One thing is certain: where the global trade in poultry goes, avian influenza goes too. When bird flu was confirmed in Nigeria two weeks ago, agriculture minister Adamu Bello was in no doubt how it had got there - via smuggled poultry and cagebirds. "Birds come every day from China and Turkey into Nigeria, and from Europe and Latin America, so Nigeria is exposed," he said.
Equally, says Richard Thomas, a spokesman for BirdLife International, a consortium of bird conservation organisations, there is a good correlation of H5N1 outbreaks with major road and rail links between China, where the recent episodes started, and eastern Europe.
"There is already a precedent for long-distance movement of poultry leading to outbreaks at distant sites," he says. "According to the journal Science, an outbreak at the main poultry market in Lhasa, Tibet, in early 2004 was traced back to birds transported some 1,500km away from the city of Lanzhou, which is also on a major railway line connecting southern China to Kazakhstan, Russia and eastern Europe."
But the constant suggestions that migratory birds are responsible for the spread of H5N1 avian bird flu virus has led to the kind of popular coverage epitomised by the Sun's notorious "Ducks of Death" photomontage of a flock of flying waterfowl menacing London. A mob in Romania mutilated and kicked to death 300 waterfowl, immobilised by the cold, when the disease was found there. Spattered with the birds' blood, the people had to be quarantined.
The demonisation of wild birds is getting serious. Politicians in Iran and Russia have called hunters to arms to wipe out incoming migrant birds, and some governments in Asia and the Middle East have begun reviving plans to drain wetlands, under the pretext of denying waterfowl landing and breeding places.
Some of the world's rarest birds are bound to be put in jeopardy, and indeed are already at risk from the virus itself. Up to 10% of the world's population of bar-headed geese died at Qinghai, where the disease was found last year, and at least two red-breasted geese are among the casualties of the current European outbreaks. Both species are globally threatened.
In Hong Kong, where a scattering of new cases of avian flu in birds has involved at least one chicken smuggled from mainland China, the Mai Po Marshes nature reserve has been closed to visitors. The Department of Microbiology at Hong Kong University has been monitoring wild birds at Mai Po since 1997, and none have tested positive for H5N1 virus. Mai Po is a popular attraction, and one local conservationist expressed relief that the closure would protect the reserve's population of endangered black-faced spoonbills from visitors bringing the virus from the city on their boots.
Will bird flu change our attitude to birds here in Britain? Andy Evans, the RSPB's head of terrestrial research, thinks not. The British have got the message that the risk to human health from wild birds carrying the virus is minimal. "We're not aware of any drop in visitor numbers," he says. "I can think of only one instance of a school cancelling a reserve visit because of the risk."
Evans says taking sensible precautions, such as not touching dead wild birds or bird faeces, and washing your hands thoroughly if you do, is all that is needed. "People can continue to enjoy the countryside and carry on feeding birds," he insists.
If support for bird conservation starts to fall, the world's birds will be victims twice over: casualties of a virus that the poultry industry propagated and helped to spread, and scapegoats for an alliance of food producers and UN agencies in denial about the consequences of their policies and practices.
· Nick Langley writes for BirdLife International
