Whenever a predator population
at the first moment prey
population tends to . At a
second moment decrease of the
prey and the bigger
population of predators cause
the population to decrease.
The population then reverts the
to decrease and begins
grow.

If variations in size of populations
occur an unexpected intensity
(different the usual intensity of
ecological interaction) for example,
to ecological accidents killing
prey, the prey-predator equilibrium
disturbed and both species be
harmed. The existence the predator
sometimes is for the
survival of prey population, since
the of predatism favours the
of the prey and, some
cases, when the proliferation
creates a population over the
sustenance capacity the ecosystem,
environmental degradation and
the entire prey is destroyed.