scholarly journals Analysis of adaptive foraging in an intraguild predation system

Web Ecology ◽  
2003 ◽  
Vol 4 (1) ◽  
pp. 1-6 ◽  
Author(s):  
T. Okuyama ◽  
R. L. Ruyle
Keyword(s):  
Foraging Behavior ◽  
Adaptive Behavior ◽  
Intraguild Predation ◽  
Indirect Effects ◽  
Species Interactions ◽  
Community Dynamics ◽  
Antipredator Behavior ◽  
Density Dependent ◽  
Top Predators ◽  
Adaptive Foraging

Abstract. An intraguild predation (IGP) system with adaptive foraging behavior was analyzed using a simple mathematical model. The main aim was to explore how the adaptive behavior affects species interactions as well as how such interactions derived from adaptive behavior affect community stability. The focal system contained top predators, intermediate predators, and basal prey. Intermediate predators exhibit antipredator behavior and balance costs (e.g. perceived predation risk) and benefits (e.g. resource intake) to determine their foraging effort. Density-dependent foraging behavior with the unique connectance of the IGP food web created unusual species interactions. Notably, increased prey density can transmit negative indirect effects to top predators while increased top predator density transmits positive indirect effects to prey population. The nature of these interactions is density-dependent. The results suggest that both IGP (as opposed to linear food chain) and adaptive foraging behaviors may strongly influence community dynamics due to emergent interactions among direct effects and indirect effects. Furthermore, the adaptive foraging of intermediate predators may stabilize the community as a whole.

A question of size and fear: competition and predation risk perception among frugivores and predators

2020 ◽  
Vol 101 (3) ◽  
pp. 648-657
Author(s):  
Daiane Cristina Carreira ◽  
Jedediah F Brodie ◽  
Calebe P Mendes ◽  
Katia Maria P M B Ferraz ◽  
Mauro Galetti
Keyword(s):  
Risk Perception ◽  
Predation Risk ◽  
Indirect Effects ◽  
Species Interactions ◽  
Human Impacts ◽  
Activity Patterns ◽  
Fruit Trees ◽  
Visitation Rates ◽  
Top Predators ◽  
Large Predators

Abstract Mammalian spatial and temporal activity patterns can vary depending on foraging behavior or the perception of predation or competition risk among species. These behaviors may in turn be altered by human influences such as defaunation. Herein, we evaluate whether frugivores avoid areas with high visitation rates by potential predators or competitors, and whether this avoidance changes in areas with different degrees of defaunation. We installed 189 cameras under fruit trees in six areas of the Atlantic Forest, Brazil, that differ in the abundance of top predators and large frugivores. Small predators and small frugivores were more frequent at night while large frugivores were more frequent during the day, but small frugivores visited and spent less time at fruiting trees on brighter nights, unlike large predators and large frugivores. Small frugivores also were less frequent in areas with high visitation by large frugivores and more frequent in highly defaunated areas. Our results suggest that the dynamics among mammalian functional groups varied according to diel patterns, potential competitors, and defaunation. We highlight the importance of understanding how species interactions are changing in areas exposed to strong human impacts to mitigate the indirect effects of defaunation.

scholarly journals An invasive herbivore structures plant competitive dynamics

2017 ◽  
Vol 13 (11) ◽  
pp. 20170374
Author(s):  
Lydia Wong ◽  
Tess Nahanni Grainger ◽  
Denon Start ◽  
Benjamin Gilbert
Keyword(s):  
Invasive Species ◽  
Indirect Effects ◽  
Species Interactions ◽  
Native Species ◽  
Community Dynamics ◽  
Aphid Species ◽  
Ecological Communities ◽  
Native Plant ◽  
Native Communities ◽  
Species Invasions

Species interactions are central to our understanding of ecological communities, but may change rapidly with the introduction of invasive species. Invasive species can alter species interactions and community dynamics directly by having larger detrimental effects on some species than others, or indirectly by changing the ways in which native species compete among themselves. We tested the direct and indirect effects of an invasive aphid herbivore on a native aphid species and two host milkweed species. The invasive aphid caused a 10-fold decrease in native aphid populations, and a 30% increase in plant mortality (direct effects). The invasive aphid also increased the strength of interspecific competition between the two native plant hosts (indirect effects). By investigating the role that indirect effects play in shaping species interactions in native communities, our study highlights an understudied component of species invasions.

scholarly journals Timing and duration of phenological subsidies: toward a mechanistic understanding of impacts on community structure and ecosystem processes in stream food chains

2019 ◽  
Author(s):  
Gaku Takimoto ◽  
Takuya Sato
Keyword(s):  
Life History ◽  
Indirect Effects ◽  
Species Interactions ◽  
Community Dynamics ◽  
Food Chains ◽  
Cascading Effects ◽  
Litter Processing ◽  
Phenological Changes ◽  
Field Manipulation

ABSTRACTPhenological resources are common across many ecological communities, and can strongly affect community dynamics. Recent field manipulation experiments in stream food chains found that seasonal timing and duration of terrestrial prey inputs affected the feeding behavior, growth, and maturation of fish predators, caused predator-mediated indirect effects on aquatic prey, and modified trophic-cascading effects on litter processing. These experiments described impacts of resource phenological changes over a few month period, and long-term impacts of continued changes in resource phenology are unknown. Here we develop a mathematical model to extrapolate long-term predictions about the effects of changes in resource phenology from the results of field manipulation experiments. The model predicts that advanced timing generally decreases aquatic prey and litter processing and prolonged duration will either increase or decrease aquatic prey and litter processing depending on the total amount and pre-disturbed timing and duration of terrestrial prey inputs. Importantly, our modeling approach clarifies the mechanisms by which stage-specific responses of life history processes in fish, such as growth, maturation, and reproduction, respond to phenological changes in terrestrial prey inputs and mediate indirect effects on aquatic prey and litter processing. Stage-specific responses of life history processes are an integral part of the mechanisms with which to predict the consequences of phenological species interactions at the community and ecosystem levels.

scholarly journals Multi-species mechanistic model of functional response provides new insights into predator-mediated interactions in a vertebrate community

2021 ◽  
Author(s):  
Andréanne Beardsell ◽  
Dominique Gravel ◽  
Jeanne Clermont ◽  
Dominique Berteaux ◽  
Gilles Gauthier ◽  
...  
Keyword(s):  
Functional Response ◽  
Foraging Behavior ◽  
Indirect Effects ◽  
Interaction Strength ◽  
Arctic Tundra ◽  
The Arctic ◽  
Short Term ◽  
Density Dependent ◽  
Predator Foraging ◽  
Prey Handling

Prey handling processes are considered a key driver of short-term positive indirect effects between prey sharing the same predator. However, a growing body of research indicates that predators are rarely limited by such processes in the wild. Density-dependent changes in predator foraging behavior can also generate positive indirect effects but they are rarely included as explicit functions of prey densities in functional response models. With the aim of untangling proximate drivers of species interactions in natural communities and improve our ability to quantify interaction strength, we extended the Holling multi-species model by including density-dependent changes in predator foraging behavior. Our model, based on species traits and behavior, was inspired by the vertebrate community of the arctic tundra, where the main predator (the arctic fox) is an active forager feeding primarily on cyclic small rodent (lemming) populations and eggs of various tundra-nesting bird species. Short-term positive indirect effects of lemmings on birds have been documented over the circumpolar Arctic but the underlying proximate mechanisms remain poorly known. We used a unique data set, containing high-frequency GPS tracking, accelerometer, behavioral, and experimental data to parameterize the multi-species model, and a 15-year time series of prey densities and bird nesting success to evaluate interaction strength between species. Our results showed that: (i) prey handling processes play a minor role in our system and (ii) density-dependent changes in predator foraging behavior can be the proximate drivers of a predominant predator-mediated interaction observed in the arctic tundra. Mechanisms outlined in our study have been little studied and may play a significant role in natural systems. We hope that our study will provide a useful starting point to build mechanistic models of predation, and we think that our approach could conceivably be applied to a broad range of food webs.

Trophic Cascades in Grasslands

2018 ◽  
Author(s):  
Brian J. Wilsey
Keyword(s):  
Indirect Effects ◽  
Prey Species ◽  
Trophic Levels ◽  
Herbaceous Plant ◽  
Direct Effects ◽  
Temperate Grasslands ◽  
Cascading Effect ◽  
Top Predators ◽  
Invertebrate Predators ◽  
Ecology Of Fear

Top predators have effects that can ‘cascade down’ on lower trophic levels. Because of this cascading effect, it matters how many trophic levels are present. Predators are either ‘sit and wait’ or ‘active’. Wolves are top predators in temperate grasslands and can alter species composition of smaller-sized predators, prey, and woody and herbaceous plant species, either through direct effects or indirect effects (‘Ecology of Fear’). In human derived grasslands, invertebrate predators fill a similar ecological role as wolves. Migrating populations of herbivores tend to be more limited by food than non-migratory populations. The phenology and synchrony of births vary among prey species in a way that is consistent with an adaptation to predation. Precocious species have highly synchronous birth dates to satiate predators. Non-precocious species (‘hiders’) have asynchronous births. Results from studies that manipulate both predators and food support the hypothesis that bottom-up and top-down effects interact.

scholarly journals The importance of species interactions in eco-evolutionary community dynamics under climate change

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anna Åkesson ◽  
Alva Curtsdotter ◽  
Anna Eklöf ◽  
Bo Ebenman ◽  
Jon Norberg ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Interactions ◽  
Community Dynamics ◽  
Evolutionary Dynamics ◽  
Negative Impact ◽  
Trophic Levels ◽  
Temperature Dependent ◽  
Modeling Framework ◽  
Impact Of Climate Change ◽  
The Impact

AbstractEco-evolutionary dynamics are essential in shaping the biological response of communities to ongoing climate change. Here we develop a spatially explicit eco-evolutionary framework which features more detailed species interactions, integrating evolution and dispersal. We include species interactions within and between trophic levels, and additionally, we incorporate the feature that species’ interspecific competition might change due to increasing temperatures and affect the impact of climate change on ecological communities. Our modeling framework captures previously reported ecological responses to climate change, and also reveals two key results. First, interactions between trophic levels as well as temperature-dependent competition within a trophic level mitigate the negative impact of climate change on biodiversity, emphasizing the importance of understanding biotic interactions in shaping climate change impact. Second, our trait-based perspective reveals a strong positive relationship between the within-community variation in preferred temperatures and the capacity to respond to climate change. Temperature-dependent competition consistently results both in higher trait variation and more responsive communities to altered climatic conditions. Our study demonstrates the importance of species interactions in an eco-evolutionary setting, further expanding our knowledge of the interplay between ecological and evolutionary processes.

scholarly journals Introduction: Special issue on species interactions, ecological networks and community dynamics – Untangling the entangled bank using molecular techniques

2019 ◽  
Vol 28 (2) ◽  
pp. 157-164 ◽  
Author(s):  
Tomas Roslin ◽  
Michael Traugott ◽  
Mattias Jonsson ◽  
Graham N. Stone ◽  
Simon Creer ◽  
...  
Keyword(s):  
Species Interactions ◽  
Community Dynamics ◽  
Ecological Networks ◽  
Molecular Techniques ◽  
Special Issue

scholarly journals Does Altering Local Water Availability for an Invasive Plant (Raphanus raphanistrum) Affect Floral Morphology and Reproductive Potential?

2015 ◽  
Vol 12 (2) ◽  
Author(s):  
Natalia Pirimova ◽  
Alison Parker ◽  
Lesley Campbell
Keyword(s):  
Soil Moisture ◽  
Foraging Behavior ◽  
Water Availability ◽  
Community Dynamics ◽  
Invasive Plant ◽  
Floral Morphology ◽  
Insect Community ◽  
Raphanus Raphanistrum ◽  
Anther Length ◽  
Corolla Diameter

Abiotic environmental variation can have dramatic effects on plant floral morphology and nectar or pollen rewards. In response, pollinators may change their foraging behavior and distribution and if pollinators change their foraging behavior or distribution, this could have dramatic effects on the reproductive success of plant populations. To start tackling this problem, we measured the response of floral morphology (corolla diameter, stamen length, and ovule number) of Raphanus raphanistrum to experimental manipulations of field soil moisture. As soil moisture increased, corolla diameter and anther length grew. We expect these changes to provide more visitation rewards for insects in moist conditions. Therefore, water availability influences growth and development of flowers, and may have dramatic effects on insect community dynamics. KEYWORDS: Floral Rewards, Climate, Rain-out Shelters, Flower Morphology, Raphanus raphanistrum, Brassicaceae

The Community of Ecological Opportunities

2017 ◽  
Author(s):  
Mark A. McPeek
Keyword(s):  
Plant Species ◽  
Resource Availability ◽  
Intraguild Predation ◽  
Species Interactions ◽  
Apparent Competition ◽  
Predation Pressure ◽  
Trophic Levels ◽  
Model Species ◽  
Pollinator Species ◽  
Different Types

This chapter examines ecological opportunities that are available to species in various positions within a biological community, with particular emphasis on identifying the criteria necessary for an ecological opportunity to exist. Before discussing what performance capabilities a species must have to fill different types of ecological opportunities and what is required for invasibility of species into different functional positions in a community, the chapter considers the different frameworks that have been used to model species interactions. It then describes resource and apparent competition to show how resource availability from below and predation pressure from above can affect the types of species that can exploit specifc ecological opportunities. It also analyzes communities with three trophic levels, intraguild predation or omnivory, mutualism, the mechanisms that foster coexistence between one plant species and one pollinator species, and the case of one plant species with multiple pollinators.

scholarly journals Biotic rescaling reveals importance of species interactions for variation in biodiversity responses to climate change

2020 ◽  
Vol 117 (37) ◽  
pp. 22858-22865 ◽  
Author(s):  
Vigdis Vandvik ◽  
Olav Skarpaas ◽  
Kari Klanderud ◽  
Richard J. Telford ◽  
Aud H. Halbritter ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Interactions ◽  
Community Dynamics ◽  
Biotic Interactions ◽  
Plant Interactions ◽  
Climate Gradients ◽  
Climate Change Responses ◽  
Local Extinctions ◽  
Future Work ◽  
Underlying Processes

Generality in understanding biodiversity responses to climate change has been hampered by substantial variation in the rates and even directions of response to a given change in climate. We propose that such context dependencies can be clarified by rescaling climate gradients in terms of the underlying biological processes, with biotic interactions as a particularly important process. We tested this rescaling approach in a replicated field experiment where entire montane grassland communities were transplanted in the direction of expected temperature and/or precipitation change. In line with earlier work, we found considerable variation across sites in community dynamics in response to climate change. However, these complex context dependencies could be substantially reduced or eliminated by rescaling climate drivers in terms of proxies of plant−plant interactions. Specifically, bryophytes limited colonization by new species into local communities, whereas the cover of those colonists, along with bryophytes, were the primary drivers of local extinctions. These specific interactions are relatively understudied, suggesting important directions for future work in similar systems. More generally, the success of our approach in explaining and simplifying landscape-level variation in climate change responses suggests that developing and testing proxies for relevant underlying processes could be a fruitful direction for building more general models of biodiversity response to climate change.

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