  This paper is devoted to the study of a predator-prey model with predator-age
structure that involves Michaelis-Menten type ratio-dependent functional
response. We study some dynamical properties of the model by using the theory
of integrated semigroup and the Hopf bifurcation theory for semilinear
equations with non-dense domain. The existence of Hopf bifurcation is
established by regarding the biological maturation period $\tau$ as the
bifurcation parameter. The computer simulations and sensitivity analysis on
parameters are also performed to illustrate the conclusions.
