Mange joins traffic as the urban fox's biggest killer

Britain's urban fox population has been severely reduced by outbreaks of a devastating disease, and is now much lower than was previously thought, experts said yesterday.

The disease, sarcoptic mange, reduced Bristol's fox population by more than 90 per cent in the late 1990s, and has since spread across the south of England and Midlands. Dr Rob Atkinson, head of wildlife services at the RSPCA, described it as "a huge problem".

Dr Phil Baker of Bristol University says the UK has fewer urban foxes than the 35,000 widely quoted. And London experts dismissed claims of 15,000 foxes living within the M25, saying the true figure is a third of that.

The news of the outbreak comes a few days after a fox was reported to have bitten a baby while she slept in her Kent home. Trevor Williams, of the Fox Project, who was consulted by the doctor treating the child, is convinced the animal was concussed. He cited the mildness of the injuries, described to him by the doctor as "nips".

Other experts are sceptical about a fox being responsible. They say that an oft-quoted previous incident of a fox biting a baby turned out to have been made by a family who had fed a family of foxes and then, when they followed them into their home, demanded that the local council take action. According to Mr Williams, when none was forthcoming, the attack was reported but it turned out to be a cat bite.

Defamation is, however, the least of the urban fox's problems. Nearly two-thirds of all foxes in the UK die each year, with traffic the chief cause of death. But in some areas, mange is as big a danger as cars. The disease makes the fur fall out and the skin is covered with a thick crust crawling with mites.

Some experts now believe that global warming is contributing to the spread of the disease. Historically it has been endemic in the South-west, but, as winters are no longer cold enough to kill it off, it has spread east and north.

The only bright spot is that the Mammal Society has reported some success at treating the disease with a homeopathic remedy containing arsenic and sulphur.