A small-bodied human species nicknamed the Hobbits may have been pushed to extinction by worsening droughts on their isolated island home around 50,000 years ago.
New evidence from cave deposits on the Indonesian island of Flores suggests that a long-term drop in rainfall, especially during the wet summer months, dried up vital water sources and strained food supplies for Homo floresiensis and its main prey, a pygmy elephant called Stegodon. Researchers pieced together this climate history using chemical signals in a stalagmite from a cave near the famous Liang Bua site, where Hobbit bones were first discovered in 2003.
The team analyzed magnesium and oxygen isotopes in the stalagmite, which acts like a natural rain gauge preserved over tens of thousands of years. Their data show a steady decline in average annual rainfall from about 1,560 millimeters to 990 millimeters between 76,000 and 61,000 years ago. Even more striking, summer rains plummeted to a low of around 450 millimeters from 61,000 to 55,000 years ago—less than half of today’s levels—turning the landscape increasingly arid.
This drying trend lines up with a sharp drop in Stegodon fossils at Liang Bua. Once abundant, the elephant remains dwindle after 62,000 years ago, with the last dated to about 57,000 years ago. Hobbit bones vanished around 61,000 years ago, well before modern humans arrived on the island around 46,000 years ago. The researchers link the extinctions to shrinking rivers and waterholes, forcing the Hobbits and elephants to compete fiercely for scarce resources.
“Our findings point to climate change, potentially in combination with predator-prey dynamics, as a contributor to the decline of H. floresiensis and S. florensis insularis prior to their disappearance at Liang Bua,” the team writes. “These findings increase the likelihood that progressive landscape aridification, and intensified human-faunal competition for dwindling resources, culminated in abandonment of Liang Bua.”
The Hobbits, who stood about a meter tall and used stone tools to hunt, had survived on Flores for at least a million years alongside Stegodon. But this intense arid phase, amid a cooling global climate, may have tipped the balance. While volcanoes or other factors could have played a role, the study highlights how even ancient humans weren’t immune to environmental shifts.
Citations: Communications Earth & Environment. DOI: 10.1038/s43247-025-02961-3.
