The secret life of urban foxes
Foxes are one of the most recognisable wild animals in Britain. These wily animals are extraordinarily adaptable and as at home in urban and suburban areas as they are in the countryside.
There are many species of fox thriving around the world, from scorching deserts to the Arctic. The most widespread is the red fox (Vulpes vulpes), thought to be the first and most common non-domestic carnivore in cities all around the world.
Discover what makes urban spaces so appealing to the iconic red-furred fox.
What do urban foxes eat?
Foxes are part of the Canidae family - the same group as wolves and domestic dogs. Foxes are categorised as carnivores (sitting within the order Carnivora), but will eat almost anything.
Rural red fox diets are around 95% meat, and supplemented with insects, worms and fruit. In urban areas meat only makes up around half of their diets, the other half being household refuse.
Foxes have developed strong stomachs and immune systems, so they're unlikely to be affected by rotting food scraps. Urban foxes primarily scavenge for food, but when they hunt it is usually for birds or small mammals such as rats and mice, helping to keep rodent numbers under control.
The Fox Project, a UK-based charity dedicated to protecting the red fox, state that in 26 years of work and 12,000 foxes rescued, they are 'yet to find a starving adult fox'.
Where do urban foxes live?
Foxes dig out dens to provide a safe underground space that is mostly used for raising fox cubs, also called kits. In urban areas, the dens - known as earths - are commonly located under sheds, but they can also be among tree roots, in bushes or on railway embankments.
Foxes will visit these burrows throughout the year for shelter, although you may also spot them relaxing out in the open during summer.
Becoming city dwellers
Foxes have been documented in Britain's southern urban areas since the 1930s. The expansion of these areas during the interwar period created an ideal new habitat with an abundance of food.
The number of foxes living across the UK isn't officially recorded, however a 2013 report by the Department for Environment, Food and Rural Affairs (DEFRA) estimates that there are around 430,000 - roughly one fox for every 150 people in the UK.
The number in urban areas is thought to have increased from 33,000 in 1995 to 150,000 in 2017. However, in 2018 there was a 42% decline in red foxes in Britain, although the cause is unknown.
Fox populations are self-regulating, with attempted culls proving unsuccessful. In the 1970s, London boroughs were responsible for their resident foxes. In Bromley, a fox-control officer killed 300 foxes a year, but made no dent in the population. Urban fox control was abandoned in the 1980s.
If you remove a fox from an area, their territory will likely be claimed by another within a matter of days. Removing foxes also usually results in a larger breeding population the next year.
Foxes are resourceful in exploiting new territories. In 2011, as the Shard skyscraper was being built in London, a fox moved in on the seventy-second floor, surviving on food scraps left by workers.
Even at the Museum there are a few footprints preserved in the concrete floor of the Darwin Centre collection's space from a fox exploring the site as it was being built.
What noises do foxes make?
Red foxes are very vocal compared to other fox species. They use barks, whines and throaty noises for a number of communication purposes, from conversations with their young to alarm calls and aggressive 'gekkering'.
Foxes live in social groups of two to six adults, although they mostly forage independently. They use vocalisations to communicate to nearby foxes. A study in Bristol found that when different groups of foxes encounter each other, it almost always results in aggression to defend territory.
Although vocalisation is important for foxes, their keen sight and smell are also key factors in detecting other social groups.
Why do foxes scream?
Foxes are perhaps best known for their 'screams', which are mostly heard at night, when the animals are most active.
The high-pitched wails are made by vixens (female foxes), mostly in the breeding season, which begins in January.
It has been suggested that the screams are sounds of pain when foxes are locked together during mating, but this is an urban myth. The screams are actually the females trying to summon a mate.
When do foxes have cubs?
Most foxes are born in March in litters of around four to five cubs. The baby foxes remain with their mother for around two weeks, so during this period she is fed by other members of the social group.
The kits emerge from the ground in April and at around seven months old have reached their adult size. Some vixens will have their first litter at the age of one.
City living is tough
Wild red foxes generally live up to nine years. However, on average, foxes only survive between one and three years.
The most common cause of fox deaths is road accidents, particularly for males and younger animals as they start exploring and disperse from a breeding site from August to December. Some cubs will remain with their family group for their whole life, however.
Do foxes carry diseases?
You may have noticed your local foxes looking a little rough around the edges. This could simply be seasonal moulting, or it may be something more troublesome for the fox.
Sarcoptic mange, also known as canine scabies, is caused by the parasitic mite Sarcoptes scabei canis. It is highly contagious between foxes and dogs but treatable. The mites can be passed to humans, but they can't complete their life cycle on a non-canine host.
The mite burrows into the fox's skin, causing lesions and the iconic red fur to fall out. This leaves bald patches, whereas when the animal moults for summer, the new coat is already visible beneath.
Without treatment, mange lesions can lead to secondary infections that can be fatal in extreme cases.
In some parts of the world, foxes carry rabies. But in the UK and most of Europe, the rabies virus has been eradicated in all animals, domestic and wild, except some species of bat. According to Public Health England, the last non-bat case of rabies in the UK was in 1902.
Foxes can also carry toxoplasmosis, a common parasitic infection. While foxes can't pass this infection to humans, we can become infected, most commonly through exposure to infected cat faeces. Although toxoplasmosis has little effect on humans, in foxes it can dramatically alter behaviour, such as reduce fear and aggression levels, which foxes rely on for survival in the wild.
Foxes can be wonderful to watch in the garden, and many people enjoy observing 'their' foxes, particularly as cubs become more active.
Dawn Scott at the University of Brighton has been studying urban foxes and their interactions with humans. She discovered fox feeding is prevalent in many urban areas, providing many people with a valued interaction with wildlife.
Foxes can become very reliant on regular feeding, so it is best not to do it too often or with large quantities of potentially inappropriate food. But putting the occasional fresh egg out on a saucer and watching it in the evening or even putting a trail camera out to watch after dark can yield fantastic sightings.
Foxes are scavengers and are seen by some as pests. Our gardens are appealing to foxes because they offer food and shelter. If you'd prefer they don't hang around for too long, humane deterrents are the best option.
It's best to keep food waste in secure bins. Scavenging foxes can easily tear their way into bags left out in the open, causing a mess.
Foxes are able to squeeze through even a 12-centimetre gap. To stop them from entering your property, keep garages, ground-floor windows, doors and cat flaps closed at night.
Don't try to fill in gaps in garden fences or walls as these can be important wildlife corridors for other urban wildlife, including hedgehogs. Foxes are also excellent climbers so it would make little to no difference to a fox entering a garden.
Small pets, such as rabbits, guinea pigs and birds, could make an easy meal for a hungry fox. If you leave your pets outside, they should be kept in properly secured pens and cages. Chicken wire is not strong enough to keep out a fox.
To help prevent foxes claiming your garden as their territory, there are non-toxic animal repellents on the market. You should only use those approved for use against foxes as other repellents can be damaging to other wildlife in the garden.
Red fox distribution in urban areas of the UK: results of a TV-driven nation-wide survey published in PLOS One.
Linnean Society video of Prof Dawn Scott's talk on the adaptations of mammals to urban living.
Your local council website may have more information about foxes in your area.
Do not try to handle or transport an injured fox yourself. If you see an injured fox, contact the RSPCA: +44 (0)300 1234 999