Common raccoon dog

Name and taxonomy

John Edward Gray described the species in 1834 from a Chinese specimen. The genus name Nyctereutes is thought to mean night wanderer in Greek, and procyonoides means raccoon-like. Writers call it the Chinese or the Asian raccoon dog when they need to separate it from the Japanese one. Mammal Species of the World recognised four subspecies in 2005. GBIF lists five, named by Gray, Mori, Thomas, Matschie and Temminck between 1834 and 1923.

The Japanese raccoon dog, the tanuki, was long counted as one of those subspecies. Most authorities now give it species rank as Nyctereutes viverrinus. The Japanese animal has 38 chromosomes and the mainland animal 54, so the two probably cannot interbreed. In Sweden, Norway and Denmark the animal is the marten-dog. Furriers sell its pelt as Finn raccoon, Asiatic raccoon, murmansky or tanuki.

Evolution and relatives

The genus Nyctereutes is one of the oldest dog lineages of the Old World. It arose in northern China about 5.5 million years ago, late in the Miocene. Fossil species lived across Eurasia and Africa, from Spain to Ethiopia and Morocco. Nyctereutes donnezani lived in Europe from 9.0 to 3.4 million years ago, and N. sinensis in East Asia until about 781,000 years ago.

The genus belongs to the tribe Vulpini, beside the true foxes of the genus Vulpes. Its skull looks much like that of the South American crab-eating fox, but genes show the two are not close. The mainland and Japanese lineages parted about 0.5 million years ago, well ahead of the final glaciation. Among all canids, only the North American gray fox shares its habit of climbing trees, and that fox is not a close relative either. The real raccoon is a musteloid, on a different branch of the carnivores altogether.

Appearance

The raccoon dog has a long body, short legs and a short, bushy tail. Total length runs from 45 to 71 centimetres, with a tail of 12 to 18 cm. It stands 38.1 to 50.8 cm at the shoulder. Weight changes with the season: about 3 kilograms in March and 6.5 to 7 kg in late summer. The heaviest animals reach 9 to 10 kg before winter. Animals from Japan and Russia average larger than those from China.

The winter coat is long and thick, with guard hairs up to 120 millimetres, and keeps out cold down to minus 20 to 25 degrees. It is a dirty earth brown or brownish grey, and the guard hairs are tipped black. A dark stripe runs down the back and widens over the shoulders into a cross. The face carries a black mask around the eyes, a white muzzle and long whiskery cheek hair. The chest and legs are blackish brown, and the belly is yellowish brown. The summer coat is thinner and a brighter reddish straw colour.

The ears are short and round and barely show above the fur. The teeth suit an omnivore: small canines, weak carnassials and flat molars. The gut is 1.5 to 2.0 times longer than in other canids, to digest plant food. A rare white form occurs in China, and yellow animals also appear.

Habitat and range

The native range covers eastern Siberia, northern China, Korea, Mongolia and northern Vietnam. Japan holds the closely related Japanese raccoon dog. Between 1928 and 1958 the Soviet Union released 10,000 animals in 76 districts to improve the fur supply. Releases in Siberia and the mountains of the Caucasus failed, but those in European Russia, Ukraine and the Baltic states thrived. Latvia received 35 animals in 1948, and by 1960 hunters there took 4,210 in a year.

The species is now abundant in Finland, Estonia, Latvia and Lithuania. It has reached Scandinavia, Germany, the Low Countries, France, Switzerland and the Balkans. Denmark aimed for zero breeding by 2015, yet by 2018 the animal was established across Jutland. A 2021 British study named it one of 20 invasive species likely to reach the United Kingdom. GBIF holds occurrence records from 41 countries.

It favours forest, forest edge, marsh and reedbed, wherever there is thick cover near water. It lives from sea level to above 3,000 metres. It also scavenges around villages and town edges. For its den it takes over burrows left by foxes and badgers.

Diet and feeding

The raccoon dog is a gatherer rather than a hunter. It walks with its nose to the ground and eats whatever it finds. The list includes insects, voles, gerbils, shrews, hedgehogs, frogs, toads, birds, eggs, fish, snakes, lizards, molluscs, crabs and sea urchins. Plant food covers bulbs, roots, oats, millet, maize, nuts, berries, grapes, melons, pumpkins and tomatoes. It also eats carrion, droppings and household rubbish.

The menu shifts with the season. Rodents and carrion dominate in late autumn and winter, frogs and insects in spring, and nesting birds, fruit and grain in summer. Voles lead the diet in marshes, and gerbils replace them on the dry plains near Astrakhan. Large moles are the main food in the Ussuri region. It can eat toads with poisonous skin by producing a flood of saliva that dilutes the toxin.

It fishes in lakes and streams, scooping prey out with its paws, and it will dive for food. On the coast it eats beached fish and anything the tide leaves. In Japan it relies heavily on rubbish, insects, crabs and the fruit of buckthorn and hornbeam. In floodplains and estuaries it eats little but eggs and chicks in spring, and birds reach 48.6% of the diet in the Voronezh Reserve.

Behaviour and social life

Raccoon dogs live and forage in pairs or small family groups, though people usually see one alone. A pair shares one home range and often stays close while active. Neighbours whose ranges overlap ignore each other, so the species is not territorial. Home ranges vary from 2.8 to 200 hectares. Resting pairs stay in contact, and social grooming matters to them.

It is active mainly at night, but recent studies record activity at dusk and by day too. It is slow, never runs prey down, and swims and climbs well. It is the only canid known to hibernate. In early winter it adds 18 to 23% to its fat under the skin, and an animal may gain 50% of its body weight. Animals that fail to fatten usually die before spring.

Pairs hibernate together from November to as late as early April, and the metabolism drops by 25%. Once snow reaches 15 to 20 centimetres, activity falls and the animal stays within 150 to 200 metres of its den. In milder regions, and in most of its European range, it sleeps only through severe snowstorms. In the south of the range it does not hibernate at all. Activity picks up in February, when females come into season and food returns.

Communication and senses

Smell is the main sense, because the raccoon dog's eyesight is poor for a canid. Families share latrines, fixed spots where every member urinates and defecates. The latrine works as a notice board, and animals change their behaviour after they smell a known or unknown neighbour there. Scent marking rises before the mating season.

Unlike every other canid, the raccoon dog does not bark. It whines, whimpers and mews in friendly or submissive moods, and growls when frightened or angry. Males in rut yelp and growl, but otherwise the animal is usually silent. A male holds his tail in an inverted U to show arousal and dominance. Touch is probably important between mates and between parents and pups.

Reproduction and life cycle

Raccoon dogs are monogamous, and pairs form in autumn. Captive males, though, have mated with four or five females. Mating runs from January to April, depending on latitude, and follows hibernation. Males fight briefly for mates, but not to the death. A female is in heat for a few hours to six days and may mate up to five times. Mating happens at night or at dawn and lasts 6 to 9 minutes.

Gestation lasts 59 to 70 days, and pups arrive in April or May in a burrow or dense cover. A litter usually holds 6 to 8 pups, and ADW records a record of 19. First-time mothers bear fewer. Newborns weigh 60 to 110 grams and are blind, with soft black wool. Eyes open at 9 to 10 days and teeth appear at 14 to 16 days. The mother suckles for 45 to 60 days, but pups take solid food from three weeks.

The father matters. He brings food to the pregnant female and guards the pups while she forages. Early Soviet releases of pregnant females without males failed, and releases of pairs succeeded. Pups reach full size at 4.5 months and leave their parents in late August or September. They pair up by October and can breed at 8 to 11 months. Wild animals seldom pass 7.5 years, and one captive animal lived 16.6 years.

Predators and threats

Wolves are the main predator and kill large numbers in spring and summer. In Tatarstan wolves cause more than half of raccoon dog deaths, and in northwestern Russia almost two thirds. Red foxes kill pups and sometimes adults, and badgers kill raccoon dogs that enter their setts. Eagle owls, goshawks and both golden and white-tailed eagles take them, and lynx do so rarely. Domestic dogs and hunters are major killers in Finland and the former Soviet Union.

The animal carries 32 kinds of parasitic worm, including the dangerous tapeworm Echinococcus. Rabies has been recorded in raccoon dogs in Lithuania, Voronezh and the lower Volga, and distemper in the northern Caucasus. Its introduction to Europe is thought to have brought ticks carrying the Asian tick-borne encephalitis virus. Mange infects it but does not cut its numbers the way it does in foxes. None of these threatens the species as a whole.

Population and conservation

The IUCN lists the common raccoon dog as Least Concern. It is common throughout its native range and still spreading in Europe. In Japan the related species reaches densities of 0.46 to 0.86 per hectare, far above the 0.0014 to 0.048 recorded in Europe. Nobody appears to have estimated the world population.

In Europe the effort runs the other way: governments try to remove it. Since 2019 the European Union has banned its import, breeding, sale and release. Finland hunted 60,000 to 70,000 in 2000 and 170,000 in 2009. Poland shot 6,200 in 2002 to 2003, and Sweden and Denmark catch only two to seven a year. Japan culled an average of 4,529 tanuki a year between 1990 and 1998. It harms ground-nesting birds, muskrat colonies, vineyards and melon fields, which is the main reason for control.

Relationship with humans

Fur is the reason people moved this animal across a continent. World trade in its pelts reached 260,000 to 300,000 a year in 1907 to 1910. Soviet farms began breeding it in 1928, with 15 state farms by 1934, and Ukraine made it the chief farmed furbearer. China raised about 1.5 million raccoon dogs for fur in 2004 to 2005, by one animal welfare estimate. The coarse guard hairs mean the pelt goes mostly into trim on hoods and collars.

Its fur has been sold as fake fur more than once. In 2006 Macy's withdrew Sean John jackets labelled faux fur that were raccoon dog. In 2013 three American retailers settled with the Federal Trade Commission over the same mislabelling. In Japan people have eaten the animal and used its hair for calligraphy brushes. In the Far East hunters run it down at night with laika dogs. Dogs succeed in 80 to 90% of hunts, guns in 8 to 10%.

The species entered public health news through live-animal markets. A SARS-like virus was isolated from a raccoon dog in a Guangdong market in 2003. Swabs from the Huanan market in Wuhan in early 2020 held SARS-CoV-2 and raccoon dog genetic material together. Virologists such as Christian Drosten consider it a likely intermediate host between bats and people, though this is not proven.

In culture and myth

The folklore belongs to the tanuki, the Japanese raccoon dog, a close relative once counted as a subspecies. In Japanese tradition the tanuki changes shape and plays tricks for fun, where the fox tempts people. It drums on its belly, a sound the stories write as pom poko. Pictures give it an enormous scrotum, a joke that started with Kanazawa goldsmiths who beat gold thin inside tanuki skin. Written tanuki stories go back to the Nara period.

In the tale Bunbuku Chagama a tanuki becomes a monk's teakettle that never runs dry. In Kachi-kachi Yama it is the foolish villain, and a children's song has tanuki drumming under the moon at Shojoji temple. Ceramic tanuki stand outside shops and restaurants across Japan. Their eight lucky traits, from the straw hat to the sake bottle, were invented in 1952 by Shigaraki potters. The 1994 Studio Ghibli film Pom Poko carried the shapeshifting tanuki to the world, where many viewers took it for a raccoon.