Researchers from Princeton University recently published a paper in Science investigating what happens when large carnivores are eliminated from an ecosystem.

The Mozambican civil war, which lasted from 1977 to 1992, eliminated the large carnivores that once roamed the country’s Gorongosa National Park.

“That’s a tragic thing, but what it does is enable us to study how behavior and ecology changes when the predators are removed,” said Robert Pringle, the lead author of the paper and an associate professor of ecology and evolutionary biology.  

The researchers found that with the elimination of the carnivores, a “landscape of fearlessness” had been created, whereby formerly timid herbivores, such as bushbucks, now browsed freely — to the detriment of the local vegetation.

But when researchers protected plants from the bushbucks, they found that the plants grew back rapidly. This suggests that when predators are reintroduced and the bushbuck retreat to woody areas, the plants will rebound strongly.

“Our work really underscores the importance of top carnivores, which are declining globally,” said Ryan Long, an assistant professor of fish and wildlife sciences at the University of Idaho, who was a co-author on the project. “Carnivores influence ecosystems in complex ways that go beyond just killing and eating other animals.”