A note on the existence of periodic solutions in discrete predator–prey models

This note investigates the existence of periodic solutions for discrete semi-ratio-dependent predator–prey models with functional response. New criteria are derived in which this system with prey-dependent (monotonic or non-monotonic) and predator-dependent functional response bounded by polynomials in R+R+ always has at least one ωω-periodic solution, which improves and extends many previous results [1], [2], [3], [4] and [5]. Some interesting numerical examples are given to illustrate our results.