Raccoon Dogs Nyctereutes procyonoides are native to the far east of Asia, particularly Korea and Japan (where they are called ‘Tanuki’). They are not related to Raccoons; rather, they are the one of the most primitive extant canids. They spend very cold winter days in a state of torpor, but do not properly hibernate.
Predominately inhabiting deciduous forests, damp areas and river banks, Raccoon Dogs are largely nocturnal, with a home range of between 540 and 2,000 hectares depending upon habitat. They are opportunistic omnivores, feeding on small animals (predominantly amphibians and insects), fruit and refuse.
Introduction to Europe and Current Distribution
There are 44 alien mammal species in Europe, 33 of which are considered established (i.e. they form self-sustaining populations). Of these, the Raccoon Dog is one of the most successful alien carnivores. Between 1928 and 1957 the former Soviet Union introduced around 9,100 Raccoon Dogs into its western territories. These animals were first bred on fur farms and then released deliberately for hunting. Releases also occurred in Estonia in the 1950s, on the Karelian Isthmus near Finland in 1953 and in Belarus in 1963.
These introduced animals thrived, with populations expanding at an estimated rate of 120km per year. For example, in Finland, following colonisation in 1953 and a time-lag of around ten years, rapid population growth started in the 1960s and lasted into the 1970s before slowing somewhat (although numbers are still rising gradually). Today the Raccoon Dog is the most common medium-sized carnivore in Finland; the hunting bag increasing from 818 in 1970/71 to 172,000 in 2009. The rapid increase in Finland was consequence of the scarcity of natural predators (i.e. Eurasian Lynx Lynx lynx and Wolves Canis lupis).
Natural expansion of the population led to Racoon Dogs reaching Germany, where numbers remained low until the 1990s. Since then however the hunting bag in Germany has increased exponentially, evidenced in Brandenburg where 398 were killed in 1995/96 rising to 11,659 in 2001/02. Conversely, in Estonia Raccoon Dogs were widely distributed across the country in the 1950s, although their numbers have remained comparatively low due to the presence of healthy populations of predators.
This species is now present across northern and eastern Europe, particularly in Scandinavia and parts of the former Soviet Union.
Why is the Raccoon Dog so Successful?
The key factors in the population growth of Raccoon Dogs across Europe is this species’ natural tendency and ability to disperse, coupled with the fact that mass introductions of animals occurred over wide areas that included a large degree of genetic variation. Added to this is the Raccoon Dogs ability to adapt to different environments, in addition to a high reproductive rate (mean litter size of 8-10, with up to 16 recorded), low mortality rate and the absence of healthy predator populations in many regions.
The full range of impacts that result from the presence of this invasive species are not well studied or fully understood. However, the likely key direct impacts are as follows:
- Artificially high predation rates of small vertebrates of conservation concern (birds and mammals predominantly, and game species) leading to declines of these species.
- They compete with native carnivores for den sites and carrion, which may result in range contraction of some native species with marginal populations.
- They are a vector for rabies, trichinella, toxocara sp and a wide range of parasites and zoonoses that could affect humans, livestock, domestic animals and wildlife.
Status in the UK, Legislation and the Future
There have been two sightings of Raccoon Dogs in the UK, one involving a roadkill near Loch Lomond in the 1990s and one more recently in Berkshire in 2005.
Raccoon Dogs are currently still sold into the UK pet trade, with animals costing between £150 and £400; the RSPCA are making efforts to put an end to this trade. It is also possible that Raccoon Dogs could enter the UK as ‘hitchhikers’ from continental Europe due to the high volume of freight traffic. The EU Invasive Alien Species (IAS) Regulation (1143/2014), which came into force on 1 January 2015, imposes strict restrictions on a list of species known as ‘species of Union concern’. These are species whose potential adverse impacts across the European Union are such that concerted action across Europe is considered necessary. Initially, this list included 23 animals and 14 plants but on 2 August 2017 a further 12 species were added to the list, including the Racoon Dog. This should go some way to reducing the risk of this species colonising the UK.
Nevertheless, within their risk assessment in relation to this species, the GB Non-native Species Secretariat (NNSS) categorise the risk of this species entering Britain as ‘Likely’ at a ‘High’ degree of confidence. Should this occur, taking into account the complete absence of predators, and the wide availability of suitable habitat a rapid establishment would be expected without concerted control efforts.
Raccoon Dogs are regularly observed from our wildlife-watching hide in western Estonia, despite the presence of breeding Eurasian Lynx on site. We have at least one resident pair that utilise the nature reserve, successfully raising young there in 2014-15. Despite the frequency of sightings, they do not seem to be any commoner than other medium-sized carnivores on the reserve that supports healthy populations of everything from Badger Meles meles to martens, Least Weasels Mustela nivalis and Polecats Mustela putorius.