Meles anakuma
Japanese badger

Japanese badgers (Meles anakuma) are endemic to Japan, inhabiting Honshu, Kyushu, Shikoku, and Shodoshima, Japan. (Tanaka, et al., 2002; Wilson and Reeder, 2005)

Meles anakuma is a terrestrial mammal that inhabits deciduous woods, mixed woods, copses. THis species is occasionally sighted in suburban and agricultural areas as well. Setts, or its den, are constructed in covered areas to allow it to emerge and retreat inconspicuously. Hills and slopes facilitate the removal of soil and increase drainage, making them a preferred location for sett construction. Meles anakuma can be found from sea level to 1700 m in elevation throughout its geographic range. (Neal, 1986; Tanaka, 2005; Tanaka, et al., 2002)

Japanese badgers are dark brown with a white face and a chocolate-brown eye stripe on their face that runs from the snout to the ear. In some specimens the stripe is reduced to a ring around the eye giving the animal a panda-like appearance. Males and females are indistinguishable by fur color. Vibrissae are present on the elongated snout and act as a tactile sense organ. Their ears are small and lie close to the side of the head. Feet are broad and have five digits with non-retractable claws. Japanese badgers are stocky with short robust limbs and a short tail. (Kaneko and Sasaki, 2008; Neal, 1986)

On average, Japanese badgers are smaller than Eurasian badgers. Skull size and sexual dimorphism is less pronounced than in Eurasian badgers. Average body weight during spring (April to July) exhibits a great deal of variation from one location to the next. In Yamaguchi, average spring body weight is 5.7±0.4 kg for males and 4.5±0.8 kg for females, whereas in Tokyo, average spring body weight is 7.7±1.3 kg in males and 5.4±0.8 kg in females in Tokyo. Yearling females weigh 3.6±0.6 kg, while yearling males weigh 4.2±0.6 kg. Total body length in adults (i.e., greater than 2 years old) is 78.7±4.9 cm in males and 72.0±2.3 cm in females. (Abramov and Puzachenko, 2005; Neal, 1986; Wilson and Reeder, 2005)

Japanese badgers are polygynandrous. Males and females copulate with multiple mates throughout the year. Males signal interest to females by raising their tails into a vertical position while emitting a deep whinny purr. Prior to mating, violent interactions may occur and can include musk emission. (Neal, 1986)

Reproduction in Japanese badgers is similar to that of Eurasian badgers. Litters typically consist of 1 to 4 young, but sometimes as many as 6. Birth mass ranges from 75 to 90 g, with an average of 80 g. On average, weaning is complete by 5 weeks after birth, with most individuals weaned by 4 to 6 weeks of age. Male offspring remain with their mother for up to 26 months, whereas female offspring share a sett with the mother for only 14 months. On average, females reach sexual maturity at 24 months, while males typically reach sexual maturity at 15 months. (Neal and Cheeseman, 1996; Neal, 1986)

Unlike Eurasian badgers, Japanese badgers do not form male-female bonds for rearing cubs. During mating season, males expand their home range to overlap with those of 2 to 3 females. Male badgers are solitary most of the year, but form temporary bonds with one or several females during breeding season. Mating and fertilization can occur at any time throughout the year, but cubs are only born during spring. This is possibly due to delayed implantation, a condition in which a fertilized egg reaches the uterus but delays implantation in the uterine lining. Birthing takes place in underground dens during spring (April to June). (Neal, 1986)

On average, young Japanese badgers are weaned by 5 weeks after birth, with most individuals weaned between 4 and 6 weeks of age. Male offspring remain with their mother for up to 26 months, whereas female offspring share a sett with the mother for only 14 months. On average, females reach sexual maturity at 24 months, while males typically reach sexual maturity at 15 months. There is no information available regarding paternal care in this species. (Kaneko and Sasaki, 2008; Neal, 1986; Tanaka, et al., 2002)

Little information is available concerning the lifespan of Meles anakuma. Research suggests an average lifespan of 10 years for wild individuals, but life expectancy can vary greatly depending on environment. The oldest known captive individual lived to be 19.5 years old, however, average lifespan in captivity is 13 years. (Neal, 1986)

Most badgers are social and often live together in groups. However, Meles anakuma is more solitary than its close relative, Meles meles, and mating pairs of M. anakuma often live in separate setts. Currently, there is no explanation for solitary behavior in this species. (Neal, 1986; Tanaka, 2006)

Badgers are fossorial and inherit underground burrow systems called "setts". The interlocking tunnels provide shelter during the day and are also used for breeding. Setts vary in size and are expanded and refined throughout the year. Communal setts are passed on for generations, although Japanese badgers have been known to relocate. Numerous setts can be located within one home range of a particular badger. On average an adult male badger has 32 to 71 setts, while females have 20 to 41 setts. There are 4 different types of setts: main, annex, subsidiary, and outlier. Setts are classified based on the number of entrances and paths nearby. A main sett has more than 5 entrances, numerous worn paths, and large heaps of scat. Japanese badgers are territorial and often mark the outside of setts and boundaries of their territory with secretions from their subcaudal glands. (Neal, 1986; Tanaka, 2005; Tanaka, et al., 2002)

In general, Japanese badgers are nocturnal and hibernate during winter, from mid-December to February. They sleep in their setts during daytime, although during spring, breeding females are active during daylight. (Neal, 1986; Tanaka, 2006)

Meles anakuma eyes are unusually small for a nocturnal animal, suggesting that sight is less important than its other senses. Tapetum lucidum and a high number rod photo-receptors help M. anakuma see in the dark. Facial stripes are thought to accentuate any aggressive signals towards conspecifics. (Neal and Cheeseman, 1996)

Japanese badgers have an extremely well developed sense of smell. Secretions from the sub-caudal gland are used by to 'mark' territorial boundaries. The dominant member of each social group often scent marks each member of their group, which helps conspecifics identify dominant individuals as well as group membership. Evidence suggests urine may also be used as a scent marker. (Neal, 1986)

The diet of the Japanese badger consists of insects, earthworms, and fruit. They are opportunistic foragers, rather than hunters. Japanese badgers rely heavily on their sense of smell to guide them to small prey. They also consume carrion when available. (Neal and Cheeseman, 1996; Neal, 1986; Tanaka, 2005)

Known predators of Meles anakuma include wolves, foxes, feral dogs, and humans. Similar to other mammalian species, M. anakuma uses piloerection in an attempt to deter potential predators. Its fossorial and group lifestyle may help it avoid predators. (Neal, 1986)

By digging burrows, Meles anakuma helps aerate soil and increase water penetration. It feeds on earthworms, berries, and insects, and may help control insect pest species as well as disperse seeds throughout its geographic range. Badgers are an important prey item for wolves, feral dogs, and humans. There is no information available concerning parasites specific to this species. (Neal, 1986; Wilson and Reeder, 2005)

There are no known adverse effects of Meles anakuma on humans.

Meles anakuma have been known to cause minor damage to lawns and crops while foraging for food. (Neal and Cheeseman, 1996)

Japanese badgers are a species of least concern on the IUCN's Red List of Threatened Species. Despite this, the population and distribution of Japanese badgers has been in decline over the last 30 years. Habitat loss due to development and agriculture is its biggest threat. Many badgers are killed due to road and rail traffic; tunnels and other efforts have been made in order to deter animals from crossing major roads. In addition, Northern raccoon pose a major threat to their persistence as well. Japanese badgers are considered game in Japan, but hunting has declined since the 1970s. Studies estimate there are as many as 4 adults/km² in Tokyo suburbs. (Kaneko and Sasaki, 2008; Neal, 1986)