  We perform a detailed analysis of the behaviour of a non-autonomous
prey-predator model where age based growth with age discriminatory harvesting
in prey and predator's reliance upon alternative food in the absence of that
particular prey are considered. We begin by deriving certain sufficient
conditions for permanence and positive invariance and then proceed to construct
a Lyapunov function to derive some constraints for global attractivity. With
the help of continuation theorem we arrive at the best fit criterion to prove
the occurrence of a positive periodic solution. Moreover, using Arzela-Ascoli
theorem we formulate a proof for a unique positive solution to be almost
periodic and we carry out numerical simulation to verify the analytical
findings. With the aid of graphs and tables we show the nature of the
prey-predator system in response to the alternative food and delays.
