1
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Choh Y, Janssen A. Sister predatory mites collectively protect their eggs against predators. Oecologia 2024; 204:653-660. [PMID: 38461225 DOI: 10.1007/s00442-024-05521-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 01/29/2024] [Indexed: 03/11/2024]
Abstract
Group-living animals sometimes cooperatively protect their offspring against predators. This behavior is observed in a wide range of taxa but, to the best of our knowledge, this is the first report of its occurrence in arthropods that are not eusocial. Adult female predatory mites Gynaeseius liturivorus protect their eggs against egg predators, the predatory mite species Neoseiulus californicus. In the field, several adult female G. liturivorus were often found on the same plant structures such as folded leaves. We tested whether these females might protect their eggs cooperatively, focusing on kinship between the females. When two adult female G. liturivorus were kept in the absence of egg predators, their reproduction was not affected by their kinship. The presence of egg predators reduced the number of G. liturivorus eggs. However, reproduction of two G. liturivorus sisters was higher than that of two non-sisters. Together, sisters guarded the oviposition site longer than non-sisters. We further tested if non-sisters increased egg guarding by having developed together from eggs to adults and found no such effect. Although it remains unclear how adult female G. liturivorus recognize conspecifics as kin or sisters, our results suggest that G. liturivorus sisters reduced predation on their offspring by cooperatively guarding their eggs.
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Affiliation(s)
- Yasuyuki Choh
- Laboratory of Applied Entomology, Department of Horticulture, Chiba University, 648 Matsudo, Chiba,, 271-8510, Japan.
| | - Arne Janssen
- Institute for Biodiversity and Ecosystem Dynamics, Department of Evolutionary and Population Biology, University of Amsterdam, Amsterdam, The Netherlands
- Department of Entomology, Federal University of Viçosa, Viçosa, Brazil
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2
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Oliveira P, Gomes V, Riaño G, Rato C. Ontogenic differences and sexual dimorphism of the locomotor performance in a nocturnal gecko, Tarentola mauritanica. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2023; 339:28-36. [PMID: 35871279 DOI: 10.1002/jez.2645] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 12/15/2022]
Abstract
Locomotion performance in reptiles is deeply associated with habitat use, escape from predators, prey capture, and territory defense. As ectotherms, this trait in lizards is extremely sensitive to body temperature (BT). However, most studies rarely look at locomotion patterns in an ontogenic perspective. The Moorish gecko, Tarentola mauritanica, was used to investigate the possible effects of distinct BTs on the locomotor performance within juveniles and adults. Not surprisingly, adult individuals significantly outperform the juveniles in speed at every BT. Moreover, except in the 30-day-old juveniles, there is a general trend for an increase of speed with BT. The comparison of these speed values with the ones obtained for diurnal lizard species, corroborates the premise that because nocturnal species are subject to low thermal heterogeneity, little selection for behavioral thermoregulation, but strong selection for high performance at relatively cool temperatures are expected. Furthermore, the higher locomotor performance in adults at 29°C, roughly coincides with previously obtained preferred BTs. However, further studies need to be conducted to build the full performance curve, and to validate the existence of coadaption between behavioral thermoregulation and thermal sensitivity of physiological performance. Finally, this study has found that adult males run significantly faster than females at the highest BTs, highlighting the importance in understanding sex differences, and its potential to drive sex-specific behaviors, ecology, and ultimately fitness.
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Affiliation(s)
- Pedro Oliveira
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vila do Conde, Vairão, Vila do Conde, Portugal
| | - Verónica Gomes
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vila do Conde, Vairão, Vila do Conde, Portugal.,BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
| | - Gabriel Riaño
- Institute of Evolutionary Biology (CSIC-UPF), Barcelona, Spain
| | - Catarina Rato
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vila do Conde, Vairão, Vila do Conde, Portugal.,BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
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3
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Rosenheim JA, Schreiber SJ. Pathways to the density-dependent expression of cannibalism, and consequences for regulated population dynamics. Ecology 2022; 103:e3785. [PMID: 35818739 DOI: 10.1002/ecy.3785] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/13/2022] [Accepted: 04/21/2022] [Indexed: 12/13/2022]
Abstract
Cannibalism, once viewed as a rare or aberrant behavior, is now recognized to be widespread and to contribute broadly to the self-regulation of many populations. Cannibalism can produce endogenous negative feedback on population growth because it is expressed as a conditional behavior, responding to the deteriorating ecological conditions that flow, directly or indirectly, from increasing densities of conspecifics. Thus, cannibalism emerges as a strongly density-dependent source of mortality. In this synthesis, we review recent research that has revealed a rich diversity of pathways through which rising density elicits increased cannibalism, including both factors that (a) elevate the rate of dangerous encounters between conspecifics and (b) enhance the likelihood that such encounters will lead to successful cannibalistic attacks. These pathways include both features of the autecology of cannibal populations and features of interactions with other species, including food resources and pathogens. Using mathematical models, we explore the consequences of including density-dependent cannibal attack rates on population dynamics. The conditional expression of cannibalism generally enhances stability and population regulation in single-species models but also may increase opportunities for alternative states and prey population escape from control by cannibalistic predators.
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Affiliation(s)
- Jay A Rosenheim
- Department of Entomology and Nematology, University of California, Davis, California, USA
| | - Sebastian J Schreiber
- Department of Evolution and Ecology, University of California, Davis, California, USA
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4
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Influence of habitat complexity on the prey mortality in IGP system involving insect predators (Heteroptera) and prey (Diptera): Implications in biological control. PLoS One 2022; 17:e0264840. [PMID: 35286333 PMCID: PMC8920208 DOI: 10.1371/journal.pone.0264840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 02/17/2022] [Indexed: 11/30/2022] Open
Abstract
Intraguild predation (IGP) is common in the freshwater insect communities, involving a top predator, intraguild prey (IG prey) and a shared prey. Influence of the habitat complexity on the prey-predator interactions is well established through several studies. In the present instance, the IGP involving the heteropteran predators and the dipteran prey were assessed in the background of the habitat complexity. The three predators Diplonychus rusticus, Ranatra filiformis, and Laccotrephes griseus, one intraguild prey Anisops bouvieri and two dipteran prey Culex quinquefasciatus and Chironomus sp. were used in different relative density against the complex habitat conditions to deduce the impact on the mortality on the prey. In comparison to the open conditions, the presence of the macrophytes and pebbles reduced the mortality of the shared prey under intraguild system as well as single predator system. The mortality of the shared prey was however dependent on the density of the predator and prey. Considering the shared prey mortality, predation on mosquito larvae was always higher in single predator system than chironomid larvae irrespective of identity and density of predators. However, for both the shared prey, complexity of habitat reduced the prey vulnerability in comparison to the simple habitat condition. Higher observed prey consumption depicts the higher risk to predation of shared prey, though the values varied with habitat conditions. Mortality of IG prey (A. bouvieri) in IGP system followed the opposite trend of the shared prey. The lower mortality in simple habitat and higher mortality in complex habitat conditions was observed for the IG prey, irrespective of shared prey and predator density. In IGP system, the shared prey mortality was influenced by the habitat conditions, with more complex habitat reducing the vulnerability of the shared prey and increased mortality of the IG prey. This implies that the regulation of the mosquitoes, in the IGP system will be impeded by the habitat conditions, with the heteropteran predators as the top predator.
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5
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Yarwood E, Drees C, Niven JE, Gawel M, Schuett W. Sex differences in morphology across an expanding range edge in the flightless ground beetle, Carabus hortensis. Ecol Evol 2021; 11:9949-9957. [PMID: 34367551 PMCID: PMC8328432 DOI: 10.1002/ece3.7593] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 03/14/2021] [Accepted: 03/31/2021] [Indexed: 11/22/2022] Open
Abstract
Species' ranges are dynamic, changing through range shifts, contractions, and expansions. Individuals at the edge of a species' shifting range often possess morphological traits that increase movement capacity, that are not observed in individuals farther back within the species' range. Although morphological traits that increase in proportion toward the range edge may differ between the sexes, such sex differences are rarely studied.Here, we test the hypotheses that body size and condition increase with proximity to an expanding range edge in the flightless ground beetle, Carabus hortensis, and that these trait changes differ between the sexes.Male, but not female, body size increased with proximity to the range edge. Body size was positively correlated with male front and mid tibia length and to female hind tibia length, indicating that body size is indicative of movement capacity in both sexes. Body condition (relative to body size) decreased with increasing population density in males but not females. Population density was lowest at the range edge.Our results indicate that sex is an important factor influencing patterns in trait distribution across species' ranges, and future studies should investigate changes in morphological traits across expanding range margins separately for males and females. We discuss the implications for sex differences in resource allocation and reproductive rates for trait differentiation across species' shifting ranges.
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Affiliation(s)
| | - Claudia Drees
- School of Life SciencesUniversity of SussexFalmerEast SussexUK
- Institute of ZoologyUniversität HamburgHamburgGermany
| | - Jeremy E. Niven
- School of Life SciencesUniversity of SussexFalmerEast SussexUK
| | - Marisa Gawel
- Institute of ZoologyUniversität HamburgHamburgGermany
| | - Wiebke Schuett
- School of Life SciencesUniversity of SussexFalmerEast SussexUK
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6
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Sauve AMC, Barraquand F. From winter to summer and back: Lessons from the parameterization of a seasonal food web model for the Białowieża forest. J Anim Ecol 2020; 89:1628-1644. [PMID: 32248533 DOI: 10.1111/1365-2656.13227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 03/11/2020] [Indexed: 11/30/2022]
Abstract
Dynamic food web models describe how species abundances change over time as a function of trophic and life-history parameters. They are essential to predicting the response of ecosystems to perturbations. However, they are notoriously difficult to parameterize, so that most models rely heavily either on allometric scaling of parameters or inverse estimation of biomass flows. The allometric approach makes species of comparable body mass have near-identical parameters which can generate extinctions within a trophic level. The biomass flow approach is more precise, but is restricted to steady-states, which is not appropriate for time-varying environments. Adequately parameterizing large food webs of temperate and arctic environments requires dealing both with many species of similar sizes and a strongly seasonal environment. Inspired by the rich empirical knowledge on the vertebrate food web of the Białowieża forest, we parameterize a bipartite food web model comprising 21 predators and 124 prey species. Our model is a non-autonomous coupled ordinary differential equations system that allows for seasonality in life-history and predation parameters. Birth and death rates, seasonal descriptions of diet for each species, food requirements and biomass information are combined into a seasonal parameterization of a dynamic food web model. Food web seasonality is implemented with time-varying intrinsic growth rate and interaction parameters, while predation is modelled with both type I and type II functional responses. All our model variants allow for >80% persistence in spite of massive apparent competition, and a quantitative match to observed (seasonal) biomasses. We also identify trade-offs between maximizing persistence, reproducing observed biomasses, and ensuring model robustness to sampling errors. Although multi-annual cycles are expected with type II functional responses, they are here prevented by a strong predator self-regulation. We discuss these results and possible improvements on the model. We provide a general workflow to parameterize dynamic food web models in seasonal environments, based on a real case study. This may help to better predict how biodiverse food webs respond to changing environments.
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Affiliation(s)
- Alix M C Sauve
- LabEx COTE, Integrative and Theoretical Ecology, University of Bordeaux, Bordeaux, France
| | - Frederic Barraquand
- LabEx COTE, Integrative and Theoretical Ecology, University of Bordeaux, Bordeaux, France.,Institute of Mathematics of Bordeaux, CNRS, Talence, France
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7
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Start D. Abundance and traits link predator ontogeny to prey communities. Ecology 2020; 101:e03044. [PMID: 32222071 DOI: 10.1002/ecy.3044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/10/2020] [Accepted: 03/16/2020] [Indexed: 11/09/2022]
Abstract
Function and abundances shape species interactions and thus ecological communities. While communities are often summarized as the mean function of each species, intraspecific variation in traits and thus function is an important driver of community composition. Ontogeny is a common source of intraspecific variation, but while age-related functional changes can alter species interactions, so too can the effects of those functions on the density of the focal organism. For instance, ontogenetic variation can trigger higher levels of cannibalism, reducing abundances and altering interspecific interactions. I manipulate ontogenetic variation in damselfly larvae to show that intraspecific variation can impact communities through two distinct mechanisms. First, within-species differences affect population sizes, and thus indirectly shape communities (indirect effect). In particular, ontogenetic variation resulted in smaller damselfly populations, likely because of increased cannibalism rates, and thus ontogenetically diverse populations had a smaller total effect on their prey. Second, trait variation can affect communities by creating differences in the strength of per capita species interactions (direct effect). In this case, damselfly populations with greater age variation had smaller per capita effects on prey communities. I conclude that ontogeny of a single species can directly and indirectly shape community composition.
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Affiliation(s)
- Denon Start
- Center for Population Biology, University of California at Davis, Davis, California, 95616, USA
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8
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Tringali A, Sherer DL, Cosgrove J, Bowman R. Life history stage explains behavior in a social network before and during the early breeding season in a cooperatively breeding bird. PeerJ 2020; 8:e8302. [PMID: 32095315 PMCID: PMC7020825 DOI: 10.7717/peerj.8302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 11/26/2019] [Indexed: 12/03/2022] Open
Abstract
In species with stage-structured populations selection pressures may vary between different life history stages and result in stage-specific behaviors. We use life history stage to explain variation in the pre and early breeding season social behavior of a cooperatively breeding bird, the Florida scrub-jay (Aphelocoma coerulescens) using social network analysis. Life history stage explains much of the variation we observed in social network position. These differences are consistent with nearly 50 years of natural history observations and generally conform to a priori predictions about how individuals in different stages should behave to maximize their individual fitness. Where the results from the social network analysis differ from the a priori predictions suggest that social interactions between members of different groups are more important for breeders than previously thought. Our results emphasize the importance of accounting for life history stage in studies of individual social behavior.
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Affiliation(s)
- Angela Tringali
- Avian Ecology Program, Archbold Biological Station, Venus, FL, United States of America
| | - David L Sherer
- Avian Ecology Program, Archbold Biological Station, Venus, FL, United States of America.,Department of Biology, University of Central Florida, Orlando, FL, United States of America
| | - Jillian Cosgrove
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, United States of America
| | - Reed Bowman
- Avian Ecology Program, Archbold Biological Station, Venus, FL, United States of America
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9
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Predator population size structure alters consumption of prey from epigeic and grazing food webs. Oecologia 2020; 192:791-799. [PMID: 32086561 DOI: 10.1007/s00442-020-04619-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Accepted: 02/07/2020] [Indexed: 10/24/2022]
Abstract
Numerous studies have found that predators can suppress prey densities and thereby impact important ecosystem processes such as plant productivity and decomposition. However, prey suppression by spiders can be highly variable. Unlike predators that feed on prey within a single energy channel, spiders often consume prey from asynchronous energy channels, such as grazing (live plant) and epigeic (soil surface) channels. Spiders undergo few life cycle changes and thus appear to be ideally suited to link energy channels, but ontogenetic diet shifts in spiders have received little attention. For example, spider use of different food channels may be highly specialized in different life stages and thus a species may be a multichannel omnivore only when we consider all life stages. Using stable isotopes, we investigated whether wolf spider (Pardosa littoralis, henceforth Pardosa) prey consumption is driven by changes in spider size. Small spiders obtained > 80% of their prey from the epigeic channel, whereas larger spiders used grazing and epigeic prey almost equally. Changes in prey consumption were not driven by changes in prey density, but by changes in prey use by different spider size classes. Thus, because the population size structure of Pardosa changes dramatically over the growing season, changes in spider size may have important implications for the strength of trophic cascades. Our research demonstrates that life history can be an important component of predator diet, which may in turn affect community- and ecosystem-level processes.
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10
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Park J. Nonlinear dynamics with Hopf bifurcations by targeted mutation in the system of rock-paper-scissors metaphor. CHAOS (WOODBURY, N.Y.) 2019; 29:033102. [PMID: 30927841 DOI: 10.1063/1.5081966] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 02/05/2019] [Indexed: 06/09/2023]
Abstract
The role of mutation, which is an error process in gene evolution, in systems of cyclically competing species has been studied from various perspectives, and it is regarded as one of the key factors for promoting coexistence of all species. In addition to naturally occurring mutations, many experiments in genetic engineering have involved targeted mutation techniques such as recombination between DNA and somatic cell sequences and have studied genetic modifications through loss or augmentation of cell functions. In this paper, we investigate nonlinear dynamics with targeted mutation in cyclically competing species. In different ways to classic approaches of mutation in cyclic games, we assume that mutation may occur in targeted individuals who have been removed from intraspecific competition. By investigating each scenario depending on the number of objects for targeted mutation analytically and numerically, we found that targeted mutation can lead to persistent coexistence of all species. In addition, under the specific condition of targeted mutation, we found that targeted mutation can lead to emergences of bistable states for species survival. Through the linear stability analysis of rate equations, we found that those phenomena are accompanied by Hopf bifurcation which is supercritical. Our findings may provide more global perspectives on understanding underlying mechanisms to control biodiversity in ecological/biological sciences, and evidences with mathematical foundations to resolve social dilemmas such as a turnover of group members by resigning with intragroup conflicts in social sciences.
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Affiliation(s)
- Junpyo Park
- Department of Mathematical Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea
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11
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Griffin JN, Silliman BR. Predator size-structure and species identity determine cascading effects in a coastal ecosystem. Ecol Evol 2018; 8:12435-12442. [PMID: 30619556 PMCID: PMC6308854 DOI: 10.1002/ece3.4571] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 08/22/2018] [Accepted: 08/30/2018] [Indexed: 11/24/2022] Open
Abstract
Cascading consequences of predator extinctions are well documented, but impacts of perturbations to predator size-structure and how these vary across species remain unclear. Body size is hypothesized to be a key trait governing individual predators' impact on ecosystems. Therefore, shifts in predator size-structure should trigger ecosystem ramifications which are consistent across functionally similar species. Using a US salt marsh as a model system, we tested this hypothesis by manipulating size class (small, medium, and large) and size diversity (combination of all three size classes) within two closely related and functionally similar predatory crab species over 4 months. Across treatments, predators suppressed densities of a dominant grazer and an ecosystem engineer, enhanced plant biomass, and altered sediment properties (redox potential and saturation). Over the metabolically equivalent experimental predator treatments, small size class predators had stronger average impacts on response variables, and size class interacted with predator species identity to drive engineer suppression. Within both predator species, size diversity increased cannibalism and slightly weakened the average impact. These results show that predator impacts in a salt marsh ecosystem are determined by both size class and size diversity; they also highlight that size class can have species-dependent and response-dependent effects, underlining the challenge of generalizing trait effects.
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Affiliation(s)
| | - Brian R. Silliman
- Division of Marine Science and Conservation, Nicholas School of the EnvironmentDuke UniversityBeaufortNorth Carolina
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12
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Maritz B, Alexander GJ, Maritz RA. The underappreciated extent of cannibalism and ophiophagy in African cobras. Ecology 2018; 100:e02522. [PMID: 30276813 DOI: 10.1002/ecy.2522] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 08/21/2018] [Accepted: 08/30/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Bryan Maritz
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville, 7535, South Africa
| | - Graham J Alexander
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, P.O. Wits, 2050, South Africa
| | - Robin A Maritz
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville, 7535, South Africa
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13
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Start D. Ontogeny and Consistent Individual Differences Mediate Trophic Interactions. Am Nat 2018; 192:301-310. [DOI: 10.1086/698693] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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14
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Abstract
The size or stage of interacting individuals is known to affect the outcome of ecological interactions and can have important consequences for population dynamics. This is also true for intraguild predation (the killing and eating of potential competitors), where the size or ontogenetic stage of an individual determines whether it is the intraguild predator or the intraguild prey. Studying size- or stage-specific interactions is therefore important, but can be challenging in species with complex life histories. Here, we investigated predatory interactions of all feeding stages of the two predatory mite species Neoseiulus californicus and Phytoseiulus macropilis, both of which have complex life cycles, typical for predatory arthropods. Populations of these two species compete for two-spotted spider mites, their prey. We evaluated both the capacity to kill stages of the other predator species and the capacity to benefit from feeding on these stages, both prerequisites for the occurrence of intraguild predation. Ontogeny played a critical role in the occurrence of intraguild predation. Whereas the juveniles of P. macropilis developed from larva until adulthood when feeding on N. californicus eggs, interestingly, adult female P. macropilis did not feed on the smaller stages of the other species. We furthermore show that intraguild predation was reciprocal: both juveniles and adult females of N. californicus preyed on the smallest stages of P. macropilis. These results suggest that a proper analysis of the interactions between pairs of species involved in intraguild predation should start with an inventory of the interactions among all ontogenetic stages of these species.
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15
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Robinson NJ, Peters WS. Complexity of the prey spectrum of Agaronia propatula (Caenogastropoda: Olividae), a dominant predator in sandy beach ecosystems of Pacific Central America. PeerJ 2018; 6:e4714. [PMID: 29736346 PMCID: PMC5933343 DOI: 10.7717/peerj.4714] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/16/2018] [Indexed: 11/20/2022] Open
Abstract
Olivid gastropods of the genus Agaronia are dominant predators within invertebrate communities on sandy beaches throughout Pacific Central America. At Playa Grande, on the Pacific Coast of Costa Rica, we observed 327 natural predation events by Agaronia propatula. For each predation event, we documented prey taxa and body size of both predator and prey. The relationship between predator and prey size differed for each of the four main prey taxa: bivalves, crustaceans, heterospecific gastropods, and conspecific gastropods (representing cannibalism). For bivalve prey, there was increased variance in prey size with increasing predator size. Crustaceans were likely subdued only if injured or otherwise incapacitated. Heterospecific gastropods (mostly Olivella semistriata) constituted half of all prey items, but were only captured by small and intermediately sized A. propatula. Large O. semistriata appeared capable of avoiding predation by A. propatula. Cannibalism was more prevalent among large A. propatula than previously estimated. Our findings suggested ontogenetic niche shifts in A. propatula and a significant role of cannibalism in its population dynamics. Also indicated were size-dependent defensive behavior in some prey taxa and a dynamic, fine-scale zonation of the beach. The unexpected complexity of the trophic relations of A. propatula was only revealed though analysis of individual predation events. This highlights the need for detailed investigations into the trophic ecology of marine invertebrates to understand the factors driving ecosystem structuring in sandy beaches.
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Affiliation(s)
- Nathan J Robinson
- Cape Eleuthera Island School, Cape Eleuthera Institute, Eleuthera, The Bahamas.,Goldring-Gund Marine Biology Station, Playa Grande, Santa Cruz, Guanacaste, Costa Rica
| | - Winfried S Peters
- Goldring-Gund Marine Biology Station, Playa Grande, Santa Cruz, Guanacaste, Costa Rica.,School of Biological Sciences, Washington State University, Pullman, WA, USA
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16
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Okano JI, Okuda N. Effects of resource-dependent cannibalism on population size distribution and individual life history in a case-bearing caddisfly. PLoS One 2018; 13:e0191925. [PMID: 29466375 PMCID: PMC5842876 DOI: 10.1371/journal.pone.0191925] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 01/12/2018] [Indexed: 11/18/2022] Open
Abstract
Resource availability often determines the intensity of cannibalism, which has a considerable effect on population size distribution and individual life history. Larvae of the caddisfly Psilotreta kisoensis build portable cases from sedimentary sands and often display cannibalism. For this species, the availability of preferable case material is a critical factor that affects larval fitness, and material is locally variable depending on the underlying geology. In this study, we investigated how sand quality as a case material determines cannibalism frequency among larvae and, in turn, how the differential cannibalism frequency affects the body-size distribution and voltinism. Rearing experiments within a cohort revealed that a bimodal size distribution developed regardless of material quality. However, as the preferable material became abundant, the proportion of larger to smaller individuals increased. Consecutive experiments suggested that smaller larvae were more frequently cannibalized by larger ones and excluded from the population when preferable smooth material was abundant. This frequent cannibalism resulted in a bimodal size distribution with a significantly higher proportion of larger compared to smaller individuals. The size-dependent cannibalism was significantly suppressed when the larvae were raised in an environment with a scarcity of the preferable case material. This is probably because larvae cannot enjoy the benefit of rapid growth by cannibalism due to the difficulties in enlarging their case. At low cannibalism the growth of smaller individuals was stunted, and this was probably due to risk of cannibalism by larger individuals. This growth reduction in small individuals led to a bimodal size-distribution but with a lower proportion of larger to smaller individuals compared to at high cannibalism. A field study in two streams showed a similar size distribution of larvae as was found in the rearing experiment. The bimodal ratio has consequences for life history, since a size-bimodal population causes a cohort splitting: only larvae that were fully grown at 1 year had a univoltine life cycle, whereas larvae with a stunted growth continued their larval life for another year (semivoltine). This study suggests that availability of preferable case building material is an important factor that affects cannibalism, which in turn affects larval population size structure and cohort splitting.
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Affiliation(s)
- Jun-ichi Okano
- Center for Ecological Research, Kyoto University, Hirano, Otsu, Shiga, Japan
- * E-mail:
| | - Noboru Okuda
- Center for Ecological Research, Kyoto University, Hirano, Otsu, Shiga, Japan
- Research Institute for Humanity and Nature, Motoyama, Kamigamo, Kyoto, Japan
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Al Basheer A, Parshad RD, Quansah E, Yu S, Upadhyay RK. Exploring the dynamics of a Holling–Tanner model with cannibalism in both predator and prey population. INT J BIOMATH 2018. [DOI: 10.1142/s1793524518500109] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cannibalism is an intriguing life history trait, that has been considered primarily in the predator, in predator–prey population models. Recent experimental evidence shows that prey cannibalism can have a significant impact on predator–prey population dynamics in natural communities. Motivated by these experimental results, we investigate a ratio-dependent Holling–Tanner model, where cannibalism occurs simultaneously in both the predator and prey species. We show that depending on parameters, whilst prey or predator cannibalism acting alone leads to instability, their joint effect can actually stabilize the unstable interior equilibrium. Furthermore, in the spatially explicit model, we find that depending on parameters, prey and predator cannibalism acting jointly can cause spatial patterns to form, while not so acting individually. We discuss ecological consequences of these findings in light of food chain dynamics, invasive species control and climate change.
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Affiliation(s)
- Aladeen Al Basheer
- Mathematics Department, The University of Georgia, 240A Riverbend Rd, Athens GA 30602, USA
| | - Rana D. Parshad
- Department of Mathematics, Clarkson University, Potsdam, New York 13699, USA
| | | | - Shengbin Yu
- Department of Basic Teaching and Research, Yango University, Fuzhou, Fujian 350015, P. R. China
| | - Ranjit Kumar Upadhyay
- Department of Applied Mathematics, Indian Institute of Technology (ISM), Dhanbad 826004, Jharkhand, India
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18
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Emergence of unusual coexistence states in cyclic game systems. Sci Rep 2017; 7:7465. [PMID: 28785001 PMCID: PMC5547111 DOI: 10.1038/s41598-017-07911-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/04/2017] [Indexed: 11/08/2022] Open
Abstract
Evolutionary games of cyclic competitions have been extensively studied to gain insights into one of the most fundamental phenomena in nature: biodiversity that seems to be excluded by the principle of natural selection. The Rock-Paper-Scissors (RPS) game of three species and its extensions [e.g., the Rock-Paper-Scissors-Lizard-Spock (RPSLS) game] are paradigmatic models in this field. In all previous studies, the intrinsic symmetry associated with cyclic competitions imposes a limitation on the resulting coexistence states, leading to only selective types of such states. We investigate the effect of nonuniform intraspecific competitions on coexistence and find that a wider spectrum of coexistence states can emerge and persist. This surprising finding is substantiated using three classes of cyclic game models through stability analysis, Monte Carlo simulations and continuous spatiotemporal dynamical evolution from partial differential equations. Our finding indicates that intraspecific competitions or alternative symmetry-breaking mechanisms can promote biodiversity to a broader extent than previously thought.
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Start D, Kirk D, Shea D, Gilbert B. Cannibalism by damselflies increases with rising temperature. Biol Lett 2017; 13:rsbl.2017.0175. [PMID: 28515331 DOI: 10.1098/rsbl.2017.0175] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 04/19/2017] [Indexed: 11/12/2022] Open
Abstract
Trophic interactions are likely to change under climate warming. These interactions can be altered directly by changing consumption rates, or indirectly by altering growth rates and size asymmetries among individuals that in turn affect feeding. Understanding these processes is particularly important for intraspecific interactions, as direct and indirect changes may exacerbate antagonistic interactions. We examined the effect of temperature on activity rate, growth and intraspecific size asymmetries, and how these temperature dependencies affected cannibalism in Lestes congener, a damselfly with marked intraspecific variation in size. Temperature increased activity rates and exacerbated differences in body size by increasing growth rates. Increased activity and changes in body size interacted to increase cannibalism at higher temperatures. We argue that our results are likely to be general to species with life-history stages that vary in their temperature dependencies, and that the effects of climate change on communities may depend on the temperature dependencies of intraspecific interactions.
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Affiliation(s)
- Denon Start
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada M5S 3B3
| | - Devin Kirk
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada M5S 3B3
| | - Dylan Shea
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada M5S 3B3
| | - Benjamin Gilbert
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada M5S 3B3
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Sex and species specific isotopic niche specialisation increases with trophic complexity: evidence from an ephemeral pond ecosystem. Sci Rep 2017; 7:43229. [PMID: 28233858 PMCID: PMC5324113 DOI: 10.1038/srep43229] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 01/20/2017] [Indexed: 11/17/2022] Open
Abstract
It is generally accepted that organisms that naturally exploit an ecosystem facilitate coexistence, at least partially, through resource partitioning. Resource availability is, however, highly variable in space and time and as such the extent of resource partitioning must be somewhat dependent on availability. Here we test aspects of resource partitioning at the inter- and intra-specific level, in relation to resource availability in an atypical aquatic environment using an isotope approach. Using closely related key organisms from an ephemeral pond, we test for differences in isotopic signatures between two species of copepod and between sexes within each species, in relation to heterogeneity of basal food resources over the course of the ponds hydroperiod. We show that basal food resource heterogeneity increases over time initially, and then decreases towards the end of the hydroperiod, reflective of the expected evolution of trophic complexity for these systems. Resource partitioning also varied between species and sexes, over the hydroperiod with intra- and inter-specific specialisation relating to resource availability. Intra-specific specialisation was particularly evident in the omnivorous copepod species. Our findings imply that trophic specialisation at both the intra- and inter-specific level is partly driven by basal food resource availability.
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Start D, Gilbert B. Predator personality structures prey communities and trophic cascades. Ecol Lett 2017; 20:366-374. [PMID: 28120366 DOI: 10.1111/ele.12735] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 10/03/2016] [Accepted: 12/19/2016] [Indexed: 11/30/2022]
Abstract
Intraspecific variation is central to our understanding of evolution and population ecology, yet its consequences for community ecology are poorly understood. Animal personality - consistent individual differences in suites of behaviours - may be particularly important for trophic dynamics, where predator personality can determine activity rates and patterns of attack. We used mesocosms with aquatic food webs in which the top predator (dragonfly nymphs) varied in activity and subsequent attack rates on zooplankton, and tested the effects of predator personality. We found support for four hypotheses: (1) active predators disproportionately reduce the abundance of prey, (2) active predators select for predator-resistant prey species, (3) active predators strengthen trophic cascades (increase phytoplankton abundance) and (4) active predators are more likely to cannibalise one another, weakening all other trends when at high densities. These results suggest that intraspecific variation in predator personality is an important determinant of prey abundance, community composition and trophic cascades.
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Affiliation(s)
- Denon Start
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada, M5S 3B3
| | - Benjamin Gilbert
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada, M5S 3B3
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Takatsu K, Rudolf VHW, Kishida O. Giant cannibals drive selection for inducible defence in heterospecific prey. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12912] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Kunio Takatsu
- Division of Biosphere Science; Graduate School of Environmental Science; Hokkaido University; Toikanbetsu Horonobe Hokkaido 098-2943 Japan
| | - Volker H. W. Rudolf
- Department of Ecology and Evolutionary Biology; Rice University; Houston TX 77005 USA
| | - Osamu Kishida
- Field Science Center for Northern Biosphere; Hokkaido University; Takaoka Tomakomai Hokkaido 053-0035 Japan
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23
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Anderson TL. Predation risk between cannibalistic aeshnid dragonflies influences their functional response on a larval salamander prey. J Zool (1987) 2016. [DOI: 10.1111/jzo.12376] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- T. L. Anderson
- Division of Biological Sciences; University of Missouri; Columbia MO USA
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Abstract
Although natural populations consist of individuals with different traits, and the degree of phenotypic variation varies among populations, the impact of phenotypic variation on ecological interactions has received little attention, because traditional approaches to community ecology assume homogeneity of individuals within a population. Stage structure, which is a common way of generating size and developmental variation within predator populations, can drive cannibalistic interactions, which can affect the strength of predatory effects on the predator's heterospecific prey. Studies have shown that predator cannibalism weakens predatory effects on heterospecific prey by reducing the size of the predator population and by inducing less feeding activity of noncannibal predators. We predict, however, that predator cannibalism, by promoting rapid growth of the cannibals, can also intensify predation pressure on heterospecific prey, because large predators have large resource requirements and may utilize a wider variety of prey species. To test this hypothesis, we conducted an experiment in which we created carnivorous salamander (Hynobius retardatus) populations with different stage structures by manipulating the salamander's hatch timing (i.e., populations with large or small variation in the timing of hatching), and explored the resultant impacts on the abundance, behavior, morphology, and life history of the salamander's large heterospecific prey, Rana pirica frog tadpoles. Cannibalism was rare in salamander populations having small hatch-timing variation, but was frequent in those having large hatch-timing variation. Thus, giant salamander cannibals occurred only in the latter. We clearly showed that salamander giants exerted strong predation pressure on frog tadpoles, which induced large behavioral and morphological defenses in the tadpoles and caused them to metamorphose late at large size. Hence, predator cannibalism arising from large variation in the timing of hatching can strengthen predatory effects on heterospecific prey and can have impacts on various, traits of both predator and prey. Because animals commonly broaden their diet as they grow, such negative impacts of predator cannibalism on the heterospecific prey may be common in interactions between predators and prey species of similar size.
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Cecala KK, Price SJ, Dorcas ME. Stream Salamanders Accurately Assess Size-Dependent Predation Threats. HERPETOLOGICA 2015. [DOI: 10.1655/herpetologica-d-14-00031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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26
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Familiarity, prior residency, resource availability and body mass as predictors of the movement activity of the European catfish. J ETHOL 2015. [DOI: 10.1007/s10164-015-0441-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Yamaguchi A, Kishida O. Antagonistic indirect interactions between large and small conspecific prey via a heterospecific predator. OIKOS 2015. [DOI: 10.1111/oik.02443] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aya Yamaguchi
- Graduate School of Environmental Science, Hokkaido Univ; Toikanbetsu, Horonobe JP-098-2943 Hokkaido Japan
- Teshio Experimental Forest, Field Science Center for Northern Biosphere, Hokkaido Univ.; Toikanbetsu, Horonobe JP-098-2943 Hokkaido Japan
| | - Osamu Kishida
- Teshio Experimental Forest, Field Science Center for Northern Biosphere, Hokkaido Univ.; Toikanbetsu, Horonobe JP-098-2943 Hokkaido Japan
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28
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Bunke M, Alexander ME, Dick JTA, Hatcher MJ, Paterson R, Dunn AM. Eaten alive: cannibalism is enhanced by parasites. ROYAL SOCIETY OPEN SCIENCE 2015; 2:140369. [PMID: 26064614 PMCID: PMC4448826 DOI: 10.1098/rsos.140369] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 02/16/2015] [Indexed: 06/01/2023]
Abstract
Cannibalism is ubiquitous in nature and especially pervasive in consumers with stage-specific resource utilization in resource-limited environments. Cannibalism is thus influential in the structure and functioning of biological communities. Parasites are also pervasive in nature and, we hypothesize, might affect cannibalism since infection can alter host foraging behaviour. We investigated the effects of a common parasite, the microsporidian Pleistophora mulleri, on the cannibalism rate of its host, the freshwater amphipod Gammarus duebeni celticus. Parasitic infection increased the rate of cannibalism by adults towards uninfected juvenile conspecifics, as measured by adult functional responses, that is, the rate of resource uptake as a function of resource density. This may reflect the increased metabolic requirements of the host as driven by the parasite. Furthermore, when presented with a choice, uninfected adults preferred to cannibalize uninfected rather than infected juvenile conspecifics, probably reflecting selection pressure to avoid the risk of parasite acquisition. By contrast, infected adults were indiscriminate with respect to infection status of their victims, probably owing to metabolic costs of infection and the lack of risk as the cannibals were already infected. Thus parasitism, by enhancing cannibalism rates, may have previously unrecognized effects on stage structure and population dynamics for cannibalistic species and may also act as a selective pressure leading to changes in resource use.
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Affiliation(s)
- Mandy Bunke
- School of Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Mhairi E. Alexander
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland 7602, South Africa
| | - Jaimie T. A. Dick
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast BT9 7BL, , UK
| | | | - Rachel Paterson
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast BT9 7BL, , UK
| | - Alison M. Dunn
- School of Biology, University of Leeds, Leeds LS2 9JT, UK
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29
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Nilsson-Örtman V, Rogell B, Stoks R, Johansson F. Ontogenetic changes in genetic variances of age-dependent plasticity along a latitudinal gradient. Heredity (Edinb) 2015; 115:366-78. [PMID: 25649500 DOI: 10.1038/hdy.2014.126] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Revised: 10/17/2014] [Accepted: 11/27/2014] [Indexed: 11/09/2022] Open
Abstract
The expression of phenotypic plasticity may differ among life stages of the same organism. Age-dependent plasticity can be important for adaptation to heterogeneous environments, but this has only recently been recognized. Whether age-dependent plasticity is a common outcome of local adaptation and whether populations harbor genetic variation in this respect remains largely unknown. To answer these questions, we estimated levels of additive genetic variation in age-dependent plasticity in six species of damselflies sampled from 18 populations along a latitudinal gradient spanning 3600 km. We reared full sib larvae at three temperatures and estimated genetic variances in the height and slope of thermal reaction norms of body size at three points in time during ontogeny using random regression. Our data show that most populations harbor genetic variation in growth rate (reaction norm height) in all ontogenetic stages, but only some populations and ontogenetic stages were found to harbor genetic variation in thermal plasticity (reaction norm slope). Genetic variances in reaction norm height differed among species, while genetic variances in reaction norm slope differed among populations. The slope of the ontogenetic trend in genetic variances of both reaction norm height and slope increased with latitude. We propose that differences in genetic variances reflect temporal and spatial variation in the strength and direction of natural selection on growth trajectories and age-dependent plasticity. Selection on age-dependent plasticity may depend on the interaction between temperature seasonality and time constraints associated with variation in life history traits such as generation length.
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Affiliation(s)
- V Nilsson-Örtman
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - B Rogell
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - R Stoks
- Laboratory of Aquatic Ecology and Evolutionary Biology, University of Leuven, Leuven, Belgium
| | - F Johansson
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
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30
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Krenek L, Rudolf VHW. Allometric scaling of indirect effects: body size ratios predict non-consumptive effects in multi-predator systems. J Anim Ecol 2014; 83:1461-8. [DOI: 10.1111/1365-2656.12254] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 05/30/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Lauren Krenek
- Department of Ecology and Evolutionary Biology; Rice University; Houston TX 77005 USA
| | - Volker H. W. Rudolf
- Department of Ecology and Evolutionary Biology; Rice University; Houston TX 77005 USA
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31
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Nilsson-Örtman V, Stoks R, Johansson F. Competitive interactions modify the temperature dependence of damselfly growth rates. Ecology 2014; 95:1394-406. [DOI: 10.1890/13-0875.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Encinas-Viso F, Revilla TA, Etienne RS. Shifts in pollinator population structure may jeopardize pollination service. J Theor Biol 2014; 352:24-30. [PMID: 24607744 DOI: 10.1016/j.jtbi.2014.02.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 02/21/2014] [Accepted: 02/25/2014] [Indexed: 11/19/2022]
Abstract
Plant-pollinator interactions are among the best known and ubiquitous plant-animal mutualisms and are crucial for ecosystem functioning and the maintenance of biodiversity. Most pollinators are insects with several life-stages (e.g. egg, larva, pupa, adult) and the mutualistic interaction depends on the pollinator surviving these different life-stages. However, to our knowledge, pollinator population structure has been ignored in most theoretical models of plant-pollinator dynamics, and we lack understanding of the role of different life-stages in determining the stability of the mutualism. Here we therefore develop a simple plant-pollinator model with a facultative plant and an obligate pollinator with stage-structure. Our model predicts a globally stable equilibrium when pollinator demography is dominated by adults and a locally stable equilibrium when the plants are strongly dependent on pollination and pollinator demography is dominated by the larval stage. In the latter case, the mutualism is vulnerable to fluctuations in the pollinator population size or structure caused by external factors (e.g. pesticides) reducing larval development and increasing adult mortality. This may cause a sudden collapse rather than gradual decrease of the mutualism, after which the pollination service cannot be recovered by reducing these detrimental external factors, but must be accompanied by large increases in pollinator populations. This highlights the importance of considering population structure in plant-pollinator interactions.
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Affiliation(s)
| | | | - Rampal S Etienne
- Community and Conservation Ecology, University of Groningen, The Netherlands.
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33
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Moya-Laraño J, Bilbao-Castro JR, Barrionuevo G, Ruiz-Lupión D, Casado LG, Montserrat M, Melián CJ, Magalhães S. Eco-Evolutionary Spatial Dynamics. ADV ECOL RES 2014. [DOI: 10.1016/b978-0-12-801374-8.00003-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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34
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Mott CL, Steffen MA. Associations between Non-Lethal Injury, Body Size, and Foraging Ecology in an Amphibian Intraguild Predator. Ethology 2013. [DOI: 10.1111/eth.12178] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Cy L. Mott
- Department of Biology; Valdosta State University; Valdosta GA USA
- Cooperative Wildlife Research Laboratory; Department of Zoology; Southern Illinois University; Carbondale IL USA
| | - Michael A. Steffen
- Department of Biological Sciences; University of Tulsa; Tulsa OK USA
- Department of Zoology; Southern Illinois University; Carbondale IL USA
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35
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Liu Z, Zhang F. Species coexistence of communities with intraguild predation: the role of refuges used by the resource and the intraguild prey. Biosystems 2013; 114:25-30. [PMID: 23891843 DOI: 10.1016/j.biosystems.2013.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 07/12/2013] [Accepted: 07/16/2013] [Indexed: 10/26/2022]
Abstract
In this paper, we develop a three-species intraguild predation model which incorporates refuges used by the resource and the intraguild prey, and focus on the effects of refuges on the three species coexistence. The invasion condition and parameter region for coexistence are obtained using invasion analysis. The new invasion condition requires that all boundary states with one missing species can be invaded by the missing species. Numerical simulations show that refuges have a major influence on species coexistence of intraguild predation system, and the results strongly depend on the types of refuges introduced into the model. Our study also shows that prey's refuges are detrimental to species coexistence except the resource using refuges. In contrast to previous research, we find that spatial structure may play an important role in effects of refuges on species coexistence of intraguild predation systems. Our results may shed new light on understanding the mechanisms and the persistence of multi-species predators-prey system.
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Affiliation(s)
- Zhiguang Liu
- Institute of Applied Mathematics, School of Mathematics and Information Sciences, Henan University, Kaifeng 475004, People's Republic of China.
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36
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Bleakley BH, Welter SM, McCauley-Cole K, Shuster SM, Moore AJ. Cannibalism as an interacting phenotype: precannibalistic aggression is influenced by social partners in the endangered Socorro Isopod (Thermosphaeroma thermophilum). J Evol Biol 2013; 26:832-42. [PMID: 23516960 DOI: 10.1111/jeb.12098] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 11/28/2012] [Accepted: 12/05/2012] [Indexed: 11/29/2022]
Abstract
Models for the evolution of cannibalism highlight the importance of asymmetries between individuals in initiating cannibalistic attacks. Studies may include measures of body size but typically group individuals into size/age classes or compare populations. Such broad comparisons may obscure the details of interactions that ultimately determine how socially contingent characteristics evolve. We propose that understanding cannibalism is facilitated by using an interacting phenotypes perspective that includes the influences of the phenotype of a social partner on the behaviour of a focal individual and focuses on variation in individual pairwise interactions. We investigated how relative body size, a composite trait between a focal individual and its social partner, and the sex of the partners influenced precannibalistic aggression in the endangered Socorro isopod, Thermosphaeroma thermophilum. We also investigated whether differences in mating interest among males and females influenced cannibalism in mixed sex pairs. We studied these questions in three populations that differ markedly in range of body size and opportunities for interactions among individuals. We found that relative body size influences the probability of and latency to attack. We observed differences in the likelihood of and latency to attack based on both an individual's sex and the sex of its partner but found no evidence of sexual conflict. The instigation of precannibalistic aggression in these isopods is therefore a property of both an individual and its social partner. Our results suggest that interacting phenotype models would be improved by incorporating a new conditional ψ, which describes the strength of a social partner's influence on focal behaviour.
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Affiliation(s)
- B H Bleakley
- Department of Biology, Stonehill College, Easton, MA 02357, USA.
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37
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Greig HS, Wissinger SA, McIntosh AR. Top-down control of prey increases with drying disturbance in ponds: a consequence of non-consumptive interactions? J Anim Ecol 2013; 82:598-607. [DOI: 10.1111/1365-2656.12042] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 11/29/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Hamish S. Greig
- School of Biological Sciences; University of Canterbury; Private Bag 4800; Christchurch; New Zealand
| | | | - Angus R. McIntosh
- School of Biological Sciences; University of Canterbury; Private Bag 4800; Christchurch; New Zealand
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Impacts of enemy-mediated effects and the additivity of interactions in an insect trophic system. POPUL ECOL 2012. [DOI: 10.1007/s10144-012-0352-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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40
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Kratina P, LeCraw RM, Ingram T, Anholt BR. Stability and persistence of food webs with omnivory: Is there a general pattern? Ecosphere 2012. [DOI: 10.1890/es12-00121.1] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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41
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Rudolf VHW. Seasonal shifts in predator body size diversity and trophic interactions in size-structured predator-prey systems. J Anim Ecol 2011; 81:524-32. [PMID: 22191419 DOI: 10.1111/j.1365-2656.2011.01935.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
1. Theory suggests that the relationship between predator diversity and prey suppression should depend on variation in predator traits such as body size, which strongly influences the type and strength of species interactions. Prey species often face a range of different sized predators, and the composition of body sizes of predators can vary between communities and within communities across seasons. 2. Here, I test how variation in size structure of predator communities influences prey survival using seasonal changes in the size structure of a cannibalistic population as a model system. Laboratory and field experiments showed that although the per-capita consumption rates increased at higher predator-prey size ratios, mortality rates did not consistently increase with average size of cannibalistic predators. Instead, prey mortality peaked at the highest level of predator body size diversity. 3. Furthermore, observed prey mortality was significantly higher than predictions from the null model that assumed no indirect interactions between predator size classes, indicating that different sized predators were not substitutable but had more than additive effects. Higher predator body size diversity therefore increased prey mortality, despite the increased potential for behavioural interference and predation among predators demonstrated in additional laboratory experiments. 4. Thus, seasonal changes in the distribution of predator body sizes altered the strength of prey suppression not only through changes in mean predator size but also through changes in the size distribution of predators. In general, this indicates that variation (i.e. diversity) within a single trait, body size, can influence the strength of trophic interactions and emphasizes the importance of seasonal shifts in size structure of natural food webs for community dynamics.
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Affiliation(s)
- Volker H W Rudolf
- Department of Ecology & Evolutionary Biology, Rice University, Houston, TX 77005, USA.
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42
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Better the devil you know: familiarity affects foraging activity of red-backed salamanders, Plethodon cinereus. Anim Behav 2011. [DOI: 10.1016/j.anbehav.2011.07.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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43
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44
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Miller TEX, Rudolf VHW. Thinking inside the box: community-level consequences of stage-structured populations. Trends Ecol Evol 2011; 26:457-66. [PMID: 21680049 DOI: 10.1016/j.tree.2011.05.005] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 05/15/2011] [Accepted: 05/16/2011] [Indexed: 11/17/2022]
Abstract
Ecologists have historically represented consumer-resource interactions with boxes and arrows. A key assumption of this conceptualization is that all individuals inside a box are functionally equivalent. Demographic stage structure, however, is a widespread source of heterogeneity inside the boxes. Synthesizing recent studies, we show that stage structure can modify the dynamics of consumer-resource communities owing to stage-related shifts in the nature and strength of interactions that occur within and between populations. As a consequence, stage structure can stabilize consumer-resource dynamics, create possibilities for alternative community states, modify conditions for coexistence of competitors, and alter the strength and direction of trophic cascades. Consideration of stage structure can thus lead to outcomes that are not expected based on unstructured approaches.
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Affiliation(s)
- Tom E X Miller
- Department of Ecology and Evolutionary Biology, Rice University, MS-170, Houston, TX 77005, USA
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45
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Kishida O, Trussell GC, Ohno A, Kuwano S, Ikawa T, Nishimura K. Predation risk suppresses the positive feedback between size structure and cannibalism. J Anim Ecol 2011; 80:1278-87. [PMID: 21668893 DOI: 10.1111/j.1365-2656.2011.01871.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
1. Cannibalism can play a prominent role in the structuring and dynamics of ecological communities. Previous studies have emphasized the importance of size structure and density of cannibalistic species in shaping short- and long-term cannibalism dynamics, but our understanding of how predators influence cannibalism dynamics is limited. This is despite widespread evidence that many prey species exhibit behavioural and morphological adaptations in response to predation risk. 2. This study examined how the presence and absence of predation risk from larval dragonflies Aeshna nigroflava affected cannibalism dynamics in its prey larval salamanders Hynobius retardatus. 3. We found that feedback dynamics between size structure and cannibalism depended on whether dragonfly predation risk was present. In the absence of dragonfly risk cues, a positive feedback between salamander size structure and cannibalism through time occurred because most of the replicates in this treatment contained at least one salamander larvae having an enlarged gape (i.e. cannibal). In contrast, this feedback and the emergence of cannibalism were rarely observed in the presence of the dragonfly risk cues. Once salamander size divergence occurred, experimental reversals of the presence or absence of dragonfly risk cues did not alter existing cannibalism dynamics as the experiment progressed. Thus, the effects of risk on the mechanisms driving cannibalism dynamics likely operated during the early developmental period of the salamander larvae. 4. The effects of dragonfly predation risk on behavioural aspects of cannibalistic interactions among hatchlings may prohibit the initiation of dynamics between size structure and cannibalism. Our predation trials clearly showed that encounter rates among hatchlings and biting and ingestion rates of prospective prey by prospective cannibals were significantly lower in the presence vs. absence of dragonfly predation risk even though the size asymmetry between cannibals and victims was similar in both risk treatments. These results suggest that dragonfly risk cues first suppress cannibalism among hatchlings and then prevent size variation from increasing through time. 5. We suggest that the positive feedback dynamics between size structure and cannibalism and their modification by predation risk may also operate in other systems to shape the population dynamics of cannibalistic prey species as well as overall community dynamics.
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Affiliation(s)
- Osamu Kishida
- Teshio Experimental Forest, Field Science Center for Northern Biosphere, Hokkaido University, Horonobe, Hokkaido 098-2943, Japan.
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46
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47
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Bolnick DI, Amarasekare P, Araújo MS, Bürger R, Levine JM, Novak M, Rudolf VHW, Schreiber SJ, Urban MC, Vasseur DA. Why intraspecific trait variation matters in community ecology. Trends Ecol Evol 2011; 26:183-92. [PMID: 21367482 PMCID: PMC3088364 DOI: 10.1016/j.tree.2011.01.009] [Citation(s) in RCA: 1214] [Impact Index Per Article: 93.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Revised: 01/25/2011] [Accepted: 01/25/2011] [Indexed: 11/17/2022]
Abstract
Natural populations consist of phenotypically diverse individuals that exhibit variation in their demographic parameters and intra- and inter-specific interactions. Recent experimental work indicates that such variation can have significant ecological effects. However, ecological models typically disregard this variation and focus instead on trait means and total population density. Under what situations is this simplification appropriate? Why might intraspecific variation alter ecological dynamics? In this review we synthesize recent theory and identify six general mechanisms by which trait variation changes the outcome of ecological interactions. These mechanisms include several direct effects of trait variation per se and indirect effects arising from the role of genetic variation in trait evolution.
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Affiliation(s)
- Daniel I Bolnick
- Howard Hughes Medical Institute, Section of Integrative Biology, University of Texas at Austin, TX 78712, USA.
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48
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Stouffer DB, Rezende EL, Amaral LAN. The role of body mass in diet contiguity and food-web structure. J Anim Ecol 2011; 80:632-9. [PMID: 21401590 PMCID: PMC3792558 DOI: 10.1111/j.1365-2656.2011.01812.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. The idea that species occupy distinct niches is a fundamental concept in ecology. Classically, the niche was described as an n-dimensional hypervolume where each dimension represents a biotic or abiotic characteristic. More recently, it has been hypothesised that a single dimension may be sufficient to explain the system-level organization of trophic interactions observed between species in a community. 2. Here, we test the hypothesis that species body mass is that single dimension. Specifically, we determine how the intervality of food webs ordered by body size compares to that of randomly ordered food webs. We also extend this analysis beyond the community level to the effect of body mass in explaining the diets of individual species. 3. We conclude that body mass significantly explains the ordering of species and the contiguity of diets in empirical communities. 4. At the species-specific level, we find that the degree to which body mass is a significant explanatory variable depends strongly on the phylogenetic history, suggesting that other evolutionarily conserved traits partly account for species' roles in the food web. 5. Our investigation of the role of body mass in food webs thus helps us to better understand the important features of community food-web structure and the evolutionary forces that have led us to the communities we observe.
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Affiliation(s)
- Daniel B Stouffer
- Integrative Ecology Group, Estación Biológica de Doñana-CSIC, c/ Américo Vespucio s/n, 41092 Sevilla, Spain.
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49
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Rudolf VHW, Lafferty KD. Stage structure alters how complexity affects stability of ecological networks. Ecol Lett 2010; 14:75-9. [PMID: 21114747 DOI: 10.1111/j.1461-0248.2010.01558.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Resolving how complexity affects stability of natural communities is of key importance for predicting the consequences of biodiversity loss. Central to previous stability analysis has been the assumption that the resources of a consumer are substitutable. However, during their development, most species change diets; for instance, adults often use different resources than larvae or juveniles. Here, we show that such ontogenetic niche shifts are common in real ecological networks and that consideration of these shifts can alter which species are predicted to be at risk of extinction. Furthermore, niche shifts reduce and can even reverse the otherwise stabilizing effect of complexity. This pattern arises because species with several specialized life stages appear to be generalists at the species level but act as sequential specialists that are hypersensitive to resource loss. These results suggest that natural communities are more vulnerable to biodiversity loss than indicated by previous analyses.
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Affiliation(s)
- V H W Rudolf
- Department of Ecology and Evolutionary Biology, Rice University, Houston, TX, USA.
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50
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Greenwood MJ, McIntosh AR, Harding JS. Disturbance across an ecosystem boundary drives cannibalism propensity in a riparian consumer. Behav Ecol 2010. [DOI: 10.1093/beheco/arq140] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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