# Japanese black bear

The Japanese black bear (Ursus thibetanus japonicus) is a subspecies of the Asian black bear that lives on two main islands of Japan: Honshu and Shikoku. There are an estimated 10,000 black bears in Japan. The population of black bears on Shikoku is endangered at less than 30 individuals and the last confirmed sighting of a bear on the island of Kyushu was in 1987, making them likely extinct on the island prior to the 21st century. There is a high price on bear parts in the black market, which threatens all bear populations in Japan. This particular species of bear are typically smaller, with males only reaching 60–120 kilograms (130–260 lb) and females only weighing about 40–100 kilograms (88–220 lb). Their body length is about 120–140 centimetres (47–55 in) long.
The Japanese black bear migrated from the Asian continent to the Japanese archipelago in the Pleistocene, where it appears to have differentiated into several geographically restricted groups, around 100,000 to 500,000 years ago. However, based on mitochondrial DNA analysis, it has been suggested these differences only became pronounced genetically around 30,000 years ago.

## Diet

These bears are typically herbivorous, eating mainly grasses and herbs during the spring. During the summer, they switch to berries and nuts to feed themselves for their hibernation. The bear is able to get the berries and nuts by climbing trees and using their claws to grab the food. These animals can be omnivorous and eat other wild animals and livestock when there is a need. Typical prey species include Japanese serow, wild boar, and sika deer. Like other bears, cannibalism occurs, as has been demonstrated when bone fragments and claws of a cub were found inside the stomach of a male black bear. They have also been documented consuming invasive species such as nutria.
Japanese beech mast (seeds) are one of the staple foods for the Japanese black bear, particularly in eastern Japan. The beech mast is produced every few years by the trees, which are widespread throughout Japan as far north as the Oshima Peninsula. Bears also feed on the young leaves, buds, and reproductive organs of the beech trees; the beech tree is the single most valuable food source for bears in areas where beech forests are found.

## Habitat

The bears live on two Japanese islands: Honshu and Shikoku. They can be found in the northeastern high snow region and the southwestern low snow region; however, they have been spotted as high as the alpine region more than 3,000 metres (9,800 feet) high. They tend to live in areas where there is an abundance of grasses and trees with berries to support their diet, particularly broad-leaved, deciduous forests.

### Population isolation

Due to the mountainous nature of Japan, bears are often geographically isolated from each other. In Iwate Prefecture, which has a large population of black bears, the population has been divided into two distinct groups: those in the Ōu Mountains and those in the Kitakami Mountains.

## Seed dispersal

Forests rely on bears as a great method for plants and trees to spread their seeds. The bears will consume the seeds and move 40% farther than a distance of 500 m from the parent tree. They have the potential to spread seeds over huge areas, helping the plant life spread throughout the area. In autumn, the bears have a greater seed dispersal rate and usually the males have a larger dispersal areas than females.

## Conservation

There has been a huge impact on Japanese black bears' populations due to human interference. Habitat destruction is a problem for these bears as peoples' villages begin to grow. Over-hunting and poaching is also a problem. Bears' parts can be sold on the black market for a high price, which makes them very desirable. People kill a lot of these bears, reducing their numbers drastically. Because of this and the carrying capacity reduction due to habitat destruction has resulted in the recognition that the Japanese black bear is at a high risk of extinction. The subspecies will likely be gone within the next 100 years at the rate they are currently declining.

### Interactions with humans

Due to both the expansion of the distribution of bears and human encroachment into bear habitat, contact between bears and humans has increased. In addition to the damage to the bear population caused by habitat destruction, these interactions increase the risk of humans exposure to zoonotic diseases, such as filarial infections, babesiosis, and trichinosis. The appearance of black bears around both suburban and rural residential areas is associated with the failure of hard mast seed production from Japanese beech or mizunara oak trees; in the face of food shortages, bears extend their foraging ranges. Standing Japanese persimmon or chestnuts orchards may attract bears to residential areas.