We consider the nonlinear age-dependent population growth model introduced by Gurtin-MacCamy [Arch. Rat. Mech. Anal. 54, 281-300 (1974)] to which is added a harvest of members at a rate which is constant in time but may depend on the age of members being harvested. This partial differential equation may be transformed by the method of characteristics into a pair of functional equations for the total population size and the birth rate. We discuss the behaviour of solutions when the birth and death moduli are functions of a single variable, either the age or the total population size.
ASJC Scopus subject areas
- Modeling and Simulation
- Computational Theory and Mathematics
- Computational Mathematics