At Kenya's Mpala Research Center, a 15-year experiment has revealed something that ecologists have long theorized but rarely proven in the real world: the loss of one keystone species can trigger a cascading collapse throughout an entire ecosystem.
When African elephants disappeared from the fenced experimental plots at Mpala, something unexpected followed. The dung beetles that had thrived in those landscapes plummeted. Plots without elephants contained 67% fewer dung beetles, 51% less beetle biomass, and 23% fewer beetle species—a loss that matched, almost precisely, what computer simulations had predicted for the extinction of the world's largest land mammal.
This finding matters because dung beetles are far more than curiosities. These insects are ecosystem engineers. By feeding on and burying animal dung, they recycle nutrients, disperse seeds, improve soil quality, and suppress parasites. The economic value of these services to the cattle industries in the U.S. and U.K. alone is estimated at roughly $1.6 billion annually. Lose the beetles, and you lose functions that sustain not just wildlife but human agricultural systems.
The research, led by Princeton University doctoral student Finote Gijsman and co-authored by University of Florida Professor Todd Palmer, was published in the journal Science. It emerged from one of the world's most rigorous long-term ecological experiments: the UHURU project, established at Mpala in 2008.
The UHURU experiment is elegant in design. Researchers created a series of large, fenced plots that selectively exclude mammals by body size—some exclude only the largest herbivores like elephants and giraffes, others exclude smaller animals like duikers and dik-diks, and some remain completely open as controls. This design simulates real-world extinction patterns, in which large animals typically vanish first, hunted or displaced by human activity before smaller species disappear.
To understand how strongly beetles depend on large mammals, researchers first examined which types of dung attracted the greatest diversity and abundance of insects. Elephant dung overwhelmingly dominated the results. The reason is striking: elephants spend up to 18 hours per day feeding, consuming about 300 pounds of food and excreting up to 200 pounds of feces daily. They are, in Palmer's words, "the most connected, most important node in the whole network."
What makes this study exceptional is its depth. Many ecological studies last only a few years, capturing snapshots of ecosystems that are constantly shifting. At Mpala, researchers have watched these plots for 15 years, long enough to witness patterns that emerge only over time. In elephant-free plots, dung decomposition slowed significantly, and seed dispersal declined. These are not abstract measures—they are the fundamental processes that sustain savanna health.
Perhaps most striking is that when researchers excluded all the other large herbivores alongside elephants, it made almost no additional difference to beetle diversity. It was elephants specifically, not large mammals in general, that mattered.
This finding reframes how we think about conservation. Elephants have long received attention for their charisma and cultural significance. Palmer's research adds a pragmatic argument: elephants are infrastructural. Their dung subsidizes an entire community of insects that collectively perform services worth billions of dollars annually. Protect elephants, and you protect not just the species itself but an entire web of ecological function that human economies depend upon.