Whenever a predator population increases, the prey population
tends to decrease at first. Afterwards, the decrease in the prey
population and the bigger population density of predators cause the
predator population to decrease.
The prey population then reverts the decreasing and begins to
grow.
If size of population vary at an unexpected intensity that is
they are different from the usual intensity of the ecological
interaction, then theprey and the predator species is harmed.
Due to ecological accidents that kill a large amount of prey,
the prey-predator equilibrium is disrupted and both species may be
harmed.