For more than three years Polish Konik horses have been controlling tree growth on a small island in the middle of the Rhine River, said Lilla Lovász, a PhD candidate at the University of Basel, just a few miles south of the reserve in neighboring Switzerland.

In 2018 a team of conservationists and scientists brought four mares and two geldings to the island, part of the Petite Camargue Alsacienne Nature Reserve, and they added a stallion last year. Now with two foals on the way, the herd will have grown to nine horses by mid-2022.

By eating unwanted plants and fertilizing the ground with their feces and urine, the large feral herbivores “serve as a part of a functioning ecosystem,” much like their predecessors did thousands of years ago, said Lovász.

“Since the end of the last ice age, about ten thousand years ago, human impact has been increasing and, together with it, the large herbivore fauna has been decreasing,” she said. “We (humans) gradually took over most of the areas on the planet and killed or domesticated a lot of animals. So that’s where we are now.”

Lovász, along with the Petite Camargue team, is trying to fix that problem—at least on this small island in eastern France—with the help of horses.

A Green Energy Site Dedicated to Getting Back to Nature

When the French electric company Electricité de France (EDF) acquired rights from the French government to use the land to construct dams and water-based power plants, the government required a significant investment in environmental compensation, said Lovász. Consequently, EDF opted to bring the surrounding area back to a “wild” state, clearing out the cropland and reviving a filled-in branch of the river, which is “essential in a riverine ecosystem,” she said.

To follow the changes in biodiversity, the researchers at the University of Basel sample an analyze flora and fauna on a regular basis.

While the renovation work provided an ideal environment for local plant and animal species to thrive, it couldn’t bring back certain local large herbivore species that have long since disappeared—primarily wild horses, wild cattle, bison, and deer.

Thousands of years ago, regular flooding would wash away seedlings and tree sprouts, and the large herbivores would trample and rip out many more, said Lovász. This system helped maintain a healthy balance of forest and clearings on the island.

“Normally in nature, such an area of flood plain should be regulated by regular floods and also large herbivores, which would give the area a natural, functioning ecosystem,” she explained.

Flooding is no longer possible due to the regulation of the Rhine and a canal running parallel to it, said Lovász. And wild large herbivores, including red deer, haven’t inhabited the region for the past several centuries. “So we had to do something, because otherwise it was just going to all be forest within about five years,” she said. “And we didn’t really want people going into this natural environment with machines to cut down trees all the time. So the question was, ‘Okay, what do we do?’”

Feral Horses and Cattle: Nature’s Groundkeepers

Lovász and her colleagues decided to fill the role of the ancient herbivores with modern species that were as close as possible to the original wild ones. For Lovász, horses were the clear choice.

“I’m a horse freak—that’s what everybody says—so of course I suggested, ‘Why don’t we have horses?’” she said.

“And cattle, too,” she added. “Together, they would fulfill a very similar ecological role as the ancient herbivore assemblage used to. And having these two species together grazing this area would result in quite a similar ecosystem that used to exist before humans took over.”

The team chose Highland cattle, a rustic Scottish breed with long wooly hair and wide horns.

As for the horses, the scientists originally hoped to rewild with Przewalski’s horses, she said. But administrative constraints would have pushed back the introduction of the animals several more years.

So, instead, the team opted for the Polish Konik.

Healthy, Rustic Koniks Living the Wild Life

According to legend, Konik horses are the only true descendants of the Tarpan, the original “European wild horse”—which is actually just a “made-up term,” Lovász said. In reality there is no evidence that Tarpan horses were wild, nor that Koniks descended from them, she explained.

Even so, Koniks are small, rustic horses that have been historically kept feral and have been used successfully in other rewilding efforts in Europe, Lovász said.

In the Petite Camargue Alsacienne, the Konik herd is carrying out their maintenance tasks efficiently, she said. The island continues to have a good balance of trees and clear areas, making ideal homes for the natural fauna and flora.

The animals are thriving well on the island, with minimal human intervention, she added. Lovász only interacts with the horses to safely place GPS collars on them for tracking and research purposes. Otherwise, the horses go without veterinary or farrier care (with an emergency plan in place to intervene only if a horse needs immediate care), living entirely independently of humans.

Even so, Lovász said she wants to keep a close eye on the horses’ genetic health. The Konik breed, having been “saved” as legendary Tarpan descendants, was built from only 22 individuals about 100 years ago. The few genetic studies carried out on the genetic makeup of modern Koniks suggests the long-held belief in this legend has led to inbreeding, Lovász said. Therefore, she said she wants to ensure the animals get as much genetic diversity as possible, even if that means switching out group members from time to time.

“After the stallion has done his role, we’ll either exchange him with another nature reserve or we’ll sterilize him,” she said, adding that she’s actively working to establish networks among nature reserves with Konik herds.

The horses seem to be well-adjusted and comfortable, both physically and mentally, said Lovász.

The team, however, does receive criticism from people who believe the horses are suffering from a lack of care by living this “wild life,” she added.

“They are really fine without us,” Lovász said. “They are just part of nature. And, yet, it’s very hard, I think, for people to imagine that these are animals that don’t need human care. We had activists coming and telling me that they want to close our project, because horses should be in boxes and covered with rugs in winter.

“But this is an animal that’s living in its natural conditions, and they’re just fine,” she explained.

“European wild horse: An origin story with conservation implications,” was published in the December 2021 issue of Global Ecology and Conservation.