Complex dynamics of the population with a simple age structure

The effects of the following modes of density-dependent control of population growth: density-dependent birth rate, adult survival rate, juvenile survival rate are compared based on the mathematical model of population dynamics. It is shown that the most efficient mechanisms limiting population size are decreasing with the growth of the adult population birth rate and/or the decreasing survival rate of the offspring with the increase in their number. However, these same mechanisms are responsible for oscillations of the population size and its chaotic change. The density-dependence of the adult survival rate is not efficient in constraining the population growth, but it can substantially limit the magnitude of oscillations of the population size.

► We investigate various types of density-dependent control of population growth.
► Birth rate decrease with the growth of number of adults.
► Survival rate of juveniles decrease with the growth of number of juveniles.
► These mechanisms of population growth control can lead to complex population oscillations.
► The density-dependence of the adult survival rate is not efficient in constraining the population growth.