Antipredator Behavior Research Articles

DYNAMICAL BEHAVIORS OF A STOCHASTIC PREDATOR-PREY MODEL WITH ANTI-PREDATOR BEHAVIOR

In this paper, a stochastic predator-prey model is proposed and studied, where the model has anti-predator behavior. By constructing a suitable Lyapunov function, combined with the Itô’s formula and the stochastic comparison theorem, the existence and uniqueness of the global positive solution of the system are proved. Then the stochastic boundedness of the system is established, and we discussed the asymptotic behavior of the solution which fluctuates around the equilibrium point of the deterministic model. Moreover, we provide sufficient conditions for the persistence and extinction of the predator and prey. Finally, the results obtained in this paper are verified by numerical simulation, and the anti-predator behavior and stochastic perturbation are analyzed as well.

A fishery predator-prey model with anti-predator behavior and complex dynamics induced by weighted fishing strategies

In this work, a fishery predator-prey model with anti-predator behavior is presented according to the anti-predator phenomenon in nature. On the basis of this model, a capture model guided by a discontinuous weighted fishing strategy is established. For the continuous model, it analyzes how anti-predator behavior affects system dynamics. On this basis, it discusses the complex dynamics (order-m periodic solution (m=1,2)) induced by a weighted fishing strategy. Besides, in order to find the capture strategy that maximizes the economic profit in the fishing process, this paper constructs an optimization problem based on the periodic solution of the system. Finally, all of the results of this study have been verified numerically in MATLAB simulation.

Analysis of a Holling-type IV stochastic prey-predator system with anti-predatory behavior and Lévy noise

<abstract><p>In this paper, we investigate a stochastic prey-predator model with Holling-type IV functional responses, anti-predatory behavior (referring to prey resistance to predator), gestation time delay of prey and Lévy noise. We investigate the existence and uniqueness of global positive solutions through Itô's formulation and Lyapunov's method. We also provide sufficient conditions for the persistence and extinction of prey-predator populations. Additionally, we examine the stability of the system distribution and validate our analytical findings through detailed numerical simulations. Our paper concludes with the implications of our results.</p></abstract>

The dynamics of a stage-structure prey-predator model with hunting cooperation and anti-predator behavior

The dynamics of a stage-structure prey-predator model with hunting cooperation and anti-predator behavior

Predator–prey ecological system with group defense and anti-predator traits of the preys: Synergies between two important ecological actions

During smart anti-predator adaptations, preys use their size, fleeing capability and herd in their evolutionary tug-of-war with the predators. Predator–prey ecology is teeming with such examples where predators can be defeated or even killed by the group of victims, that is, preys, banding together. In this paper, we focus on a stage-structured predator–prey model with herd behavior and anti-predator phenomenon that results in the lesser ecological opportunities for predation in the presence of the smart anti-predatory constraints. It is our purpose in this paper to illustrate the combined effects of the herd behavior and anti-predator strategy on the predator–prey ecology. By constructing the model equations, we present an analytical study of the system and the occurrence of Hopf and transcritical bifurcation for the anti-predator rate as a bifurcation parameter. Conditions for co-existence under global stable interior equilibrium as well as permanence region for the survival of all species is adequately discussed. Also, the extinction of predators is explored via numerical simulations, that is, the prey population survives successfully in the habitat due to their defense mechanism and anti-predator behavior. In order to better understand the role of anti-predator traits in predator–prey system with square root functional response, we compare the theoretical and numerical results of the proposed model with a similar predator–prey system having Holling type-I functional response. Our findings show that the predator–prey dynamics under prey’s herd behavior and anti-predator tactics can have large influence on shifting the paradigm of predator–prey relationship by turning the predator–prey dynamics into the prey dominant dynamics, which is indeed, due to the smart synergy between both ecological actions. When underdog, sticking together, fights back, that would be a headache to deal with, no matter how menacing the predator is.

Contribution of hunting cooperation and antipredator behavior to the dynamics of the harvested prey-predator system

Contribution of hunting cooperation and antipredator behavior to the dynamics of the harvested prey-predator system

Effects of ocean acidification and ocean warming on the behavior and physiology of a subarctic, intertidal grazer

The global ocean is expected to both acidify and warm concurrently; thus, multiple-stressor manipulative experimentation is an emergent area of study that ultimately aims to examine the individual and interactive effects of these factors on marine organisms. We characterized the physiological responses to acidification and warming of the intertidal grazer Lottia scutum, and examined how these ocean change variables influenced predator-prey dynamics with Evasterias troschelii, a key sea star predator. Specifically, we conducted a laboratory experiment where we exposed limpets to factorial combinations of temperature (11 and 15°C) and pH (7.6 and 8.0), and measured effects on thermal tolerance, metabolic rate, cortisol concentrations, and behavioral responses to the predator. We found that ocean warming (OW) decreased the critical thermal maxima (CTmax) and increased cortisol levels in L. scutum, whereas ocean acidification (OA) increased the mass-specific metabolic rate in this species. Additionally, we found that there was no significant effect of OA or OW on the anti-predator behavior of L. scutum when exposed to E. troschelii. These results highlight the need for future studies to integrate multidisciplinary experimental designs (i.e. behavior and physiology) that span multiple levels of biological organization to make ecologically relevant predictions for how marine organisms will respond to ocean change.

Stability and Hopf bifurcation in an eco-epidemiological system with the cost of anti-predator behaviors.

The fear effect is a powerful force in prey-predator interaction, eliciting a variety of anti-predator responses which lead to a reduction of prey growth rate. To study the impact of the fear effect on population dynamics of the eco-epidemiological system, we develop a predator-prey interaction model that incorporates infectious disease in predator population as well as the cost of anti-predator behaviors. Detailed mathematical results, including well-posedness of solutions, stability of equilibria and the occurrence of Hopf bifurcation are provided. It turns out that population density diminishes with increasing fear, and the fear effect can either destabilize the stability or induce the occurrence of periodic behavior. The theoretical results here provide a sound foundation for understanding the effect of the anti-predator behaviors on the eco-epidemiological interaction.

Mathematical model of evasion of immune system by virus

Virus needs to infect cells to spread the disease in the host and to achieve this, they have developed specific tactics to evade the immune system, which is in charge of trying to prevent any infection. In this way, we develop a mathematical model to represent the evasion of immune system by virus using a non-monotonic functional response describing an antipredator behavior, where the virus is the prey and the immune cells are the predator. We found four equilibrium points, the disease free equilibrium, immune evasion equilibrium and two immune activation equilibrium points. The disease free equilibrium is globally asymptotically stable if R0 ≤ 1, the immune evasion equilibrium and two immune activation equilibria are locally asymptotically stable if R0 >1. We conclude that in our model the evasion of immune system is always possible when there is a inoculation of virus in the host, but there is also a chance to control the infection or to activate the immune system when there are a cross-reactive antibodies.

Antipredatory call behavior of lapwing species in an Afrotropical environment

Predation is an important source of natural selection on prey species and has resulted in adaptations such as antipredator vocal signals, which can alert others to the presence of predators and solicit cooperative attack. Although vocal alarm signals of birds have been well studied, they are poorly known in tropical African species. To address this lack of information, the antipredatory signals and responses of two lapwings (Wattled Lapwing Vanellus senegallus and Spur-winged Lapwing Vanellus spinosus) to potential predators were investigated using data collected from focal observation, distance measurements, focal recordings, and playback experiment. The lapwing calls elicited to predators were classified as alarm or mobbing calls based on whether the calls elicited alert behavior or attack from other lapwings. Discriminant linear analysis (DLA) was used to compare the time and frequency parameters of the call types measured in Raven PRO. Also, lapwings’ responses to intruders, alert and start distance, time of day, and latency, as well as the effects of flock size and distance to cover were examined. About 48% of all calls was correctly classified by DLA. The best predictors of call type for the lapwings were maximum frequency and high frequency. Both alarm and mobbing calls were elicited by African Wattled Lapwings to dogs and humans. Mobbing calls were elicited to intruders by the Spur-winged Lapwings. Alert distance was positively associated with start distance, and differed between morning and evening in both lapwings. With scarce information from tropical Africa, this study put in perspective vocal and antipredator behavior of lapwing species in Africa.

Effects of Body Size and Condition on Antipredator Behavior Related to Nuchal Glands in Rhabdophis subminiatus

Effects of Body Size and Condition on Antipredator Behavior Related to Nuchal Glands in Rhabdophis subminiatus

I love to hate my neighbour: how recognition of dear enemies affects male antipredator behaviours in a lizard species

I love to hate my neighbour: how recognition of dear enemies affects male antipredator behaviours in a lizard species

Chick survival in a high-density Northern Lapwing (Vanellus vanellus) population on the river islets of the middle Pripyat River, Belarus

The field studies were conducted in three ephemeral river islets of the middle Pripyat River, southern Belarus in 2006–2007. Nestlings of the Northern Lapwing (Vanellus vanellus) were ringed soon after hatching, and reencountered during subsequent visits. Post-hatching survival was estimated by capture-mark-recapture models. Daily survival rates of the Northern Lapwing chicks were very high, varying between 0.90 and 0.99, and the cumulative survival rates over 35 days between hatching and fledging were 0.54 and 0.70 in 2006 and 2007, respectively. Survival rate was lower in the first ten days of life, which is similar to that reported in other precocial species. The key factor supporting this high breeding success is low predation due to nesting of lapwings on periodic river islets that naturally restrict access by mammalian predators and apparent scarcity of terrestrial and avian predators. River islet habitats with co-occurrence of dry and wet fertile microhabitats provide optimum feeding conditions for the Lapwing chicks with a wide range of aquatic, ground and surface invertebrates. Moreover, semicolonial breeding of the Northern Lapwing (about 30 nests/ha) with other waders, terns and gulls increases the effectiveness of anti-predator behaviour. Consequently as a result of low predation pressure and good foraging conditions, in 2006 and 2007, productivity was 2.1 and 2.8 fledged young per single nest with four chicks respectively, a value hardly reported in Europe, except in managed sites.

Infection with an acanthocephalan helminth reduces anxiety-like behaviour in crustacean host

Trophically transmitted heteroxenous parasites of diverse clades can decrease or reverse antipredator behaviours in their intermediate hosts, thereby increasing their chances of reaching their final hosts. Such behavioural alterations could result from compromised cognitive abilities affecting fear- or more generally stress-related neurophysiological pathways. We tested this hypothesis in a key model system in the study of parasitic manipulation, the fish acanthocephalan parasite Pomphorhynchus tereticollis and its intermediate crustacean host Gammarus fossarum, using the ‘threat of electric shock’ paradigm. We exposed uninfected and infected G. fossarum to chronic and/or acute electric shock programs at two different intensities (voltage), and then quantified their sheltering behaviour as a proxy for anxiety-like state. Infected gammarids did not express anxiety-like response to electric shocks, while uninfected gammarids hid more when exposed to acute treatments, and when exposed to the high intensity chronic treatment. Interestingly, the lack of response in infected gammarids depended on parasite developmental stage. Our results support the hypothesis that this acanthocephalan parasite impacts the general anxiety-like circuitry of their intermediate host. Further studies are needed to investigate whether it involves inappropriate processing of information, impaired integration, or altered activation of downstream pathways initiating behavioural action.

Complex dynamics of two prey–one predator model together with fear effect and harvesting efforts in preys

In this paper, a two prey–one predator model with different types of growth rate and mixed functional responses is proposed and analysed. Moreover, we considered anti-predation behaviour and constant harvesting effort in both the prey populations. The positivity and boundedness of the system are studied. The criteria for the extinction of the predator–prey populations are discussed. Analytically, we have studied the criteria for existence and stability of different equilibrium points. In addition, we have derived sufficient conditions for local bifurcations such as transcritical and Hopf bifurcation. We discussed that the effect of fear not only reduces prey populations, but also decreases the rate of growth of the predator population. Computer simulations are performed to validate our analytical results. The biological implications of analytical and numerical results are critically discussed.

Copper Exposure Affects Anti-Predatory Behaviour and Acetylcholinesterase Levels in Culex pipiens (Diptera, Culicidae).

Copper is an essential metal that occurs chronically in the environment and affects the development and physiology of aquatic insects. In excess amounts, it can impair their nervous system and behaviour. We tested the anti-predatory behaviour of Cx. pipiens larvae after seven days exposure with several concentrations of copper up to 500 mg L-1. We measured responses to non- consumptive (predation cues) and consumptive predation (dragonfly larvae) across two generations. We also tested the accumulated effect of copper on AChE enzyme activity. We exposed half of treated and control larvae to predation cues (water with predator odour and crushed conspecifics) and the other half to water without predation cues. We evaluated total distance moved and velocity. Copper reduced the distance moved and velocity, with stronger effects in the second generation. Copper had no significant effect on larvae eaten by dragonflies. Copper inhibited the AChE enzyme across both generations at 500 µg L-1. Copper can affect the nervous system directly by inhibiting AChE activity, and possibly also by impairing the olfaction sensors of the larvae, resulting in larval inability to detect predation cues.

Behavioural responses to chemical cues of predators differ between fire salamander larvae from two different habitats

AbstractPrey organisms need to detect predators and respond with adequate antipredator behaviours. To recognize predators, chemosensory cues play a pivotal role, particularly in aquatic ecosystems, where sight may be restricted. However, it is less known whether the ability to use these cues, enabling appropriate antipredator behaviour, varies between subpopulations occupying different habitats with different predation risks. We examined antipredator behaviour of wild‐caught larval fire salamanders (Salamandra salamandra) from two different habitats, ponds and streams. Ponds and streams are inhabited by habitat‐specific predators, such as alpine newts (Ichthyosaura alpestris), which only occur in ponds. We confronted larvae from both habitats with either tap water (control) or tap water that had contained alpine newts (newt treatment) and investigated potential behavioural differences in activity and shelter emergence. In the activity test, pond larvae, but not stream larvae, were significantly less active when faced with chemical cues (potentially kairomones) from newts than those faced with a control stimulus, but stream larvae generally exhibited significantly lower activity than pond larvae. In the shelter‐emergence test, larvae from both habitats spent significantly less time outside a shelter in the newt treatment than in control water. This suggests that larval fire salamanders, independent of their habitat, recognize chemical cues from potential predators and alter their behaviour accordingly. Larvae of both habitats were able to detect and use chemical cues released from potential predators, but they differed slightly in their response to these chemical cues. This finding reflects varying antipredator strategies in response to the habitat‐specific differences.

Social dynamics impact scolding behaviour in captive groups of common ravens (Corvus corax)

BackgroundPredator avoidance can have immense impacts on fitness, yet individual variation in the expression of anti-predator behaviour remains largely unexplained. Existing research investigating learning of novel predators has focused either on individuals or groups, but not both. Testing in individual settings allows evaluations of learning or personality differences, while testing in group settings makes it impossible to distinguish any such individual differences from social dynamics. In this study, we investigate the effect of social dynamics on individual anti-predator behaviour. We trained 15 captive ravens to recognize and respond to a novel experimental predator and then exposed them to this predator in both group and isolation settings across 1.5 years to tease apart individual differences from social effects and evaluate two hypotheses: (1) weaker anti-predator responses of some individuals in the group occurred, because they failed to recognize the experimental predator as a threat, leading to weak responses when separated, or (2) some individuals had learned the new threat, but their scolding intensity was repressed in the group trials due to social dynamics (such as dominance rank), leading to increased scolding intensity when alone.ResultsWe found that dominance significantly influences scolding behaviour in the group trials; top-ranked individuals scold more and earlier than lower ranking ones. However, in the separation trials scolding duration is no longer affected by rank.ConclusionsWe speculate that, while top-ranked individuals use their anti-predator responses to signal status in the group, lower-ranking ravens may be suppressed from, or are less capable of, performing intense anti-predator behaviour while in the group. This suggests that, in addition to its recruitment or predator-deterrent effects, alarm calling may serve as a marker of individual quality to conspecifics.

Memory effect on prey–predator dynamics: Exploring the role of fear effect, additional food and anti-predator behaviour of prey

Memory over past events has great importance on the survival of species in an ecological system. It is helpful in searching favourite food, escaping from predator attacks, group defence, use of environmental protection in the future time for the species. To explore the role of different ecological effects like fear effect, additional food and anti-predator behaviour of prey in the presence memory on an ecological system, in this paper we have proposed a two-dimensional prey–predator model and formulated mathematically using a system of two fractional order differential equations. Here the Caputo sense fractional derivative is used to construct the fractional order differential equations. The existence–uniqueness, non-negativity and boundedness of system solutions have been established. The detailed mathematical and graphical analysis for the feasibility of different equilibrium points and their analytical conditions for local asymptotic stability has been studied. The sufficient parametric conditions for the global stability of non-trivial equilibrium points are investigated. The Hopf bifurcation analysis of the system around the coexistence equilibrium point is derived in terms of system parameters. Using numerical simulations we have established that the memory effect can stabilize the system from an unstable periodic situation and makes the above-considered ecological effects more positively effective.

How local antipredator response unbalances the rock-paper-scissors model.

Antipredator behavior is a self-preservation strategy present in many biological systems, where individuals join the effort in a collective reaction to avoid being caught by an approaching predator. We study a nonhierarchical tritrophic system, whose predator-prey interactions are described by the rock-paper-scissors game rules. We perform a set of spatial stochastic simulations where organisms of one out of the species can resist predation in a collective strategy. The drop in predation capacity is local, which means that each predator faces a particular opposition depending on the prey group size surrounding it. Considering that the interference in a predator action depends on the prey's physical and cognitive ability, we explore the role of a conditioning factor that indicates the fraction of the species apt to perform the antipredator strategy. Because of the local unbalancing of the cyclic predator-prey interactions, departed spatial domains mainly occupied by a single species emerge. Unlike the rock-paper-scissors model with a weak species because of a nonlocal reason, our findings show that if the predation probability of one species is reduced because individuals face local antipredator response, the species does not predominate. Instead, the local unbalancing of the rock-paper-scissors model results in the prevalence of the weak species' prey. Finally, the outcomes show that local unevenness may jeopardize biodiversity, with the coexistence being more threatened for high mobility.