Trophic downgrading of planet Earth

Estes and a large group of coauthors synthesized evidence that the loss of apex consumers, including big cats, is among humanity's most pervasive influences on nature. The review marshaled cases across terrestrial, marine and freshwater systems showing that removing top predators triggers cascading changes in herbivory, disease, fire, nutrient cycling, invasions and biodiversity. For felids it frames lions, tigers, leopards and pumas as keystone regulators whose decline reverberates through mesopredator release and prey irruptions. The paper argued that top-down forcing is a normal feature of ecosystems and that conserving large predators is essential to ecosystem function. It is a landmark conceptual reference for the ecological importance of large carnivores worldwide.