1
|
Labadie G, Hardy C, Boulanger Y, Vanlandeghem V, Hebblewhite M, Fortin D. Global change risks a threatened species due to alteration of predator–prey dynamics. Ecosphere 2023. [DOI: 10.1002/ecs2.4485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023] Open
|
2
|
Slade A, White A, Lurz PW, Shuttleworth C, Tosh DG, Twining JP. Indirect effects of pine marten recovery result in benefits to native prey through suppression of an invasive species and a shared pathogen. Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2022.110216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
|
3
|
Srednick G, Cohen A, Diehl O, Tyler K, Swearer SE. Habitat attributes mediate herbivory and influence community development in algal metacommunities. Ecology 2023; 104:e3976. [PMID: 36691779 DOI: 10.1002/ecy.3976] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 11/24/2022] [Accepted: 12/07/2022] [Indexed: 01/25/2023]
Abstract
Understanding the drivers and impacts of spatiotemporal variation in species abundance on community trajectories is key to understanding the factors contributing to ecosystem resilience. Temporal variation in species trajectories across patches can provide compensation for species loss and can influence successional patterns. However, little is known about the underlying mechanisms that lead to patterns of species or spatial compensation and how those patterns may be mediated by consumer-resource relationships. Here we describe an experiment testing whether habitat attributes (e.g., structural complexity and spatial heterogeneity) mediate the effects of herbivory on tropical marine macroalgal communities by reducing accessibility and detectability, respectively, leading to variable trajectories among algal species at community (within patch) and metacommunity (i.e., among patch) scales. Reduced accessibility (greater habitat complexity) decreased the effects of herbivory (i.e., depressed consumption rate, increased algal species richness), and both accessibility and detectability (spatial heterogeneity) influenced algal community structure. Moreover, decreased accessibility at the community scale and a mosaic of accessibility at the metacommunity scale led to variation in community assembly. We suggest that habitat attributes can be important influencers of consumer-resource interactions on coral reefs, which in turn can increase species diversity, promote species succession, and enhance stability in algal metacommunities.
Collapse
Affiliation(s)
- Griffin Srednick
- National Centre for Coasts and Climate, School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - Alyssa Cohen
- Department of Biology, California State University, Northridge, Northridge, California, USA
| | - Olivia Diehl
- Department of Biology, California State University, Northridge, Northridge, California, USA
| | - Kaela Tyler
- Department of Biology, California State University, Northridge, Northridge, California, USA
| | - Stephen E Swearer
- National Centre for Coasts and Climate, School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| |
Collapse
|
4
|
Twining JP, Lawton C, White A, Sheehy E, Hobson K, Montgomery WI, Lambin X. Restoring vertebrate predator populations can provide landscape-scale biological control of established invasive vertebrates: Insights from pine marten recovery in Europe. GLOBAL CHANGE BIOLOGY 2022; 28:5368-5384. [PMID: 35706099 PMCID: PMC9542606 DOI: 10.1111/gcb.16236] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/01/2022] [Accepted: 04/26/2022] [Indexed: 06/15/2023]
Abstract
Invasive species pose one of the greatest global threats to biodiversity. There has been a long history of importing coevolved natural enemies to act as biological control agents to try to suppress densities of invasive species, with historically limited success and frequent adverse impacts on native biodiversity. Our understanding of the processes and drivers of successful biological control has been focussed on invertebrates and is evidently limited and potentially ill-suited with respect to biological control of vertebrate populations. The restoration of native vertebrate predator populations provides a promising nature-based solution for slowing, halting, or even reversing the spread of some invasive vertebrates over spatial scales relevant to the management of wildlife populations. Here, we first review the growing literature and data from the pine marten-red and grey squirrel system in Europe. We synthesise a multi-decadal dataset to show that the recovery of a native predator has resulted in rapid, landscape-scale declines of an established invasive species. We then use the model system, predator-prey interaction theory, and examples from the literature to develop ecological theory relating to natural biological control in vertebrates and evolutionary processes in native-invasive predator-prey interactions. We find support for the hypotheses that evolutionary naivety of invasive species to native predators and lack of local refuges results in higher predation of naive compared to coevolved prey. We apply lessons learnt from the marten-squirrel model system to examine the plausibility of specific native predator solutions to some of the Earth's most devastating invasive vertebrates. Given the evidence, we conclude that depletion of vertebrate predator populations has increased ecosystem vulnerability to invasions and thus facilitated the spread of invasive species. Therefore, restoration of vertebrate predator populations is an underappreciated, fundamental, nature-based solution to the crisis of invasive species and should be a priority for vertebrate invasive species management globally.
Collapse
Affiliation(s)
- Joshua P. Twining
- Department of Natural ResourcesCornell UniversityIthacaNew YorkUSA
- School of Biological SciencesQueen's UniversityBelfastUK
| | - Colin Lawton
- School of Natural Sciences, Ryan InstituteNational University of Ireland GalwayGalwayIreland
| | - Andy White
- Maxwell Institute for Mathematical Sciences, Department of MathematicsHeriot‐Watt UniversityEdinburghUK
| | - Emma Sheehy
- School of Natural Sciences, Ryan InstituteNational University of Ireland GalwayGalwayIreland
| | - Keziah Hobson
- School of Biological SciencesUniversity of AberdeenAberdeenUK
| | | | - Xavier Lambin
- School of Biological SciencesUniversity of AberdeenAberdeenUK
| |
Collapse
|
5
|
Kelt DA, Heske EJ, Lambin X, Oli MK, Orrock JL, Ozgul A, Pauli JN, Prugh LR, Sollmann R, Sommer S. Advances in population ecology and species interactions in mammals. J Mammal 2019. [DOI: 10.1093/jmammal/gyz017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
AbstractThe study of mammals has promoted the development and testing of many ideas in contemporary ecology. Here we address recent developments in foraging and habitat selection, source–sink dynamics, competition (both within and between species), population cycles, predation (including apparent competition), mutualism, and biological invasions. Because mammals are appealing to the public, ecological insight gleaned from the study of mammals has disproportionate potential in educating the public about ecological principles and their application to wise management. Mammals have been central to many computational and statistical developments in recent years, including refinements to traditional approaches and metrics (e.g., capture-recapture) as well as advancements of novel and developing fields (e.g., spatial capture-recapture, occupancy modeling, integrated population models). The study of mammals also poses challenges in terms of fully characterizing dynamics in natural conditions. Ongoing climate change threatens to affect global ecosystems, and mammals provide visible and charismatic subjects for research on local and regional effects of such change as well as predictive modeling of the long-term effects on ecosystem function and stability. Although much remains to be done, the population ecology of mammals continues to be a vibrant and rapidly developing field. We anticipate that the next quarter century will prove as exciting and productive for the study of mammals as has the recent one.
Collapse
Affiliation(s)
- Douglas A Kelt
- Department of Wildlife, Fish, & Conservation Biology, University of California, Davis, CA, USA
| | - Edward J Heske
- Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM, USA
| | - Xavier Lambin
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Madan K Oli
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA
| | - John L Orrock
- Department of Integrative Biology, University of Wisconsin, Madison, WI, USA
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Jonathan N Pauli
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, WI, USA
| | - Laura R Prugh
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, USA
| | - Rahel Sollmann
- Department of Wildlife, Fish, & Conservation Biology, University of California, Davis, CA, USA
| | - Stefan Sommer
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| |
Collapse
|
6
|
Weterings MJA, Ewert SP, Peereboom JN, Kuipers HJ, Kuijper DPJ, Prins HHT, Jansen PA, van Langevelde F, van Wieren SE. Implications of shared predation for space use in two sympatric leporids. Ecol Evol 2019; 9:3457-3469. [PMID: 30962905 PMCID: PMC6434570 DOI: 10.1002/ece3.4980] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 11/11/2018] [Accepted: 11/14/2018] [Indexed: 11/13/2022] Open
Abstract
Spatial variation in habitat riskiness has a major influence on the predator-prey space race. However, the outcome of this race can be modulated if prey shares enemies with fellow prey (i.e., another prey species). Sharing of natural enemies may result in apparent competition, and its implications for prey space use remain poorly studied. Our objective was to test how prey species spend time among habitats that differ in riskiness, and how shared predation modulates the space use by prey species. We studied a one-predator, two-prey system in a coastal dune landscape in the Netherlands with the European hare (Lepus europaeus) and European rabbit (Oryctolagus cuniculus) as sympatric prey species and red fox (Vulpes vulpes) as their main predator. The fine-scale space use by each species was quantified using camera traps. We quantified residence time as an index of space use. Hares and rabbits spent time differently among habitats that differ in riskiness. Space use by predators and habitat riskiness affected space use by hares more strongly than space use by rabbits. Residence time of hare was shorter in habitats in which the predator was efficient in searching or capturing prey species. However, hares spent more time in edge habitat when foxes were present, even though foxes are considered ambush predators. Shared predation affected the predator-prey space race for hares positively, and more strongly than the predator-prey space race for rabbits, which were not affected. Shared predation reversed the predator-prey space race between foxes and hares, whereas shared predation possibly also released a negative association and promoted a positive association between our two sympatric prey species. Habitat riskiness, species presence, and prey species' escape mode and foraging mode (i.e., central-place vs. noncentral-place forager) affected the prey space race under shared predation.
Collapse
Affiliation(s)
- Martijn J. A. Weterings
- Resource Ecology GroupWageningen UniversityWageningenThe Netherlands
- Department of Animal Management, Wildlife ManagementVan Hall Larenstein University of Applied SciencesLeeuwardenThe Netherlands
| | - Sophie P. Ewert
- Department of Animal Management, Wildlife ManagementVan Hall Larenstein University of Applied SciencesLeeuwardenThe Netherlands
| | - Jeffrey N. Peereboom
- Department of Animal Management, Wildlife ManagementVan Hall Larenstein University of Applied SciencesLeeuwardenThe Netherlands
| | - Henry J. Kuipers
- Department of Animal Management, Wildlife ManagementVan Hall Larenstein University of Applied SciencesLeeuwardenThe Netherlands
| | | | | | - Patrick A. Jansen
- Resource Ecology GroupWageningen UniversityWageningenThe Netherlands
- Smithsonian Tropical Research InstituteBalboaPanamá
| | - Frank van Langevelde
- Resource Ecology GroupWageningen UniversityWageningenThe Netherlands
- School of Life SciencesUniversity of KwaZulu‐NatalDurbanSouth Africa
| | | |
Collapse
|
7
|
Barbar F, Lambertucci SA. The roles of leporid species that have been translocated: a review of their ecosystem effects as native and exotic species. Mamm Rev 2018. [DOI: 10.1111/mam.12126] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Facundo Barbar
- Grupo de Investigaciones en Biología de la Conservación; Laboratorio Ecotono; INIBIOMA - CONICET (Universidad Nacional del Comahue); Quintral 1250, San Carlos de Bariloche Bariloche Río Negro 8400 Argentina
| | - Sergio A. Lambertucci
- Grupo de Investigaciones en Biología de la Conservación; Laboratorio Ecotono; INIBIOMA - CONICET (Universidad Nacional del Comahue); Quintral 1250, San Carlos de Bariloche Bariloche Río Negro 8400 Argentina
| |
Collapse
|
8
|
Barbar F, Ignazi GO, Hiraldo F, Lambertucci SA. Exotic lagomorph may influence eagle abundances and breeding spatial aggregations: a field study and meta-analysis on the nearest neighbor distance. PeerJ 2018; 6:e4746. [PMID: 29761058 PMCID: PMC5949207 DOI: 10.7717/peerj.4746] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/20/2018] [Indexed: 11/20/2022] Open
Abstract
The introduction of alien species could be changing food source composition, ultimately restructuring demography and spatial distribution of native communities. In Argentine Patagonia, the exotic European hare has one of the highest numbers recorded worldwide and is now a widely consumed prey for many predators. We examine the potential relationship between abundance of this relatively new prey and the abundance and breeding spacing of one of its main consumers, the Black-chested Buzzard-Eagle (Geranoaetus melanoleucus). First we analyze the abundance of individuals of a raptor guild in relation to hare abundance through a correspondence analysis. We then estimated the Nearest Neighbor Distance (NND) of the Black-chested Buzzard-eagle abundances in the two areas with high hare abundances. Finally, we performed a meta-regression between the NND and the body masses of Accipitridae raptors, to evaluate if Black-chested Buzzard-eagle NND deviates from the expected according to their mass. We found that eagle abundance was highly associated with hare abundance, more than with any other raptor species in the study area. Their NND deviates from the value expected, which was significantly lower than expected for a raptor species of this size in two areas with high hare abundance. Our results support the hypothesis that high local abundance of prey leads to a reduction of the breeding spacing of its main predator, which could potentially alter other interspecific interactions, and thus the entire community.
Collapse
Affiliation(s)
- Facundo Barbar
- Grupo de Biología de la Conservación, Ecotono Laboratory, INIBIOMA-CONICET (Universidad Nacional del Comahue), San Carlos de Bariloche, Río Negro, Argentina
| | - Gonzalo O Ignazi
- Grupo de Biología de la Conservación, Ecotono Laboratory, INIBIOMA-CONICET (Universidad Nacional del Comahue), San Carlos de Bariloche, Río Negro, Argentina
| | - Fernando Hiraldo
- Departamento de Biología de la Conservación, Estación Biológica Doñana-CSIC España, Sevilla, España
| | - Sergio A Lambertucci
- Grupo de Biología de la Conservación, Ecotono Laboratory, INIBIOMA-CONICET (Universidad Nacional del Comahue), San Carlos de Bariloche, Río Negro, Argentina
| |
Collapse
|
9
|
Abstract
Most species have one or more natural enemies, e.g., predators, parasites, pathogens, and herbivores, among others. These species in turn typically attack multiple victim species. This leads to the possibility of indirect interactions among those victims, both positive and negative. The term apparent competition commonly denotes negative indirect interactions between victim species that arise because they share a natural enemy. This indirect interaction, which in principle can be reflected in many facets of the distribution and abundance of individual species and more broadly govern the structure of ecological communities in time and space, pervades many natural ecosystems. It also is a central theme in many applied ecological problems, including the control of agricultural pests, harvesting, the conservation of endangered species, and the dynamics of emerging diseases. At one end of the scale of life, apparent competition characterizes intriguing aspects of dynamics within individual organisms—for example, the immune system is akin in many ways to a predator that can induce negative indirect interactions among different pathogens. At intermediate scales of biological organization, the existence and strength of apparent competition depend upon many contingent details of individual behavior and life history, as well as the community and spatial context within which indirect interactions play out. At the broadest scale of macroecology and macroevolution, apparent competition may play a major, if poorly understood, role in the evolution of species’ geographical ranges and adaptive radiations.
Collapse
Affiliation(s)
- Robert D. Holt
- Department of Biology, University of Florida, Gainesville, Florida 32611 USA
| | - Michael B. Bonsall
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
| |
Collapse
|
10
|
Cooke BD, Soriguer RC. Do dingoes protect Australia's small mammal fauna from introduced mesopredators? Time to consider history and recent events. FOOD WEBS 2017. [DOI: 10.1016/j.fooweb.2016.04.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
11
|
Atuo FA, O'Connell TJ. Spatial heterogeneity and scale-dependent habitat selection for two sympatric raptors in mixed-grass prairie. Ecol Evol 2017; 7:6559-6569. [PMID: 28861257 PMCID: PMC5574806 DOI: 10.1002/ece3.3182] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 05/11/2017] [Accepted: 05/26/2017] [Indexed: 11/18/2022] Open
Abstract
Sympatric predators are predicted to partition resources, especially under conditions of food limitation. Spatial heterogeneity that influences prey availability might play an important role in the scales at which potential competitors select habitat. We assessed potential mechanisms for coexistence by examining the role of heterogeneity in resource partitioning between sympatric raptors overwintering in the southern Great Plains. We conducted surveys for wintering Red‐tailed hawk (Buteo jamaicensis) and Northern Harrier (Circus cyanea) at two state wildlife management areas in Oklahoma, USA. We used information from repeated distance sampling to project use locations in a GIS. We applied resource selection functions to model habitat selection at three scales and analyzed for niche partitioning using the outlying mean index. Habitat selection of the two predators was mediated by spatial heterogeneity. The two predators demonstrated significant fine‐scale discrimination in habitat selection in homogeneous landscapes, but were more sympatric in heterogeneous landscapes. Red‐tailed hawk used a variety of cover types in heterogeneous landscapes but specialized on riparian forest in homogeneous landscapes. Northern Harrier specialized on upland grasslands in homogeneous landscapes but selected more cover types in heterogeneous landscapes. Our study supports the growing body of evidence that landscapes can affect animal behaviors. In the system we studied, larger patches of primary land cover types were associated with greater allopatry in habitat selection between two potentially competing predators. Heterogeneity within the scale of raptor home ranges was associated with greater sympatry in use and less specialization in land cover types selected.
Collapse
Affiliation(s)
- Fidelis Akunke Atuo
- Department of Natural Resource Ecology and Management Oklahoma State University Stillwater OK USA
| | - Timothy John O'Connell
- Department of Natural Resource Ecology and Management Oklahoma State University Stillwater OK USA
| |
Collapse
|
12
|
Atuo FA, O'Connell TJ. The landscape of fear as an emergent property of heterogeneity: Contrasting patterns of predation risk in grassland ecosystems. Ecol Evol 2017; 7:4782-4793. [PMID: 28690807 PMCID: PMC5496548 DOI: 10.1002/ece3.3021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 03/21/2017] [Accepted: 04/01/2017] [Indexed: 11/16/2022] Open
Abstract
The likelihood of encountering a predator influences prey behavior and spatial distribution such that non‐consumptive effects can outweigh the influence of direct predation. Prey species are thought to filter information on perceived predator encounter rates in physical landscapes into a landscape of fear defined by spatially explicit heterogeneity in predation risk. The presence of multiple predators using different hunting strategies further complicates navigation through a landscape of fear and potentially exposes prey to greater risk of predation. The juxtaposition of land cover types likely influences overlap in occurrence of different predators, suggesting that attributes of a landscape of fear result from complexity in the physical landscape. Woody encroachment in grasslands furnishes an example of increasing complexity with the potential to influence predator distributions. We examined the role of vegetation structure on the distribution of two avian predators, Red‐tailed Hawk (Buteo jamaicensis) and Northern Harrier (Circus cyaneus), and the vulnerability of a frequent prey species of those predators, Northern Bobwhite (Colinus virginianus). We mapped occurrences of the raptors and kill locations of Northern Bobwhite to examine spatial vulnerability patterns in relation to landscape complexity. We use an offset model to examine spatially explicit habitat use patterns of these predators in the Southern Great Plains of the United States, and monitored vulnerability patterns of their prey species based on kill locations collected during radio telemetry monitoring. Both predator density and predation‐specific mortality of Northern Bobwhite increased with vegetation complexity generated by fine‐scale interspersion of grassland and woodland. Predation pressure was lower in more homogeneous landscapes where overlap of the two predators was less frequent. Predator overlap created areas of high risk for Northern Bobwhite amounting to 32% of the land area where landscape complexity was high and 7% where complexity was lower. Our study emphasizes the need to evaluate the role of landscape structure on predation dynamics and reveals another threat from woody encroachment in grasslands.
Collapse
Affiliation(s)
- Fidelis Akunke Atuo
- Department of Natural Resource Ecology and Management Oklahoma State University Stillwater OK USA
| | - Timothy John O'Connell
- Department of Natural Resource Ecology and Management Oklahoma State University Stillwater OK USA
| |
Collapse
|
13
|
Cerri J, Ferretti M, Bertolino S. Rabbits killing hares: an invasive mammal modifies native predator-prey dynamics. Anim Conserv 2017. [DOI: 10.1111/acv.12343] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. Cerri
- Istituto di Management; Scuola Superiore Sant'Anna; Pisa Italy
| | - M. Ferretti
- Regione Toscana; Corso Gramsci; Pistoia Italy
| | - S. Bertolino
- Department of Life Sciences and Systems Biology; Torino Italy
| |
Collapse
|
14
|
Pita R, Lambin X, Mira A, Beja P. Hierarchical spatial segregation of two Mediterranean vole species: the role of patch-network structure and matrix composition. Oecologia 2016; 182:253-63. [DOI: 10.1007/s00442-016-3653-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 05/03/2016] [Indexed: 11/30/2022]
|
15
|
Harvey E, MacDougall AS. Spatially Heterogeneous Perturbations Homogenize the Regulation of Insect Herbivores. Am Nat 2015; 186:623-33. [PMID: 26655775 DOI: 10.1086/683199] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Anthropogenic influences on resources and consumers can affect food web regulation, with impacts on trophic structure and ecosystem processes. Identifying how these impacts unfold is challenging because alterations to one or both resources and consumers can similarly transform community structure, especially for intermediate consumers. To date, empirical testing of perturbations on trophic regulation has been limited by the difficulty in separating the direct effect of perturbations on species composition and diversity from those unfolding indirectly via altered feeding pathways. Moreover, disentangling the independent and interactive impacts of covarying stressors that characterize human-altered systems has been an ongoing analytical challenge. We used a large-scale metacommunity experiment in grasslands to test how resource inputs, stand perturbation, and spatial factors affect regulation of insect herbivores in tritrophic grassland food webs. Using path-model comparisons, we observed significant simplification of food web regulation on insect herbivores, shifting from mixed predator-resource regulation in unaltered mainland areas to strictly resource-based regulation with landscape perturbation and fragmentation. Most changes were attributed to homogenization of plant community caused by landscape fragmentation and the deterministic influence of eutrophication that reduced among-patch beta diversity. This led to a simplified food web dominated by fewer but more abundant herbivore taxa. Our work implies that anthropogenic perturbation relating to resources and spatial isolation can transform the regulation of food web diversity, structure, and function.
Collapse
Affiliation(s)
- Eric Harvey
- Department of Integrative Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | | |
Collapse
|
16
|
Ross BE, Hooten MB, DeVink JM, Koons DN. Combined effects of climate, predation, and density dependence on Greater and Lesser Scaup population dynamics. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2015; 25:1606-17. [PMID: 26552268 DOI: 10.1890/14-0582.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
An understanding of species relationships is critical in the management and conservation of populations facing climate change, yet few studies address how climate alters species interactions and other population drivers. We use a long-term, broad-scale data set of relative abundance to examine the influence of climate, predators, and density dependence on the population dynamics of declining scaup (Aythya) species within the core of their breeding range. The state-space modeling approach we use applies to a wide range of wildlife species, especially populations monitored over broad spatiotemporal extents. Using this approach, we found that immediate snow cover extent in the preceding winter and spring had the strongest effects, with increases in mean snow cover extent having a positive effect on the local surveyed abundance of scaup. The direct effects of mesopredator abundance on scaup population dynamics were weaker, but the results still indicated a potentil interactive process between climate and food web dynamics (mesopredators, alternative prey, and scaup). By considering climate variables and other potential effects on population dynamics, and using a rigorous estimation framework, we provide insight into complex ecological processes for guiding. conservation and policy actions aimed at mitigating and reversing the decline of scaup.
Collapse
|
17
|
Abstract
Multiple invasive species have now established at most locations around the world, and the rate of new species invasions and records of new invasive species continue to grow. Multiple invasive species interact in complex and unpredictable ways, altering their invasion success and impacts on biodiversity. Incumbent invasive species can be replaced by functionally similar invading species through competitive processes; however the generalized circumstances leading to such competitive displacement have not been well investigated. The likelihood of competitive displacement is a function of the incumbent advantage of the resident invasive species and the propagule pressure of the colonizing invasive species. We modeled interactions between populations of two functionally similar invasive species and indicated the circumstances under which dominance can be through propagule pressure and incumbent advantage. Under certain circumstances, a normally subordinate species can be incumbent and reject a colonizing dominant species, or successfully colonize in competition with a dominant species during simultaneous invasion. Our theoretical results are supported by empirical studies of the invasion of islands by three invasive Rattus species. Competitive displacement is prominent in invasive rats and explains the replacement of R. exulans on islands subsequently invaded by European populations of R. rattus and R. norvegicus. These competition outcomes between invasive species can be found in a broad range of taxa and biomes, and are likely to become more common. Conservation management must consider that removing an incumbent invasive species may facilitate invasion by another invasive species. Under very restricted circumstances of dominant competitive ability but lesser impact, competitive displacement may provide a novel method of biological control.
Collapse
|
18
|
Melero Y, Palazón S, Lambin X. Invasive crayfish reduce food limitation of alien American mink and increase their resilience to control. Oecologia 2013; 174:427-34. [PMID: 24065555 DOI: 10.1007/s00442-013-2774-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 09/02/2013] [Indexed: 11/24/2022]
Abstract
Trophic relationships between invasive species in multiply invaded ecosystems may reduce food limitation relative to more pristine ecosystems and increase resilience to control. Here, we consider whether invasive predatory American mink Neovison vison are trophically subsidized by invasive crayfish. We collated data from the literature on density and home range size of mink populations in relation to the prevalence of crayfish in the diet of mink. We then tested the hypothesis that populations of an invasive predator reach higher densities and are more resilient to lethal control when they have access to super-abundant non-native prey, even in the absence of changes in density dependence, hence compensatory capacity. We found a strong positive relationship between the proportion of crayfish in mink diet and mink population density, and a negative relationship between the proportion of crayfish in mink diet and mink home range size, with crayfish contribution to mink diet reflecting their abundance in the ecosystem. We then explored the consequence of elevated mink density by simulating a hypothetical eradication program with a constant harvest in a Ricker model. We found that mink populations were more resilient to harvest in the presence of crayfish. As a result, the simulated number of mink harvested to achieve eradication increased by 500% in the presence of abundant crayfish if carrying capacity increased by 630%. This led to a threefold increase in time to eradication under a constant harvest and an approximately 20-fold increase in the cumulative management cost. Our results add to evidence of inter-specific positive interactions involving invasive species, and our simple model illustrates how this increases management cost.
Collapse
Affiliation(s)
- Yolanda Melero
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK,
| | | | | |
Collapse
|
19
|
García-Díaz P, Arévalo V, Vicente R, Lizana M. The impact of the American mink (Neovison vison) on native vertebrates in mountainous streams in Central Spain. EUR J WILDLIFE RES 2013. [DOI: 10.1007/s10344-013-0736-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
20
|
Sundararaj V, McLaren BE, Morris DW, Goyal SP. Can rare positive interactions become common when large carnivores consume livestock? Ecology 2012; 93:272-80. [PMID: 22624309 DOI: 10.1890/10-2050.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Livestock populations in protected areas are viewed negatively because of their interaction with native ungulates through direct competition for food resources. However, livestock and native prey can also interact indirectly through their shared predator. Indirect interactions between two prey species occur when one prey modifies either the functional or numerical responses of a shared predator. This interaction is often manifested as negative effects (apparent competition) on one or both prey species through increased predation risk. But indirect interactions can also yield positive effects on a focal prey if the shared predator modifies its functional response toward increased consumption of an abundant and higher-quality alternative prey. Such a phenomenon between two prey species is underappreciated and overlooked in nature. Positive indirect effects can be expected to occur in livestock-dominated wildlife reserves containing large carnivores. We searched for such positive effects in Acacia-Zizhypus forests of India's Gir sanctuary where livestock (Bubalus bubalis and Bos indicus) and a coexisting native prey (chital deer, Axis axis) are consumed by Asiatic lions (Panthera leo persica). Chital vigilance was higher in areas with low livestock density than in areas with high livestock density. This positive indirect effect occurred because lion predation rates on livestock were twice as great where livestock were abundant than where livestock density was low. Positive indirect interactions mediated by shared predators may be more common than generally thought with rather major consequences for ecological understanding and conservation. We encourage further studies to understand outcomes of indirect interactions on long-term predator-prey dynamics in livestock-dominated protected areas.
Collapse
Affiliation(s)
- Vijayan Sundararaj
- Faculty of Natural Resources Management, Lakehead University. Thunder Bay, Ontario P7B 5El Canada.
| | | | | | | |
Collapse
|
21
|
|
22
|
Affiliation(s)
- E. Bonnaud
- Ecologie, Systématique & Evolution; Univ. Paris Sud; Orsay; France
| | - F. Courchamp
- Ecologie, Systématique & Evolution; Univ. Paris Sud; Orsay; France
| |
Collapse
|
23
|
GORINI L, LINNELL JDC, MAY R, PANZACCHI M, BOITANI L, ODDEN M, NILSEN EB. Habitat heterogeneity and mammalian predator-prey interactions. Mamm Rev 2011. [DOI: 10.1111/j.1365-2907.2011.00189.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
24
|
Vlautin CT, Hobbs NJ, Ferkin MH. Male and Female Meadow Voles, Microtus pennsylvanicus, Differ in Their Responses to Heterospecific/Conspecific Over-Marks. Ethology 2010. [DOI: 10.1111/j.1439-0310.2010.01803.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
25
|
Smith DHV, Moller H, Wilson DJ, Murphy EC. Prey switching by stoats (Mustela erminea): a supplemental food experiment. WILDLIFE RESEARCH 2010. [DOI: 10.1071/wr10088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context
Prey switching by invasive carnivorans to changing food supply could severely impact on endemic prey of conservation importance, but experimental evidence for prey switching in carnivorans is rare. Stoats (Mustela erminea) were introduced to New Zealand and now threaten survival of many native birds, reptiles and invertebrates.
Aim
Our primary objective was to see whether abundant food caused stoats inhabiting an alpine grassland site to alter the rate at which they preyed upon weta (Orthoptera : Hemiandrus sp.), hares (Lepus europeus), birds and mice (Mus musculus).
Methods
We used dead rabbits as supplemental food in a before-after-control-impact experiment. Stoat scats were collected from a treatment and non-treatment site before and following food supplementation. Percentage frequency occurrence of the different prey types was assessed for the two sites during each experimental phase.
Conclusions
Stoats ate fewer ground weta and hares, the two most abundant prey types, when supplemental food was added. In contrast, consumption of mice remained relatively stable at both sites throughout the experiment, and the consumption of birds declined at both sites.
Implications
Our experiment suggests that stoats may continue to eat scarce endemic prey at similar per capita rates even when alternative prey are available. However, endemic prey that are locally or regionally abundant may be indirectly impacted by fluctuations in alternative prey.
Collapse
|