Dynamical complexities in seasonally perturbed prey predator systems

Abstract

In the modeling of predator-prey dynamics, the attacking rate of predator is not newlineconstant but varies with time. Since every predator has different limits of starvation, newlineso digestive time depends on starvation and different environmental fluctuations [20]. newlineThus, seasonal variations have significant impact on predator-prey interactions. Many newlineresearchers have constructed differential equations and shown how seasonal change newlinein attacking rate affects predator-prey interactions [5, 6]. Lakes, ponds and rivers newlineof mountain, temperate and tropical regions show seasonal natural fluctuations of newlinewater level. Changes of water level cause significant variations on littoral habitat newlinecharacteristics: on physical-chemical conditions of water, on coverage of shoreline newlinevegetation [8] and in general on its complexity [4], then reducing its suitability as newlinerefuge and breeding area for benthic invertebrates and fish, both preys and predators newline[9]. newlineRecently, researchers have focused on a more effective approach, the indirect newlineattack of predation [18, 19]. It gives stress on prey and changes different physiological newlinebehaviors of prey [14]. Prey always feels the risk of fear of predator. They may stop newlinesearching for food and suffer starvation. Moreover, fear may affect the physiological newlinecondition of juvenile prey and leave harmful impacts on their survival as adults [3]. newlineIn theoretical ecology, a most pertinent behavioural topic on prey-predator system newlineis spatial refuge. It is an important biological phenomenon by which prey species newlineprevent themselves from predations [16]. Prey tries to protect himself from predator newlineby hiding in an area where it is unreachable or cannot easily be found. newline