A tsunami triggered by a magnitude 9.0 earthquake - the biggest ever recorded in Japan - ravaged the island country on March 11, 2011.

The tsunami also caused an accident at a nuclear plant in Japan's Fukushima area, forcing 164,000 people to flee a 20-kilometer radius around the facility.

Pig farmers were among the refugees who left their pigs behind to escape the fear of nuclear radiation. 

Pigs Left Behind

Little Pigs
(Photo : Photo by Kenneth Schipper Vera on Unsplash)

According to a study published Wednesday in the journal Proceedings of the Royal Society B, the lack of people and the abrupt release of pigs into the wild resulted in novel boar-pig hybrids that are now recovering Fukushima - though experts aren't sure how long these hybrids will endure.

Co-author Donovan Anderson, a Ph.D. student at Fukushima University, said that "while people cannot return, animals did return and even flourished in this human abandoned landscape."

Several stories of animals recovering urban spaces surfaced in the early days of the pandemic, ranging from coyotes roaming the streets of San Francisco to goats encroaching on a Welsh village. Then, after pandemic-related lockdowns, animal lovers rejoiced that nature had finally "healed."

Related Article: Pigs Cut While Still Alive: Hidden Cam Showed Extreme Animal Cruelty in Slaughterhouse

Reentering Natural Habitats

Animals reentering natural habitats or increasing their range, on the other hand, have a long history that predates pandemics and often occurs in the aftermath of calamities. The most well-known example is the 1986 Chernobyl nuclear disaster, widely regarded as the worst nuclear reactor accident in history.

Black Boar
(Photo : Photo from Pixabay)

Following the Chernobyl nuclear reactor disaster, which caused the evacuation of human residents, wolf and elk populations increased in the so-called "exclusion zone," prospering in the absence of humans. This is because animals can adapt to changing surroundings in ways that humans do not.

"Wildlife, enormous animals, may now genetically mingle with new populations that they couldn't previously," Anderson adds. "Perhaps they can wander to new regions, or they must scatter longer distances to hunt for food supplies as a result of rising population densities."

In recent years, plants at Chernobyl have even thrived, regrowing new cells and adapting to a changing environment. The Chernobyl Exclusion Zone currently houses several vulnerable animals from around Europe, including wild Przewalski's horses.

Rise in Wild Boar Population
'Baby Boom' At Zoo Cologne - Eight Very Rare Swabian-Hall Swine Born
(Photo : Photo by Andreas Rentz/Getty Images)

In the aftermath of the disaster, wild boar numbers rose in Chernobyl, according to the authors of the boar-pig research. However, this population ultimately stabilized, then began to decrease, perhaps foreshadowing the fate of the boar-pig hybrids in Fukushima.

Wild boars from surrounding hills came into evacuated villages after the Fukushima accident. According to research, these wild boars are "relatively" radioactive, and measures to kill and remove them from the area have been made.

According to this recent study, several of these boars came upon abandoned pigs and mated with them.

Fukushima Wild Boar Population and Hybrid

(Photo : Brett Sayles)

The researchers looked at the wild boar populations in Fukushima's evacuation zone and discovered that 31, or 16 percent of the total, were hybrids of pure wild boar and domestic pigs.

These hybrid boars didn't travel far from Fukushima's natural regions. Within 20 kilometers of the nuclear reactor site, almost 75% of the hybrid boars were found. Only one female hybrid was discovered outside the original 20-kilometer evacuation zone, according to researchers.

Furthermore, even though the pigs interbred with the wild boars, their DNA did not appear to be passed down through the generations. Researchers discovered that, on average, boars with pig heritage had just 8% pig DNA.

Also Read: Elephant Herd to be Moved to Kenya for "Rewilding" in a Monumental Conservation Effort

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