Polymorphism in UK Foxes
The vast majority of foxes in the UK are red in colour but black (melanistic) or white (leucistic or albino) foxes are occasionally spotted from time to time. Foxes with white patches (piebald foxes), are relatively common in comparison, especially in urban areas. Historically, wild populations of anomalous colour morphs were so highly prized for their pelts that they were hunted to near extinction. The frequency of black foxes seen in the UK has been historically low as a result and such sightings appear far less frequently than in other areas of the world. For this reason, black foxes have been a thing of myth and folklore within the UK.
In the UK nearly all foxes are of the standard red colouration, however, the red fox is known to come in a variety of colours - with over 85 different colour variations recorded within fur farm populations.
The four naturally occurring colour morphs of red foxes consist of:
Silver foxes are a domesticated strain of the melanistic North American Red fox. They have been farmed for selected traits desired by the fur trade for over 100 years and display genetic, phenotypical and behavioural differences in comparison to their wild counterparts. Fur farming ended in the UK at the turn of the millennium, but feral farm fox descendants are spotted from time to time. It is thought that up to 70% of the fur industry's production of fox fur sill originates from Europe to this day, despite the global movement to ban fur farming.
Hybrids between the North American Red fox (vulpes vulpes fulvus) and the European Red fox (vulpes vulpes crucigera) are possible as they are both vulpes vulpes. Though it is interesting to note that the North American Red fox and the European red fox were once classified two separate species - vulpes vulpes in Eurasia and "vulpes fulva" in the Americas (Tesky, 1995), being considered a singular species since 1959 - of which there are currently forty five subspecies. Modern technology however, has recently provided evidence that our original assumption on species divergence may have been correct, detecting two distinct red fox lineages that were isolated from each other during the last glaciation.
Hybrids between the Red fox and the Arctic fox (vulpes lagopus, previously known as "alopex lagopus"), have also been recorded within both wild and captive bred populations (hybrids are known as alopex -vulpes). There have been no sightings on UK shores of any such hybrids but it is important to note that both Silver foxes and Blue foxes (the farm versions of the Red and Arctic fox), were once bred here by the fur trade and both species are kept here as exotic pets today. There have been a handful of "white fox" sightings reported in the UK, which are noted to have been that of lost, captive bred Arctic foxes.
The increase of colour morphs seen in the UK fox population coincides with the keeping of foxes as pets. While anomalous coat colours do occur naturally, some do not and are a product of domestication processes. Previous sightings have occurred far less frequently than they have over recent years and due to the physical phenotypes of some of the individuals identified in reports, it is clear that some of the sightings have been that of escaped pets or of feral fur farm descendants, rather than that of melanistic native foxes.
Melanism & Fox Genetics
Melanism is a recessive trait that allows for greater expression of the pigment melanin in an animals skin or coat, which gives the animal a darker colouration. Melanistic coat colouration's are a rare polymorphic trait in UK red foxes (fully and partially melanistic foxes are much more common among North American foxes), and both parents must carry the recessive gene for full melanism to be expressed. In the wild, melanistic foxes would rarely get the opportunity to reproduce with other foxes of the same colour morph. In farms, silver foxes are explicitly bred with others that share the same recessive melanistic trait, this selective breeding has resulted in coat colours that do not exist in wild populations and has altered the physiological and behavioural profile of the silver fox in comparison to it's wild cousin.
"Psysiological causes of coloration, including melanism, are evident but poorly researched. The relative importance of evolutionary forces responsible for external coloration varies greatly between vertebrate taxa, but the reasons for this variation are not yet understood"
The Adaptive Significance Of Coloration In Mammals, BioScience 2015
"Overall, silver foxes account for about 10% of colour morphs. Jet black foxes are, however, very rare in Europe; in his 2005 Carnivores of the World, Ronald Nowak notes that such foxes are confined to the extreme north of Europe and make up about 1% of the population"
Red Fox (Vulpes Vulpes): Wildlife Online (Updated 3rd July 2015)
Inheritance of melanism in red foxes can be explained through Mendelian genetics. Belyaev's farm fox experiment demonstrated how Mendel's theories were correct, disproving Lamarack's theory of inheritance of acquired characteristics and the Lysenkoism opposition which dominated at the time. Today, we consider Mendel's theories the cornerstone of modern day genetics, with Belyaev's farm fox experiment sparking the start of a new field of scientific research.
To show their respect to the scientific contribution of Dmitry Belyaev, the Institute of Cytology and Genetics recently announced they will be holding a conference in his honour, to mark the 100th anniversary of his birth.
"Belyaev knew his genetics and firmly believed that Lysenko's views were false.. working as a young man at the Central Research Laboratory of Fur Breeding in Moscow, he rashly expressed his opposition. He was fired from his job as a result... Belyaev searched for a topic that was scientifically interesting but not politically dangerous. He felt drawn to the issue of animal domestication. He chose foxes, common in Siberia..."
Lysenko's Ghost: The Friendly Siberian Foxes - Loren Graham
"Belyayev's experiments were the result of a politically motivated demotion, in response to defying the now discredited non-Mendellian theories of Lysenkoism, which were politically accepted in the Soviet Union at the time. Belyayev has since been vindicated in recent years by major scientific journals, and by the Soviet establishment as a pioneering figure in modern genetics"
Dmitry Belyayev (zoologist) - Wikipedia
Red Fox, Melanism & Mendelian Genetics: Why Are Black Foxes So Rare?
UK Fox Genetics:
While there is much research on foxes, there is very little research into the population genetics of wild red foxes in the UK. Research is now beginning to focus on this field of study, and tests are being developed to help distinguish different genetic populations.
"There are no published reports on the population genetics of foxes in Britain. In this study, we aim to provide an insight into recent historical movement of foxes within Britain, as well as a current assessment of the genetic diversity and gene flow within British populations"
Population Genetic Structure Of The Red Fox (Vulpes vulpes ) In The UK: Helen Atterby et al. (December 2014)
Initial results from the latest research demonstrates it is possible to distinguish wild foxes from captive bred foxes, as well as distinguishing between regional differences in the genetics of wild and farmed foxes. Such information will allow researchers to gain a better understanding of the genetic variation within the UK fox population.
"Analysis of the origin of domestic animals is of wide interest and has many practical applications in areas such as agriculture and evolutionary biology. Identification of an ancestor and comparison with the domesticated form allows for an analysis of genetic, physiological, morphological and behavioral effects of domestication. Because fox breeding has been an ongoing process for over a century, differences are expected between farm and wild populations at the chromosomal level"
Polymorphism of Cytogenetic Markers in Wild and Farm Red Fox (Vulpes vulpes) Populations - Monika Bugno-Poniewierska et al. (2013)
"For each of the genes investigated specific SNP profiles characteristic only for farm foxes and only for wild foxes were noted. At the same time, specific SNP profiles were noted for wild foxes from North America and from Europe."
Genetic Differentiation of Common Fox (Vulpes Vulpes) - Annals of Animals Science (November 2014)
Farm Foxes & The Silver Rush
The silver fox is the domesticated version of the melanistic North American red fox. It is a selectively bred farm animal that exists as a result of The Silver Rush, which is thought to have started on Prince Edward Island around 150 years ago. Fox farming began as an alternative to hunting foxes, as a means to improve pelt production and quality, resulting in the increased popularity of fox fur as a result. Over the years - as a direct result of selectively breeding foxes for coat colour and quality - new coat colour morphs began to appear - which do not (and could not), exist in wild populations naturally.
The commercial selective breeding of melanistic foxes in captivity by man for the fur trade pre-dates our production of inbred laboratory strains of rodents (early 1900's). In fact, it was the fox farming community that provided the formulated and pelleted diets that allowed the scientific community to improve the welfare and longevity of laboratory rodents. Fox farmers even contributed to veterinary and animal science directly, by developing the first distemper vaccine - which our pets use modern versions of today.
The silver fox's status as a domesticated farm animal is not fully recognised (only the experimental foxes are officially considered domesticated), though it is acknowledged in Canadian and EU literature that farm foxes are to be treated as "domesticated farm animals" under farming regulations.
While farm foxes have been historically bred for unique colour traits and not for temperament, modern fur farming accepts that foxes which can tolerate human handling have higher welfare standards. As a result, fox farmers in Europe are now required to breed for improved temperament and reduced fear of man.
As a result of their domestication, silver foxes display a much greater variety of polymorphism than what is seen in wild red foxes in the UK;
- Silver foxes are slightly larger,
- have larger, fuller tails and longer white tail tips,
- have shorter, broader faces,
- as well as thicker, longer coats, with a much wider variety of colouration's.
Below is an example of the Georgian Red silver fox colour morph. The Georgian colour morph is considered the Russian version of the marbled silver fox, it is a rare colour morph that is a direct product of intensive selective breeding for unique colour traits:
"The Georgian [fox], also called the snow mutant, was first documented in Russia in 1943. It is a white fox with black spots on the face, back and feet... These foxes are often described as 'freckled'. The gene is incompletely dominant, and is lethal in homozygous condition... These foxes were heavily restricted when they were first discovered during the period of the USSR, and for a time only existed in Russia. They now are present across Europe, but they are not in the North American [or UK] pet trade at this time, except for Russian domesticated foxes imported to the US"
Georgian Fox - Fox Fanatic
Historical records show that the earliest reports of fox farming in the UK can be dated back to the early 1800's;
"A more unusual trade to be recorded by the archaeological record is that of silver fox farming. A brick tower (NHER 8023) that stands south of Heath Farm on the Short-Thorn Road supposedly belonged to a post medieval silver fox farm, with the farmer sitting in the tower to watch the foxes"
Parish Summary:Sutton Strawless - Norfolk Heritage Explorer
However, the Silver Rush and commercial fox farming wasn't to hit the UK until the early 1900's;
"Seven 'Silver Foxes' are recorded as having been born in the Gardens 1857-1862, and also five hybrids between this species and the European Fox, two in 1832, three in 1870. The farming of foxes for the fur industry started in the British Isles in 1920 and by 1932 there were 115 breeders across the country"
First and Early Breeding Records for Mammals in the UK and Eire: Carnivora (Silver Fox) - The Bartlett Society
“In 1887… silver fox (Vulpes vulpes) farming was begun; however, in the UK fur farming was not undertaken until the early twentieth century…. Good husbandry, sanitation, feeding and management are essential and the early fur farmers had a great deal to learn in understanding the animals’ habits and general characteristics. They also needed an understanding of genetics and a planned and well recorded breeding programme in order to have the likelihood of breeding good stock and not in-breeding too closely and thus have weaknesses occur in successive generations”
Fur farming wasn't the only commercial use of foxes in the UK in the early 1900's. English rat catcher John Wheeldon, trained foxes for "economic use" by teaching them to assist him and his dogs with providing rat catching services (a practice adopted by the Chinese in 2004, to keep mole rat plagues under control);
"John Wheeldon, better known as John Gaunt. He lived at Sawmills but worked for the Midland Railway Company, travelling the lines as a rat catcher. He is the only person known to have successfully trained foxes to 'rat' for economic use, and claimed they were better than terriers because they could hold five rats in their mouths at once. The rat catcher had to be quick because, unlike a terrier, foxes did not kill the rats outright. His best two foxes, however, were killed accidentally by gamekeepers. Such was his national fame that he was described in a book as a 'great sportsman great Englishman'. He died , aged seventy three, at the home of a friend in Belper in November 1924, and was buried in Crich churchyard. He was also a prize-winning member of Ambergate Cottage Garden Society"
Today, the attitude to wearing fur in the UK is very different from what it once was, with fur farming being banned under the Fur Farming (Prohibition) Act 2000 - prohibiting the keeping of animals solely or primarily for the value of their fur.
There were 11 fur farms left in the UK just prior to the ban, most of which had ceased breeding foxes many years earlier. UK fox farms included: Hollywood Silver Fox Farm in Lincolnshire (who's tort law case demonstrates how anti fox farming views have existed since the practice began), Mytholm Fur Farm in Halifax (the release of farm foxes in this area at the start of WWII is believed to be the reason why melanistic traits are greater in foxes in and around Halifax), Lumphanan Silver Fox Farm in Aberdeenshire and Sheringham Zoo and Silver Fox Farm in Norfolk
"I was 20 years old in 1932... I only worked on the farm for a few months during the summer of that year... A driveway along side of the bungalow led down to the Fox Kitchen and the Offices, the kitchen was used for the fox's food, which as far as I can remember consisted of a lot of eggs and baby turkeys, there were a lot them about, and I do remember that the kitchen was spotlessly clean. I had to feed the baby turkeys with crushed stinging nettles which I had gathered from round about the farm.
The foxes themselves were housed in pens completely made up of chicken wire both round the sides and on the floor, presumably to stop them digging their way out. They were beautiful creatures with black and silver fur. I supposed they were bred for their fur. There must have been just under a hundred as far as I can remember... I presume the foxes were transported for slaughter, I don't remember it happening on the farm. I hope this is of some interest to you, and wish I could remember more"
Doris Louisa Bohannan nee Peg - At Sheringham Norfolk
In 2000, as a tribute to their historical involvement in the once thriving trade of UK fur production, the Shetland Museum opened an exhibition dedicated to the history of fox and mink farming on the isles, documenting their involvement in the fur trade, as well as the humane farming practices the isles brought to the industry.
The Domesticated Silver Fox
In 1959, a Russian experiment into domestication processes began selectively breeding farm foxes for desired behaviours towards humans; both tame and aggressive behaviour. The study - which continues today - demonstrates the phenotypical changes that occurred during this process of selective breeding and how selectively breeding solely for tameness, results in foxes that are comfortable around humans an much more dog-like in both appearance and behaviour.
Both farmed silver foxes and Russian domesticated foxes have a greater ability to cope with stress, making them bolder than their wild counterparts. A trait that is believed to be the result of a lower production of adrenaline;
"It is not the case that coat color causes a difference in temperament, but rather that certain physiological processes underlie facets of both coat color and behavior. In particular, the hormones and neurotransmitters involved in the stress response and other behaviors are closely integrated with pigment production.
For example, the neurotransmitter dopamine and the hormones noradrenaline and adrenaline, which are involved in the stress response, have the same biochemical precursor as the melanin pigments (Anonymous 1971, Ferry and Zimmerman 1964).
In addition, dopamine directly influences pigment production by binding to the pigment-producing cells (Burchill et al. 1986). Dopamine indirectly influences pigment production by inhibiting pituitary melanotropin, also known as melanocyte stimulating hormone (MSH), which is responsible for stimulating pigment cells to produce pigment (Tilders and Smelik 1978)"
Jennifer Ormond, MA - Quora, 2015
Given that the parent population of experimental foxes were obtained from Canadian fur farms, and that there are only forty genes found to differ between domesticated and non-domesticated farm-raised foxes, (with 2,700 genes difference between the wild foxes and either set of farm-raised foxes), it makes sense that all sliver foxes display phenotypes and behavioural traits not seen in wild foxes, despite the different forms of domestication. However, there are further differences between those foxes scientifically domesticated for tameness and their fur farm counterparts, which includes;
- Tame, dog-like behaviours like whining to get attention, licking, tail-wagging, playfulness, and barking.
- Shorter legs, shorter and curled tails and spotted fur.
- Narrower skulls and shorter snouts than that of wild foxes.
- Females began to come into heat twice a year instead of just once as in the case of wild foxes.
- Tame fox cubs opened their eyes sooner and developed a fear response later than wild fox cubs
The foxes in this experiment were selectively bred for over 50 generations for their suitability to be around people and are considered scientifically "domesticated pets". They are still bred today, being sold (neutered), for several thousands of pounds by the Institute of Cytology and Genetics (ICG). These foxes have behaviour that is scientifically selected to ensure tameness, unlike that of fur farm foxes.
The "Siberian Cupcakes" - Sophie, Boris, Maks, Viktor and Mikhail, are Russian domesticated silver foxes living as ambassador animals at the JAB Canine and Education Centre in the USA. In the video below, they are providing saliva samples that will help to assist in oncology research, in order to further scientific understanding of disease development in both humans and animals.
To date, only one Russian domesticated silver fox has been sold by the ICG to live as a pet in the UK, though sadly, it did not make it's journey. However, the experiment continues and foxes remain available for purchase for those with the funds, means and knowledge.
Pet Foxes in the UK
The practice of keeping foxes in captivity is nothing new in the UK. They have been kept for commercial purposes (such as rat catching, fur production or as educational animals), and as pets (when rehabilitation and release have not been possible) throughout history, and people still keep foxes in the UK today, both wild animals that cannot be released for welfare reasons and the silver foxes bred to be kept as pets. There is even evidence the practice of keeping foxes may date back as early as 14,000 BC.
Silver foxes are farm animals that have been domesticated for coat colour and quality, they have only recently been bred by exotic pet breeders for traits such as tameness and suitability to live as a pet here in the UK. They are not the same as the experimental foxes people think of when discussing domesticated pet foxes, nor are they the same as the native wild animals that are kept as pets because they cannot be released.
While they are often compared to dogs and cats, silver foxes do not behave like either. Instead, their behaviour is uniquely fox - independent, strong willed and defensive - which is why keeping foxes is considered a specialist hobby for those with specific interests in exotic animal education, management and behaviour. Temperament-wise, farm foxes could be considered similar to those "unselected foxes" in the domestication experiment - which were selected for neither tame nor aggressive behaviour, displaying traits from both the tame and aggressive groups
It requires a lot of time, knowledge and resources to keep exotic pets correctly and out of all the exotic pets kept, foxes are one of the more difficult species to keep due to their curious and cunning nature. They have many natural behavioural traits that most would consider undesirable in a pet, from their pungent smell to their destructive and territorial tendencies. They are long lived, living up to 10-12 years in captivity, are great escape artists (requiring a secure enclosure) and they are difficult to lead and litter train. They also require a specialist diet, specialist vets and lots of species specific enrichment. But, for specialist keepers - who dedicate their lives to gaining knowledge and understanding on these animals - they can be fun and fascinating companions, as Mr Scamper de Fox demonstrates below;
UK Legislation on Keeping Foxes:
Foxes are given very little protection under UK law - partly because of the historical practice of fox hunting and fox farming, and partly due to increasing population numbers and the resulting conflicts with man. As a result, it remains legal to humanely trap and kill foxes as a form of pest control.
Being a native species, it has always been legal to keep foxes (vulpes vulpes) under certain exceptions - providing certain welfare regulations are met - and throughout history, people have taken on and rehabilitated foxes in need. The ban of fur farming in 2000, together with changes to legislation in keeping exotic pets in 2006 - which removed many animals from the Schedule of the Dangerous Wild Animals Act (1976) (red foxes were never on this schedule) - resulted in a greater understand that silver foxes existed, and that it was legal to keep and breed them, providing it was not to kill them for their fur.
Although they are both a different subspecies, domesticated silver foxes and native red foxes are considered the same from the viewpoint of UK law, they are both vulpes vulpes and the law applies to each subspecies without distinction. That being said, interpretation of the law on foxes differs depending on the age and health of the animal, as well as if the animal was captive bred or wild caught;
- It is considered breech of the Animal Welfare Act 2006 to capture healthy wild foxes for the purpose of keeping them contained in captivity to live as pets.
- It is considered breech of the Animal Welfare Act 2006 to breed wild foxes in captivity for the purpose of keeping the offspring contained in captivity to live as pets (all reasonable attempts to rehabilitate such offspring for release must be made - except in the case of non-native animals or their hybrids, which cannot be released).
- It is considered breech of both the Animal Welfare Act 2006 and the Wildlife and Countryside Act 1981 to intentionally or unintentionally release into the wild; domesticated animals, captive wild animals which cannot be released for welfare reasons and non-native animals or their hybrids.
- It is legal to humanely trap both sick or injured wild foxes and captive bred foxes (with permission of the landowner), if the intention is for treatment, rehabilitation and release (in the case of wild foxes), or if the intention is to return them to captivity (in instances of domesticated animals, captive wild animals that cannot be released for welfare reasons and non-native animals or their hybrids).
Regulations relating to foxes in the UK includes;
- Protection of Animals Act 1911
- Performing Animals Act 1925
- The Pet Animals Act 1951
- The Abandonment of Animals Act 1960
- Wildlife & Countryside Act 1981
- Wild Mammals Protection Act 1996
- Fur Farming (Prohibition) Act 2000
- Hunting Act 2004
- Animal Welfare Act 2006
- Infrastructure Act 2015
- Animal Health and Welfare (Scotland) Act 2002
- Protection of Wild Mammals (Scotland) 2002
- Fur Farming (Prohibition) (Scotland) Act 2002
Basic Requirements for Keeping a Pet Fox:
Exotic pets like foxes require a lot more time, money and dedication to keep happy in comparison to domesticated pets. Foxes are not a species recommended for novice animal keepers and their timid nature also means that in general, they do not make suitable subjects for exotic animal handling and education businesses.
If you do consider keeping a domestic silver fox as a pet, please ensure you do your research. There is little support and very few options when it comes to re-homing unwanted pet foxes in the UK. Ensure you are certain you can take on the commitment before making any decisions and adequately invest in the equipment required to keep them effectively, prior to bringing one home.
Essentials required for keeping silver foxes includes;
- Books on Foxes and Keeping Exotic Pets
- Exotic Mammal Vet (Including funds for first vet visit, vaccinations, parasite treatment, microchipping and neutering)
- A Spare room with Extra Large Dog Crate or Large Indoor Cat House
- Medium-sized Heavy Duty Transport Carrier
- Min. 100 sq ft Enclosure with Secure Roofing and Flooring (min. of 16 gauge heavy duty wire and a double door entry system)
- Outdoor Shelter
- Outdoor and Emergency Lighting
- Large Digging Box
- Logs and Branches/Platforms for Climbing
- Non Tip Food and Water Bowls
- Small GPS Tracking Collar (or leather collar and ID tag)
- Harness and Non-Chew Lead
- Bedding and Substrate
- Toys and Enrichment
- Grooming and Training Products
- Pet-Safe Cleaning Products (steam cleaners and jet washers also come in handy)
- Gauntlets/Cat Gloves (for safe restraint)
- Soft Muzzle (for safe restraint)
- Catchpole/Cat Grasper (for emergencies)
- Long Handled Net (for emergencies)
- Fox Trap (for emergencies)
At Black Foxes UK we believe there needs to be more control and regulation on the keeping and breeding of exotic pets, especially with regards to silver foxes. In the absence of such regulations and because there is limited information out there on the needs of captive foxes (especially with regards to keeping them privately at home), we supply a list of webpages on silver foxes as well as a Comprehensive Silver Fox Guide for those seeking more information. If there are any websites you would like to see on the list, then please do contact us to let us know.
Black Foxes UK's Forever Foxy Campaign aims to reduce the burden upon animal welfare charities as a result of pet foxes by providing the essentials required to ensure the welfare and security of rescued silver foxes and silver foxes in need. If you would like to donate to the cause, then please follow the link below;
Anomalous Red Foxes In the UK
A catalogue of images of anomalous Red foxes reported in the UK (please be aware - there are images of deceased foxes included);
*Many of the images below were provided directly to Black Foxes UK and we would like to say a special thank you to those who have shared their images with us. Please find direct links to images which were sourced through the media and via social media, in our Further Reading section below.
A catalogue of videos of anomalous Red foxes reported in the UK;
Polymorphism in Foxes:
Melanism & Mendalian Genetics:
Genetic Differentiation of Common Fox Vulpes Vulpes (Linnaeus, 1758) on the Basis of the Insulin-Like Growth Factor 1 (Igf1), Myosin-Xv (Myo15a) and Paired Box Homeotic 3 (Pax3) Genes Fragments Polymorphism - Andrzej Jakubczak, et. al., 2015