We used an “ecosystem energetics” approach to quantify how energy flows through food webs—from sunlight captured by plants to the animals that consume it. Using data from more than 3,000 bird and mammal species across 317,000 landscapes covering forests, savannas, and deserts, we combined six major ecological datasets, including the Biodiversity Intactness Index for Africa built with local expert knowledge.
Africa’s ecosystems are running on less than two-thirds of the natural energy they once had. The study reveals a dramatic loss of wildlife “power” across the continent – the energy that drives vital ecosystem functions such as nutrient cycling and seed dispersal – posing growing risks to biodiversity and the livelihoods that depend on it.
Beyond diagnosing decline, the study offers a way forward. Its energy-based framework can help governments, conservationists, and companies meet the growing demand for metrics that track not just species counts but ecosystem functionality – a true measure of recovery.
Across Africa, ambitious restoration programmes are underway to bring back wildlife and repair degraded landscapes. But until now, ecologists have struggled to predict how shifts in animal communities, such as the replacement of elephants and buffalo by smaller antelope in Mozambique’s Gorongosa National Park, affect ecosystem processes like vegetation growth and water cycling.
“Restoration isn’t just about bringing animals back, it’s about bringing back what they do,” said Loft. “An energetics approach gives practitioners a way to measure that, and to prioritise the functions that make ecosystems resilient.”
Loft et al. (2025) Energy flows reveal declining ecosystem functions by animals across Africa. Nature https://www.nature.com/articles/s41586-025-09660-1