scholarly journals Evidence for Resistance to Coagulotoxic Effects of Australian Elapid Snake Venoms by Sympatric Prey (Blue Tongue Skinks) but Not by Predators (Monitor Lizards)

Toxins ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 590
Author(s):  
Nicholas J. Youngman ◽  
Joshua Llinas ◽  
Bryan G. Fry
Keyword(s):  
Prey Species ◽  
Sympatric Species ◽  
Coagulation Cascade ◽  
Snake Venoms ◽  
Diverse Range ◽  
Predator Species ◽  
Predator Prey ◽  
Evolution Of Resistance ◽  
Prey Handling ◽  
Monitor Lizards

Some Australian elapids possess potently procoagulant coagulotoxic venoms which activate the zymogen prothrombin into the functional enzyme thrombin. Although the activity of Australian elapid prothrombin-activators has been heavily investigated with respect to the mammalian, and in particular, human clotting cascades, very few studies have investigated the activity of their venom upon reptile plasmas. This is despite lizards representing both the primary diet of most Australian elapids and also representing natural predators. This study investigated the procoagulant actions of a diverse range of Australian elapid species upon plasma from known prey species within the genera Tiliqua (blue tongue skinks) as well as known predator species within the genera Varanus (monitor lizards). In addition to identifying significant variation in the natural responses of the coagulation cascade between species from the genera Tiliqua and Varanus relative to each other, as well as other vertebrate lineages, notable differences in venom activity were also observed. Within the genus Tiliqua, both T. rugosa and T. scincoides plasma displayed significant resistance to the procoagulant activity of Pseudechis porphyriacus venom, despite being susceptible to all other procoagulant elapid venoms. These results indicate that T. rugosa and T. scincoides have evolved resistance within their plasma to the coagulotoxic venom activity of the sympatric species P. porphyriacus. Other venoms were able to activate Tiliqua prothrombin, which suggests that the lessened activity of P. porphyriacus venom is not due to modifications of the prothrombin and may instead be due to a serum factor that specifically binds to P. porphyriacus toxins, as has been previously seen for squirrels resistant to rattlesnake venom. In contrast, none of the predatory lizards studied (Varanus giganteus, V. mertensi and V. varius) demonstrated resistance to the venom. This suggests that the mechanical protection afforded by thick osteodermic scales, and prey handling behaviour, removes a selection pressure for the evolution of resistance in these large predatory lizards. These results therefore reveal differential interactions between venoms of snakes with sympatric lizards that are on opposite sides of the predator–prey arms race.

scholarly journals Coexistence for an Almost Periodic Predator-Prey Model with Intermittent Predation Driven by Discontinuous Prey Dispersal

2017 ◽  
Vol 2017 ◽  
pp. 1-15
Author(s):  
Yantao Luo ◽  
Long Zhang ◽  
Zhidong Teng ◽  
Tingting Zheng
Keyword(s):  
Growth Rates ◽  
Prey Species ◽  
Impulsive Differential Equations ◽  
Comparison Theorems ◽  
Almost Periodic ◽  
Predator Species ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Prey Model ◽  
Predator Prey Models

An almost periodic predator-prey model with intermittent predation and prey discontinuous dispersal is studied in this paper, which differs from the classical continuous and impulsive dispersal predator-prey models. The intermittent predation behavior of the predator species only happens in the channels between two patches where the discontinuous migration movement of the prey species occurs. Using analytic approaches and comparison theorems of the impulsive differential equations, sufficient criteria on the boundedness, permanence, and coexistence for this system are established. Finally, numerical simulations demonstrate that, for an intermittent predator-prey model, both the intermittent predation and intrinsic growth rates of the prey and predator species can greatly impact the permanence, extinction, and coexistence of the population.

PERMANENCE IN A PERIODIC PREDATOR–PREY SYSTEM WITH PREY DISPERSAL AND PREDATOR DENSITY-INDEPENDENT

2006 ◽  
Vol 14 (04) ◽  
pp. 491-507 ◽  
Author(s):  
LONG ZHANG ◽  
ZHIDONG TENG
Keyword(s):  
Periodic Solution ◽  
Prey Species ◽  
Positive Periodic Solution ◽  
Analytic Method ◽  
Predator Density ◽  
Volterra Type ◽  
Predator Species ◽  
Predator Prey ◽  
Prey System ◽  
Theoretical Results

In this paper, we study two-species predator–prey Lotka–Volterra-type dispersal system with periodic coefficients, in which the prey species can disperse among n-patches, but the predator species which is density-independent is confined to some patches and cannot disperse. By utilizing the analytic method, sufficient and realistic conditions on the boundedness, permanence, extinction, and the existence of positive periodic solution are established. The theoretical results are confirmed by a special example and numerical simulations.

scholarly journals Dynamic behaviors of a Lotka-Volterra type predator-prey system with Allee effect on the predator species and density dependent birth rate on the prey species

2019 ◽  
Vol 17 (1) ◽  
pp. 1186-1202 ◽  
Author(s):  
Fengde Chen ◽  
Xinyu Guan ◽  
Xiaoyan Huang ◽  
Hang Deng
Keyword(s):  
Birth Rate ◽  
Allee Effect ◽  
Prey Species ◽  
Positive Equilibrium ◽  
Volterra Type ◽  
Predator Species ◽  
Dynamic Behaviors ◽  
Predator Prey ◽  
Density Dependent ◽  
Prey System

Abstract A Lotka-Volterra type predator-prey system with Allee effect on the predator species and density dependent birth rate on the prey species is proposed and studied. For non-delay case, such topics as the persistent of the system, the local stability property of the equilibria, the global stability of the positive equilibrium are investigated. For the system with infinite delay, by using the iterative method, a set of sufficient conditions which ensure the global attractivity of the positive equilibrium is obtained. By introducing the density dependent birth rate, the dynamic behaviors of the system becomes complicated. The system maybe collapse in the sense that both the species will be driven to extinction, or the two species could be coexist in a stable state. Numeric simulations are carried out to show the feasibility of the main results.

scholarly journals The uneasy coexistence of predators and pathogens

2020 ◽  
Vol 43 (7) ◽  
Author(s):  
Andreas Eilersen ◽  
Kim Sneppen
Keyword(s):  
Host Species ◽  
Prey Species ◽  
Scaling Relations ◽  
Predator Species ◽  
Predator Prey ◽  
Mass Scaling ◽  
Prey System ◽  
Model Equations ◽  
Extinction Events ◽  
Parameter Values

Abstract. Disease and predation are both highly important in ecology, and pathogens with multiple host species have turned out to be common. Nonetheless, the interplay between multi-host epidemics and predation has received relatively little attention. Here, we analyse a model of a predator-prey system with disease in both prey and predator populations and determine reasonable parameter values using allometric mass scaling relations. Our analysis focuses on the possibility of extinction events rather than the linear stability of the model equations, and we derive approximate relations for the parameter values at which we expect these events to occur. We find that if the predator is a specialist, epidemics frequently drive the predator species to extinction. If the predator has an additional, immune prey species, predators will usually survive. Coexistence of predator and disease is impossible in the single-prey model. We conclude that for the prey species, carrying a pathogen can be an effective weapon against predators, and that being a generalist is a major advantage for a predator in the event of an epidemic affecting the prey or both species. Graphical abstract

scholarly journals The uneasy coexistence of predators and pathogens

2019 ◽  
Author(s):  
Andreas Eilersen ◽  
Kim Sneppen
Keyword(s):  
Host Species ◽  
Prey Species ◽  
Scaling Relations ◽  
Predator Species ◽  
Predator Prey ◽  
Mass Scaling ◽  
Prey System ◽  
Model Equations ◽  
Extinction Events ◽  
Parameter Values

Disease and predation are both highly important in ecology, and pathogens with multiple host species have turned out to be common. Nonetheless, the interplay between multi-host epidemics and predation has received relatively little attention. Here, we analyse a model of a predator-prey system with disease in both prey and predator populations and determine reasonable parameter values using allometric mass scaling relations. Our analysis focuses on the possibility of extinction events rather than the linear stability of the model equations. We find that if the predator is a specialist, epidemics frequently drive the predator species to extinction. If the predator has an additional, immune prey species, predators will usually survive. Coexistence of predator and disease is impossible in the single-prey model. We conclude that for the prey species, carrying a pathogen can be an effective weapon against predators, and that being a generalist is a major advantage for a predator.

Activity pattern of puma (Puma concolor) and its main prey in central Mexico

2016 ◽  
Vol 66 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Leroy Soria-Díaz ◽  
Octavio Monroy-Vilchis ◽  
Zuleyma Zarco-González
Keyword(s):  
Activity Pattern ◽  
Prey Species ◽  
Puma Concolor ◽  
Anthropogenic Factors ◽  
The Moon ◽  
Dasypus Novemcinctus ◽  
Predator Species ◽  
Predator Prey ◽  
Main Prey ◽  
Nasua Narica

Predator–prey dynamics are primarily determined by the predator’s ability to hunt and the prey’s strategies to avoid it. This dynamic can be influenced by ecological, environmental or anthropogenic factors. We analyzed the activity pattern of puma (Puma concolor) and its main prey species, armadillo (Dasypus novemcinctus), coati (Nasua narica) and white-tailed deer (Odocoileus virginianus) by means of photographic records. The pattern of activity of the predator species is not distributed uniformly throughout the day. No dependence of the activity pattern of the species on the moon phase was found. In addition, a statistically significant relationship between the activity pattern of puma and its main prey (armadillo) was obtained.

Predator-Prey Interactions

2001 ◽  
Author(s):  
Peter A. Abrams
Keyword(s):  
Natural Selection ◽  
Basic Property ◽  
Prey Species ◽  
Living Organism ◽  
Considerable Change ◽  
Evolutionary Change ◽  
Predator Species ◽  
Predator Prey ◽  
Rate Of Increase ◽  
History Of

Predation has been given many different definitions. For the purposes of this chapter, it is an interaction in which one free-living individual kills and derives resources from another organism. This definition includes finches that consume seeds but does not include fish that eat the siphons of clams that are unable to retract them quickly enough (assuming the clam usually survives the loss of tissue). Both broader and narrower definitions of predation are possible, and a variety can be found in ecology textbooks. Because broad definitions include herbivory and parasitism as forms of predation, the definition used here was chosen to minimize overlap with other chapters in this section. Predation probably arose early in the history of life, and since then, it has been a major source of natural selection on both parties in the interaction. Given the lethal consequences of predation, it is clear that predators will usually have some effect on the rate of increase of their prey. If prey differ in their susceptibility to predators due to heritable differences in characteristics, evolutionary change in antipredator traits will ensue. Because predators must consume prey to survive and reproduce, the selective importance of predation-related traits is obvious. Predators have undergone considerable change and diversification since the first predatory protocell evolved from what was probably a scavenging ancestor. Darwin regarded some of the clearest cases of natural selection as due to the interactions between predator and prey, and that viewpoint is also held by many current-day evolutionary biologists (e.g., Dawkins and Krebs 1979; Vermeij 1994). Predation can be regarded as the most basic interaction between populations. Herbivory and parasitism share the basic property of predation, that one organism consumes some or all of another living organism. Many cases of competition involve predation on the same set of prey species by two or more different predator species. Even when competitors consume nonliving foods, many aspects of the consumption process are similar to consumption of prey by predators. Even mutualism frequently involves one organism eating parts or products of another.

scholarly journals Development of a method for assessing the security of cyber-physical systems based on the Lotka–Volterra model

2021 ◽  
Vol 5 (9 (113)) ◽  
pp. 30-47
Author(s):  
Serhii Yevseiev ◽  
Serhii Pohasii ◽  
Stanislav Milevskyi ◽  
Oleksandr Milov ◽  
Yevgen Melenti ◽  
...  
Keyword(s):  
Cyber Security ◽  
Prey Species ◽  
Cyber Physical Systems ◽  
Volterra Model ◽  
Expert Assessment ◽  
Security Level ◽  
Protection Measures ◽  
Predator Species ◽  
Predator Prey ◽  
Physical Systems

The paper presents the results of the development of a method for assessing the security of cyber-physical systems based on the Lotka–Volterra model. Security models of cyber-physical systems are proposed: “predator–prey” taking into account the computing capabilities and focus of targeted cyberattacks, “predator–prey” taking into account the possible competition of attackers in relation to the “prey”, “predator–prey” taking into account the relationships between “prey species” and “predator species”, “predator–prey” taking into account the relationship between “prey species” and “predator species”. Based on the proposed approach, the coefficients of the Lotka–Volterra model α=0.39, β=0.32, γ=0.29, φ=0.27 were obtained, which take into account the synergy and hybridity of modern threats, funding for the formation and improvement of the protection system, and also allow determining the financial and computing capabilities of the attacker based on the identified threats. The proposed method for assessing the security of cyber-physical systems is based on the developed threat classifier, allows assessing the current security level and provides recommendations regarding the allocation of limited protection resources based on an expert assessment of known threats. This approach allows offline dynamic simulation, which makes it possible to timely determine attackers' capabilities and form preventive protection measures based on threat analysis. In the simulation, actual bases for assessing real threats and incidents in cyber-physical systems can be used, which allows an expert assessment of their impact on both individual security services and security components (cyber security, information security and security of information). The presented simulation results do not contradict the graphical results of the classical Lotka–Volterra model, which indicates the adequacy of the proposed approach for assessing the security of cyber-physical systems

GLOBAL ANALYSIS OF A HARVESTED PREDATOR–PREY MODEL INCORPORATING A CONSTANT PREY REFUGE

2010 ◽  
Vol 03 (02) ◽  
pp. 205-223 ◽  
Author(s):  
LIUJUAN CHEN ◽  
FENGDE CHEN
Keyword(s):  
Prey Species ◽  
Global Analysis ◽  
Sufficient Conditions ◽  
Equilibrium Density ◽  
Prey Refuge ◽  
Predator Species ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Prey Model ◽  
Density Values

A predator–prey model with Holling type II functional response incorporating a constant prey refuge and independent harvesting in either species is investigated. Some sufficient conditions of the instability and stability properties to the equilibria and the existence and uniqueness to limit cycles for the model are obtained. We also show that influence of prey refuge and harvesting efforts on equilibrium density values. One of the surprising finding is that for fixed prey refuge, harvesting has no influence on the final density of the prey species, while the density of predator species is decreasing with the increasing of harvesting effort on prey species and the fixation of harvesting effort on predator species. Numerical simulations are carried out to illustrate the obtained results and the dependence of the dynamic behavior on the harvesting efforts or prey refuge.

The population dynamics of bite-sized predators: prey dependence, territoriality, and mobility

2018 ◽  
Author(s):  
Xavier Lambin
Keyword(s):  
Prey Species ◽  
Top Down ◽  
Predator Prey ◽  
Biological Barrier ◽  
Reciprocal Interactions ◽  
Demographic Rates ◽  
Risk Of Predation ◽  
Increased Risk ◽  
Rodent Prey ◽  
Small Mustelids

The dependency of mustelid demographic rates on prey abundance has the potential to cause a strong coupling between predator-prey populations. Data on mustelid dynamics show that such strong reciprocal interactions only materialise in some restricted conditions. Bite-size mustelid predators searching for scarce, depleted prey expose themselves to increased risk of predation by larger predators of small mammal that are themselves searching for similar prey species. As voles or muskrats become scarcer, weasels and mink searching for prey over larger areas become increasingly exposed to intra-guild predation, unless they operate in a habitat refuge such as the sub-nivean space. Where larger predators are sufficiently abundant or exert year-round predation pressure on small mustelids, their impact on mustelids may impose biological barrier to dispersal that are sufficient to weaken the coupling between small mustelids and their rodent prey, and thus impose a degree of top down limitation on mustelids.

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