Who, What, Why: Are urban fox numbers rising?
There have been calls for more to be done about urban foxes after a four-week-old baby boy was attacked in his south-east London home. But are urban fox numbers rising?
Reports that a baby's finger was severed in a fox attack have raised concern about urban foxes.
Although such cases are rare, it is not the first time a fox has attacked a child in a city.
In 2010, two baby sisters were reportedly mauled while sleeping at their home in Hackney, east London. Isabella Koupparis suffered arm injuries while her twin Lola suffered injuries to both her face and arm, with both having to undergo surgery.
The same year, three-year-old Jake Jermy was bitten on the arm after disturbing a fox hiding beneath a temporary building while at a party in Brighton, East Sussex.
After the latest incident, London Mayor Boris Johnson said urban foxes were a "growing problem", and the attack "must serve as a wake up call to London's borough leaders, who are responsible for pest control".
- There are about 33,000 urban foxes in Britain
- Numbers haven't significantly changed since the 1980s
- Foxes are getting braver
But are urban fox numbers actually rising?
Recent estimates as to the number of foxes living in British cities are hard to come by, but the University of Bristol's Mammal Research Unit says that contrary to what some people might expect, little has changed since the last national census in the 1980s, which found about 33,000 urban foxes across Britain.
That compares with about 225,000 adult rural foxes.
The Veterinary Association for Wildlife Management cites similar figures, saying urban foxes still account for 14% of the total population.
Dr Phil Baker, an expert on urban foxes at the University of Reading, agrees with the analysis.
"There are currently no data to suggest that the numbers of foxes in areas where they have been present for decades have increased significantly at a national level," he says.
In fact according to Baker, the only major change that has occurred in urban fox populations over the past 30 years has been down to an outbreak of sarcoptic mange, a common disease of mammals, which severely reduced fox numbers in some cities.
- Live in family groups in dens
- Natural scavengers - will eat small mammals, fruit, carrion and discarded food
- Back gardens are the most important foraging habitat for urban foxes, say researchers
- Much fox communication is done by smell - specifically urine, which contains hormones
- Fox control is expensive, notes the Global Invasive Species Database
- On its list of 100 "world's worst" invaders
After an outbreak in Bristol in 1994, numbers declined by over 96% in just two years, he says.
Fox numbers have recovered since then, but the total in Bristol is still a little lower than before the outbreak.
However Baker says given that urban areas have increased in size since the last estimate, it is probably fair to say the total area occupied by foxes has also changed.
"But the density of foxes in these new areas is likely to be slightly lower than you see in those areas where they have been long established simply because the types of housing in areas of urban expansion are not the best type of habitat for urban foxes," he adds.
So if urban fox numbers aren't rising, what's happening?
Animal behaviour experts says it's possible we are seeing more of them, as urban foxes are becoming more accustomed to humans and getting braver.
"They are coming closer, collecting food, rolling over, even allowing petting - in some instances the behaviour is more dog-like than fox-like," says Dr Roger Mugford, an animal psychologist who runs the Animal Behaviour Centre.
But he says a large part of the equation is also down to the behaviour of adults.
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"People seem to be giving food handouts, leaving their bins in places where foxes can rip them open, and letting them be if they discover a den under their garden shed," he says.
"But if people don't want foxes in their garden they should block up holes or use repellent, and take simple steps to protect their property like shutting downstairs windows, or invest in a cat flap which has personal cat ID," he says.
Richard Moseley, technical manager at British Pest Control Association, says the association has seen an increasing number of calls about urban foxes over last few years, particularly in London, where about 10,000 foxes are thought to live, but also in Manchester, Leeds and Liverpool.
But he agrees it is hard to know whether numbers are rising.
"This unfortunate attack on a child is very rare, and has created lots of media coverage, which means people are more likely to take a note when they see a fox.
"Plus we are in the breeding season at the moment, so they are very noisy at night," he says.