Humans have deserted the region, but not the animals. Wolves, dogs, frogs, wild boars and deer now live in the Chernobyl exclusion zone, far from humans. The perimeter of more than 2,600 km2 around the nuclear reactor, straddling Ukraine and Belarus, has gradually become a privileged playground for scientists interested in the long-term effects of ionizing radiation.
On April 26, 1986, during a safety test, a series of explosions destroyed part of the Chernobyl power plant, expelled radionuclides into the environment and exposed the reactor core to the open air. The disaster directly affects hundreds of thousands of people, forced to evacuate. It also leaves behind a contaminated environment that researchers around the world are still trying to understand 40 years later.
Among the fields of research, wildlife figures prominently. How can it survive at levels of radioactivity so conducive to cancer? In 2014, a team from Princeton University (United States) collared the gray wolves of Chernobyl. The radiation dosimeters attached to it find radiation exposure six times the legal limit for human beings.
In March 2026, a new Princeton team, led by biologist Cara Love, published a new study in the journal Molecular Ecology, which Popular Mechanics echoes. She focuses on radiation-induced stress and potential selection toward immunity in Chernobyl wolves.
The paper confirms several specificities of the exclusion zone: modification of the immune system, genetic modulation linked to radioactivity, accelerated divergence in areas of DNA which manage immunity and protection against cancer. In other words, the Chernobyl wolves carry immune and genetic signals adapted to life under chronic radioactive stress. The publication does not, however, prove that these gray wolves have less cancer or that they no longer die from it at all.
Humans, worse scourge than radiation
Focusing on wolves in the exclusion zone is of particular interest because they are apex predators and at the top of the food chain. Normally, this is the dream position, but in an ecosystem devastated by a nuclear disaster, the superpredator must feed on irradiated prey, having themselves eaten irradiated plants, which grew in irradiated soil. Far from ideal, then.
Cara Love and her colleagues were therefore surprised to see that wolves were not at all on the verge of extinction, despite their irradiated meals. Better still, their population in the exclusion zone is seven times denser than in the areas of Belarus where they are a protected species, right next door. A brand new study explains this resurgence of mammals in Chernobyl: there are simply no humans.
The fact remains that abundance is not adaptation. The surprising number of wolves in the exclusion zone may be due solely to the space it provides, the prey it contains, and the lack of human disturbance. This does not mean that the wolves there are healthy. On the other hand, we now know that their genes and their immune system seem resilient to radioactivity.
“Grey wolves allow us to better understand the consequences of chronic exposure, at low doses and over several generations, to ionizing radiationenthuses Princeton co-author Shane Campbell-Stanton to NPR. As an evolutionary biologist, the first question I ask myself is whether these radiations are a sufficient factor to have an impact on natural selection.
