Dynamics of a Leslie-Gower type predation model with a non-monotonic
functional response
Abstract
In the ecological literature, many models for the predator-prey
interactions consider the monotonic functional responses to describe the
action of the predators. However, there exist antipredator behaviors
which are best represented by non-monotonic functions. The mathematical
results on the predator-prey models provide very useful information to
understand the complex food webs; they also help to the insight of the
mechanisms that govern the evolution of ecological systems. The aim of
this paper is to show, the dynamics of a modified Leslie-Gower model,
assuming a rational non-monotonic functional response or Holling type
IV. A principal target is to compare the obtained properties with other
cases, in which different non-monotonic functional responses are
incorporated. The model is described by an autonomous bi-dimensional
ordinary differential equation system (ODEs), assuming that the prey and
predator growth functions are the logistic type. The proposed model is
not defined in $(0,0)$; considering a topological equivalent system,
it is possible that to prove the origin is a non-hyperbolic saddle
point. We also have established, there are subsets of the parameter
space in which: i) there exists a unique positive equilibrium point, ii)
a heteroclinic curve exists. iii) two concentric limit cycles exist, the
innermost unstable and the outermost stable. Numerical simulations are
given to endorse the analytical results and to exhibit the richness of
the dynamics in the system.