By Stephen Harris

Urbane Urban Foxes

As hard as it might be to believe, foxes are living on Downing Street and visiting Buckingham Palace. It's true—foxes (Vulpes vulpes) have joined rats, mice, gray squirrels, and hedgehogs in colonizing British cities, even the very heart of London. In fact, about 14 percent of all the foxes in Britain now live in urban areas, where they can reach densities ten or more times higher than those in the countryside. So in Britain foxes really are familiar urban neighbors. Safe from persecution and welcomed by most people, it's hardly surprising that foxes can be seen walking the streets in the middle of the day.

Foxes live in many European cities, although rarely at British densities. They've even made it to Australia, where they were introduced in the late 1800s for hunting. The newcomers spread rapidly—decimating many native species and colonizing most of the larger cities. The situation is different in North America—foxes are widespread but not so numerous in urban and suburban areas, probably because of competition with raccoons and coyotes. Even in British cities foxes are rare in areas with lots of stray dogs.

Foxes began colonizing British cities in the late 1930s, when land was cheap and houses were often built with large gardens. The maturing gardens provided excellent cover and food for the foxes, who readily moved into this new habitat. After World War II, the cost of land grew, so gardens tended to be smaller. Although foxes can be found in more modern (and older) gardens, they are still most abundant in the established, 1930s-era suburbs.

At first, urban fox numbers remained low, and their diet was probably little different from that in rural areas—small mammals, birds, insects, and earthworms. Cities also offered bird seed under feeders, pet food left outside, and scraps from compost heaps and garbage cans. But contrary to popular belief, foxes never scavenged from garbage cans very much, and the secure lids of modern cans have all but closed this resource. As urban fox populations grew in the 1940s and 1950s, they also became increasingly popular with local residents. Many people started to feed them, and their diet slowly changed. I have been monitoring the foxes in the city of Bristol continuously since 1977, and 10 percent of all households in the early 1990s were putting out food for the foxes on most nights. So it makes sense that the foxes were not very interested in scraps from garbage cans; the food supplied by people made up about 60 percent of their diet.

And the large amount of human-supplied food had a big impact on the foxes. There was so much available that they lived in very large social groups—one group in Bristol had 10 adult foxes living in an area less than a quarter of a square kilometer! Despite the number of foxes, they caused few problems and most people welcomed them—they would hardly have been so well fed by the locals if they were a nuisance.

Sadly, all this changed in 1994 with the arrival of sarcoptic mange, a highly contagious and generally fatal disease. Mange first appeared in the rural fox population in southwest England. When it reached Bristol it spread with frightening speed; within two years at least 95 percent of all the foxes in Bristol had died. It was a devastating experience, not least for the people of the city. To watch the foxes they knew so well dying from such an unpleasant disease was extremely distressing, and many people spent a great deal of time and money adding various treatments to the food they left out for the foxes to try to save them. Sadly, their efforts accomplished little.

In the immediate aftermath of the epidemic, it was very strange to see the streets of Bristol devoid of foxes, and even now, six years later, the fox population is still only about 10 percent of that before the outbreak. The good news is that the fox population is recovering, and people are reestablishing their neighborly relationships with them. But it will be a very long time before Bristol again sees the remarkable numbers of urban foxes it did a decade ago.

Stephen Harris, Ph.D., D.Sc., is a professor of environmental science at the University of Bristol in England.