On Isla Nublar, InGen attempted to control the dinosaurs numbers by keeping them from breeding and separating them. John Arnold would later try to disprove Chaos Theory in his conversation with Donald Gennaro by claiming that Living Systems were never in a state of Equilibrium. According to him, living systems were unstable constantly in a state of change and in danger of collapse.
However, once power was restored it was observed that there were fewer animals in the park. Alan Grant explained it as a product of Equilibrium, of the animals mingling with each other and thus settling into a stable ecosystem resembling a true Jurassic Equilibrium.
Jurassic Park by Michael Crichton page 247, 370 (First Edition, Thirty Fourth printing)