The high moors and wilderness places of the Bradford district have become hunting grounds for a new foe - bird flu.

As yet Britain stands as a citadel, officially untouched by the disease, which has already hit seven European countries.

With officials sweeping on a poultry unit in France, yesterday, the first farm in western Europe suspected of having the disease, the threat gets closer.

Thankfully, the nine dead swans found in Britain last week and tested for Avian Influenza were found to be free of the disease.

But many experts are debating not whether it will arrive on our shores, but rather when. The fear is that the disease, carried by wild birds, will lead to widescale infection of the county's poultry flock. Migrating birds are expected to be arriving in Britain for about another month.

Among poultry rearers in the Bradford area concerned about his flock of pure breeds is Edward Boothman, of Howden Park Farm, Silsden, who keeps between 3000 and 4,000 hens.

He fears a reaction from the Government, like that during the Foot and Mouth crisis, which saw wholescale slaughter of animals, could be disastrous with many rare strains of poultry being wiped out.

He said: "If it comes to an all-out cull we could see strains lost forever. If it does arrive in this country, I want the Government to provide holding stations where these breeds can be kept and eggs hatched."

He believed that good husbandry and hygiene rules would help to keep it at bay, but in the end it might be necessary to bring birds inside.

Since 1997 the deadly virus H5N1 has spread from Hong Kong to ten countries, has affected over 200 million domestic poultry and 60 people have died.

The big fear is that it will mutate and spread from human to human.

So it means everybody being on high alert to spot if and when it arrives in the UK.

And especially on the front line are people like Bradford's official rural guardians, the Countryside Wardens.

Bradford council has six countryside officers, five rights-of-way staff and a number of people who carry out practical work.

In their jobs overseeing the countryside they will be on the look-out for infected animals and have been informed about how to spot the tell-tale signs.

They have received special instructions about what to look for and have direct contact with Defra, the Government department charged with spearheading action to combat any outbreak.

A Bradford Council spokesman said: "Our park rangers and countryside officers are being vigilant and are aware of what to do if they are told about or find a dead bird."

City Hall was working with with Defra on what was being described as a "potential emergency."

Danny Jackson, Bradford Council's Countryside and Rights-of-Way officer, said his staff had been made aware of the Defra guidance.

He said: "We will be following that advice and when we are out we will be looking for anything suspicious.

"Anything we are worried about we will report back to the council's animal health department who will keep Defra informed."

The two major areas to oversee are Ilkley Moor and the Penistone Hill area of Haworth.

Mr Jackson said: "There's about another month for migrating birds to be coming back into the country so we will be keeping a weather eye over that period."

Joining the wardens on the front line are the district veterinary surgeons, likely to be seeing people anxious about their feathered pets.

Vet Simon Thomas, whose practice has surgeries at Allerton, Bingley and Haworth, says veterinary surgeons will be important in helping detect and fight the disease if it hits the UK.

He believes vets are likely to be faced by people bringing in their sick pet birds fearful they have the disease.

"It will be about trying to take a sensible balance between panicking and taking a thoughtful measured approach," he said.

He reckons that budgies and parrots would not be affected although some people were already dumping parrots, frightened that they could become infected.

Most likely first signs for vets would be from the many people in the Bradford area who keep a few hens for eggs, he said.

"This is more to worry about than people who keep parrots or budgies indoors.

"If bird flu does arrive in wild birds then hens scratching around outside are vulnerable and the danger is if some die and then are handled by humans."

Vaccination of the birds was a preventative measure, but there still was a danger in that some vaccinated birds could get the disease and be carries for a short while and so potentially infectious.

He said: What might be best - but at the same time horrid - would be to let them die and in that way we would know they had it and then take action."

Ultimately, it might be necessary for all poultry to be brought inside to prevent the spread.

Meanwhile, it was important to make sure that even if hens did go outside, their food was undercover where wild birds could not get at it or their dropping fall on it, he urged.

Chris Davis, head of wildlife disease and epidemiology with the Game Conservancy Trust, said the likelihood of bird flu hitting the UK was still low.

But the risks were not short term and he believed we would have to face the treat of an outbreak in the UK for the foreseeable future.

Bradford Council is urging members of the public not to handle any dead birds.

A spokesman said: "If you have to handle birds, please make sure you have received suitable training or handling dead or alive animals and you have appropriate equipment."

If dead birds were found they must be reported to Defra which has launched a bird flu number on 08459 335577.