Chernobyl, Ukraine – In contaminated lands too dangerous for human life, the wildest horses in the world roam freely.
On the other side of the Chernobyl exclusion zone, Przewalski’s stocky, sand-colored, almost toy-like horses graze in a radioactive landscape larger than Luxembourg.
On April 26, 1986, an explosion at the Ukrainian nuclear power plant sent radiation across Europe and forced the evacuation of entire cities, displacing tens of thousands of people. It was the worst nuclear disaster in history.
Four decades later, Chernobyl – which in Ukraine is transliterated as “Chornobyl” – is still too dangerous for humans. But the fauna has settled back in.
Wolves now prowl the vast no man’s land spanning Ukraine and Belarus, and brown bears have returned after more than a century. Populations of lynx, elk, red deer and even packs of loose dogs have recovered.
Przewalski’s horses, native to Mongolia and once on the brink of extinction, were introduced here in 1998 as an experiment.
Known as “takhi” in Mongolia (“spirit”), horses are distinct from domestic breeds, with 33 pairs of chromosomes compared to 32 in domesticated horses. The modern name comes from the Russian explorer who first formally identified them.
“The fact that Ukraine now has a population in the wild is kind of a small miracle,” says Denys Vyshnevskyi, the area’s top natural scientist.
With human pressure gone, some parts of the exclusion zone now resemble European landscapes from centuries past, he said, adding: “Nature is recovering relatively quickly and efficiently.”
The transformation is visible everywhere. Trees cut through abandoned buildings, roads dissolve into the forest, and Soviet-era signs stand alongside leaning wooden crosses in overgrown cemeteries.
Hidden cameras show horses adapting in unexpected ways. They seek shelter in ruined barns and abandoned houses to escape the elements and insects, and even sleep inside.
The animals live in small social groups – usually a stallion with several mares and their offspring – alongside separate bands of younger males. Many died after its introduction, but others adapted.
Tracking them down takes time. Vyshnevskyi often drives alone for hours, placing motion-sensitive camera traps in camouflaged housings attached to trees.
Despite the persistent radiation, scientists have not recorded widespread mortality, although they have recorded more subtle effects. Some frogs have developed darker skin and birds in areas of higher radiation are more likely to develop cataracts.
However, new threats have emerged.
The 2022 Russian invasion sparked fighting in the exclusion zone as troops advanced toward kyiv, digging defenses into contaminated soil. Fires related to military activity devastated the forests.
The harsh winters of the war have also taken their toll. Damage to the power grid has left surrounding managed areas without resources, and scientists report an increase in fallen trees and dead animals, victims of both the extreme conditions and hastily constructed fortifications.
“Most forest fires are caused by downed drones,” explains Oleksandr Polischuk, who heads a firefighting unit in the area. “Sometimes we have to travel dozens of kilometers to reach them.”
Fires can return radioactive particles to the air.
Today, the area is no longer just an accidental refuge for wildlife. It has become a heavily guarded military corridor, marked by concrete barriers, barbed wire and minefields – a landscape of what some call grim beauty.
Staff come and go to limit radiation exposure. Chernobyl is likely to remain a forbidden place for generations: too dangerous for people, but full of life.
“For those of us dedicated to conservation and ecology, it is wonderful,” says Vyshnevskyi. “This land was once heavily used: agriculture, cities, infrastructure. But nature has done a factory reset.”
This story was translated from English to Spanish with an artificial intelligence tool and was reviewed by an editor before publication.