Ecological meltdown in predator-free forest fragments

Terborgh and colleagues exploited a natural experiment created by a Venezuelan hydroelectric reservoir that isolated land-bridge islands lacking large predators such as jaguars and pumas. On predator-free islands, herbivores including howler monkeys, iguanas and leaf-cutter ants irrupted to extreme densities and devastated tree seedling recruitment, foreshadowing an ecological meltdown. The study provided rare experimental-scale evidence that the loss of top felids and other predators releases herbivores with cascading consequences for plant communities. It strengthened the case that large cats exert top-down control in tropical forests and that their removal restructures whole ecosystems, making it a frequently cited demonstration of predator regulation in Neotropical systems.