A pure white, thin body with a short tail. In the woodlands of the Tokachi region, I encountered the world’s smallest carnivorous mammal at approximately 20 centimeters long, the least weasel.

The least weasel does not often show itself around people in its natural environment. They avoid contact with their natural predators, the birds of prey and the ezo red fox, and move about amidst shrubs that block visibility with countless branches from fallen trees and marshland area thickly covered by reeds. And because they dig tunnels in the snow when traveling across open areas, large animals cannot give chase.

Though small in form, these weasels are ferocious hunters, and prey mainly on mouse-like rodents. At times, they even climb trees and attack wild birds or squirrels. In addition to Hokkaido, the lesser weasel widely inhabits the Eurasian and North American continents as well. However, partially because it is small and difficult to spot, research on the lesser weasel has not advanced substantially, and the details of its biology are not well known.

After spotting it, I readied my camera and focused in about one to two seconds. As soon as I clicked the camera shutter, it disappeared into the snow.