A large owl of forests along rivers and around lakes in Hokkaido. It eats fish and small mammals and nests in holes in large trees.
The Ministry of the Environment gives a body length of about 70 cm for the Hokkaido subspecies.
The Hokkaido subspecies nests in holes in large tree trunks. It eats fish and small mammals, and parents continue feeding young for about a year after they leave the nest.
An extinction-risk assessment has not been added yet.