It’s been over five years since tsunami waves crashed into the Fukushima Daiichi power plant and led to its nuclear meltdown. While 20 kilometers (12 miles) of the land around the plant remains a dangerous exclusion zone, the area's wildlife is taking full advantage of the peace.

Since the nuclear disaster, the population of wild boars has rocketed, much to the dismay of surrounding communities, The Times has reported. In the four years following the disaster, the population of boars is thought to have boomed from 3,000 to 13,000. You might think this ancient Japanese symbol of prosperity and fertility might be welcomed, but it’s estimated they have caused $15 million worth of damage to local agriculture.

Assistant ecology professor Okuda Keitokunin told the Japanese Mainichi newspaper that wild boar, along with racoons, have been using the abandoned houses and emptied buildings in the evacuation zone as a place to breed and shelter.

Aerial drone footage from 2015 showing the state of the area surrounding the Fukushima Daiichi power plant

However, this post-nuclear meltdown town isn't exactly a safe haven for the boars. It’s thought their diet of roots, nuts, berries and water all contain particularly high concentrations of radiation. The animals show no immediate signs of harm from the radiation, however samples from Fukushima's wild boar meat has shown they contain 300 times the safe amount of the radioactive element caesium-137. Another study on the area’s fir trees showed evidence of growth mutations.

Hunters have been offered rewards to cull the boars by local authorities. However, the animals are breeding so quickly they can’t keep up. The city of Nihonmatsu, around 56 kilometers (35 miles) from the Fukushima plant, has dug three mass graves capable of holding 1,800 dead boars. Recently, these have become overfilled and authorities are now struggling to cope with the influx of culled beasts.

The boom in boars is a similar story to Chernobyl’s post-meltdown wildlife. A study from late last year showed that the populations of deer and wild boar are thriving in the area surrounding the Ukrainian nuclear power plant.

In a statement Jim Smith, one of the authors of the Chernobyl study, explained, “It's very likely that wildlife numbers at Chernobyl are much higher than they were before the accident. This doesn't mean radiation is good for wildlife, just that the effects of human habitation, including hunting, farming, and forestry, are a lot worse.”

Main image credit: Daisuke Tomiyasu/Flickr. (CC BY-NC-ND 2.0)