Study finds hybrid pig population expanding near Fukushima Daiichi

A population of hybrid pigs, descended from domestic pigs and wild boars, is expanding rapidly in the evacuation zone surrounding Japan's Fukushima Daiichi Nuclear Power Plant, according to a new scientific study. The research indicates these animals have inherited a key reproductive trait that is accelerating their population growth in the abandoned landscape.

The situation originated in the aftermath of the March 2011 disaster, when a magnitude 9.0 earthquake and tsunami triggered a nuclear accident. The evacuation of approximately 164,000 residents created an extensive exclusion zone. In the chaos, domestic pigs escaped from farms and entered nearby forests, where they began interbreeding with native wild boars.

A team of researchers from Fukushima University and Hirosaki University analyzed genetic material from 191 wild boars and hybrids collected between 2015 and 2018. Their study, published in the Journal of Forest Research, found that the hybrid offspring inherited the domestic pig's capacity for a rapid, year-round reproductive cycle, unlike wild boars which typically breed once annually. This trait is passed down through the maternal lineage.