The Japanese badger is a species of carnivoran

Carnivora

The diverse order Carnivora |Latin]] carō "flesh", + vorāre "to devour") includes over 260 species of placental mammals. Its members are formally referred to as carnivorans, while the word "carnivore" can refer to any meat-eating animal...

 of the family Mustelidae

Mustelidae

Mustelidae , commonly referred to as the weasel family, are a family of carnivorous mammals. Mustelids are diverse and the largest family in the order Carnivora, at least partly because in the past it has been a catch-all category for many early or poorly differentiated taxa...

, the weasel

Weasel

Weasels are mammals forming the genus Mustela of the Mustelidae family. They are small, active predators, long and slender with short legs....

s and their kin. It is endemic to Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, where it is found on Honshu

Honshu

is the largest island of Japan. The nation's main island, it is south of Hokkaido across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyushu across the Kanmon Strait...

, Kyushu

Kyushu

is the third largest island of Japan and most southwesterly of its four main islands. Its alternate ancient names include , , and . The historical regional name is referred to Kyushu and its surrounding islands....

, Shikoku

Shikoku

is the smallest and least populous of the four main islands of Japan, located south of Honshū and east of the island of Kyūshū. Its ancient names include Iyo-no-futana-shima , Iyo-shima , and Futana-shima...

, and Shodoshima

Shodoshima

is an island located in the Inland Sea of Japan. The name means literally "Island of Small Beans". There are two towns on the island: Tonoshō and Shōdoshima, comprising the district of Shōzu.The island is famous for its stages of Twenty-Four Eyes...

. Japanese badgers are smaller (average length 79 cm in males, 72 cm in females) and less sexually dimorphic

Sexual dimorphism

Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...

 than their Asian counterparts.

Origin

The absence of badgers from Hokkaido

Hokkaido

, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...

, and the presence of related M. leucurus in Korea

Korea

Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...

, suggest that the ancestral badgers reached Japan from the southwest via Korea. Genetic studies indicate that there are substantial differences between Japanese and Asian badgers, which were formerly considered conspecific

Conspecificity

Conspecificity is a concept in biology. Two or more individual organisms, populations, or taxa are conspecific if they belong to the same species....

, and that the Japanese badgers are genetically more homogenous.

Habits

Japanese badgers are nocturnal and hibernate

Hibernation

Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate...

 during the coldest months of the year. Beginning at 2 years of age, females mate and give birth to litters of two or three cubs in the spring (March-April). They mate again shortly afterwards, but delay implantation

Embryonic diapause

Delayed Implantation or Embryonic Diapause is a reproductive strategy used by approximately 100 different mammals in seven or eight different orders. In embryonic diapause, the embryo does not immediately implant in the uterus, but is maintained in a state of dormancy. Little to no development...

 until the following February. Japanese badgers are more solitary than European badgers; they do not aggregate into social clans, and mates do not form pair bond

Pair bond

In biology, a pair bond is the strong affinity that develops in some species between the males and females in a pair, potentially leading to breeding. Pair-bonding is a term coined in the 1940s that is frequently used in sociobiology and evolutionary psychology circles...

s. During mating season, the range of a male badger overlaps with those of 2 to 3 females.

Diet

Japanese badgers have an omnivorous diet that includes worms, beetles, berries and persimmon

Persimmon

A persimmon is the edible fruit of a number of species of trees in the genus Diospyros in the ebony wood family . The word Diospyros means "the fire of Zeus" in ancient Greek. As a tree, it is a perennial plant...

s.

Threats

Although they remain common, their range has shrunk recently. They presently range over about 29 per cent of the country, an area that has shrunk 7 per cent over the last 25 years. Increased land development and agriculture, as well as competition from introduced raccoon

Raccoon

Procyon is a genus of nocturnal mammals, comprising three species commonly known as raccoons, in the family Procyonidae. The most familiar species, the common raccoon , is often known simply as "the" raccoon, as the two other raccoon species in the genus are native only to the tropics and are...

s are threats. Hunting is legal but has declined sharply since the 1970s.