Rare animals thrive in the Chernobyl Exclusion Zone

In research published in the journal Proceedings of the Royal Society B This week, the authors used camera traps to compare the status of wildlife in the Chernobyl Exclusion Zone (CEZ) with the Drevlianskyi nature reserve and nearby unprotected areas. As a result, CEZ excels in wildlife with the highest species diversity and animal habitat ratio, followed by nature reserves, then unprotected areas.

The CEZ was established by the Soviet Union after the reactor explosion at the Chernobyl nuclear power plant in 1986. This area is 2,700 square kilometers around the plant, fenced with a radius of about 30 km and prohibited for people to access due to pollution.

Theo IFL Sciencewhat surprised the group of scientists the most was that CEZ especially promoted the recovery of rare animals, including Przewalski’s horse, lynx, elk, red deer, raccoon, brown bear. Meanwhile, more common species with high adaptability such as red foxes are not thriving as predicted.

“I was surprised to see that the overall species diversity in nature reserves is lower than in the CEZ despite strict protection management. I also expected to see more red foxes because they are highly adaptable,” Ukrainian ecologist Svitlana Kudrenko, associate professor at the University of Freiburg and lead author of the study, shared with IFL Science.

Przewalski’s horse is an interesting case. Once extinct in the wild, this rare wild horse was reintroduced into some areas of Ukraine in the late 1990s. In the new study, camera traps recorded Przewalski’s horses more than 1,000 times in the CEZ, but no individuals were detected outside this area.

Scientists suspect a recent ecological upheaval has prompted the horse herd to recover. “We conducted field research from 2020 to 2021, immediately after the large wildfires in the CEZ. The lush vegetation that grew after the fires attracted ungulates, including Przewalski’s horses,” Kudrenko said.

Similarly, the research team also recorded several images of brown bears in the CEZ, but did not detect any individuals outside. Red deer were photographed thousands of times in the CEZ, but only a few hundred times in the nature reserve and none elsewhere.

Theo Science Alertthe research team was not trying to investigate the effects of radiation on animals but wanted to assess what would happen when humans were no longer present. Research results show that reducing human activity benefits wildlife. Nature reserves are most effective when they are large enough for animals to roam freely, connected to each other rather than isolated, and tightly managed to truly keep people out.

According to research published in 2024 by Jim Beasley, an expert at the University of Georgia, and his colleagues, populations of large mammals increased after humans left the CEZ. They are widely distributed throughout the restricted area, including more heavily polluted areas around old nuclear power plants.

Some animals are even adapting to harsh environments. A 2024 study by Cara Love, an evolutionary biologist and ecotoxicologist from Princeton University, showed that the immune systems of gray wolves in the CEZ were altered similarly to patients undergoing radiation therapy. They may also have developed protective mutations that increase their chances of surviving cancer.

In research published in the journal Evolutionary Applications In 2022, the skin color of eastern tree frogs at CEZ changes from green to black. The team found that the darker color may not be due to a random mutation but rather an adaptive response to protect the frogs from high radiation.