Raccoon dogs only conquered Europe once their fathers came along
When fur farmers first released pregnant raccoon dogs into the wild in 1928, few took hold. From 1929 they released pairs instead, and the species spread across much of Europe. The difference was the fathers: male raccoon dogs play a large part in raising pups, and without them litters struggled.
Despite the name and the masked face, the common raccoon dog of East Asia is no relative of the raccoon, which belongs to a different branch of carnivores. It is a canid most closely related to true foxes. Its only living sibling species is the Japanese tanuki. Stocky, long-bodied and short-legged, it measures 45 to 71 centimetres with a short tail, and its weight swings from about 3 kilograms in March to 6.5 or 7 by late summer.
Two habits set it apart from other dogs. Only the North American gray fox shares its knack for climbing trees, and it is the only canid known to hibernate. Before winter it adds 18 to 23 percent to its fat under the skin, and animals that fail to bulk up usually die. Dormant, its metabolism drops by a quarter, although in milder places it sleeps through only the worst snowstorms. Thick winter fur protects it down to about minus 25 degrees.
It eats almost anything: voles, frogs, birds and eggs, stranded fish, crabs and sea urchins, carrion and rubbish, fruit, grain and melons. It even manages toxic toads by producing floods of saliva that dilute their skin poisons. Its menu tracks the seasons, from rodents and carrion in winter to fruit, insects and amphibians in spring. Wolves are its main predator; in parts of northwestern Russia they account for almost two-thirds of deaths.
Pairs form in autumn and are monogamous in the wild. After about two months of pregnancy, females usually bear six to eight pups, occasionally 15 or 16. Pups open their eyes at nine or ten days and are full-sized at four and a half months. Because of its spread, the European Union has since 2019 listed it among invasive species that may not be imported, bred, traded or released.
Source: Common raccoon dog
