Japanese raccoon dog

The Japanese raccoon dog (Nyctereutes viverrinus, or tanuki (Japanese: 狸, タヌキ)) is a species of canid that is endemic to Japan.^[1] It is one of two species in the genus Nyctereutes, alongside the common raccoon dog (N. procyonoides),^[2] of which it is considered to be a subspecies by some taxonomic authorities.

Japanese raccoon dog
In Higashiyama Zoo and Botanical Gardens
Conservation status
Least Concern  (IUCN 3.1)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Canidae
Genus:	Nyctereutes
Species:	N. viverrinus
Binomial name
Nyctereutes viverrinus (Temminck, 1838)
Synonyms
Nyctereutes procyonoides viverrinus

Japanese raccoon dogs have had a significant role in Japanese folklore since ancient times. They are reputedly mischievous and jolly, masters of disguise and shapeshifting, but somewhat gullible and absent-minded. The animals are common in Japanese art, particularly as statues.

Description

The Japanese raccoon dog has a smaller stomach and shorter fur of lesser insulation value than mainland raccoon dogs.^[3] A white color type is rare.^[4] In mainland Japan, oculocutaneous albinism is caused by a mutation in the third and fifth exon of the TYR nucleotide sequence, which is responsible for melanin pigmentation.^[5]

Behavior

The Japanese raccoon dog is mainly nocturnal. It vocalizes by growling or with groans that have pitches resembling those of the domesticated cat. Like the cat, its back arches to intimidate other animals. It assumes a defensive posture similar to that of other canids, showing submission by lowering its body and showing its belly.

Usually, social groups are limited to a breeding pair, but the individual Japanese raccoon dog may stay in a group of non-paired individuals until finding a mate.^[6]

The species is predominantly monogamous. The breeding period for the species is synchronized between females and males and lasts between February and April. A litter (typically with 4–6 pups) is born after a gestation period of 9 weeks. The parents look after their pups at a den for around one month, and then for another month after the pups leave the den.

Japanese raccoon dogs live for 7–8 years in the wild and have reached the age of 13 in captivity.^[6]

It has been observed climbing trees to forage for fruits and berries,^[7][8] using their curved claws to climb.^[9]

Taxonomy

Japanese raccoon dogs at Fukuyama, Hiroshima

Several raccoon dogs are at Tobu Zoo in Saitama prefecture.

The Japanese raccoon dog is classified as its own distinct species due to unique chromosomal, behavioral, and morphological characteristics absent in mainland raccoon dogs.^[10] Genetic analysis has confirmed unique sequences of mtDNA, classifying it as a distinct isolation species, based on evidence of eight Robertsonian translocations. Following morphological and genetic analysis across multiple studies, all of which indicated that N. viverrinus was a distinct species, it was later classified as such by the American Society of Mammalogists.^[2][11] However, the International Union for Conservation of Nature Canid Group's Canid Biology and Conservation Conference in September 2001 rejected the classification of the Japanese raccoon dog as a separate species, but its status is still disputed, based on its elastic genome.^[12] Aggregators on mammal taxonomy are inconsistent on the issue. Both the IUCN and Mammal Species of the World (2005) consider the Japanese raccoon dog to be a subspecies of the common raccoon dog (N. procyonoides), whereas the American Society of Mammalogists includes N. viverrinus as a valid species in its Mammal Diversity Database.^[13][14]

The karyotype of Japanese raccoon dogs is different from that of the mainland raccoon dogs.^[15] Though it is unknown whether mainland raccoon dogs and Japanese raccoon dogs can produce fertile offspring, it is assumed that the chromosomal differences between them would have deleterious effects on the fertility of the potential offspring and this would be indicative of speciation.^[16][12][17]

Researchers suggest that raccoon dogs of Japan could be further divisible into separate subspecies as N. p. procyonoides and N. p. albus, but both views are controversial.^[12] The raccoon dogs from Hokkaido are sometimes recognized as the subspecies Nyctereutes viverrinus albus, a taxon that is synonymized with N. p. viverrinus in Mammal Species of the World,^[15][13] but comparative morphometric analysis supports recognizing the Hokkaido population as a distinct subspecific unit.^[15]

Conservation

The IUCN places the raccoon dog at "least concern" status due to the animal's wide distribution in Japan and abundant population, including as an introduced species throughout northeastern Europe. In many European countries, it is legal to hunt raccoon dogs, as they are considered a harmful and invasive species.^[18] In Japan, the species is hunted mainly to prevent crop damage; however, its fur is desired for use in calligraphy brushes and was exported chiefly to the United States before the outbreak of World War II. The animal suffers a conservative estimate of up to 370,000 deaths by vehicles each year in Japan.^[6]

In folklore and tradition

Taxidermy of a Japanese raccoon dog, wearing waraji on its feet. This tanuki is displayed in a Buddhist temple in Japan, in the area of the folktale "Bunbuku Chagama".

Tanuki statue at Shigaraki, Kōka, Shiga prefecture.

Japanese raccoon dogs, known in Japanese as tanuki, have a long history in Japanese legend and folklore. Bake-danuki is a kind of supernatural being in the classics, folklore, and legends of various places in Japan.

Although the Japanese raccoon dog is a real animal, the bake-danuki that appears in literature has always been depicted as a strange or supernatural animal. Its earliest appearance in literature is in the chapter about Empress Suiko in the Nihon Shoki written during the Nara period, with such passages as "in two months of spring, there are tanuki in the country of Mutsu,^[19] they turn into humans and sing songs".^[20][21][22] Bake-danuki subsequently appear in such classics as the Nihon Ryōiki^[21][23][24] and the Uji Shūi Monogatari.^[21] In some regions of Japan, bake-danuki reputedly have abilities similar to those attributed to foxes, so they can shapeshift into other things or people,^[21][24] and can possess human beings.^[21][25]

Many legends of Japanese raccoon dogs are from the Sado Islands of Niigata Prefecture and in Shikoku. They include the Danzaburou-danuki of Sado, the Kinchō-tanuki and Rokuemon-tanuki of Awa Province (Tokushima Prefecture), and the Yashima no Hage-tanuki of Kagawa Prefecture. The tanuki with special abilities were given names, and became the subject of rituals.^[26]

In popular culture

The Japanese raccoon dog (or its folklore version bake-danuki) is a recurring theme in Japanese popular culture. The first exposure of non-Japanese to tanuki usually comes through exported Japanese media. In translation, they are often described or assumed as the raccoon.^[27]

• In Nintendo's video games, Mario can wear a Tanooki Suit with the appearance of a tanuki, so he can fly and shapeshift into an Ojizō-sama statue, much like a bake-danuki. This power-up is based on the mythology of tanuki using leaves to transform.^[27]
• The 1994 Studio Ghibli film Pom Poko features a group of tanuki using shapeshifting powers to defend their habitat against human developers.^[28]
• A running joke in the One Piece manga and anime series is that the character Tony Tony Chopper, a shape-shifting reindeer, is frequently mistaken for a tanuki by other characters. In return, he angrily corrects them that he is a "tonakai" (Japanese for "reindeer").^[29]
• The 2020 Studio Trigger TV anime BNA: Brand New Animal features main protagonist Michiru Kagemori, a humanoid shape-shifting tanuki who is often mistaken as a raccoon.^[30]