The British hedgehog population has plummeted by up to half over the course of a decade, a survey suggests.

The report has prompted fears that the population of the prickly creatures is slowly being wiped out.

The count was conducted by volunteers for a survey funded by Mammals Trust UK and the Joint Nature Conservation Committee.

We tend to assume there are lots of hedgehogs around because we see them in our gardens

Paul Bright, University of London

Intensified farming methods are mooted as the main reason for the sharp decline in hedgehog numbers but other human activities are also blamed.

Even as the survey results were being released it emerged that fast food chain McDonald's had agreed to alter the design of its ice cream containers, which wildlife campaigners claimed were death-traps to hungry hedgehogs.

The poll was carried out in 2001 and compared with a previous, similar study undertaken in 1991.

Decrease

Hedgehog numbers are shown to have dropped nationally by 20-30% - a reduction of around 2.5 million in the overall population.

Hedgehog Facts

An adult hedgehog can have up to 7,500 spines The name hedgehog dates back to 1450 A hedgehog can house up to 1,000 fleas Slugs, snails and worms are their diet When frightened they curl up in a ball Famous hedgehogs include Mrs Tiggy-Winkle, created by Beatrix Potter

But in some areas, notably East Anglia, the decrease is up to 50%, while a 40% drop was recorded in Yorkshire, Humberside and the South East.

Paul Bright, of Royal Holloway College, University of London, who analysed the study, said the results were "worrying".

"We tend to assume there are lots of hedgehogs around because we see them in our gardens but that does not necessarily mean they are in abundance in the countryside," he said.

The popular belief that hedgehogs die as a result of being knocked down in the road is not seen as the main reason for their decline.

Predators and disease are factors but intensive farming and pesticides are thought to be big killers.

Mr Bright said the removal of short grassland around the margins of fields had lost the hedgehog its favoured habitat.

Stuck in a McFlurry

Animal welfare groups have also welcomed the move by McDonald's to issue "hedgehog-friendly" ice cream cups, after a spate of deaths.

The animals were getting their heads stuck inside the McDonald's McFlurry containers while sniffing for food, ending up starving to death.

Selected restaurants will stock the new style pots from next month.

The company blames the problem on litter bugs.

Meanwhile in the Uists islands in Scotland, where hedgehog numbers have spiralled to at least 5,000, Mammals Trust UK is working to stop a hedgehog cull taking place.

Scottish Natural Heritage wants to exterminate 5,000 hedgehogs, which they believe are responsible for the decline in internationally important populations of birds.

Mammals Trust UK has applied for a licence to relocate approximately 50 hedgehogs, as part of a trial translocation.