What is a typical pattern of predator and prey population dynamics over time due to their interactions?

• A. Prey constant, predators increase indefinitely
• B. Oscillations where prey rise as predators fall and vice versa
• C. Both populations increase together
• D. Prey always declines to extinction

Answer: (B)

Predator and prey populations in nature often show regular cycles because each group responds to the abundance of the other. When prey are plentiful, predators have plenty of food and their numbers start to rise. As more predators appear, they eat more prey, causing the prey population to fall. With fewer prey available, predator numbers soon drop because food is scarce. As predators decrease, prey recover and begin to increase again, and the cycle repeats. This creates oscillations where prey rise as predators fall and then prey fall while predator numbers rise, and so on. Other patterns—prey staying constant while predators rise indefinitely, both populations growing together, or prey steadily declining to extinction—don’t capture how interdependent feeding 상황 drives the ups and downs in typical predator–prey systems.