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This summer has seen ferocious wildfires tearing across southern Europe earlier in the season than usual. More than 240,000 acres of land have already been destroyed across Spain, with a recent blaze in the south quickly turning into one the country’s deadliest.

Preventing wildfires has become a high-tech endeavor of satellites, drones and AI systems. But 80 miles south of Barcelona, an ancient solution is quietly roaming across the mountain. It’s a herd of donkeys.

Tivissa Donkey Firefighters, a nonprofit in southern Catalonia, rehabilitates mistreated and abandoned donkeys and puts them to work as “firefighters.” By grazing the most flammable grasses in mountains and rural areas, they carve natural firebreaks across the dry Mediterranean landscape.

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Founder Joan Cedó Sans took in the first few donkeys in 2020; he now has a herd of 62, moving across the region to clear private and public lands thanks to their seemingly endless appetites. “We’re grateful for the animals that we feel deserve a second opportunity,” he told CNN, in Catalan.

Remembering the fires that swept near his land in Catalonia, northeastern Spain, in 2013, he decided to test if the first donkeys would clear the forest undergrowth around it. “They ate everything,” he said.

The experiment turned into a full-time operation, and Cedó, now mayor of the small town of Tivissa, handed the day-to-day operations to Jordi García, a volunteer who joined in 2021. “It’s very gratifying,” Garcia said in Spanish. “You’re out in nature, and you’ve given these animals a chance.”

One of the first arrivals was Roberto, a former racing donkey sent to the slaughterhouse after he stopped winning because of his bulky build. “He is special, and I think he knows it,” Cedó said. Another donkey, Paloma, arrived with an obesity problem from being “fed supermarket cookies and sugar cubes,” Cedó added. “That’s not a diet for an animal like this … It’s a kind of mistreatment as well.”

Cedó believes the project is mutually beneficial: the donkeys prevent fires, and the work gives them a “dignified life” — a herd to belong to, medical care from a voluntary vet, and supplementary feed of donated produce from local farms and a nearby theme park.

And their work has never been more crucial. In 2025, the European Union recorded its most destructive wildfire season on record, with Spain losing close to a million acres to fires.

Donkeys are grazers and favor the grasses that dry out over the summer to form “fine fuel” — the plant biomass that ignites most easily and accelerates the fire spread — explained Dr. Jordi Bartolomé Filella, a professor at the Universitat Autònoma de Barcelona (UAB) and researcher in herbivore ecology.

For a “very thorough effect, it works well to combine different types of herbivores,” Bartolomé explained, “so that they act on the different layers and species of the undergrowth.”

Goats, which quickly clear woody plants have sparked “goatscaping businesses” in California, which rent herds to graze hillsides that are difficult for humans to clear.

But Cedó sees something special in his animals: “The work donkeys do, neither goats nor sheep can do,” he said. “They weigh more, so every time they tread, they tread harder, they eat more.” By trampling the ground, they break the connected layer of dry foliage a fire needs to spread.

Research has shown that grazing animals can be an effective defense and cheaper than cutting firebreaks with machinery — but like fire prevention in general, is not a silver bullet. “It is difficult to guarantee that with livestock grazing there will be no fires,” Bartolomé said, “but it can make them lower in intensity, and therefore easier to extinguish.”

Tivissa’s donkeys also help maintain human-made firebreaks cut in the mountains. “It’s a win-win,” Cedó said. “They open the firebreaks, we put the animals there, and we keep it clean.” Cedó added that the paths trodden by donkeys can be used “to run hoses if there’s a fire.”

Fire has always been a characteristic of the Mediterranean, and the grazing of both wild and domestic animals has long kept dry areas in check.

“Without large herbivores, sooner or later this biomass would be ‘eaten’ by fire. Unlike the herbivores, fire consumes it suddenly — with wide-ranging consequences for the ecosystem and risks to people,” Bartolomé said.

European wildfires released a record 13 million tons of climate-heating carbon in 2025, and their damage outlasts the flames: a burned forest stops absorbing CO₂, and the smoke can persist for weeks, threatening human health even thousands of miles away.

Cedó took inspiration and advice from “El Burrito Feliz,” (Happy Little Donkey) a pioneering nonprofit in southern Spain where rescued donkeys have grazed the edges of Doñana National Park since 2014.

Similar projects are springing up across the country. Rewilding efforts in Galicia, northwestern Spain, are bringing back wild horses to act as “natural lawnmowers” in the country’s most fire-prone region.

In Catalonia, the “Ramats de Foc” (Fire Flocks) initiative pairs sheep and goat shepherds with local firefighters to graze fire-critical zones. The meat and cheese from those flocks is sold under a wildfire-prevention label, so shoppers help fund the work.

Authorities recognize the value of livestock in preventing fires, Bartolomé said, but are unsure how to act on it. He argues that grazing initiatives will scale only when governments pay for them as an ecosystem service, in the same way “as mechanical clearing is paid for.”

Cedó said herders are paid up to 80 euros per hectare ($37 an acre) cleared on private land and up to 300 euros per hectare ($138 an acre) on public land — too little to sustain their work. Currently, Tivissa Donkey Firefighters relies on donations and partnerships to care for the herd.

“This project was born from nothing, by chance,” Cedó said. “But it’s been a profound lesson — socially, personally.”

“We aren’t doing anything our ancestors didn’t do,” he added. “All we’re doing is putting value back on those rural tasks, that way of life that depended so much on animals.”

Correction: An earlier version of this story misstated that firefighters cut firebreaks on training exercises, and didn’t reflect how much herders earn for clearing public land.

https://www.cnn.com/world/europe/firefighters-donkeys-spain-c2e-spc