the food chain refers to a natural system by which energy is transmitted from one organism to another. in fact, a food chain consists of producers, consumers and decomposition. presence of complex food web increase the stability of the ecosystem. classical food chain theory arises from lotka-volterra model. in the present paper, the dynamics behavior of three level food chain is studied. a syst...

A simple food chain which consists of nutrient, prey and predator with intratrophic predation of the predator is proposed and analyzed. The dynamics of the model depend on the basic reproductive numbers of the prey and predator. Intratrophic predation can have impact on the system only if the basic reproductive number of the predator is greater than 1. In this case, the system may have multiple...

A predator’s per capita feeding rate on prey, or its functional response, provides a foundation for predator–prey theory. Since 1959, Holling’s prey-dependent Type II functional response, a model that is a function of prey abundance only, has served as the basis for a large literature on predator–prey theory. We present statistical evidence from 19 predator–prey systems that three predator-depe...

Predator-prey relationships are a central component of community dynamics. Classic approaches have tried to understand and predict these relationships in terms of consumptive interactions between predator and prey species, but characterizing the interaction this way is insufficient to predict the complexity and context dependency inherent in predator-prey relationships. Recent approaches have b...

In this survey, we briefly review some of our recent studies on predator-prey models with discrete delay. We first study the distribution of zeros of a second degree transcendental polynomial. Then we apply the general results on the distribution of zeros of the second degree transcendental polynomial to various predator-prey models with discrete delay, including Kolmogorov-type predator-prey m...

Predator switching is often assumed to be a stabilizing force in predator–prey interactions. Recent models, however, have shown that predator switching can have a destabilizing effect on populations, creating cycles or even extinctions of predators and prey. However, most of these models have been traditional top-down mathematical models that do not incorporate individual variability or evoluti...

In this work we present a predator–prey model that incorporates individual behavior of the predators. A classical Lotka–Volterra model with self-limiting prey describes the predator–prey interaction. Predator individuals can use two behavioral tactics to dispute a prey when they meet, the classical hawk and dove tactics. Each individual can use both tactics along its life. The predator behavior...

study of the spatial distribution of a pest and its natural enemies provides better decision tool for integrated pest management. the spatial distribution and seasonal activity of panonychus ulmi (koch) and its predator zetzellia mali (ewing) were studied in an apple orchard in khoramdareh (zanjan province, iran) during 2007. the interaction (density dependence) between the prey and its predato...

Traditionally, predator switching has been assumed to be a stabilizing force in ecological systems. Recent work, however, has shown that predator switching can be either stabilizing or destabilizing. Most models of predator switching, to date, assume that prey are behaviorally passive and do not respond to predators. We allowed prey to respond behaviorally to predators, so as to avoid capture, ...