Red fox

Latin name: Vulpes vulpes
Class: Mammals
Group: Foxes

Humans have a long history with the Red fox (Vulpes vulpes). Some regard it as nothing more than chicken-stealing vermin to be exterminated. Others see it as an attractive and fascinating inclusion in Britain's native fauna; one of the few mammals seeming to thrive in our increasingly developed and polluted world. Irrespective of emotions, foxes have an important role in our terrestrial ecosystems, some of which we've only recently begun to understand. Standing defiant in the face of almost boundless human persecution, the Red fox's tumultuous history with mankind seems set to continue for generations to come.

That which follows is a reasonably comprehensive overview of Red fox evolution, taxonomy, biology, ecology and history, although there is much more to the natural history of these canids than can be covered here and new observations are being made all the time. Certain aspects of the fox's natural history that warrant more detailed discussion have been split from the main overview into their own Q/A.

A Red fox (Vulpes vulpes) lying in the grass. - Credit: Marc Baldwin

The Red fox at a glance

Size: Foxes generally have a head and body length of 60-90 cm (2-3 ft.), but can reach 165 cm (5.4 ft.) including tail/brush. In Britain, the average weight of an adult male is around 6.5 kg (14 lbs), while adult females are about 5.5kg (12 lbs), but this varies considerably with age, season, and habitats. The global range for adults is generally considered to be 3-16 kg (6.6-35 lbs), although there are outliers. The largest confirmed specimen appears to be a male shot on a farm in Scotland during 2012 that weighed 17.2 kg (38 lb. 1 oz.) and measured 145 cm (4 ft. 9 in.) nose to tail tip. There are reports of larger animals, weighing 20 kg (41 lbs) or more, but these remain unverified.

Appearance: An archetypal small canid body form: erect ears, a slender muzzle running down from yellow/hazel eyes (with more cat-like vertically-slit pupils), a long tail (called a "brush") that's typically carried horizontally. The body usually slim with relatively long legs terminating in five paws on the front legs and four on the rear; sharply pointed, prominent, slender canine teeth. Coat colour is highly variable, ranging from a yellow-red to black ("silver"). The chin, underbelly, and tip of the tail ("tag") are typically white, while the muzzle, back of the ears, and lower legs ("socks") are sooty-black. Four main colour phases are recognised in the wild (i.e., Red, White, Silver, and Cross), which are genetically inherited. Selective breeding on fur farms has produced many more phases, but these are seldom, if ever, encountered in wild populations.

Distribution: Found widely throughout the UK and most of Europe, North Africa, North America, Canada as far north as some arctic islands, and parts of Asia. Also found throughout China, northern India and Australia where it was introduced for hunting during the mid-1800s. Some recent anecdotal observations that fox distribution in Britain may be shifting in response to very heavy persecution by landowners.

Longevity: Typically, foxes live for only 2 or 3 years, esp. in urban environments, although more generally a range of 2 to 8 years can be expected. The upper limit in wild is generally considered 6 or 8 years, although some have been recorded reaching their mid-teens. The oldest captive animal reached nearly 24 years old.

Sexing: Little sexual dimorphism (i.e., sexes look very similar), particularly among younger animals. Males are larger than females, on average, with broader (more domed) heads and longer, narrower snouts, although this is most obvious in older animals and some females can present with broad faces. Older males will often carry wounds from fights with other males and a heavily battle-scarred individual is likely to be a male. During the winter breeding season the cream-coloured scrotum of the male is descended, helping with sexing, while females with young will often have bald stomachs and enlarged teats during the summer. Males are called dogs, females are vixens, and young are variously called cubs (Britain and Europe), kits (North America) or pups (Asia).

Activity: Contrary to popular misconception, foxes are active throughout the day and night, and it is not necessarily either uncommon or a bad sign to see one during the day, particularly during the late winter and early summer. They are, nonetheless, predominantly crepuscular and nocturnal (i.e., most of their activity takes place between dusk and dawn). Unlike we humans, who nowadays tend to get our sleep in one stint overnight, foxes, like most animals, move through any given 24-hour period with a series of resting and active periods. Indeed, tracking data from urban areas suggest during winter and spring the nights are typically divided into several short periods of activity (2-2.5 hours each) interspersed with similar periods of rest. Few data exist for rural foxes, but on study in Switzerland found bouts of inactivity were usually short (i.e., less than 15 mins), with periods of up to an hour being uncommon. Generally, longer periods of activity are followed by longer rest periods, although there was much individual variation. Some observations suggest foxes become increasingly nocturnal where persecution is high.

Dens: Dens (also known as earths in Britain) are used predominantly during the cub-rearing months, although they may also be used during periods of particularly inclement weather or as refuge from mounted hunts. Vixens will identify and/or dig out and earth during February in the northern hemisphere and then restrict themselves to it in the days leading up to, and immediately prior to, giving birth. Outside of the cubbing season foxes typically lie up in vegetation or in sunny spots (e.g., shed roofs or low branches of trees). An earth will typically have more than one entrance (allowing for escape) and several dens may exist per territory.

Territory & Home Range: Range use is resource-based, resulting in substantial variation by habitat. Rural foxes commonly have territories between 200 and 600 ha. (500-1,500 acres), extending to 4,000 ha (10,000 ac.) in poor habitat (e.g., Scottish Highlands). Based on data from several European cities urban foxes appear to forage over smaller areas, i.e., 40-90 ha (100-200 ac.). Territories are sometimes composed of two areas; a larger (home range) area containing a smaller (core/exclusive area) territory. Home ranges may overlap with neighbours, while core areas are violently defended against interlopers. Territories may split or merge in accordance with fluctuating resource availability, or shift in response to the loss of neighbouring animals.

Diet: Foxes are highly opportunistic predators with a catholic diet consisting of mammals up to the size of small deer, birds and their eggs, reptiles and their eggs, insects, fish, amphibians, fruits and vegetables, and anthropogenic foods, the latter being both deliberately provided and scavenged from rubbish.

Reproduction: Foxes are short-day breeders, i.e., the breeding season runs from late December to early February in the northern hemisphere, with most matings taking place during late December or January. Male will follow the female closely and mate multiple times while she's in oestrus, after which there is a temporary "lock" during which the animals stand back-to-back. Generally, foxes seem generally monogamous, although studies in Bristol have found multiple paternity - males mating with multiple vixens and v/v. Were daughters remain in a territory, the dominant vixen is likely to be the only breeding female. An average of 4-6 cubs are usually born during March and April (peak mid-March) after a gestation of about 7.5 weeks; some cubs born as early as late January or as late as early May. Cubs are born with eyes and ears closed, weigh 50-150 g (1.8-5.3 oz.), and are dependent on the vixen for initial warmth. As such the vixen will restrict herself to the earth for several days post partum and afterwards leave the cubs for only brief periods. Eyes and ears open around 10-14 days old, and cubs are presented with solid food from 3 wks, emerging from the den in early May at around 6 wks old. Cubs are weaned by about 8 wks and considered independent by 3-5 months. Sexual maturity is reached at ca. 10 months old.

Behaviour & Sociality: Normally found solitarily or in pairs, but can occur in family groups where resources allow (e.g., suburban areas). When in groups, family members may help care for cubs (i.e., guard, feed and play with cubs). Often drawn to gardens with small livestock (e.g., chickens, guinea pigs, rabbits) and may both predate these animals and/or cause damage to gardens. When presented with prey abundant prey that does not or cannot flee foxes may engage in "surplus killing" where multiple individuals are killed. Given the opportunity, multiple observations suggest carcasses will be recovered on subsequent visits, but this has nonetheless led to a reputation that foxes "kill for fun/sport". Considerable data from captivity and the wild demonstrating that caching of left-over/surplus food is an innate behaviour, present from cubhood. Foxes can be excluded from pet/livestock enclosures with effort, but are very difficult to exclude completely from a garden. Calling/vocalisation is mostly during the breeding season, although is occasionally heard outside this period, particularly during disputes in the late summer/autumn. Foxes also communicate with scent and, at close range, body language, and identifying meaning in a call is often only possible when heard with corresponding body language. The family unit tends to breakdown from September onwards, with males more prone to dispersal than females.

Threats: Hunted for sport and as a pest throughout much of its range, although this seems to have little impact on overall numbers perhaps to the exclusion of heavy and persistent shooting around game estates in Britain. Many are killed by cars, although some data suggest foxes may become road aware in towns and cities, thereby reducing the risk. Outbreaks of mange has decreased numbers significantly in parts of Britain and Europe in recent history, with up to 95% of animals killed in some populations. Low level mange may persist in urban areas and this likely impacts survival and/or breeding potential. In Britain, adult foxes are susceptible only to badgers, other adult foxes, domestic dogs and golden eagles, although the latter likely to be the only true predator. In Europe, adults are vulnerable to wolf and lynx predation, while coyotes appear to be their most significant predator in North America. Cubs may fall victim to various predators, including larger birds of prey (e.g., golden eagles and eagle owls) and larger mammalian carnivores such as other foxes, badgers, wolves, coyotes, and lynx. Infanticide has been reported, although it is unclear how common it is.

Bibliography

A Fox’s Tale: The secret life of the fox - by Robin Page
Hodder and Stoughton -- 1986 -- ISBN: 978-0340382561

A New Forest Fox Family - by Thelma Clarke
Barny Books -- 2000 -- ISBN: 978-0948204463

Atlas of the Mammals of Great Britain & Northern Ireland - by Multiple Contributors
Pelagic Publishing -- 2020 -- ISBN: 978-1784272043

Britain’s Mammals 2018: The Mammal Society’s Guide to their Population & Conservation Status - by Multiple Contributors
The Mammal Society -- 2020 -- ISBN: 978-0993567339

British Wildlife: Foxes - by Sally Morgan
Franklin Watts -- 2005 -- ISBN: 978-0749679101

Collins Field Guide: Mammals of Britain and Europe - by David MacDonald and Priscilla Barrett
HarperCollins Publishers -- 1993 -- ISBN: 978-0002197793

Country Foxes - by Hugh Kolb
Whittet Books -- 1996 -- ISBN: 978-1873580295

Dogs: Their fossil relatives and evolutionary history - by Xiaoming Wang and Richard Tedford
Columbia University Press -- 2008 -- ISBN: 978-0231135290

Fauna Britannica - by Stefan Buczacki
Hamlyn Publishing -- 2002 -- ISBN: 978-0600598671

Fox - by Martin Wallen
Reaktion Books -- 2006 -- ISBN: 978-1861892973

Foxes (Mammal Society Series) - by Steve Harris
Anthony Nelson Ltd. -- 1984 -- ISBN: 978-0904614121

Foxes Unearthed: A Story of Love and Loathing in Modern Britain - by Lucy Jones
Elliott & Thompson -- 2016 -- ISBN: 978-1783961498

Foxwatching: In the shadow of the fox - by Martin Hemmington
Whittet Books -- 1997 -- ISBN: 978-1873580318

Free Spirit: A brush with a fox - by Michael Chambers
Methuen London -- 1990 -- ISBN: 978-0413629807

Highland Deer Forest - by Lea MacNally
J.M. Dent & Sons Ltd. -- 1970 -- ISBN: 978-0330234665

How to Spot a Fox - by J. David Henry
Chapters Publishing Ltd. -- 1993 -- ISBN: 978-1881527176

Just About Me - by Mike Towler
Vulpine Publishing -- 2006 -- ISBN: N/A

Mammals of the British Isles: Handbook, 4th Edition - by Stephen Harris and Derek Yalden (eds)
The Mammal Society -- 2008 -- ISBN: 978-0906282656
The natural history "bible" covering all British mammals with detailed coverage of their biology, behaviour, ecology and taxonomy written by experts in the field and referenced to the primary literature.

Mind the Gap: Postglacial colonization of Ireland - by John L. Davenport, David P. Sleeman & Peter C. Woodman (eds)
Irish Naturalists' Journal -- 2008

My Friends the Foxes - by Mike Towler
Vulpine Publishing -- 2015 -- ISBN: N/A

My Life With Foxes - by Eric Ashby
Robert Hale Books -- 2000 -- ISBN: 978-0709065616

Nick Baker’s British Wildlife: A month by month guide - by Nick Baker
New Holland Publishers -- 2003 -- ISBN: 978-1845171131

Red Fox: The Catlike Canine - by J. David Henry
Smithsonian Institution Press -- 1996 -- ISBN: 978-1560986355

Running with the Fox - by David MacDonald
UnwinHyman -- 1987 -- ISBN: 978-0816018864

Silent Fields: The long decline of a nation’s wildlife - by Roger Lovegrove
Oxford Univesrity Press -- 2007 -- ISBN: 978-0199548156

Simon King’s Wildguide - by Simon King
BBC Books -- 1994 -- ISBN: 978-0563364962

The British Mammal Guide - by Steve Evans & Paul Wetton
Isabelline Films -- 2015 -- ISBN: N/A

The Complete Fox - by Les Stocker
Chatto and Windus, Ltd. -- 1994 -- ISBN: 978-0701137762

The Darkness is Light Enough: The field journal of a night naturalist - by Chris Ferris
Sphere Books Ltd. -- 1986 -- ISBN: 978-0718126902

The Encyclopaedia of Mammals - by David MacDonald (ed.)
Brown Reference Group -- 2006 -- ISBN: 978-0199206087

The Hidden World of the Fox - by Adele Brand
William Collins -- 2020 -- ISBN: 978-0008327286

The Mammals of the Palaearctic Region: A Taxonomic Review - by Gordon Corbet
Cornell University Press -- 1978 -- ISBN: 978-0801411717

The Nature of Foxes: Hunters of the shadows - by Rebecca Gambo
Greystone Books -- 1995 -- ISBN: 978-1550541847

The New Amateur Naturalist - by Nick Baker
HarperCollins Publishers -- 2004 -- ISBN: 978-0007157310

The Wildlife Trust’s Handbook of Garden Wildlife - by Nicholas Hammond
Bloombury -- 2014 -- ISBN: 978-1472915863

Town Fox, Country Fox - by Brian Vezey-Fitzgerald
The Country Book Club -- 1968 -- ISBN: 978-0552092111

UK Mammals: Species Status & Population Trends - by The Tracking Mammals Partnership
JNCC/TMP -- 2005 -- ISBN: 978-1861075680

Unearthing the Urban Fox - by Trevor Williams and Andrew Wilson
The Fox Project -- 2011 -- ISBN: 978-0956961402

Urban Carnivores: Ecology, Conflict, & Conservation - by Stanley Gehrt, Seth Riley & Brian Cypher
John Hopkins University Press -- 2010 -- ISBN: 978-0801893896

Urban Foxes - by Stephen Harris & Phil Baker
Whittet Books -- 2001 -- ISBN: 978-1873580516

Urban Mammals: A Concise Guide - by David Wembridge
Whittet Books -- 2012 -- ISBN: 978-1873580851

Urban Wildlife - by Peter Shirley
Whittet Books -- 1996 -- ISBN: 978-1873580233

Wild Animals of Britain & Europe - by Helga Hofmann
HarperCollins Publishers -- 1995 -- ISBN: 978-0007627271

Wild Fox: A complete study of the Red fox - by Roger Burrows
David and Charles Publishers -- 1968 -- ISBN: 978-0330238007
Note: Burrows provides some interesting observations in this book, but frequently arrives at spurious conclusions. As such, this book should be interpreted with caution.

The Red fox at a glance

Bibliography

Links

Red fox in detail