A Study Of Predators’s Mechanisms Of Movement And Habitat Selection Base On IFD Model

This thesis synthesize previous theory on ideal free habitat selection and reaction-diffusion-advection system to develop a model of predator movement mechanisms,when both predators and prey are mobile.With this model,this thesis consider an adaptive dynamics approach to two main questions.First,can it be adaptive for predators to base their movement solely on the density of the prey’s resource?Second,should predator movements be exclusively biased toward higher densities of prey/resources,or is there an optimal balance between random and biased movements?This thesis consists of four chapters.It is arranged as follows.In Chapter one,we mainly introduce the IFD theory,IFD model and a very general class of movement rules(1)random diffusion,(2)movement in the direction of higher prey density,(3) movement in the direction of higher density of the prey’s resource.We also introduce the background of IFD models and basic knowledges which will be used later.In Chapter two,we give the IFD models to study the steady state equation for prey when none of the predators are present.We also study the properties of solutions to the steady state equation.Meanwhile.under the condition of τ2<τ1,α1=α2and a disturbance, we obtain a condition which the predator can invade.In Chapter three,we study the asymptotic behavior of k*(α,τ) for large a,under the condition of τ1=τ2,α1>α2and a disturbance,we obtain a condition which the predator can invade..In Chapter four,we study the local bifurcation of steady state (0,0,θ) by local bifurcation theorem.In Chapter five, we study the stability of the local bifurcations,get some new results.