated the consequences of surplus food on the population dynamics of scavengers, relatively little is known about the effects of such practices at the individual level. Within the long-term monitored breeding population of Canarian Egyptian vultures (Neophron percnopterus majorensis) we investigated individual bird’s patterns of use of a supplementary feeding station at Fuerteventura (Canary Islands), over the course of breeding (2001, 2002; 2004-2011) and non-breeding seasons (2000-2010). Our results show that during the breeding season the individual use of the supplementary feeding station was inversely related to the distance to the breeding territory, which suggests the existence of central-place foraging constraints. In addition, larger birds of poor body-condition and individuals that ultimately failed to fledge young were detected more frequently at the feeding station. During the non-breeding season, and because most breeding birds abandoned the breeding territories, the overall abundance of Egyptian vultures at the feeding station grew. Moreover, the only variable increasing the probability of presence of individuals was poor body condition so that birds with lower wing residual visited the feeding station more frequently. Supplementary feeding may benefit individuals who would otherwise have been subject to selective pressures. From our results it follows that this conservation strategy must be used with caution because it can have consequences on an individual level and thus potentially affect the viability of endangered populations.
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Affiliation(s)
- Marie-Sophie García-Heras
- Department of Conservation Biology, Estación Biológica de Doñana C.S.I.C., Sevilla, Spain
- Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa
- * E-mail:
| | - Ainara Cortés-Avizanda
- Department of Conservation Biology, Estación Biológica de Doñana C.S.I.C., Sevilla, Spain
- Theoretical Ecology and Biodiversity Change Group, Centro de Biologia Ambiental, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal
| | - José-Antonio Donázar
- Department of Conservation Biology, Estación Biológica de Doñana C.S.I.C., Sevilla, Spain
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Beja P, Schindler S, Santana J, Porto M, Morgado R, Moreira F, Pita R, Mira A, Reino L. Predators and livestock reduce bird nest survival in intensive Mediterranean farmland. EUR J WILDLIFE RES 2013. [DOI: 10.1007/s10344-013-0773-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Oro D, Genovart M, Tavecchia G, Fowler MS, Martínez-Abraín A. Ecological and evolutionary implications of food subsidies from humans. Ecol Lett 2013; 16:1501-14. [PMID: 24134225 DOI: 10.1111/ele.12187] [Citation(s) in RCA: 343] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 07/15/2013] [Accepted: 08/23/2013] [Indexed: 11/28/2022]
Abstract
Human activities are the main current driver of global change. From hunter-gatherers through to Neolithic societies-and particularly in contemporary industrialised countries-humans have (voluntarily or involuntarily) provided other animals with food, often with a high spatio-temporal predictability. Nowadays, as much as 30-40% of all food produced in Earth is wasted. We argue here that predictable anthropogenic food subsidies (PAFS) provided historically by humans to animals has shaped many communities and ecosystems as we see them nowadays. PAFS improve individual fitness triggering population increases of opportunistic species, which may affect communities, food webs and ecosystems by altering processes such as competition, predator-prey interactions and nutrient transfer between biotopes and ecosystems. We also show that PAFS decrease temporal population variability, increase resilience of opportunistic species and reduce community diversity. Recent environmental policies, such as the regulation of dumps or the ban of fishing discards, constitute natural experiments that should improve our understanding of the role of food supply in a range of ecological and evolutionary processes at the ecosystem level. Comparison of subsidised and non-subsidised ecosystems can help predict changes in diversity and the related ecosystem services that have suffered the impact of other global change agents.
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Affiliation(s)
- Daniel Oro
- Population Ecology Group, IMEDEA (CSIC-UIB), Esporles, 07190, Spain
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36
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Moreno-Opo R, Margalida A. Carcasses provide resources not exclusively to scavengers: patterns of carrion exploitation by passerine birds. Ecosphere 2013. [DOI: 10.1890/es13-00108.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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37
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DeVault TL, Olson ZH, Beasley JC, Rhodes OE. Mesopredators dominate competition for carrion in an agricultural landscape. Basic Appl Ecol 2011. [DOI: 10.1016/j.baae.2011.02.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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38
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Moreno-Opo R, Margalida A, Arredondo Á, Guil F, Martín M, Higuero R, Soria C, Guzmán J. Factors influencing the presence of the cinereous vulture Aegypius monachus at carcasses: food preferences and implications for the management of supplementary feeding sites. WILDLIFE BIOLOGY 2010. [DOI: 10.2981/09-037] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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