Chernóbil se convierte en refugio inesperado para la vida salvaje casi 40 años después

When the reactor at Chernóbyl exploded on April 26, 1986, Soviet authorities evacuated more than 100,000 people and drew a 30-kilometer perimeter around the plant. That boundary would eventually expand to cover roughly 2,600 square kilometers of Ukrainian territory—an area about 1.7 times the size of Mexico City—where human settlement, economic activity, and public access were forbidden. For nearly four decades, the region remained one of the most radioactively contaminated places on Earth. Yet something unexpected happened in the silence that followed: the land began to flourish.

Today, the Chernóbyl Exclusion Zone shelters thriving populations of grey wolves, brown bears, Eurasian lynx, moose, wild boar, red deer, and European bison. The Przewalski horses—a species once thought extinct in the wild until its reintroduction in the late 1990s—now roam freely across the abandoned landscape. In one section of the Ukrainian zone alone, more than 150 of these horses live without human interference. The paradox is so striking that it has drawn the attention of researchers worldwide, culminating in a detailed new study published in the Proceedings of the Royal Society B by Ukrainian ecologist Svitlana Kudrenko and her team at the University of Freiburg in Germany.

Between 2020 and 2021, Kudrenko's researchers deployed camera traps across 60,000 square kilometers in northern Ukraine, covering the exclusion zone, four nearby nature reserves, and several unprotected areas. The cameras recorded 31,200 detections of 13 different wildlife species. More than half of those detections—19,832—occurred within Chernóbyl's exclusion zone itself. The statistical models built from this data revealed something that surprised even seasoned scientists: the diversity, density, and frequency of wildlife sightings were significantly higher inside the exclusion zone than in nature reserves actively managed for conservation. Kudrenko herself acknowledged the shock of finding that species diversity was actually lower in professionally managed reserves than in an abandoned nuclear disaster zone.

The obvious question is whether this flourishing happens despite the radiation or simply alongside it. The answer appears more nuanced than a simple either-or. A 2016 study showed that mammal distribution within the exclusion zone bore no clear relationship to radioactive contamination levels. Kudrenko's work took a different approach: it asked what happens when humans almost entirely vanish from a landscape. Evolutionary biologist Germán Orizaola, who has spent years studying the zone but was not involved in this research, explained the distinction plainly. When species struggle, people blame radiation, he noted. But often the environment itself has changed. Ecology and human absence are enormous factors. After the accident, hunting disappeared. Roads deteriorated. Agricultural fields were abandoned. The single greatest threat to large wildlife—human presence—nearly vanished. What remained was a territory largely forgotten by the world.

The Przewalski horses offer a particularly revealing example. Camera traps recorded them more than a thousand times inside the exclusion zone and not once outside it. Brown bears and red deer showed similar patterns, photographed thousands of times within the zone but almost absent in surrounding areas. The red fox, by contrast—a species highly adaptable to human coexistence—showed no comparable increase. This suggested to researchers that the greatest benefits of this ecological paradox favor species most sensitive to human activity. Even moose demonstrated the point: their presence visibly declined precisely when researchers themselves entered the zone to study them.

Radiation, however, is not a neutral element in this story. While many species seem to thrive in human absence, some may be showing signs of adaptation to Chernóbyl's extreme environment. Eastern tree frogs in the exclusion zone are on average 43 percent darker than their counterparts elsewhere in Ukraine. The likely explanation involves melanin, the pigment responsible for dark coloration and also protective against radiation damage. Natural selection appears to have rapidly favored darker individuals—not because new mutations emerged, but because that trait already existed in the population and proved advantageous in the radioactive environment. Even stranger adaptations occur inside the destroyed reactor itself, where black fungi rich in melanin colonize zones saturated with ionizing radiation. Laboratory experiments suggest some of these organisms may actually grow more vigorously when exposed to radiation, possibly using that energy as a metabolic source, though this remains an open hypothesis. Grey wolves have also become research subjects, with a 2024 study detecting immune system alterations similar to those seen in human radiotherapy patients, possibly linked to cellular protection mechanisms.

Kudrenko's work carries a direct message for protected area managers worldwide: size matters, connectivity matters, and genuine human exclusion matters more than strict regulations on paper. The reserves that function best are not the most tightly regulated in theory but the largest, most interconnected, and those that actually keep people out. At this scale, the mosaic of habitats becomes extensive enough to sustain viable populations of large animals over the long term. Large protected areas are vital for the long-term survival of rare species, Kudrenko insisted, and it is tempting but dangerous to lower research standards in complicated zones. Access to the region has grown more difficult since Russia's 2022 invasion, complicating future fieldwork. Yet nearly four decades after the disaster, Chernóbyl has become an ecosystem difficult to compare with any other, shaped by both radiation and decades of human abandonment. The zone does not prove radiation is harmless. But it does suggest something more uncomfortable: that for many species, the near-total absence of human activity may be more favorable than coexistence with roads, agriculture, hunting, and constant urbanization.