Key Points:
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Elephants function as a keystone species, producing large amounts of nutrient-rich dung that sustain diverse dung beetle populations and support wider ecosystem health.
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A 15-year field experiment showed that removing elephants leads to sharp declines in dung beetle abundance, biomass, and species diversity, and other herbivores cannot replace their role.
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The findings provide rare real-world evidence that losing a single, highly connected species can trigger cascading effects across ecosystems, reinforcing the importance of protecting key ecological “hubs.”
For decades, ecologists have relied on mathematical models to predict what happens when a species disappears. Those models consistently suggest a troubling possibility: Removing a single species from an ecosystem can trigger a cascade of additional extinctions.
But proving that idea in the real world has been far more difficult, said Department of Life and Environmental Sciences Professor Matthew Hutchinson, who collaborated on an innovative study led by researchers at Princeton University.
“Those predictions … rang true in computer simulations but had been really hard to prove in the real world,” he said.
The study, published in Science, offers rare, concrete evidence for this phenomenon — and it centers on one of Earth’s largest animals. The research shows that elephants act as a keystone species, an organism that has a disproportionately large impact on its natural environment relative to its population size, serving as the ecological “glue” that holds an ecosystem together. The enormous amount of waste elephants produce supports dung beetle abundance and diversity in East African savannas, which safeguards the ecological services dung beetles provide.
The findings suggest that losing even a single, well-connected species can ripple through an ecosystem in ways scientists have long expected but seldom demonstrated.
