Populations of predators and their prey usually follow
predictable cycles. When the number of prey increases, perhaps as their food
supply becomes more abundant, predator populations also grow.
When the predator population becomes too large, however, the
prey population often plummets, leaving too little food for the predators,
whose population also then crashes. This canonical view of predator-prey
relationships was first identified by mathematical biologists Alfred Lotka and
Vito Volterra in the 1920s and 1930s.