Eagles play a crucial role in maintaining the balance of ecosystems by controlling populations of prey species. As apex predators, eagles help regulate the population of their prey species, such as rodents, fish, and smaller birds. By preying on these animals, eagles prevent overpopulation, which can lead to ecosystem imbalances such as overgrazing, depletion of resources, or disruption of food chains. This helps ensure a healthy and sustainable ecosystem where each species plays its part in the natural food web.