Asian Black Bear (Ursus thibetanus japonicus) – Wildlife of Japan

Introduction

The Japanese black bear (Ursus thibetanus japonicus), also called the Asian black bear, is a medium-sized bear native to Japan. It is recognized by a white crescent mark on the chest and is the only bear species inhabiting the forests of Honshu and Shikoku.

Appearance

This is a medium-sized bear with a body length of 110–140 cm. Adult males typically weigh 60–120 kg depending on the season, while females are smaller at 40–90 kg. It has rounded ears, a sturdy build, and is an excellent climber. The white crescent on the chest is the most striking feature.

Habitat

The Japanese subspecies inhabits forests across Honshu and Shikoku, but it is considered extinct on Kyushu. It prefers broadleaf and mixed mountain forests, from low hills to high elevations. Populations are relatively stable in some areas of Honshu, but very small and endangered in Shikoku.

Behavior

Asian black bears are generally crepuscular or nocturnal near human settlements, but may be active in the daytime in remote forests. They climb trees skillfully, sometimes leaving claw marks or broken branches. Bears hibernate in dens between November and April, depending on food supply and region.

Diet

They are omnivorous. Acorns, beechnuts, chestnuts, and seasonal fruits form the bulk of their diet. They also eat insects, larvae, carrion, and sometimes small vertebrates or crops such as corn. In poor nut years, bears may enter villages and farmlands in search of food.

Reproduction

Mating occurs mainly in June–July. Like other bears, they exhibit delayed implantation: fertilized eggs implant only when hibernation begins in late autumn. Cubs, usually 1–2, are born in January–February inside the den. They are weaned by 6–8 months and become independent at about 1.5 years.

Conservation

The species (U. thibetanus) is listed as Vulnerable on the IUCN Red List. In Japan, habitat loss, mast failures, and increasing human–bear conflicts are major challenges. Encounters have risen in recent years, sometimes resulting in injuries. Conservation efforts include habitat management, monitoring populations, and public safety measures such as avoiding attractants and making human presence clear in bear habitats.

Field Notes (Author’s Impression)

I often encounter bears while hiking in the mountains, and every time my heart races with fear. Once, I came face to face with one at close range, and only by hiding behind a tree did I manage to avoid danger. From a distance they can appear almost cute, but up close they are truly dangerous animals — always treat them with caution.

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