Prey Behavior Research Articles

On the importance of concomitant conditions: Light and conspecific presence modulate prey response to predation cue.

Assessment of individual costs of the anti-predator defence translating into changes in population parameters is meagre. This is because prey responses are likely to be modulated by additional factors, commonly present in the environment, but often neglected in experimental studies. To evaluate the effect of external factors on prey behavior and physiology, we exposed amphipods Dikerogammarus villosus and Gammarus jazdzewskii to the predation cue of Perca fluviatilis in different densities and light conditions. Singletons of both species exposed to the predation cue in light modified their oxygen consumption (D. villosus: reduction, G. jadzewskii: increase) compared to their respiration in predator-free conditions. However, in the presence of conspecifics or in darkness, their respiration became insensitive to the predation cue. On the other hand, the swimming activity of prey was reduced in the presence of the predation cue irrespective of prey density and light conditions, but singletons were consistently more active than groups. Thus, external factors, such as conspecifics and darkness, constantly or periodically occurring in the field, may reduce the costs of predator non-consumptive effects compared to the costs measured under laboratory conditions (in light or absence of conspecifics). Moreover, we showed that behavioral and physiological parameters of prey may change differently in response to predation risk. Thus, conclusions drawn on the basis of single defence mechanisms and/or results obtained in artificial conditions, not reflecting the environmental complexity, strongly depend on the experimental design and endpoint selection and therefore should be treated with care.

Metacommunity stability and persistence for predation turnoff in selective patches

Predation as an important trophic interaction of ecological communities controls the large-scale patterns of species distribution, population abundance and community structure. Numerous studies address that predation can mediate diversity and regulate the ecological community and food web stability through changes in the behavior, morphology, development, and abundance of prey. Since predation has large effects on persistence and diversity, the local loss or removal of predation in a community can trigger a cascade of extinctions. In ecological theory, the effect of predation removal has been well studied in foodwebs, but it remains unclear in the case of a spatially distributed community connected by dispersal. In this study, the interaction between local and spatial processes is taken into account, we present how a predation turnoff in selective patches affects the synchronized oscillatory dynamics of a metacommunity. Using a simple predator–prey metacommunity with a diffusive dispersal, we show the impact of predation on synchronized, asynchronized and source–sink dynamics. Our results reveal that predation turnoff in very few patches stabilizes the metacommunity by damping the perfectly synchronized oscillatory state into multicluster equilibrium (i.e., steady) states. In a source–sink behavior, predation turnoff in a source patch reduces the number of sink patches and changes the clusters. In general, predation turnoff in low number of patches shows non-zero equilibrium states in both prey and predator populations, whereas predation turnoff in a larger number of patches can lead to the complete extinction of predators. Moreover, prey density from the patches where predation is absent goes to a saturating state near the carrying capacity. Thus, this study stresses that predation turnoff in selective patches acts as a stabilizing mechanism to promote the metacommunity persistence.

Should I stay or should I go: escape behaviour of Russell’s vipers, Daboia russelii (Shaw & Nodder, 1797) in India’s agricultural landscapes

Abstract Predation exerts a strong selective force on prey, and hence prey species have evolved a multitude of ways to escape predation. One strategy by which many mobile species escape predation is by fleeing when approached by predators. However, fleeing too early can have fitness costs. Thus, optimal escape theory suggests that escape behaviour in prey depends on the risk of being eaten and the fleeing costs. Several studies on mammals, birds and lizards lend support to this hypothesis. However, few studies have explored escape behaviour in snakes. Here, using radio telemetry to track snakes in the field, we study the escape behaviour in Russell’s vipers, a highly venomous and cryptic snake, responsible for the highest number of snakebite deaths in India. We show that escape response, i.e., the decision to stay or flee, was influenced by intrinsic factors such as the snake’s behaviour and body temperature. We also show that the flight initiation distance, the distance at which the snake flees, was mostly determined by habitat selection, i.e., the visibility of the snake and the distance to the nearest cover. Overall, we show that different factors could determine the decision to flee and when to flee. We also highlight how understanding escape response in such highly venomous, medically important yet secretive snakes could potentially help reduce human-snake encounters and mitigate the snakebite crisis.

Modeling prey behavior in response to fear of predation

Fractional-order differential equations allow for a more detailed and accurate model of prey-predator system

Dynamical behavior of a fractional-order prey–predator model with infection and harvesting

Dynamical behavior of a fractional-order prey–predator model with infection and harvesting

Fire as a driver and mediator of predator-prey interactions.

ABSTRACTBoth fire and predators have strong influences on the population dynamics and behaviour of animals, and the effects of predators may either be strengthened or weakened by fire. However, knowledge of how fire drives or mediates predator–prey interactions is fragmented and has not been synthesised. Here, we review and synthesise knowledge of how fire influences predator and prey behaviour and interactions. We develop a conceptual model based on predator–prey theory and empirical examples to address four key questions: (i) how and why do predators respond to fire; (ii) how and why does prey vulnerability change post‐fire; (iii) what mechanisms do prey use to reduce predation risk post‐fire; and (iv) what are the outcomes of predator–fire interactions for prey populations? We then discuss these findings in the context of wildlife conservation and ecosystem management before outlining priorities for future research. Fire‐induced changes in vegetation structure, resource availability, and animal behaviour influence predator–prey encounter rates, the amount of time prey are vulnerable during an encounter, and the conditional probability of prey death given an encounter. How a predator responds to fire depends on fire characteristics (e.g. season, severity), their hunting behaviour (ambush or pursuit predator), movement behaviour, territoriality, and intra‐guild dynamics. Prey species that rely on habitat structure for avoiding predation often experience increased predation rates and lower survival in recently burnt areas. By contrast, some prey species benefit from the opening up of habitat after fire because it makes it easier to detect predators and to modify their behaviour appropriately. Reduced prey body condition after fire can increase predation risk either through impaired ability to escape predators, or increased need to forage in risky areas due to being energetically stressed. To reduce risk of predation in the post‐fire environment, prey may change their habitat use, increase sheltering behaviour, change their movement behaviour, or use camouflage through cryptic colouring and background matching. Field experiments and population viability modelling show instances where fire either amplifies or does not amplify the impacts of predators on prey populations, and vice versa. In some instances, intense and sustained post‐fire predation may lead to local extinctions of prey populations. Human disruption of fire regimes is impacting faunal communities, with consequences for predator and prey behaviour and population dynamics. Key areas for future research include: capturing data continuously before, during and after fires; teasing out the relative importance of changes in visibility and shelter availability in different contexts; documenting changes in acoustic and olfactory cues for both predators and prey; addressing taxonomic and geographic biases in the literature; and predicting and testing how changes in fire‐regime characteristics reshape predator–prey interactions. Understanding and managing the consequences for predator–prey communities will be critical for effective ecosystem management and species conservation in this era of global change.

Urbanization affects the behavior of a predator-free ungulate in protected lands

Natural habitats have been converted to urban areas across the globe such that many landscapes now represent matrices of developed and protected lands. As urbanization continues to expand, associated pressures on wildlife will increase, including effects on animals in adjacent protected habitats. For prey species (e.g., ungulates), an understanding of the ecological impacts of urbanization is typically confounded by coincident effects from co-occurring predators. Yet, understanding how urbanization affects prey behaviors in the absence of predators is becoming increasingly relevant as many top predators face extirpation. We placed camera traps at varying distances from urban areas within protected areas in the Florida Keys, USA, to evaluate the influence of urbanization on the behavior of the key deer (Odocoileus virginianus clavium), an endangered species that has been without non-human mammalian predators for ∼ 4000 years. We predicted that as distance to urban areas decreased, key deer would use sites at the same rate, exhibit bigger group sizes, and shift activity patterns to be more nocturnal. Our results indicate that intensity of site use decreased with proximity to urban areas, potentially reflecting human avoidance. Group size increased closer to urban areas, consistent with other studies relating this behavior to anthropogenic subsidies and vigilance for humans. Activity patterns changed but did not become more nocturnal near urban areas as predicted by global analyses relating human disturbance to wildlife nocturnality. Our results have important implications for ungulate behavioral ecology and, taken together, suggest that influences on protected species from adjacent land uses are an important consideration when planning land use and designing protected areas.

A delay nonautonomous model for the effects of fear and refuge on predator–prey interactions with water-level fluctuations

The interaction of prey (small fish) and predator (large fish) in lakes/ ponds at temperate and tropical regions varies when water level fluctuates naturally during seasonal time. We relate the perceptible effect of fear and anti-predator behavior of prey with the water-level fluctuations and describe how these are influenced by the seasonal changing of water level. So, we consider these as time-dependent functions to make the system more realistic. Also, we incorporate the time-dependent delay in the negative growth rate of prey in predator–prey model with Crowley–Martin-type functional response. We clearly provide the basic dynamics of the system such as positiveness, permanence and nonpersistence. The existence of positive periodic solution is studied using Continuation theorem, and suffiecient conditions for globally attractivity of positive periodic solution are also derived. To make the system more comprehensive, we establish numerical simulations, and compare the dynamics of autonomous and nonautonomous systems in the absence as well as the presence of time delay. Our results show that seasonality and time delay create the occurrence of complex behavior such as prevalence of chaotic disorder which can be potentially suppressed by the cost of fear and prey refuge. Also, if time delay increases, then system leads a boundary periodic solution. Our findings assert that the predation, fear of predator and prey refuge are correlated with water-level variations, and give some reasonable biological interpretations for persistence as well as extinction of species due to water-level variations.

Hopf bifurcation analysis in a delayed diffusive predator-prey system with nonlocal competition and schooling behavior

<abstract><p>We consider a delayed diffusive predator-prey system with nonlocal competition in prey and schooling behavior in predator. We mainly study the local stability and Hopf bifurcation at the positive equilibrium by using time delay as the parameter. We also analyze the property of Hopf bifurcation by center manifold theorem and normal form method. Through the numerical simulation, we obtain that time delay can affect the stability of the positive equilibrium and induce spatial inhomogeneous periodic oscillations of prey and predator's population densities. In addition, we observe that the increase of space area will not be conducive to the stability of the positive equilibrium $ (u_*, v_*) $, and may induce the inhomogeneous periodic oscillations of prey and predator's population densities under some values of the parameters.</p></abstract>

Explosive tritrophic food chain model with herd behaviour of prey and finite time blow-up of the top predator

Explosive tritrophic food chain model with herd behaviour of prey and finite time blow-up of the top predator

Study of two species prey–predator model in imprecise environment with harvesting scenario

This study proposes and explores a prey–predator model that presents a functional response to group behavior of prey–predator harvesting. We study a non-linear model of prey–predator growths in two species. The proposed model is supported by theoretical and numerical results. Some numerical descriptions are provided to help our analytical and theoretical conclusions. For all possible parameter values occurring in a prey–predator system, we solved it by using both VIM (variational iteration method) and HPM (homotopy perturbation method). We also used MATLAB coding to compare our approximate analytical expressions with numerical simulations. We have found that there is no significant difference when comparing analytical and numerical results.

The role of vigilance on a discrete-time predator-prey model

<p style='text-indent:20px;'>The change of behaviors of prey in the form of vigilance significantly affects the dynamics of a predator-prey system. In this paper, we consider a discrete-time predator-prey model, where the vigilance of prey acts as a trade-off between the safety and growth rate of the prey. Mathematical properties such as stability, permanence, both flip and Neimark-Sacker bifurcations of the model are investigated. Numerical simulations are carried out to illustrate the analytical findings and to explore the impact of prey vigilance on the dynamics of the system.</p>

Explosive tritrophic food chain model with herd behaviour of prey and finite time blow-up of the top predator

Explosive tritrophic food chain model with herd behaviour of prey and finite time blow-up of the top predator

Moonlight influence on quality of nestlings of scops owls depends on paternal coloration

Abstract Lunar phases might favor the maintenance of color polymorphism via disruptive selection if the different color variants performed differently in terms of prey capture under different moonlight levels. Moonlight, however, may affect prey capture as a side effect of its influence on prey behavior. Here we combine data of parental provisioning and quality of owlets with one ex-situ study of grasshopper activity to test whether Eurasian scops owls (Otus scops) with different plumage color and their prey are differently affected by moonlight. Food provisioning increased from new- to full-moon. However, the effect of moonlight on owlet mass gain and immune response depended on paternal coloration. On the one hand, body mass gain of nestlings of the greyest fathers increased from nights with new- to full-moon, whereas it did not change with moonlight for the brownest fathers. On the other hand, PHA response of nestlings of the brownest fathers increased with high moonlight levels during the first week of life, whereas it did not change with moonlight levels for the greyest fathers. Grasshoppers were more active at new moon than at full or waning moon. Our study provides supporting evidence that moonlight influences the behavior of both scops owls and its prey and suggests that fluctuations in environmental conditions can modulate the advantages of morphs. These results are important because they provide a general insight into a little appreciated mechanism for the maintenance of color polymorphism in natural populations based on the interactive effect of different environmental factors.

The predator activity landscape predicts the anti‐predator behavior and distribution of prey in a tundra community

AbstractPredation shapes communities through consumptive and non‐consumptive effects. In the latter case, prey respond to perceived predation risk through proactive or reactive risk management strategies occurring at different spatial and temporal scales. The predator–prey space race and landscape of fear concepts are useful to better understand how predation risk affects prey behavioral decisions and distribution. We assessed predation risk effects in a terrestrial Arctic community, where the arctic fox is the main predator of ground‐nesting birds. Using high‐frequency GPS data, we estimated a predator activity landscape corresponding to fox space use patterns and validated with an artificial prey experiment that this predator activity landscape correlated with the predation risk landscape. We then investigated the effects of the fox activity landscape on multiple prey species, by assessing the anti‐predator behavior of a main prey (snow goose) actively searched for by foxes, and the nest distribution of several incidental prey species. We first found that snow geese showed a stronger level of nest defense in areas highly used by foxes, possibly responding with a reactive strategy to variation in predation risk. Then, nests of incidental prey reproducing in habitats easily accessed by foxes had a lower probability of occurrence in areas highly used by foxes, suggesting these birds may use a proactive risk management strategy by shifting their distribution away from risky areas. For incidental prey species nesting in microhabitat refuges difficult to access by foxes, probability of nest occurrence was independent of predation risk in the surrounding area, as they avoid risk at a finer spatial scale. By tracking all individuals of the dominant predator species in our study area, we demonstrated the value of using predator space use patterns to infer spatial variation in predation risk. Overall, we highlight the diversity of risk management strategies in prey sharing a common predator, hence refining our understanding of the mechanisms driving species distribution and community structure.

Turing–Hopf bifurcation in the predator–prey model with cross-diffusion considering two different prey behaviours’ transition

In this paper, we study the Turing–Hopf bifurcation in the predator–prey model with cross-diffusion considering the individual behaviour and herd behaviour transition of prey population subject to homogeneous Neumann boundary condition. Firstly, we study the non-negativity and boundedness of solutions corresponding to the temporal model, spatiotemporal model and the existence and priori boundedness of solutions corresponding to the spatiotemporal model without cross-diffusion. Then by analysing the eigenvalues of characteristic equation associated with the linearized system at the positive constant equilibrium point, we investigate the stability and instability of the corresponding spatiotemporal model. Moreover, by calculating and analysing the normal form on the centre manifold associated with the Turing–Hopf bifurcation, we investigate the dynamical classification near the Turing–Hopf bifurcation point in detail. At last, some numerical simulations results are given to support our analytic results.

The legacy of predator threat shapes prey foraging behaviour.

Predators exert strong selection on prey foraging behaviour such that prey responses may reflect a combination of ancestral effects of predators (genetic and nongenetic transgenerational effects), past individual experience with predators (phenotypic plasticity), and current exposure to predators (behavioural response). However, the importance of these factors in shaping prey foraging behaviour is not well understood. To test the relative effects of ancestry, prior experience, and current exposure, we measured foraging rates and food size preference of different ancestry and exposure groups of Western mosquitofish in the presence and absence of immediate threat from predatory largemouth bass. Our results confirm that mosquitofish had lower foraging rate in the immediate presence of predator threat. Mosquitofish also foraged at a lower rate if they had ancestry with predators, regardless of immediate threat. In contrast, individual prior experience with predators only caused reduced foraging rates in the immediate presence of a predator. This suggests that phenotypic plasticity could carry a lower risk of maladaptive antipredator responses-i.e., reduced food intake-in the complete absence of a predator. Finally, in the presence of a predator, mosquitofish with both ancestry and experience with predators consumed larger, presumably more energetically valuable, food items. Overall, our results show that non-consumptive effects of predators on prey behaviour can persist within and across generations, such that the legacy of past predator exposure-or "the ghost of predation past"-may continue to shape prey behaviour even when predators are no longer around.

Modelling hiding behaviour in a predator-prey system by both integer order and fractional order derivatives

Most of the preys are well aware of sensing predation risk. Consequently, to escape from predators they usually adopt several defense mechanisms, specially refuge themselves to become invulnerable. In view of this, a mathematical model has been formulated incorporating prey refuge, where it is assumed that prey refuge is a function of predators availability in the system. It is shown that the model system is well-posed. It has been found that the hiding level and consumption rate of predators have a suitable interrelation between them. Both the parameters act as Hopf bifurcation parameters, but they play opposite role in case of stabilization of the system dynamics. Also, hiding level plays crucial role in maintaining the mean density of both the populations. Furthermore, as hiding behaviour of prey is not instantaneous, so a time delay, namely hiding delay has been introduced to make the model system more realistic and it is observed that the delay parameter destabilizes the system. Modelling approach through fractional calculus has been further deployed to study how the process of forgetting life history influences the dynamical intricacy of the population level dynamics. All the analytical findings have been testified by proper numerical performances.

The Evolution of Predator Resemblance in Avian Brood Parasites

Predators have profound effects on prey behavior and some adult brood parasites use predator resemblance to exploit the antipredator defenses of their hosts. Clarifying host perception of such stimuli is important for understanding the adaptive significance of adult brood parasite characteristics, and the mechanisms by which they misdirect hosts. Here I review the literature to explore the adaptive basis of predator resemblance in avian brood parasites, and natural variation in host responses to these stimuli. I also provide a framework for the information ecology of predator resemblance, which is based on the principles of signal detection theory and draws from empirical evidence from the common cuckoo,Cuculus canorus, as the most widely studied system. In this species, visual and acoustic hawk-like stimuli are effective in manipulating host defenses. Overall, contrasts across host responses suggest that different modalities of information can have independent effects on hosts, and that predator resemblance takes advantage of multiple sensory and cognitive processes. Host perception of these stimuli and the degree to which they are processed in an integrated manner, and the physiological processes underlying regulation of the responses, present new avenues for brood parasitism research.

Contrasting patterns of risk from human and non-human predators shape temporal activity of prey.

Spatiotemporal variation in predation risk arises from interactions between landscape heterogeneity, predator densities and predator hunting mode, generating landscapes of fear for prey species that can have important effects on prey behaviour and ecosystem dynamics. As widespread apex predators, humans present a significant source of risk for hunted animal populations. Spatiotemporal patterns of risk from hunters can overlap or contrast with patterns of risk from other predators. Human infrastructure can also reshape spatial patterns of risk by facilitating or impeding hunter or predator movement, or deterring predators that are themselves wary of humans. We examined how anthropogenic and natural landscape features interact with hunting modes of rifle hunters and mountain lions Puma concolor to generate spatiotemporal patterns of risk for their primary prey. We explored the implications of human-modified landscapes of fear for Columbian black-tailed deer Odocoileus hemionus columbianus in Mendocino County, California. We used historical harvest records, hunter GPS trackers and camera trap records of mountain lions to model patterns of risk for deer. We then used camera traps to examine deer spatial and temporal activity patterns in response to this variation in risk. Hunters and mountain lions exhibited distinct, contrasting patterns of spatiotemporal activity. Risk from rifle hunters, who rely on long lines of sight, was highest in open grasslands and near roads and was confined to the daytime. Risk from mountain lions, an ambush predator, was highest in dense shrubland habitat, farther from developed areas, and during the night and crepuscular periods. Areas of human settlement provided a refuge from both hunters and mountain lions. We found no evidence that deer avoided risk in space at the scale of our observations, but deer adjusted their temporal activity patterns to reduce the risk of encounters with humans and mountain lions in areas of higher risk. Our study demonstrates that interactions between human infrastructure, habitat cover and predator hunting mode can result in distinct spatial patterns of predation risk from hunters and other predators that may lead to trade-offs for prey species. However, distinct diel activity patterns of predators may create vacant hunting domains that reduce costly trade-offs for prey. Our study highlights the importance of temporal partitioning as a mechanism of predation risk avoidance.