Help! Please! :) What is an example of ecology?

"Examples of objects of ecological study include: Population processes, including reproductive behavior, mortality, bioenergetics and migrations, interspecific interations such as predation, competition, parasitism and mutualism, plant and animal community structures and their function and resilience, and biogeochemical cycling. Because of its vast scope, ecological science is often closely related to other disciplines. Thus, molecular ecology addresses ecological questions using tools from genetics, paleoecology uses tools from archeology, and theoretical ecologists use often highly complex mathematical models to explore how ecosystems and their elements function."