In poaching's war on wildlife, the casualties go beyond those animals killed by bullet or toxin. As megaherbivores, elephants and rhinoceroses play key roles in their respective environments. Remove an unsustainable amount of these animals - as poachers are doing now - and the effects can ripple along the strands of the ecological web like a shockwave.
"Elephants play a really critical role in the balance between woody and savanna ecosystems" Wittemyer says. Elephant dung contains a tremendous number and variety of plant seeds, which the pachyderms can deposit up to 35 miles away from where they ate fruit. And after fire (and humans), elephants are one of the most powerful forces of destruction, tearing down trees and allowing grassland to move in.
As harbingers of both plant life and death, elephants create what Wittemyer calls "habitat mosaics." Instead of a uniform blanket of woody bush or old forest, elephants weave environments into a patchwork quilt that moves from forest to grassland and back. (Black rhinos, likewise, are particularly good at chomping down thorned plants other animals can't stomach.) This ecological tide allows for a much richer diversity of species than would be possible otherwise. A 2009 study found many more lizard species, for example, in areas where elephants had damaged trees.
Biologists have a phrase - "a trophic cascade" - for what happens after the populations of elephants and other keystone species are altered within an ecological community. If the term evokes a waterfall, or a series of falling dominoes, it's an apt metaphor. "Remove a cog in the network," Wittemyer says, "and the network is going to shift around." Without vultures or other scavengers to eat meat festering in the sun, for instance, it's possible that the incidence of disease could increase.
That poaching has such far-reaching impacts emphasizes the need for patrols in Africa's national parks and protected areas, Bell says. "Increased efforts to protect elephants results in increased protection for other species, too," he says. "In this sense, elephants are flagships for conservation, leveraging funding which goes far beyond just protecting elephants."