Prey Strategies Research Articles

Predation Fear, Prey Behavior, and Community Structure: A Brief Review of Their Relationship

Predation Fear, Prey Behavior, and Community Structure: A Brief Review of Their Relationship Hamenya Mpemba, Henry Karanja, Guangshun Jiang Abstract The main aim of this research is to review the relationship between predation fear, prey behavior, and community structure or assembly. The relationship between prey and predator is shaped around the risk of predation. A non-consumptive impact of predators on their prey seems to be more extensive and diverse, with significant consequences for community structure and function of the ecosystem. Predators have a strong direct and indirect effect on ecological communities by intimidating their prey. Ecological context including habitat structure and identity of species have influenced the strength and nature of non-consumptive effects and hence it may alter the outcome of intimidation of predator. Further, this study uses secondary data collection methods. The relationship between predation fear and aging behavior of prey, reproduction behavior of prey and territorial defense strategies of prey are detailed in the prior literature review. Since a wide range of wildlife is under existential crisis especially the predators, there is a need to understand the predator-prey relation. In the future, this work can be detailed by collecting the primary data source through a quantitative approach among various investigators. Full Text: PDF DOI: 10.15640/aijb.v7n1a1

Fear effect in prey and hunting cooperation among predators in a Leslie-Gower model.

The predation strategy for predators and the avoidance strategy of prey are important topics in ecology and evolutionary biology. Both prey and predators adjust their behaviours in order to gain the maximal benefits and to increase their biomass for each. In the present paper, we consider a modified Leslie-Gower predator-prey model where predators cooperate during hunting and due to fear of predation risk, prey populations show anti-predator behaviour. We investigate step by step the impact of hunting cooperation and fear effect on the dynamics of the system. We observe that in the absence of fear effect, hunting cooperation can induce both supercritical and subcritical Hopf- bifurcations. It is also observed that fear factor can stabilize the predator-prey system by excluding the existence of periodic solutions and makes the system more robust compared to hunting cooperation. Moreover, the system shows two different types of bi-stabilities behaviour: one is between coexisting equilibrium and limit cycle oscillation, and another is between prey-free equilibrium and coexisting equilibrium. We also observe generalized Hopf-bifurcation and Bogdanov-Takens bifurcation in two parameter bifurcation analysis. We perform extensive numerical simulations for supporting evidence of our analytical findings.

Adaptive predator–prey optimization for tuning of infinite horizon LQR applied to vehicle suspension system

This paper puts forward an adaptive predator–prey optimization algorithm to solve the weight selection problem of linear quadratic control applied for vibration control of vehicle suspension system. The proposed technique addresses the two key issues of PSO, namely (a) the premature convergence of the particles, and (b) the imbalance between exploration and exploitation of the particles in finding the global optimum. The main principle behind this optimization algorithm is that the inertia weight is adaptively updated based on the success rate of the particles to increase the convergence, and the predator–prey strategy is reinforced to avoid the particles getting trapped in a local minimum thereby, guaranteeing convergence of the particles towards the global optimal solution. The convergence of the particles towards the global minimum is guaranteed on the basis of a passivity argument. Moreover, the strength of this new adaptive optimization technique to tune the gains of linear quadratic regulator is validated experimentally on a laboratory scale active vehicle suspension system for improved ride comfort and passenger safety.

Chemical encoding of risk perception and predator detection among estuarine invertebrates

An effective strategy for prey to survive in habitats rich in predators is to avoid being noticed. Thus, prey are under selection pressure to recognize predators and adjust their behavior, which can impact numerous community-wide interactions. Many animals in murky and turbulent aquatic environments rely on waterborne chemical cues. Previous research showed that the mud crab, Panopeus herbstii, recognizes the predatory blue crab, Callinectus sapidus, via a cue in blue crab urine. This cue is strongest if blue crabs recently preyed upon mud crabs. Subsequently, mud crabs suppress their foraging activity, reducing predation by blue crabs. Using NMR spectroscopy- and mass spectrometry-based metabolomics, chemical variation in urine from blue crabs fed different diets was related to prey behavior. We identified the urinary metabolites trigonelline and homarine as components of the cue that mud crabs use to detect blue crabs, with concentrations of each metabolite dependent on the blue crab's diet. At concentrations found naturally in blue crab urine, trigonelline and homarine, alone as well as in a mixture, alerted mud crabs to the presence of blue crabs, leading to decreased foraging by mud crabs. Risk perception by waterborne cues has been widely observed by ecologists, but the molecular nature of these cues has not been previously identified. Metabolomics provides an opportunity to study waterborne cues where other approaches have historically failed, advancing our understanding of the chemical nature of a wide range of ecological interactions.

Social transmission of avoidance among predators facilitates the spread of novel prey.

Warning signals are an effective defence strategy for aposematic prey, but only if they are recognized by potential predators. If predators must eat prey to associate novel warning signals with unpalatability, how can aposematic prey ever evolve? Using experiments with great tits (Parus major) as predators, we show that social transmission enhances the acquisition of avoidance by a predator population. Observing another predator's disgust towards tasting one novel conspicuous prey item led to fewer aposematic than cryptic prey being eaten for the predator population to learn. Despite reduced personal encounters with unpalatable prey, avoidance persisted and increased over subsequent trials. Next we use a mathematical model to show that social transmission can shift the evolutionary trajectory of prey populations from fixation of crypsis to fixation of aposematism more easily than was previously thought. Therefore, social information use by predators has the potential to have evolutionary consequences across ecological communities.

Collective strategies and cyclic dominance in asymmetric predator-prey spatial games

Predators may attack isolated or grouped prey in a cooperative, collective way. Whether a gregarious behavior is advantageous to each species depends on several conditions and game theory is a useful tool to deal with such a problem. We here extend the Lett et al. (2004) to spatially distributed populations and compare the resulting behavior with their mean-field predictions for the coevolving densities of predator and prey strategies. Besides its richer behavior in the presence of spatial organization, we also show that the coexistence phase in which collective and individual strategies for each group are present is stable because of an effective, cyclic dominance mechanism similar to a well-studied generalization of the Rock-Paper-Scissors game with four species, a further example of how ubiquitous this coexistence mechanism is.

Multi-objective mean–variance–skewness model for nonconvex and stochastic optimal power flow considering wind power and load uncertainties

This paper presents a multi-objective mean–variance–skewness (MVS) model for reliably assessing the problem of nonconvex and stochastic optimal power flow (NSOPF), considering valve-point effect, stochastic load and uncertain integrated wind power. The MVS model aims to maximize both the expected return and skewness while simultaneously minimizing the risk, which is formulated as a competing and conflicting three-objective optimization problem. Based on such a model, we propose a multi-objective optimization algorithm, multiple preys based evolutionary predator and prey strategy (MPEPPS), to provide Pareto solutions, which show the trade-off relationship among the expected return, the skewness and the risk of the dispatching objective. Subsequently, a multi-criteria decision making method, the technique for order preference by similarity to an ideal solution (TOPSIS), is applied for determining the final dispatch solution. The objective of this paper is to develop a reliable model to assess the NSOPF from the perspective of economics and reliability of power system operation, and propose an efficient algorithm to obtain a solution that considers all of the possible load and wind power simultaneously. Simulation results based on a modified IEEE 30-bus power system demonstrate the reliability and effectiveness of the MVS and MPEPPS in solving NSOPF.

A faster escape does not enhance survival in zebrafish larvae.

An escape response is a rapid manoeuvre used by prey to evade predators. Performing this manoeuvre at greater speed, in a favourable direction, or from a longer distance have been hypothesized to enhance the survival of prey, but these ideas are difficult to test experimentally. We examined how prey survival depends on escape kinematics through a novel combination of experimentation and mathematical modelling. This approach focused on zebrafish (Danio rerio) larvae under predation by adults and juveniles of the same species. High-speed three-dimensional kinematics were used to track the body position of prey and predator and to determine the probability of behavioural actions by both fish. These measurements provided the basis for an agent-based probabilistic model that simulated the trajectories of the animals. Predictions of survivorship by this model were found by Monte Carlo simulations to agree with our observations and we examined how these predictions varied by changing individual model parameters. Contrary to expectation, we found that survival may not be improved by increasing the speed or altering the direction of the escape. Rather, zebrafish larvae operate with sufficiently high locomotor performance due to the relatively slow approach and limited range of suction feeding by fish predators. We did find that survival was enhanced when prey responded from a greater distance. This is an ability that depends on the capacity of the visual and lateral line systems to detect a looming threat. Therefore, performance in sensing, and not locomotion, is decisive for improving the survival of larval fish prey. These results offer a framework for understanding the evolution of predator-prey strategy that may inform prey survival in a broad diversity of animals.

Risk-aware short term hydro-wind-thermal scheduling using a probability interval optimization model

Due to the uncertainty of wind power and complex constraints of available hydro, short term hydro-wind-thermal scheduling (HWTS) is one of the most difficult optimization problems in the operational planning of power systems. This paper presents a risk-aware optimization model, named probability interval optimization (PIO), to reliably evaluate the HWTS from the perspective of risk and profit. In PIO, the uncertain wind power is deemed as a probability interval variable, the risk of wind power is assessed by its probability distribution, and the profit is manifested by the decrease of generation cost between the same system with and without wind power integrated. For solving the PIO model, an evolutionary predator and prey strategy (EPPS) is proposed in this paper. The EPPS focuses on dynamically adjusting the algorithm’s exploration and exploitation abilities by introducing an escaping mechanism and a classification mechanism. In addition, a heuristic repair mechanism, instead of penalty function approach, is applied to handle the complex equality and inequality constraints of HWTS. Simulation studies based on three HWTS systems demonstrate that the risk-aware PIO model is well reliable and applicable to solve HWTS considering the uncertain wind power integrated, the EPPS algorithm can obtain superior solutions in comparison with other recently developed algorithms, and the heuristic repair mechanism is efficient for dealing with complex constraints of HWTS.

Differential behavioural flexibility in response to predation risk in native and introduced tropical savannah rodents

Differential predation risk between habitats, or ‘the landscape of fear’, can have profound impacts on foraging strategies of prey. Few studies, however, have described the landscape of fear in the wild, in relation to predator densities. Using giving-up density experiments, and vertebrate surveys, we described the landscape of fear for two rodent species in relation to actual predator abundances in a tropical savannah. We offered native eastern chestnut mice, Pseudomys gracilicaudatus, and introduced house mice, Mus musculus domesticus, food in the open, and under the cover of grass. When eastern brown snakes, Pseudonaja textilis, were absent, both eastern chestnut and house mice consumed more food items under grass. In habitats where snakes were abundant, however, eastern chestnut mice changed their foraging behaviour, and consumed more food items in the open than under grass. In contrast, non-native house mice reduced their foraging activity under cover, but showed no increase in foraging in the open in the presence of snakes. Thus, native eastern chestnut mice have the ability to change their foraging tactics to adjust their antipredator behaviour to remain successful in the presence of native eastern brown snakes, whereas introduced house mice did not exhibit this behaviour.

Limited spatial response to direct predation risk by African herbivores following predator reintroduction.

Predators affect ecosystems not only through direct mortality of prey, but also through risk effects on prey behavior, which can exert strong influences on ecosystem function and prey fitness. However, how functionally different prey species respond to predation risk and how prey strategies vary across ecosystems and in response to predator reintroduction are poorly understood. We investigated the spatial distributions of six African herbivores varying in foraging strategy and body size in response to environmental factors and direct predation risk by recently reintroduced lions in the thicket biome of the Addo Elephant National Park, South Africa, using camera trap surveys, GPS telemetry, kill site locations and Light Detection and Ranging. Spatial distributions of all species, apart from buffalo, were driven primarily by environmental factors, with limited responses to direct predation risk. Responses to predation risk were instead indirect, with species distributions driven by environmental factors, and diel patterns being particularly pronounced. Grazers were more responsive to the measured variables than browsers, with more observations in open areas. Terrain ruggedness was a stronger predictor of browser distributions than was vegetation density. Buffalo was the only species to respond to predator encounter risk, avoiding areas with higher lion utilization. Buffalo therefore behaved in similar ways to when lions were absent from the study area. Our results suggest that direct predation risk effects are relatively weak when predator densities are low and the time since reintroduction is short and emphasize the need for robust, long‐term monitoring of predator reintroductions to place such events in the broader context of predation risk effects.

Simple assumptions predicts prey selection by piscivorous fishes

Studies on trophic interactions permits the use of community-wide network analyses to evaluate the consequences of human interventions in natural communities. In this paper, we aimed to get insights into the underlying mechanism of prey selection for four piscivorous species, and evaluate behavioral responses to prey selection after an impoundment. We assemble six food web models to search for the hypothesis that best predict observed prey selection pattern of piscivorous fishes combining the following assumptions: (i) predation window, defined as the size range of prey species consumed by a piscivorous fish; (ii) prey strategies to avoid predation (iii) and prey abundance. We tested the probability of each hypothesis to reproduce two empirical data, one before and one after an impoundment with minimum assumptions. Before impoundment, we found that predators presented switching behavior, preying preferably on abundant prey; while after impoundment, predators consumed prey within its predation window. Those results explained better than the null hypotesis and all other assumptions; and corroborate with both theoretical and empirical studies. We conclude that different assumptions drives piscivorous fish behavior in different environments; and modelling procedures can be used to assess gaps in trophic interactions of fish communities.

The effects of steady swimming on fish escape performance

Escape maneuvers are essential to the survival and fitness of many animals. Escapes are frequently initiated when an animal is already in motion. This may introduce constraints that alter the escape performance. In fish, escape maneuvers and steady, body caudal fin (BCF) swimming are driven by distinct patterns of curvature of the body axis. Pre-existing muscle activity may therefore delay or diminish a response. To quantify the performance consequences of escaping in flow, escape behavior was examined in bluegill sunfish (Lepomis macrochirus) in both still-water and during steady swimming. Escapes executed during swimming were kinematically less variable than those made in still-water. Swimming escapes also had increased response latencies and lower peak velocities and accelerations than those made in still-water. Performance was also lower for escapes made up rather than down-stream, and a preference for down-stream escapes may be associated with maximizing performance. The constraints imposed by pre-existing motion and flow, therefore, have the potential to shape predator-prey interactions under field conditions by shifting the optimal strategies for both predators and prey.

Directional escape strategy by the striped plateau lizard (Sceloporus virgatus): turning to direct escape away from predators at variable escape angles

A prey’s orientation to a predator’s approach path affects risk of fleeing straight ahead. By turning to flee closer to straight away from the predator before fleeing, prey can reduce risk. Laboratory studies suggest that escape angles should lead away from predators and be unpredictable. I studied orientation, turn, and escape angles and in a study of striped plateau lizards,Sceloporus virgatus. Lizards fled away from a predator, but often not straight away. Escape angles were variable and bimodally distributed: one mode was straight away for distancing prey from predator and one was near 90°, which maintains ability to monitor the predator or requires turning by the predator. Turn angles increased as orientation shifted toward the predator. Escape angle was closer to straight away when turn angle was larger, but turning did not fully compensate for degree of orientation toward the predator. Directional escape strategies of diverse prey are compared.

Conservation implications of harpy eagle Harpia harpyja predation patterns

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 29:69-79 (2015) - DOI: https://doi.org/10.3354/esr00700 Conservation implications of harpy eagle Harpia harpyja predation patterns Everton B. P. Miranda* Programa de Pós-graduação em Ecologia e Conservação da Biodiversidade, Universidade Federal do Mato Grosso, Av. Fernando Corrêa da Costa, no. 2367 - Bairro Boa Esperança, Cuiabá - MT, CEP 78060-900, Brazil *Corresponding author: mirandaebp@gmail.com ABSTRACT: Knowledge of the food habits of threatened taxa is key for their effective conservation, especially in top predators where prey species are frequently also hunted by humans. The harpy eagle Harpia harpyja is the largest living eagle, and is considered Near Threatened by the IUCN. Its main threats are persecution by humans and habitat loss. Predation patterns of this species have been the subject of several descriptive studies, each reflecting the idiosyncrasies of the study area. Systematizing these data permits a transition from descriptive treatments of harpy food habits to a predictive focus, based on defensive prey strategies and foraging theory. This generates information that can enhance management and conservation decisions. Literature data were summarized and standardized, allowing comparison between studies. Results indicate that harpy eagles feed mainly on sloths and other prey with passive antipredator strategies, with sloths accounting for 50% of prey items and biomass consumed. Large monkeys such as howlers (Alouatta spp.) and capuchins (Sapajus and Cebus spp.) are the next most important prey, but combined, primates form only ~20% of the consumed prey biomass. Predation seldom occurs on animals weighing more than 5 kg. This is positive from a conservation point of view, since sloths are not game species, precluding competition between harpy eagles and subsistence hunting. KEY WORDS: Raptor · Bradypus · Choloepus · Alouatta · Prey defenses · Top predator · Diet Full text in pdf format PreviousNextCite this article as: Miranda EBP (2015) Conservation implications of harpy eagle Harpia harpyja predation patterns. Endang Species Res 29:69-79. https://doi.org/10.3354/esr00700 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 29, No. 1. Online publication date: November 25, 2015 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2015 Inter-Research.

Evolutionary predator and prey strategy for global optimization

This paper presents a novel evolutionary predator and prey strategy (EPPS) for global optimization. The EPPS is based on a dynamic predator-prey model stemmed from the study of animal group living behaviors. In the model, concepts of experienced predators, strategic predators, the prey and its safe location are developed to simulate three typical animal behaviors: scanning, hunting and escaping. To validate the applicability and practicability of EPPS, experiments were undertaken on a set of 20 benchmark functions and three real-world problems, respectively. The results show that EPPS has a more superior performance in comparison with other recently developed methods reported in the literature.

Mass enhances speed but diminishes turn capacity in terrestrial pursuit predators.

The dynamics of predator-prey pursuit appears complex, making the development of a framework explaining predator and prey strategies problematic. We develop a model for terrestrial, cursorial predators to examine how animal mass modulates predator and prey trajectories and affects best strategies for both parties. We incorporated the maximum speed-mass relationship with an explanation of why larger animals should have greater turn radii; the forces needed to turn scale linearly with mass whereas the maximum forces an animal can exert scale to a 2/3 power law. This clarifies why in a meta-analysis, we found a preponderance of predator/prey mass ratios that minimized the turn radii of predators compared to their prey. It also explained why acceleration data from wild cheetahs pursuing different prey showed different cornering behaviour with prey type. The outcome of predator prey pursuits thus depends critically on mass effects and the ability of animals to time turns precisely.

A predicted protein interactome identifies conserved global networks and disease resistance subnetworks in maize

Interactomes are genome-wide roadmaps of protein-protein interactions. They have been produced for humans, yeast, the fruit fly, and Arabidopsis thaliana and have become invaluable tools for generating and testing hypotheses. A predicted interactome for Zea mays (PiZeaM) is presented here as an aid to the research community for this valuable crop species. PiZeaM was built using a proven method of interologs (interacting orthologs) that were identified using both one-to-one and many-to-many orthology between genomes of maize and reference species. Where both maize orthologs occurred for an experimentally determined interaction in the reference species, we predicted a likely interaction in maize. A total of 49,026 unique interactions for 6004 maize proteins were predicted. These interactions are enriched for processes that are evolutionarily conserved, but include many otherwise poorly annotated proteins in maize. The predicted maize interactions were further analyzed by comparing annotation of interacting proteins, including different layers of ontology. A map of pairwise gene co-expression was also generated and compared to predicted interactions. Two global subnetworks were constructed for highly conserved interactions. These subnetworks showed clear clustering of proteins by function. Another subnetwork was created for disease response using a bait and prey strategy to capture interacting partners for proteins that respond to other organisms. Closer examination of this subnetwork revealed the connectivity between biotic and abiotic hormone stress pathways. We believe PiZeaM will provide a useful tool for the prediction of protein function and analysis of pathways for Z. mays researchers and is presented in this paper as a reference tool for the exploration of protein interactions in maize.

Stochastic eco-evolutionary model of a prey-predator community

We are interested in the impact of natural selection in a prey-predator community. We introduce an individual-based model of the community that takes into account both prey and predator phenotypes. Our aim is to understand the phenotypic coevolution of prey and predators. The community evolves as a multi-type birth and death process with mutations. We first consider the infinite particle approximation of the process without mutation. In this limit, the process can be approximated by a system of differential equations. We prove the existence of a unique globally asymptotically stable equilibrium under specific conditions on the interaction among prey individuals. When mutations are rare, the community evolves on the mutational scale according to a Markovian jump process. This process describes the successive equilibria of the prey-predator community and extends the polymorphic evolutionary sequence to a coevolutionary framework. We then assume that mutations have a small impact on phenotypes and consider the evolution of monomorphic prey and predator populations. The limit of small mutation steps leads to a system of two differential equations which is a version of the canonical equation of adaptive dynamics for the prey-predator coevolution. We illustrate these different limits with an example of prey-predator community that takes into account different prey defense mechanisms. We observe through simulations how these various prey strategies impact the community.

When Optimal Strategy Matters to Prey Fish.

Predator-prey interactions are commonly studied with an interest in determining the optimal strategy for prey. However, the implications of deviating from optimal strategy are often unclear. The present study considered these consequences by studying how the direction of an escape response affects the strategy of prey fish. We simulated these interactions with numerical and analytical mathematics and compared our predictions with measurements in zebrafish larvae (Danio rerio), which are preyed upon by adults of the same species. Consistent with existing theory, we treated the minimum distance between predator and prey as the strategic payoff that prey aim to maximize. We found that these interactions may be characterized by three strategic domains that are defined by the speed of predator relative to the prey. The "fast predator" domain occurs when the predator is more than an order of magnitude faster than the prey. The escape direction of the prey had only a small effect on the minimum distance under these conditions. For the "slow predator" domain, when the prey is faster than the predator, we found that differences in direction had no effect on the minimum distance for a broad range of escape angles. This was the regime in which zebrafish were found to operate. In contrast, the optimal escape angle offers a large benefit to the minimum distance in the intermediate strategic domain. Therefore, optimal strategy is most meaningful to prey fish when predators are faster than prey by less than a factor of 10. This demonstrates that the strategy of a prey animal does not matter under certain conditions that are created by the behavior of the predator.