During the mating season," runs the official advice leaflet from the RSPCA, Living With Foxes, "it may be worth considering the use of earplugs if the howling disturbs you." Well, that's now. Last week, this week and next week comprise the brief period of the year when foxes get it together; and when foxes that live in built-up areas get it together, they are quite likely to do so right under your bedroom window. At 3am.
And boy, do you know about it. The mating call of Vulpes vulpes is the most unearthly sound you're ever likely to hear in the suburbs (apart from a Jonathan Pearce football commentary). It is not only loud. It is weird.
It is a sort of languorous, drawn-out wailing, as if a huge drunken baby were crying. It would not be out of place in The Exorcist. It is the sort of noise guaranteed not only to wake you, but to make you shoot upright in bed exclaiming: "Wozzat?!" and then, when you hear it again, to exclaim: "Woddonearthsat?!"
But this is the sound of the city, these days, as much as motorbike engines or rap music. In fact, it has been for several decades, since foxes started the curious trek to the town that has since been followed by several prominent species of British wildlife. Out of a total British fox population of about 240,000, about 30-35,000 animals are now thought to be living at the bottom of our suburban gardens, or in neglected urban corners such as railway embankments.
According to the latest research by PhD students at Bristol University, the life of an urban fox bears an uncanny resemblance to many of its human counterparts. It enjoys a variety of sexual partners, it prefers to eat a wholesome diet and, given half a chance, spends much of its time snoozing.
The precise moment when foxes migrated to the cities is hard to establish, but the finding of a dead fox cub half a mile from Waterloo Station in 1975 probably marked a key moment, when the fox hit central London. It has been followed by the grey squirrel, and increasingly, as The Independent reported last year, by some deer species such as the muntjac. Two big, conspicuous bird species have also gone urban: the magpie (in the 1970s) and the sparrowhawk (in the 1990s).
Why have they done it? One theory is that they haven't. They haven't moved in to us, so much as human habitation, always spreading, has moved out to them. "I think the built-up suburbs eventually encompassed areas where foxes already were," says Phil Baker, of the Mammal Research Unit at Bristol University.
The Bristol unit is the leading centre of expertise on urban foxes in Europe, if not in the world, and Dr Baker and the head of the unit, Professor Stephen Harris, are joint authors of the standard urban fox study. Their PhD students spend their time following foxes around the Bristol residential suburb of Stoke Bishop in the late evening and early morning, and putting together an increasingly detailed picture of urban fox life. Luckily, the researchers don't need to break into Stoke Bishop's gardens: radio-tracking, via a collar attached to the animals, enables them to pinpoint the foxes' position and thus estimate territory size and get a good idea of their activity.
"Urban foxes behave in exactly the same way as rural foxes," Dr Baker said. "The only difference is that foxes in urban areas are more tolerant of being approached by people. You can get to within six feet of an urban fox. The distance at which they take flight in rural areas is very much greater."
For breeding, the animals tend to gather in groups of about five adults, which comprise a dominant male and female, who mate, and other subordinate young foxes, whose role is to help bring up the cubs, born in March after an average gestation period of 53 days.
The cubs spend about a month underground, stay with their parents throughout the summer, then split off to fend for themselves in the autumn. For much of the year the adult animals sleep above ground during the day - under a garden shed is a favourite place - before emerging for the night's hunting.
Like their country cousins, urban foxes are omnivorous opportunists, and eat exactly the same food: earthworms, insects, fallen fruit, small rodents and birds. The one diet item not available to rural animals is the food many people leave out for them - meat scraps, catfood or dogfood.
The RSPCA points out that, contrary to some people's belief, urban foxes are not dependent on the contents of dustbins, but will take anything edible if rubbish is not properly contained - "as do dogs, cats, squirrels and birds".
There are other urban myths about urban foxes, one of the most persistent being that they carry off cats. Dr Baker is at pains to scotch this. "It's extremely unlikely that a fox would take a cat," he said. "An adult cat is about the same size as a fox - there's not a great deal of difference. Although people think it's a problem, if your cat comes in clearly having had a fight, it's statistically much more likely to have been with another cat. In a square kilometre of suburb there may be 10 to 15 foxes, and 300 cats. We've been following foxes around for 20 years and to my knowledge we've never seen a fox and a cat come to serious blows. When they do come across each other, they just sit there and eye each other, and often, the cat will take a swipe and the fox will just run off."
Another fear is that foxes may spread disease. "The only possible danger would be from rabies, and as a country we are rabies-free," Dr Baker said. "To our knowledge there is no record of anybody catching any disease from a fox."
That is not to say that urban foxes do not fall ill. They do, and terribly so. At the moment the urban fox population over much of Britain is being hard-hit by a very unpleasant ailment indeed: sarcoptic mange. This is an infestation by a parasite which burrows into the fox's skin and causes the fur to fall out. It then produces a thick encrustation on skin, which splits open, allowing bacterial infections to get a hold on the animal (told you it was unpleasant).
The results can be alarming. My wife and children opened our suburban front door in west London to a noise one evening last year, and were shocked to see, just a few feet in front of them, an animal out of Hieronymus Bosch's Hell: a fox with most of its fur gone, so scrawny as to be hardly worthy of the name, in evident distress. It ran off before they could do anything, though what they could have done is hard to imagine.
"When they get like that they just keel over and die," Dr Baker said. "It's knocking fox numbers on the head in urban areas."
The ailment is difficult to treat, he said, because with conventional veterinary medicine, two injections, widely spaced, are necessary. But an animal charity, the National Fox Welfare Society, is offering householders free treatment for foxes suffering from sarcoptic mange. It's a homeopathic preparation which is included in food left out for the animals. Last year they sent out 6,623 treatments, which shows the extent of the problem. (Anyone interested can find more details on www.nfws.org.uk). Reassuringly, Dr Baker says there is no risk to people whatsoever.
No, that's not the problem with the foxes at the bottom of the urban garden. On the whole they're wonderful animals and most people feel thrilled and privileged to see a fox on their lawn (especially when they're playing with their cubs).
The problem is that bleeding banshee wailing in the small hours. It is not, as you perhaps might imagine, a long, deeply-satisfied groan of sexual pleasure. It is more the phone call arranging the liaison. "Both males and females give it," said Dr Baker. "Our work suggests there is a lot of long-distance mating. Male animals that are solitary for a lot of the time come from a long way away, and come together with females that are sexually receptive. When it goes on, you can't fail to hear it. People just have to put up with it. There's nothing you can really do."
THE WILD SIDE
Roe and muntjac, pictured below, are Britain's smallest deer and have been seen in gardens in Leeds, Southampton, Oxford and London.
Deer are often considered a nuisance by gardeners and can inflict extensive damage on garden shrubs and plants. One deterrent is said to be human hair hung on fences or walls.
Their impulsive nature is also a danger to drivers. Last year, at least 100 does were killed by traffic inside the M25 area of London.
With urban development encroaching into the countryside, badgers are struggling to find enough land in which to build their setts. They are now turning to urban areas - particularly gardens, where they burrow under the lawn and feed off worms.
Badgers often overturn dustbins in their search for food, especially during hot, dry summers when other sources of sustenance may be limited.
As Mr MacGregor found in Beatrix Potter's story, rabbits will eat garden plants and are a particular nuisance in vegetable plots or allotments. In winter they can destroy or injure ornamental shrubs, fruit trees or berry bushes. The best way to keep them out is to fence off vulnerable areas with chicken wire, extending it 30cm underground. Rabbits are normally nocturnal but will come out in daylight if undisturbed, especially during the long days of summer.
These solitary animals live entirely underground in a tunnel system of up to 2,000 square metres. They occur increasingly in playing fields and urban gardens, where the first sign is usually a molehill in the lawn.