Range and Habitat Edit
The raccoon dog is now found across Japan and throughout Europe where it has been introduced and appears to be thriving. Historically however, the raccoon dog's natural range stretched through Japan and across eastern China where the raccoon dog is now extinct in many parts. Raccoon dogs are found inhabiting forests and woodland, that is close to water. Today, although raccoon dog populations are thriving in their introduced habitats in Europe, wild populations in the far east have been rapidly declining mainly due to over-hunting and habitat loss.
Raccoon dogs are unique canines as they are the only dog-like mammal that hibernates through the winter. Although raccoon dog hibernation is not true hibernation, it means that raccoon dogs are able to sleep through severe snowstorms when there is not enough food to allow them to survive. Raccoon dogs usually become more active again in February when the warmer, spring weather begins to return.
There are five different species of raccoon dog found across eastern Asia and in parts of Europe, all of which have been severely affected by deforestation of their native woodlands. Raccoon dogs are also known to have incredibly dexterous front paws which come in very handy when trying to catch slippery food in the water and when climbing trees.
Reproduction and Development Edit
The mating season begins from early February to late April, depending on location. Raccoon dogs are monogamous animals, with pair formations usually occurring in autumn. Captive males, however, have been known to mate with four or five females. Males will fight briefly, but not fatally, for mates. Copulation occurs during the night or dawn and will last 6–9 minutes on average. Estrus lasts from a few hours to six days, during which females will mate up to five times. Females will enter estrus again after 20–24 days, even when pregnant.
The gestation period lasts 61–70 days, with pups being born in April–May. Litter sizes on average consist of 6–7 pups, though 15–16 pups can be born in exceptional cases. First-time mothers typically give birth to fewer pups than older ones. Males take an active role in raising the pups. This male role is very significant, as demonstrated by early releases in 1928 of pregnant females without males resulting in very limited success at introduction, while later releases of pairs from 1929 until the 1960s resulted in the raccoon dog's now extensive introduced European range.
At birth, pups weigh 60–110 grams, and are blind and covered in short, dense, soft wool lacking sight and guard hairs. Their eyes open after 9–10 days, with the teeth erupting after 14–16 days. Guard hairs begin to grow after 10 days, and first appear on the hips and shoulders. After two weeks, they lighten in colour, with black tones remaining only around the eyes. Lactation lasts for 45–60 days, though pups will begin eating food brought to them as early as the age of three weeks or one month. They reach their full growth at the age of 4.5 months. Pups will leave their parents in late August–September. By October, the pups, which by then resemble adults, will unite in pairs. Sexual maturity is reached at 8–10 months. Their longevity is largely unknown; animals 6–7 years of age have been encountered in the wild, while captive specimens have been known to live for 11 years.
Raccoon dogs are the only canids known to hibernate. In early winter, they increase their subcutaneous fat by 18–23% and their internal fat by 3–5%. Animals failing to reach these fat levels usually do not survive the winter. During their hibernation, their metabolism decreases by 25%. In areas such as Primorsky Krai and their introduced range, raccoon dogs only hibernate during severe snowstorms. In December, their physical activity decreases once snow depth reaches 15–20 cm, and will limit the range from their burrows to no more than 150–200 m. Their daily activities increase during February when the females become receptive and when food is more available.
Raccoon dogs are omnivores that feed on insects, rodents, amphibians, birds, fish, reptiles, molluscs, carrion and insectivores. Among the rodents targeted by raccoon dogs, voles seem to predominate in swampy areas, but are replaced with gerbils in flatland areas such as Astrakhan. Frogs are the most commonly taken amphibians; in the Voronezh region, they frequently eat fire-bellied toads, while European spadefoot toads are usually taken in Ukraine. Raccoon dogs are able to eat toads which have toxic skin secretions by producing copious amounts of saliva to dilute the toxins. They will prey on waterfowl, passerines and migrating birds. Grouse are commonly hunted in their introduced range, and many instances of pheasant predation are recorded in the Ussuri territory.
Raccoon dogs will eat beached fish and fish trapped in small water bodies. They rarely catch fish during the spawning season, but will eat many during the spring thaw. In their southern range, they eat young tortoises and their eggs. Insectivorous mammals hunted by raccoon dogs include shrews and hedgehogs and, on rare occasions, moles and desmans. In the Ussuri territory, large molesare their primary source of food. Plant food is highly variable, and includes bulbs, rhizomes, oats, millets, maize, nuts, fruits, berries, grapes, melons, watermelons, pumpkins and tomatoes. In Japan, they have been observed to climb trees to forage for fruits and berries, using their curved claws to climb.
Raccoon dogs will modify their diets seasonally; in late autumn and winter, they feed mostly on rodents, carrion and feces, while fruit, insects and amphibians predominate in spring. In summer, they eat fewer rodents, and mainly target nesting birds and fruits, grains and vegetables. The wolf is the main predator of the raccoon dog as packs of wolves are known to kill large numbers of raccoon dogs in the spring and summer months when they are also feeding their growing young. Foxes and wildcats are the other main predators of the raccoon dog along with humans who have hunted them for their meat and thick fur.
Like dholes, they do not bark, uttering instead a growl, followed by a long-drawn melancholy whine. Captive specimens have been known to utter daily a very different kind of sound when hungry, described as a sort of mewing plaint. Males fighting for females will yelp and growl. Japanese raccoon dogs produce sounds higher in pitch than those of domestic dogs, and sound similar to cats.
Raccoon dog pups are usually born when the summer begins in late April to early May. After a gestation period of up to 12 weeks, the female raccoon dog gives birth to a litter of between 5 and 16 raccoon dog pups which are blind when they are first born. Both raccoon dog parents help to raise their young until they are big enough to become independent and begin hunting for themselves.