The areas surrounding Fukushima, Japan, are experiencing a “rewilding” of abundant animal populations nearly a decade after the nuclear disaster that prompted the evacuation of more than 100,000 people, new research suggests.

Following the devastating 9.0 earthquake in 2011, a 15-meter (49-foot) tsunami disabled power supply to three reactors at the Fukushima Daiichi nuclear facility. Within three days, all three cores had melted and officials evacuated a zone measuring 1,150 square kilometers (444 square miles). Researchers believe it is largely due to the lack of human presence that wild animals have repopulated the region now known as the Fukushima exclusion zone (FEZ).

“Our results represent the first evidence that numerous species of wildlife are now abundant throughout the Fukushima Evacuation Zone, despite the presence of radiological contamination,” said James Beasley, associate professor at the Savannah River Ecology Laboratory and the Warnell School of Forestry and Natural Resources, in a statement.

To come to their conclusions, researchers at the University of Georgia placed 106 cameras over three research zones: one region in which humans are banned from entering due to high levels of contamination, another with restricted human access from intermediate levels of contamination, and a third with low levels of radiation where humans are allowed to inhabit. Over the course of 120 days, more than 267,000 photos captured 20 species, among them macaque monkeys, Japanese hares, and martens, as well as the fox-related raccoon dog – but it was the wild boar that was the biggest ham for the camera. A total of 46,000 images captured the wild boar, also known as the white-moustached pig, half of which were seen in uninhabited areas.  

Generally speaking, the animals’ ranges were influenced by the terrain and ecosystem, as well as were aligned with behavioral patterns. For example, nocturnal raccoons were most active during the night, while wild boar populations altered their grounds based on the presence of humans. One exception was the goat-like Japanese serow, which normally lives far away from humans but was frequently seen on camera in rural inhabited zones in a behavior that is believed to be linked to the newly established boar range.

The findings help to answer questions about how wildlife may repopulate abandoned lands in the aftermath of a nuclear accident like those that occurred in Fukushima and northern Ukraine’s Chernobyl exclusion zone (CEZ). Previous research out of UGA has found that the CEZ is seeing a resurgence of wildlife, including endangered wild horses that have taken up residence in deserted structures. In both cases, the landscape surrounding an accident zone offers “a rare opportunity to investigate the confounding effects of radiological contamination and human abandonment on ecological communities,” write the authors in Frontiers in Ecology and the Environment. The researchers note that their analysis is not an assessment of health but suspect that there may be radiation effects at the molecular level.