Editor’s note: Call to Earth is a CNN editorial series dedicated to reporting on the environmental challenges facing our planet and their solutions. Rolex’s Perpetual Planet Initiative has partnered with CNN to promote awareness and education on key sustainability issues and inspire positive action.
This summer, fierce wildfires broke out across southern Europe earlier than usual. More than 240,000 acres have already been burned across Spain, and recent wildfires in the south are quickly becoming the country’s deadliest.
Preventing wildfires has become a high-tech effort using satellites, drones, and AI systems. But 130 miles south of Barcelona, an ancient solution roams quietly across the mountains. A herd of donkeys.
Tibiza Donkey Fire Brigade, a non-profit organization in southern Catalonia, rehabilitates abused and abandoned donkeys to work as “firefighters.” By grazing the most flammable grasses in the mountains and countryside, they carve natural firebreaks in the arid Mediterranean landscape.
Founder João Sedo Sanz adopted his first few donkeys in 2020. He currently has a herd of 62 animals and his endless appetite allows them to travel throughout the region exploring private and public lands. “We are grateful for the animals that we think deserve a second chance,” he told CNN in Catalan.
Remembering the fires that occurred near his property in Catalonia, northeastern Spain, in 2013, he decided to see if his first donkey could cut down the underbrush of the surrounding forest. “They ate it all,” he said.
The experiment became a full-time operation, with Cedo, now mayor of the small town of Tibiza, handing over day-to-day operations to volunteer Jordi Garcia, who joined in 2021. “I’m very happy,” Garcia said in Spanish. “You were out in nature and you gave these animals a chance.”
One of the first to arrive was Roberto. Roberto is a former racing donkey who was sent to the slaughterhouse because he was no longer able to compete due to his size. “He’s special and I think he knows that,” Sedo said. Another donkey, Paloma, came in with an obesity problem from “being fed supermarket cookies and sugar cubes,” Sedo added. “This is not food for these animals…This is also a form of abuse.”
Mr. Sed believes the project is mutually beneficial. Donkeys prevent fires and this work provides them with a “dignified life”. These include belonging to a herd, medical care from volunteer veterinarians, and a supplementary diet of donated produce from local farms and nearby theme parks.
And their work has never been more important. In 2025, the European Union recorded its most destructive wildfire season on record, with Spain losing nearly 1 million acres to fires.
Donkeys are herbivores, preferring grasses that dry out during the summer to form “good fuel” (plant biomass that most easily ignites and promotes fire spread), explains Dr. Jordi Bartolomé Filera, a professor and researcher in herbivore ecology at the Autonomous University of Barcelona (UAB).
“To achieve a very thorough effect, it is useful to combine different types of herbivores, so that they act on different layers and species of the undergrowth,” Bartolomé explained.
Thanks to goats’ ability to quickly cut down woody vegetation, a “goat trapping business” has sprung up in California, where herds are rented out to graze hillsides that are difficult for humans to mow.
But Sedo sees something special in his animals. “Donkeys do things that goats and sheep can’t do,” he says. “Because they’re heavier, they walk harder and eat more with each step.” Trampling the ground destroys the connected layer of dry leaves necessary for the fire to spread.
Research shows that animal grazing is an effective defense and cheaper than mechanically cutting firebreaks, but like fire prevention in general, it is not a silver bullet. “It is difficult to guarantee that fires will not break out during livestock grazing, but the intensity of the fire will be reduced and it may be easier to extinguish it,” Bartolomé said.
Tibisa’s donkeys also work alongside human firefighters. Catalonia’s forest fire specialist group, GRAF, sometimes practices cutting firebreaks in the same mountains. “It’s a win-win,” Sedo said. “They open up the firebreak and we put the animals there and keep it clean.” He added that the path the donkeys walked could be used “to pull the hose in case of a fire.”
Fire has always been a feature of the Mediterranean, and has long been suppressed in arid regions by grazing by both wild and domestic animals.
“If there were no large herbivores, sooner or later this biomass would be ‘eaten’ by fire. Unlike herbivores, fire burns it down abruptly. This has far-reaching effects on the ecosystem and poses risks to people,” Bartolomé said.
Wildfires in Europe will release a record 13 million tonnes of climate-heating carbon in 2025, and the damage will outlast the flames. Burnt forests stop absorbing CO₂, and the smoke can persist for weeks, threatening human health thousands of miles away.
Sedo found inspiration and advice from El Burrito Feliz (Happy Little Donkeys), a pioneering non-profit organization in southern Spain where rescued donkeys have been grazing on the edge of Doñana National Park since 2014.
Similar projects are occurring all over the country. A rewilding effort in Galicia, northwestern Spain, is bringing back wild horses as “natural lawn mowers” in the country’s most fire-prone region.
In Catalonia, an initiative called Ramats de Foc (Fire Foc) pairs sheep and goat shepherds with local firefighters to graze fire-prone areas. Meat and cheese from these herds will be sold with wildfire-safe labels, so shoppers will help fund the effort.
Bartolomé said authorities recognize the value of livestock in fire prevention, but are unsure what to do about it. He argues that grazing efforts will only expand if governments pay for ecosystem services, “in the same way that mechanical logging is paid for.”
Sed said shepherds are paid between 70 and 80 euros ($32 to $37 per acre) per hectare cut, too little to sustain their jobs. Currently, the Tibisa Donkey Fire Brigade relies on donations and partnerships to care for the herd.
“This project came about by chance out of nothing,” Sedo said. “But it was a profound lesson, both socially and personally.”
“We’re not doing anything that our ancestors didn’t do,” he added. “All we’re doing is putting value back into rural jobs, a way of life that was heavily dependent on animals.”
