Importance of elephants for dung beetle biodiversity and ecosystem functions.

Abstract

Ecologists theorize that removing highly connected species from ecological networks will trigger waves of coextinction, but empirical evidence is scant. We show that elephants are central to a generalized network of interactions between dung beetles and large herbivores in East Africa. Computer simulations based on this network predicted disproportionate dung beetle losses if elephants go extinct, and a 15-year experiment supported this prediction: Excluding elephants diminished dung beetle abundance, diversity, and ecosystem functions, whereas excluding smaller ungulates had little added effect. Dung beetle abundance was depressed in nearby landscapes where livestock had displaced elephants, corroborating the experimental results. Our findings affirm the long-standing idea that large animals-which are inordinately extinction-prone-act as keystone species by provisioning many linked consumers with essential resources, thereby sustaining biodiversity and ecosystem services.