Wildlife has returned in great numbers to the exclusion zone surrounding the Chernobyl nuclear disaster site since humans have been banned from the area, scientists say.
Following the 1986 explosion and fire at the Chernobyl power plant, massive amounts of radiation were released into the surrounding region, forcing the evacuation of thousands of people who have never returned.
Scientists conducting a wildlife census now report the area has begun to look like a nature reserve, populated by large numbers of elk, deer, lynx, wolves and wild boars.
"It's very likely that wildlife numbers at Chernobyl are much higher than they were before the accident," says study leader Jim Smith of the University of Portsmouth in the U.K.
The census results suggest that in terms of threats to wildlife, a nuclear disaster may have fewer permanent effects than does the presence of humans, the researchers say.
Writing in the journal Current Biology, they stress they are not suggesting that radiation is in any way good for wildlife.
"It's just that the effects of human habitation, including hunting, farming, and forestry, are a lot worse," says Smith.
Following the disaster, more than 116,000 people were permanently evacuated from a 1,622-square-mile exclusion zone that is now home to a number of thriving mammals species.
For the recent census, an international group of researchers conducted survey counts in the Polessye State Radioecological Reserve, the part of the exclusion zone within Belarus.
The reserve's 836 square miles make up around half of the zone's total area.
The compared their survey results with those from other reserves in the region uncontaminated by radiation.
"The numbers of animals we see in Chernobyl is similar to the populations in uncontaminated nature reserves," Smith says.
Researchers said they were particularly surprised by the number of wolves in the exclusion zone, as much as seven times higher than was found in comparably sized nature reserves nearby.
Smith says it is likely the result of the lack of human hunting activity in the exclusion zone.
The overall conclusion of the study is that mammal populations in the zone have bounced back, the researchers say.
"These results demonstrate for the first time that, regardless of potential radiation effects on individual animals, the Chernobyl Exclusion Zone supports an abundant mammal community after nearly three decades of chronic radiation exposure," they wrote.
The results of the census are a testament to the resilience of wildlife and may also provide important lessons for understanding the potential long-term impact of the 2011 Fukushima disaster in Japan, the researchers note.