Figure 14.12 Predator–prey oscillations. The Lotka-Volterra model illustrates how the abundance of predator and prey populations cycle. With a decline in predators, prey can increase in abundance. The increase in prey then provides more food for predators; this allows predators to increase their population size through reproduction. As predators grow more numerous, they start to kill prey at such a high rate that the prey population begins to decline. A decline in available prey reduces the survival and reproduction of the predator population, which starts to decline. Over time, both populations cycle up and down in abundance, with predator abundance lagging behind prey abundance.