Modeling the dynamics of predator-prey community with age structures

A model of the predator-prey community has been proposed with specific stages of individual development and the seasonality of breeding processes. It is assumed each of the species has an age structure with two stages of development. The case typical for the community “Arctic fox – rodents” is modeled. An analytical and numerical study of the model proposed is made. It is shown that periodic, quasi-periodic and chaotic oscillations can occur in the system, as well as a shift in the dynamics mode as a result of changes in the current sizes of the community's populations. The model proposed demonstrates long-period oscillations with time delay like auto-oscillations in the classical model of Lotka–Volterra. It is shown that a transition from stable dynamics to quasi-periodic oscillations and vise verse is possible in the system, while an increase in the values of the half capturing saturation coefficient reduces the possibility of quasiperiodic oscillation emergence. Simulations demonstrate the growth in predator’s consumption of the prey average number expands the zones of multistability and quasi-periodic dynamics in the stability area of nontrivial fixed point. Therefore, the variation of the current population size of the community can lead to a change in the dynamic mode observed. The scenarios of transition from stationary dynamics to community's population fluctuations are analyzed with different values of population parameters determining the dynamics of both species and their interaction coefficient. The model shows both sustainable community development and various complex fluctuations of interacting species. At the same time, the prey dynamics affects the predator one: the prey population fluctuations initiate predator oscillations like prey’s fluctuations, while the intrapopulation parameters of the predator can give to both stationary and fluctuating dynamic modes.