scholarly journals The Combined Effects of Warming and Body Size on the Stability of Predator-Prey Interactions

2022 ◽  
Vol 9 ◽  
Author(s):  
Pavel Kratina ◽  
Benjamin Rosenbaum ◽  
Bruno Gallo ◽  
Elena L. Horas ◽  
Eoin J. O’Gorman
Keyword(s):  
Body Size ◽  
Trophic Interactions ◽  
Handling Time ◽  
Size Ratio ◽  
Interactive Effects ◽  
Functional Responses ◽  
Ample Evidence ◽  
Predator Prey ◽  
The Stability ◽  
Prey Populations

Environmental temperature and body size are two prominent drivers of predation. Despite the ample evidence of their independent effects, the combined impact of temperature and predator-prey body size ratio on the strength and stability of trophic interactions is not fully understood. We experimentally tested how water temperature alters the functional response and population stability of dragonfly nymphs (Cordulegaster boltonii) feeding on freshwater amphipods (Gammarus pulex) across a gradient of their body size ratios. Attack coefficients were highest for small predators feeding on small prey at low temperatures, but shifted toward the largest predators feeding on larger prey in warmer environments. Handling time appeared to decrease with increasing predator and prey body size in the cold environment, but increase at higher temperatures. These findings indicate interactive effects of temperature and body size on functional responses. There was also a negative effect of warming on the stability of predator and prey populations, but this was counteracted by a larger predator-prey body size ratio at higher temperatures. Here, a greater Hill exponent reduced feeding at low prey densities when predators were much larger than their prey, enhancing the persistence of both predator and prey populations in the warmer environment. These experimental findings provide new mechanistic insights into the destabilizing effect of warming on trophic interactions and the key role of predator-prey body size ratios in mitigating these effects.

scholarly journals Size-dependent functional response of Xenopus laevis on mosquito larvae

2018 ◽  
Author(s):  
Corey J Thorp ◽  
Mhairi E Alexander ◽  
James R Vonesh ◽  
John Measey
Keyword(s):  
Body Size ◽  
Xenopus Laevis ◽  
Functional Response ◽  
Handling Time ◽  
Mosquito Larvae ◽  
Agricultural Pests ◽  
Food Web Structure ◽  
Predator Prey ◽  
Predator Attack ◽  
Considerable Individual Variation

Predators can play an important role in regulating prey abundance and diversity, determining food web structure and function, and contributing to important ecosystem services, including the regulation of agricultural pests and disease vectors. Thus, the ability to predict predator impact on prey is an important goal in ecology. Often predators of the same species are assumed to be functionally equivalent, despite considerable individual variation in predator traits known to be important for shaping predator-prey interactions, like body size. This assumption may greatly oversimplify our understanding of within species functional diversity and undermine our ability to predict predator effects on prey. Here we examine the degree to which predator-prey interactions are functionally homogenous across a natural range of predator body size. Specifically, we quantify the size-dependence of the functional response of African clawed frogs (Xenopus laevis) preying on mosquito larvae (Culex pipiens). Three size classes of predators, small (15-30mm snout-vent length), medium (50-60mm) and large (105-120mm), were presented with five densities of prey to determine functional response type and to estimate search efficiency and handling time parameters generated from the models. The results of mesocosm experiments show that functional response of X. laevis changed with size: small predators exhibited a Type II response, while medium and large predators exhibited Type III responses. Both functional response and behavioural data showed an inversely proportional relationship between predator attack rate and predator size. Small and medium predators had highest and lowest handling time respectively. That the functional response changed with the size of predator suggests that predators with overlapping cohorts may have a dynamic impact on prey populations. Therefore, predicting the functional response of a single size-matched predator in an experiment may be a misrepresentation of the predator’s potential impact on a prey population.

Dynamics of a Discrete Prey–Predator Model with Mixed Functional Response

2019 ◽  
Vol 29 (14) ◽  
pp. 1950199
Author(s):  
Mohammed Fathy Elettreby ◽  
Aisha Khawagi ◽  
Tamer Nabil
Keyword(s):  
Type I ◽  
Time Behavior ◽  
Stable Fixed Point ◽  
Functional Responses ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Dynamical Behaviors ◽  
Long Time ◽  
Predator Model ◽  
The Stability

In this paper, we propose a discrete Lotka–Volterra predator–prey model with Holling type-I and -II functional responses. We investigate the stability of the fixed points of this model. Also, we study the effects of changing each control parameter on the long-time behavior of the model. This model contains a lot of complex dynamical behaviors ranging from a stable fixed point to chaotic attractors. Finally, we illustrate the analytical results by some numerical simulations.

scholarly journals Bifurcation and control of a predator-prey system with unfixed functional responses

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Lizhi Fei ◽  
Xingwu Chen
Keyword(s):  
Fixed Points ◽  
Hybrid Control ◽  
Sufficient Conditions ◽  
Rate Function ◽  
Functional Responses ◽  
Predator Prey ◽  
Prey System ◽  
The Stability ◽  
Necessary And Sufficient ◽  
And Control

<p style='text-indent:20px;'>In this paper we investigate a discrete-time predator-prey system with not only some constant parameters but also unfixed functional responses including growth rate function of prey, conversion factor function and predation probability function. We prove that the maximal number of fixed points is <inline-formula><tex-math id="M1">\begin{document}$ 3 $\end{document}</tex-math></inline-formula> and give necessary and sufficient conditions of exactly <inline-formula><tex-math id="M2">\begin{document}$ j $\end{document}</tex-math></inline-formula>(<inline-formula><tex-math id="M3">\begin{document}$ j = 1,2,3 $\end{document}</tex-math></inline-formula>) fixed points, respectively. For transcritical bifurcation and Neimark-Sacker bifurcation, we provide bifurcation conditions depending on these unfixed functional responses. In order to regulate the stability of this biological system, a hybrid control strategy is used to control the Neimark-Sacker bifurcation. Finally, we apply our main results to some examples and carry out numerical simulations for each example to verify the correctness of our theoretical analysis.</p>

Multistable Phenomena Involving Equilibria and Periodic Motions in Predator–Prey Systems

2017 ◽  
Vol 27 (03) ◽  
pp. 1750043 ◽  
Author(s):  
Jiao Jiang ◽  
Pei Yu
Keyword(s):  
Limit Cycles ◽  
Complex Dynamics ◽  
Functional Responses ◽  
Bifurcation Of Limit Cycles ◽  
Predator Prey ◽  
Physical Systems ◽  
Dynamical Behaviors ◽  
Stable Periodic ◽  
Stable Equilibria ◽  
The Stability

In this paper, we consider a number of predator–prey systems with various types of functional responses. Detailed analysis on the dynamics and bifurcations of the systems are given. Particular attention is focused on the complex dynamics due to bifurcation of limit cycles, which may generate bistable or tristable phenomena involving equilibria and oscillating motions. It is shown that predator–prey systems can exhibit such bistable or tristable phenomena due to Hopf bifurcation, giving rise to the coexistence of stable equilibria and stable periodic solutions. Explicit conditions on the system parameters are derived which can be used to determine the number of Hopf bifurcations, the stability of bifurcating limit cycles, and the parameter regime where the bistable or tristable phenomenon occurs. The method developed in this paper can be applied to study certain interesting patterns of complex dynamical behaviors in biological or other physical systems.

Bifurcation and spatiotemporal patterns of a density-dependent predator–prey model with Crowley–Martin functional response

2017 ◽  
Vol 10 (06) ◽  
pp. 1750079 ◽  
Author(s):  
M. Sivakumar ◽  
K. Balachandran ◽  
K. Karuppiah
Keyword(s):  
Neumann Boundary ◽  
Positive Equilibrium ◽  
Functional Responses ◽  
Normal Form Theory ◽  
Predator Prey ◽  
Density Dependent ◽  
Predator Prey Model ◽  
Prey Model ◽  
The Stability ◽  
Manifold Theory

In this paper, we consider a diffusive density-dependent predator–prey model with Crowley–Martin functional responses subject to Neumann boundary condition. We analyze the stability of the positive equilibrium and the existence of spatially homogeneous and inhomogeneous periodic solutions through the distribution of the eigenvalues. The direction and stability of Hopf bifurcation are determined by the normal form theory and the center manifold theory. Finally, numerical simulations are given to verify our theoretical analysis.

scholarly journals Inferring Size-Based Functional Responses From the Physical Properties of the Medium

2022 ◽  
Vol 9 ◽  
Author(s):  
Sébastien M. J. Portalier ◽  
Gregor F. Fussmann ◽  
Michel Loreau ◽  
Mehdi Cherif
Keyword(s):  
Physical Properties ◽  
Functional Response ◽  
Aquatic Organisms ◽  
Handling Time ◽  
Real Data ◽  
Physical Factors ◽  
Functional Responses ◽  
Predator Prey ◽  
Natural Systems ◽  
Physical Principles

First derivations of the functional response were mechanistic, but subsequent uses of these functions tended to be phenomenological. Further understanding of the mechanisms underpinning predator-prey relationships might lead to novel insights into functional response in natural systems. Because recent consideration of the physical properties of the environment has improved our understanding of predator-prey interactions, we advocate the use of physics-based approaches for the derivation of the functional response from first principles. These physical factors affect the functional response by constraining the ability of both predators and prey to move according to their size. A physics-based derivation of the functional response should thus consider the movement of organisms in relation to their physical environment. One recent article presents a model along these criteria. As an initial validation of our claim, we use a slightly modified version of this model to derive the classical parameters of the functional response (i.e., attack rate and handling time) of aquatic organisms, as affected by body size, buoyancy, water density and viscosity. We compared the predictions to relevant data. Our model provided good fit for most parameters, but failed to predict handling time. Remarkably, this is the only parameter whose derivation did not rely on physical principles. Parameters in the model were not estimated from observational data. Hence, systematic discrepancies between predictions and real data point immediately to errors in the model. An added benefit to functional response derivation from physical principles is thus to provide easy ways to validate or falsify hypotheses about predator-prey relationships.

scholarly journals Size-dependent functional response of Xenopus laevis on mosquito larvae

2018 ◽  
Author(s):  
Corey J Thorp ◽  
Mhairi E Alexander ◽  
James R Vonesh ◽  
John Measey
Keyword(s):  
Body Size ◽  
Xenopus Laevis ◽  
Functional Response ◽  
Handling Time ◽  
Mosquito Larvae ◽  
Agricultural Pests ◽  
Food Web Structure ◽  
Predator Prey ◽  
Predator Attack ◽  
Considerable Individual Variation

Predators can play an important role in regulating prey abundance and diversity, determining food web structure and function, and contributing to important ecosystem services, including the regulation of agricultural pests and disease vectors. Thus, the ability to predict predator impact on prey is an important goal in ecology. Often predators of the same species are assumed to be functionally equivalent, despite considerable individual variation in predator traits known to be important for shaping predator-prey interactions, like body size. This assumption may greatly oversimplify our understanding of within species functional diversity and undermine our ability to predict predator effects on prey. Here we examine the degree to which predator-prey interactions are functionally homogenous across a natural range of predator body size. Specifically, we quantify the size-dependence of the functional response of African clawed frogs (Xenopus laevis) preying on mosquito larvae (Culex pipiens). Three size classes of predators, small (15-30mm snout-vent length), medium (50-60mm) and large (105-120mm), were presented with five densities of prey to determine functional response type and to estimate search efficiency and handling time parameters generated from the models. The results of mesocosm experiments show that functional response of X. laevis changed with size: small predators exhibited a Type II response, while medium and large predators exhibited Type III responses. Both functional response and behavioural data showed an inversely proportional relationship between predator attack rate and predator size. Small and medium predators had highest and lowest handling time respectively. That the functional response changed with the size of predator suggests that predators with overlapping cohorts may have a dynamic impact on prey populations. Therefore, predicting the functional response of a single size-matched predator in an experiment may be a misrepresentation of the predator’s potential impact on a prey population.

scholarly journals Quantifying predator functional responses under field conditions reveals interactive effects of temperature and interference with sex and stage.

2021 ◽  
Author(s):  
Kyle E Coblentz ◽  
Amber Squires ◽  
Stella F. Uiterwaal ◽  
John P. DeLong
Keyword(s):  
Temperature Dependence ◽  
Bayesian Model Averaging ◽  
Model Averaging ◽  
Field Conditions ◽  
Interactive Effects ◽  
Feeding Rates ◽  
Functional Responses ◽  
Predator Prey ◽  
Jumping Spiders ◽  
Predator Interference

Predator functional responses describe predator feeding rates and are a core component of predator-prey theory. Although originally defined as the relationship between predator feeding rates and prey densities, it is now well known that predator functional responses are shaped by a multitude of factors. Unfortunately, how these factors interact with one another remains unclear, as widely used laboratory methods for measuring functional responses are generally logistically constrained to examining a few factors simultaneously. Furthermore, it is also often unclear whether laboratory derived functional responses translate to field conditions. Our goal was to apply an observational approach for measuring functional responses to understand how sex/stage differences, temperature, and predator interference interact to influence the functional response of zebra jumping spiders on midges under natural conditions. We used field feeding surveys of jumping spiders to infer spider functional responses. We applied a Bayesian model averaging approach to estimate differences among sexes and stages of jumping spiders in their feeding rates and their dependencies on midge densities, temperature, and predator interference. We find that females exhibit the steepest functional responses on midges, followed by juveniles, and then males, despite males being larger than juveniles. We also find that sexes and stages differ in the temperature dependence of their space clearance (aka attack) rates. We find little evidence of temperature dependence in females, whereas we find some evidence for an increase in space clearance rate at high temperatures in males and juveniles. Interference effects on feeding rates were asymmetric with little effect of interference on male feeding rates, and effects of interference on females and juveniles depending on the stage/sex from which the interference originates. Our results illustrate the multidimensional nature of functional responses in natural settings and reveal how factors influencing functional responses can interact with one another through behavior and morphology. Further studies investigating the influence of multiple mechanisms on predator functional responses under field conditions will provide an increased understanding of the drivers of predator-prey interaction strengths and their consequences for communities and ecosystems.

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