  We study a stochastic lattice predator-prey system by means of Monte Carlo
simulations that do not impose any restrictions on the number of particles per
site, and discuss the similarities and differences of our results with those
obtained for site-restricted model variants. In accord with the classic
Lotka-Volterra mean-field description, both species always coexist in two
dimensions. Yet competing activity fronts generate complex, correlated
spatio-temporal structures. As a consequence, finite systems display transient
erratic population oscillations with characteristic frequencies that are
renormalized by fluctuations. For large reaction rates, when the processes are
rendered more local, these oscillations are suppressed. In contrast with
site-restricted predator-prey model, we observe species coexistence also in one
dimension. In addition, we report results on the steady-state prey age
distribution.

Statistical Mechanics;Adaptation and Self-Organizing Systems;Populations and Evolution