Predator-prey Interactions Research Articles

New Geographic Records for Trichinella nativa and Echinococcus canadensis in Coyotes (Canis latrans) from Insular Newfoundland, Canada.

Coyotes (Canis latrans) rapidly expanded across North America during the 20th century and in 1987 colonized insular Newfoundland, Canada. Their arrival brought the potential for new predator-prey interactions and the potential for transmission of parasites to naïve populations. Trichinella spp. and Echinococcus spp. are zoonotic parasites not previously reported from the island of Newfoundland, Canada. Muscle samples (diaphragm and tongue) from 153 coyotes and feces from 35/153 coyotes were collected. Larvae of Trichinella spp. were recovered by muscle digestion from 6/153 coyotes (3.9%) and identified using multiplex PCR and Sanger sequencing as T. nativa. Fecal samples were screened for DNA of Echinococcus spp. using qPCR, and intestines from positive animals were examined for adult cestodes. No fecal samples were positive for DNA of E. multilocularis, and 2/35 (5.7%) samples were positive for E. canadensis, of which one was successfully genotyped as the G10 cervid strain. Echinococcus canadensis has not previously been reported on the island of Newfoundland, historically the only region of Canada where Echinococcus spp. was not known to occur. No species of Trichinella have previously been reported on the island. Both parasites are zoonotic, and hunters, trappers, dog owners, and the general public should be aware of these new risks for public health.

Beyond age‐structured single‐species management: Optimal harvest selectivity in the face of predator–prey interactions

AbstractIn the single‐species literature, it is widely acknowledged that conserving young fish for future harvesting is beneficial. This finding holds great significance in fisheries economics and has garnered substantial attention over the years. In this study, a full‐blown age‐structured predator–prey model is developed and used to demonstrate that multispecies considerations may shift the optimal selection of predators towards smaller individuals, providing valuable counteractive insights. These new results offer a fresh perspective highly relevant to regulation and choice of selectivity patterns.

Role Reversals in a Tri-Trophic Prey–Predator Interaction System: A Model-Based Study Using Deterministic and Stochastic Approaches

It is frequently observed that adult members of prey species sometimes use their predation mechanism on juvenile members of predator species. Ecological literature describes this phenomenon as prey–predator role reversal dynamics.Numerous authors have observed and described the biological development behind this feeding behaviour. However, the dynamics of this role reversal have hardly been illustrated in the literature in a precise way. In this regard, we formulated an ecological model using the standard prey–predator interactions, allowing for a reverse feeding mechanism. The mathematical model consisted of a three-species food-web structure comprising the common prey, intermediate predator, and top predator. Note that a role-reversal mechanism was observed between the intermediate and top predators based on the scarcity of the prey population. However, we observed the most critical parameters had a significant effect on this reverse feeding behaviour. The bifurcation analysis is the primary criterion for this identification. The proposed deterministic model is then extended to its stochastic analogue by allowing for environmental influences on the tri-trophic food web structure. The conditional moment approach is applied to obtain the equilibrium distribution of populations and their conditional moments in the system. The stochastic setup analysis also supports the stability of this food chain structure, with some restricted conditions. Finally, to facilitate the interpretation of our mathematical results, we investigated it using numerical simulations.

Bacterivorous nematodes decipher microbial iron siderophores as prey cue in predator-prey interactions.

The minimal levels of biological-available iron in the environment impose growth limitation on all living organisms. Microbes often secrete high iron-binding-affinity siderophores at high concentrations for scavenging iron from the iron-limited habitats. However, the high prevalence of siderophores released by bacteria into the environment raises an intriguing question whether this chemical cue can be detected by bacterivorous predators. Here, we show that the bacterivorous Caenorhabditis elegans nematode could employ its chemosensory receptor Odr-10 to detect pyoverdine, an iron siderophore secreted by an environmental bacterium, Pseudomonas aeruginosa. This enabled the nematode predator to migrate toward the prey. Our soil microcosm study showed that the detection of pyoverdine and subsequent feeding of P. aeruginosa prey by C. elegans could lead to the expansion of its population. These results showed that siderophores are a prey chemical cue by predators, with key implications in predator-prey interactions.

Distinctive chemotactic responses of three marine herbivore protists to DMSP and related compounds.

Marine planktonic predator-prey interactions occur in microscale seascapes, where diffusing chemicals may act either as chemotactic cues that enhance or arrest predation, or as elemental resources that are complementary to prey ingestion. The phytoplankton osmolyte dimethylsulfoniopropionate (DMSP) and its degradation products dimethylsulfide (DMS) and acrylate are pervasive compounds with high chemotactic potential, but there is a longstanding controversy over whether they act as grazing enhancers or deterrents. Here, we investigated the chemotactic responses of three herbivorous dinoflagellates to point-sourced, microscale gradients of dissolved DMSP, DMS, and acrylate. We found no evidence for acrylate being a chemotactic repellent and observed a weak attractor role of DMS. DMSP behaved as a strong chemoattractor whose potential for grazing facilitation through effects on swimming patterns and aggregation depends on the grazer's feeding mode and ability to incorporate DMSP. Our study reveals that predation models will fail to predict grazing impacts unless they incorporate chemotaxis-driven searching and finding of prey.

Chaos detection in predator-prey dynamics with delayed interactions and Ivlev-type functional response

<p>Regarding delay-induced predator-prey systems, extensive research has focused on the phenomenon of delayed destabilization. However, the question of whether delays contribute to stabilizing or destabilizing the system remains a subtle one. In this paper, the predator-prey interaction with discrete delay involving Ivlev-type functional response is studied by theoretical analysis and numerical simulations. The positivity and boundedness of the solution for the delayed model have been discussed. When time delay is accounted as a bifurcation parameter, stability analysis for the coexistence equilibrium is given in theoretical aspect. Supercritical Hopf bifurcation is detected by numerical simulation. Interestingly, by choosing suitable groups of parameter values, the chaotic solutions appear via a cascade of period-doubling bifurcations, which is also detected. The theoretical analysis and numerical conclusions demonstrate that the delay mechanism plays a crucial role in the exploration of chaotic solutions.</p>

Hopf bifurcation in a predator-prey model under fuzzy parameters involving prey refuge and fear effects

<p>In ecology, the most significant aspect is that the interactions between predators and prey are extremely complicated. Numerous experiments have shown that both direct predation and the fear induced in prey by the presence of predators lead to a reduction in prey density in predator-prey interactions. In addition, a suitable shelter can effectively stop predators from attacking as well as support the persistence of prey population. There has been less exploration of the effects of not only fear but also refuge factors on the dynamics of predator prey interactions. In this paper, we unveil several conclusions about a predator-prey system with fuzzy parameters, considering the cost of fear in two prey species and the effect of shelter on two prey species and one predator. As the first step of the investigation, the boundedness and non-negativity of the solutions to the system are put forward. Using the Jocabian matrix and Lyapunov function methods, we further analyze the existence and stability of the available equilibria and also the existence of Hopf bifurcation, considering the fear parameter as the bifurcation parameter that has been observed by applying the normal form theory. Finally, numerical simulations help us better understand the dynamics of the model, in which some interesting chaotic phenomena are also exhibited.</p>

Trait-based indicators of resource selection by albacore tuna in the California Current Large Marine Ecosystem

As global climate change reorganizes marine ecosystems, understanding how predators will respond to variable prey resources is critical to forecasting future community dynamics. Prey traits that affect the foraging process and recur across unrelated taxa offer a means to better anticipate predator resource use by simplifying complex foraging dynamics. Here we compare taxonomic and trait-based indicators of resource use and selection for albacore tuna (Thunnus alalunga), a commercially valuable pelagic predator undergoing climate-driven range shifts. We synthesized datasets from 2005 to 2019 to evaluate diets of albacore tuna in relation to prey availability estimates from shipboard surveys in the California Current Large Marine Ecosystem. Analyses with these data reveal that albacore and trawl surveys sample different aspects of the pelagic system, with albacore consuming a subset of taxa identified within trawls. Albacore consistently selected coastal prey that are schooling, undefended, silvered and countershaded, and have high energy density — suggesting that ecological mechanisms driving albacore foraging outcomes may be conserved across time and space. Ecological traits mediating predator-prey interactions consistently distinguished albacore diets from assemblages sampled by trawls across years and regions. We demonstrate that a traits-based approach simplifies taxonomically diverse predator-prey interactions and may be a valuable tool to facilitate predictions of prey resource use in changing environments.

МОДЕЛИРОВАНИЕ ДИНАМИКИ ВЗАИМОДЕЙСТВУЮЩИХ ПОПУЛЯЦИЙ ТИПА «ХИЩНИК–ЖЕРТВА» ПРИ ПОСТОЯННОЙ МИГРАЦИИ ОСОБЕЙ С СОПРЕДЕЛЬНЫХ ТЕРРИТОРИЙ

The article deals with the research of the dynamics of a local predator-prey community with constant migration of individuals from neighboring territories. We studied several models with a constant inflow of individuals into both predator and prey populations. It is shown that changes in the overall dynamics are significantly influenced by the number of predator migrants: their large influx leads to the rapid and almost complete extinction of preys. The model considering only a constant prey inflow is successfully applied to modeling of various processes based on the principles of predator-prey population interactions, for example, when studying the consumption of difficult-to-renewable or nonrenewable natural resources. The study of the model provides allows getting estimations of the resources use efficiency and and the degree of modernization of the consumer sector. It is shown that two-dimensional models - modifications of the basic Volterra and Bazykin models, lead to structurally stable fluctuation regimes corresponding to the focus and limit cycle. We found that these models also contain fast-slow periodic dynamics, corresponding to a maximum limit cycle with strong spikes and smoother declines in the population size. The emergence of such regimes corresponds to the alternation of periods of active extinctions of prey, accompanied by an increase in the number of predators, and periods of long-term restoration of the prey, during which there is no harvesting of prey. We used methods of dynamic systems analysis to study the models. The construction of two-dimensional parametric portraits shows that, to get stable dynamics of the basic models of two interacting biological species, no complication is required, for example, by adding nonlinear terms. Stable regimes are also observed in simpler models, such as the original Lotka-Volterra or Bazikin models, where the recovery rate of prey population is a constant value.

Predatory drilling on molluscan assemblages along the Patagonian shelf (southern Argentina)

Abstract Both present-day and fossil molluscan assemblages offer an opportunity for a better understanding of the structure and organization of both modern and past benthic communities. In this framework, drill holes are used widely to explore predator–prey interactions. This research focuses on predation marks, especially drill holes, recorded on modern molluscan assemblages in a Patagonian sector of the Argentinean continental shelf. Shelled molluscs (n = 2179) were recovered from 27 to 135 m depths covering a long latitudinal extent (between 39° and 54°S). For each station, taxonomic position, ecological composition and relative abundance of taxa were determined, and then drilling frequency (DF) was calculated to infer drilling intensity. The collected molluscs belong to 37 families, with Veneridae being the most abundant in terms of the number of specimens (n = 419). Specimens with drill holes (n = 226) belong to 21 families (with at least 33 different species). Most of them are suspension feeders (85.8%) and the remaining percentage comprised other trophic types. Naticids and muricids, as main potential predators, together account for 19.6% of the gastropods present in the molluscan assemblages. DF across all the stations was moderate (9.9%) but varied between low (0–2.4%) and high (28.9%). These results do not show a trend linked to latitude or depth, and the great variability of DF between stations suggests that other local ecological or environmental conditions would influence drilling predation at a small spatio-scale.

Stability and bifurcation analysis of a discrete predator-prey system of Ricker type with refuge effect.

The refuge effect is critical in ecosystems for stabilizing predator-prey interactions. The purpose of this research was to investigate the complexities of a discrete-time predator-prey system with a refuge effect. The analysis investigated the presence and stability of fixed points, as well as period-doubling and Neimark-Sacker (NS) bifurcations. The bifurcating and fluctuating behavior of the system was controlled via feedback and hybrid control methods. In addition, numerical simulations were performed as evidence to back up our theoretical findings. According to our findings, maintaining an optimal level of refuge availability was critical for predator and prey population cohabitation and stability.

The study on the complex nature of a predator-prey model with fractional-order derivatives incorporating refuge and nonlinear prey harvesting

<abstract> <p>The main objective of our research was to explore and develop a fractional-order derivative within the predator-prey framework. The framework includes prey refuge and selective nonlinear harvesting, where the harvesting progressively approaches a threshold value as the density of the harvested population advances. For memory effect, a non-integer order derivative is better than an integer-order derivative. The solutions to the fractional framework were shown to be existence, uniqueness, non-negativity, and boundedness. Matignon's condition was used for analysing local stability, and a suitable Lyapunov function provided global stability. While discussing the Hopf bifurcation's existence condition, we explored derivative order and refuge as bifurcation parameters. We aimed at redefining the predator-prey framework to incorporate fractional order, refuge, and harvesting. This kind of nonlinear harvesting is more realistic and reasonable than the model with constant yield harvesting and constant effort harvesting. The Adams-Bashforth-Moulton PECE algorithm in MATLAB software was used to simulate the proposed outcomes, investigate the impact on various factors, and analyse harvesting's effect on non-integer order predator-prey interactions.</p> </abstract>

Combined impact of fear and Allee effect in predator-prey interaction models on their growth

<p>We considered predator-prey models which incorporated both an Allee effect and a new fear factor effect together, and where the predator predated the prey with a Holling type I functional response. We started off with a two-dimensional model where we found possible equilibria and examined their stabilities. By using the predator mortality rate as the bifurcation parameter, the model exhibited Hopf-bifurcation for the coexistence equilibrium. Furthermore, our numerical illustrations demonstrated the effect of fear and the Allee effect on the population densities, and we found that the level of fear had little impact on the long-term prey population level. The population of predators, however, declined as the fear intensity rose, indicating that the fear effect might result in a decline in the predator population. The dynamics of the delayed system were examined and Hopf-bifurcation was discussed. Finally, we looked at an eco-epidemiological model that took into account the same cost of fear and the Allee effect. In this model, the prey was afflicted with a disease. The prey was either susceptible or infected. Numerical simulations were carried out to show that as the Allee threshold rose, the uninfected prey and predator decreased, while the population of infected prey increased. When the Allee threshold hit a certain value, all populations became extinct. As fear intensity increased, the population of uninfected prey decreased, and beyond a certain level of fear, habituation prevented the uninfected prey from changing. After a certain level of fear, the predator population went extinct and, as a result, the only interaction left was between uninfected and infected prey which increased disease transmission, and so the infected prey increased. Hopf-bifurcation was studied by taking the time delay as the bifurcation parameter. We estimated the delay length to preserve stability.</p>

How realistic features affect the stability of an Arctic marine food web model.

Rapid sea-ice decline and warmer waters are threatening the stability of Arctic ecosystems and potentially forcing their restructuring. Mathematical models that support observational evidence are becoming increasingly important. We develop a food web model for the Southern Beaufort Sea based on species with high ecological significance. Generalized modeling is applied to study the impact of realistic characteristics on food web stability; a powerful method that provides a linear stability analysis for systems with uncertainty in data and underlying physical processes. We find that including predator-specific foraging traits, weighted predator-prey interactions, and habitat constraints increase food-web stability. The absence of a fierce top predator (killer whale, polar bear, etc.) also significantly increases the portion of stable webs. Adding ecosystem background noise in terms of a collective impact of latent, minor ecosystem members shows a peak in stability at an optimum, relatively small background pressure. These results indicate that refining models with more realistic detail to account for the complexity of the ecological system may be key to bridge the gap between empirical observations and model predictions in ecosystem stability.

Predation of the endangered Ae'o (Hawaiian Stilt) by a native raptor, the Pueo (Hawaiian Short-eared Owl) on the island of O'ahu, Hawai'i, USA.

While the impact of introduced predators is a widely acknowledged issue and key component of conservation considerations for endemic waterbird populations in the Hawaiian Islands, the impact of native predators on endemic, endangered waterbirds is not as frequently discussed or factored into recovery models. The Pueo (Hawaiian Short-eared Owl; Asio flammeus sandwichensis) is a subspecies of Short-eared Owl endemic to the Hawaiian Islands and is State-listed as Endangered on the island of O'ahu. The Ae'o (Hawaiian Stilt; Himantopus mexicanus knudensi) is a subspecies of the Black-necked Stilt endemic to Hawai'i and is federally listed as Endangered throughout its range. A variety of non-native predators are confirmed to consume Ae'o eggs, chicks, and adults, including invasive mammals (e.g., feral cats), birds (e.g., Barn Owls), and amphibians (e.g., bullfrogs). While predation by native predators was suspected, there are no cases documented in the literature to date describing Pueo preying upon Ae'o. Here, we describe four events that provide evidence of Pueo predating Ae'o during the 2019-2021 breeding seasons in a wetland area on the island of O'ahu: (1) confirmed Pueo predating an Ae'o chick, (2) a suspected predation attempt of a Pueo chasing adult Ae'o, and (3) two suspected predation events based on (a) 10 adult-sized Ae'o carcasses and remains found near an active Pueo nest and (b) game camera photos of Pueo visiting two Ae'o nests. To our knowledge, these novel observations are the first published accounts of predator-prey interactions between these two subspecies.

Applying Predator—Prey Model to Companies Practicing—Undergoing Dumping. Theoretical Basis and Empirical Notes

This article explores the potential application of predator-prey theory to understand and model the dynamics of commercially aggressive companies involved in persistent price dumping. Drawing inspiration from ecological systems, where predator-prey interactions govern population dynamics, we adapt the underlying concept to the business realm, specifically focusing on companies engaging in aggressive pricing strategies that negatively impact competitors. Through a formal model inspired by Lotka-Volterra differential equations, we aim to capture the intricate interplay between predatory companies (engaging in not sporadic dumping) and their prey counterparts (those impacted by it). The explorative article concentrates on industries where aggressive pricing strategies, such as dumping, play a pivotal role, i.e. in sectors like steel production, airline services, and e-commerce (alongside insights into industry-specific dynamics and competitive landscapes). It adopts a mixed-methods approach based on a critical analysis of both literature and industry evidence, providing a theoretical and operating model complete with a numerical simulation. The application demonstrates that the dynamic interactions between prey and predator result in oscillating cycles, i.e., a delicate equilibrium and associated fluctuations (depending on the characteristics and assumptions related to aggressiveness and resilience of the two species, the estimation of parameters and growth rates, the institutional response – authorities constraints, intervention, protection, etc.) that arise as prey and predators influence each other’s populations in the shared ecosystem (market). The interdisciplinary nature of the issues provides valuable insights for policymakers, businesses managers, and industry stakeholders when navigating difficult competitive landscapes on the edge of (un)fair play and responsibility. Limitations and future directions of research are provided.

Predation risk modifies habitat use and habitat selection of diving beetles (Coleoptera: Dytiscidae) in an Urban Pondscape

Urban freshwater ecosystems often involve the introduction of predator species that affect biodiversity via both direct and indirect effects of predation, altering the distribution of prey species. Yet, limited research has explored indirect effects on aquatic invertebrates in urban pondscapes. Here, we use Dytiscidae as our study taxon to investigate how predator-prey interaction modifies the habitat use and habitat selection of macroinvertebrates in ponds of an urban landscape. We sampled dytiscids in 11 ponds with, and 15 ponds without fish, in Helsinki, Finland, during 2018 – 2020, and emergent plant cover in pond margins as a proxy for the quantity of prey refuges. We found (i) at the pond scale, vegetation cover can mitigate the negative effects of predators on dytiscid species richness and abundance, and dytiscids prefer microhabitats with bulrush and sedges to microhabitats with no vegetation or common reeds, reflecting the importance of providing aquatic plants with high structural complexity as prey refuges. (ii) At the landscape scale, small-sized dytiscids favour fishless habitats, and the community-weighted mean body size of dytiscids has seasonal fluctuations, with smaller body sizes in May and June than in July in fishless ponds, indicating that dytiscids select habitats to regulate their investment in vigilance according to their life cycles. Our findings highlight that predation can alter the habitat use and habitat selection of aquatic invertebrates. Mitigating predation risk at both the habitat scale and the landscape scale is crucial to facilitate the fitness of aquatic invertebrates, especially small-sized species, to promote their diversity in urban pondscapes.

Fractional model of prey-predator interactions in a reserved area with a competitive and toxic environment

Fractional model of prey-predator interactions in a reserved area with a competitive and toxic environment

Dynamics of a Class of Prey-Predator Interaction Model with Holling Type-II Functional Response Incorporatingthe Effect of Fear on Prey and Non-Linear Predator Harvest

Dynamics of a Class of Prey-Predator Interaction Model with Holling Type-II Functional Response Incorporatingthe Effect of Fear on Prey and Non-Linear Predator Harvest

A New Investigation of Prey-Predator Interactions Among Bacterial Species and Protozoa Under Atangana-Baleanu-Caputo Derivative

A New Investigation of Prey-Predator Interactions Among Bacterial Species and Protozoa Under Atangana-Baleanu-Caputo Derivative