Reprieved hedgehogs may be no safer on the mainland

It was a welcome piece of good news in an increasingly sad tale. The decision this week to halt the cull of hedgehogs on the Western Isles of Scotland and instead transport them alive from the wilds of the Uists back to the mainland was heralded by conservationists as a crucial step in the fight to save the creatures.

But, while animals rights campaigners celebrate, the creatures themselves have every right to feel nervous about their impending relocation - hedgehog populations across the UK have dropped by up to an estimated 50 per cent in the past 15 years and there is concern over the mysterious decline.

Research from Mammal's Trust UK reveals an average population decrease of 20 per cent - the figure is as high as 50 per cent in parts of East Anglia.

"If it continues at this rate it will be a cause for concern. We need to find out whether this is a trend or simply a population blip," said Jill Nelson, Chief Executive of the People's Trust for Endangered Species.

"There is something drastic happening to the hedgehog population."

For centuries Britain's discreet, nocturnal hedgehogs have scavenged their way into the folklore, thanks to writers such as Beatrix Potter. Yet while the image of Mrs Tiggywinkle continues to enthral, it is estimated the animals are dying out at a rate of almost a fifth of the population every four years.

They are not considered a pest by farmers and are beloved by gardeners for their diet of slugs, snails and plant-destroying bugs. But unless an answer can be found the species could be extinct in Britain by 2025.

Already numbers have declined to such an extent that there are very few in central London and fewer than half the places in the capital where they used to be found in abundance just 40 years ago have any left.

Their slow gait and tendency to curl up rather than flee danger means hedgehogs are notorious victims of road traffic accidents. New and faster highways have contributed to their decline but researchers believe there are other factors caused by farming, building developments and global warming.

The animals' natural habitat in hedgerows has been destroyed by new farming methods. The use of pesticides and slug pellets on crops inadvertently poisons hedgehogs while the relentless spread of new housing developments and roads create concrete islands within their natural habitat, making it impossible for them to forage freely. This means food sources quickly become scarce and they starve to death.

Ecologist and hedgehog expert Hugh Warwick believes the long, dry autumns caused by global warming limit their food supply as slugs and worms come out in damp conditions.

Hedgehogs' breeding season is May but during a mild year they will breed again in September. After just eight weeks the young hedgehogs, known as hoglets, are weaned from their mother and must fend for themselves. If there is a sudden autumn cold snap, fragile hoglets will struggle to survive.

The British Hedgehog Preservation Society and People's Trust for Endangered Species UK have set up a project called Hogwatch to assess the distribution of the hedgehog population throughout the country - the higher the number of road kill, the higher the population.

One striking trend is that hedgehogs are heading to suburbia. "Hedgehogs are recreating their habitat in the suburbs and are doing very well," says Mr Warwick.

Networks of cosy gardens with hedges, shrubbery and piles of messy leaves provide the cover they are being deprived of in the country.