More than 20 wild boars appeared at a farm growing Chinese yams in Aomori Prefecture, northern Japan, in June this year.

They included piglets too.

A wild boar was seen carrying a seed yam that had been planted for harvesting in the autumn.

Due to damage caused by wild boars, farmers expect that about 60 tons of Chinese yams, a specialty of Aomori, will be lost from this year’s harvest.

Aomori has seen a sharp increase in wild boar sightings and crop damage.

An expert on wild boars said they are among mammals with very high reproduction rates, and the increase in crop damage this year is likely linked to a rise in their population from last year.

The local agricultural cooperative has been working on countermeasures including setting traps.

But as wild boars are eating even the small seed yams, officials are concerned that next year’s planting may also be affected.