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Bird lovers in denial over bird flu
20 May 2006
Debora MacKenzie
MOST of us, at some time in our lives, have refused to believe something we don't want to believe despite considerable evidence that it is true. Such denial is understandable; the truth can be painful. But there are times when denial can also be dangerous. The reluctance of some ornithologists, conservationists and other members of the birding community to accept the role of wild birds in spreading H5N1 bird flu is a striking example.
Since I wrote in this magazine some eight months ago that wild birds appeared to be carrying the H5N1 flu virus, I have received dozens of critical, sarcastic, even vicious emails from such people. How can you spread this ludicrous theory, they ask. Why is New Scientist protecting the poultry industry? Where's the evidence that wild birds have been helping the virus spread?
Let's summarise the evidence. The H5N1 virus emerged and acquired its nastiness in poultry; there's no dispute about that. The trade in poultry is also overwhelmingly responsible for H5N1's spread in east Asia. It was a different story, however, when the virus, having killed wild geese at Qinghai Lake in China, spread across Russia and into Turkey, Ukraine and Romania. The strain found in all these places is identical to the one first seen at Qinghai, never in east Asian poultry, which strongly suggests that it was not carried west by poultry. Maps of the outbreaks look a lot like the migration maps of dabbling ducks - long-distance migrators that tolerate the virus.
Since then the evidence has become even clearer. There have been outbreaks in western Europe almost exclusively in wild birds, and in all cases of bird flu west of Qinghai the virus is identical, suggesting it has found a carrier where it is more stable than in chickens. Yet the critics refuse to listen. They tend to start with the conclusion that wild birds must never be blamed, and then marshal "evidence" to support their case, ignoring any that doesn't. Wild birds are being made scapegoats for a disease that evolved on battery farms, they say; they're the victims, not the vector - ignoring the fact that they can be both. Or they invoke alternative explanations and demand they be disproved: the virus found in birds in a German nature reserve could have got there in Turkish chicken waste used as fertiliser, rather than ducks migrating from Siberia.
Some have come round to the idea that the virus is being carried by wild birds, but others are still in denial.
This month we heard hopeful claims that because the spring migration across the northern hemisphere has not been accompanied by an explosion of bird flu, no wild birds are carrying the virus. Yet everything scientists know about bird flu epidemiology indicates that this is not surprising: it's likely that a few infected birds have arrived at their summer locations, that over the coming months they will infect others, and that prevalence will peak in the autumn.
I am not the only one concerned about all this. "The ornithology community has been slow to acknowledge that wild birds might be playing some role," says one senior European virologist. A top American virologist who himself resisted the evidence about wild birds admitted: "It's a political debate, not science." A UN official told me: "They aren't speaking from evidence."
Their attitude could have consequences for how we tackle the spread of H5N1. We need birding experts to predict where the virus might migrate next, rather than deny that it will. The influence of birders is said to underlie the British government's decision not to force poultry farmers to keep their birds inside.
If nothing else, wild birds are indeed victims of this virus, and their advocates should be fighting to protect them from it, not denying it is there.
Ask birders why they are scared of implicating wild birds and they'll say it encourages people to cull them and undermines conservation efforts. It's true that some people worried about bird flu have threatened to shoot birds or destroy wetlands, but as far as I have been able to discover nothing much has materialised.
I'm sceptical that this is the real reason. A clue as to what this might be emerged in April at the first, hastily arranged World Migratory Bird Day in Nairobi, Kenya, which was described by its conservationist organisers as happening "at a time when migratory birds are being unfairly portrayed solely as the harbingers of death and disease" - an absurdly exaggerated claim. Another critic said: "The real question is not, are wild birds to blame, but why are wild birds being blamed?" In other words, this isn't about evaluating evidence, it's about building conspiracies.
The only reason I can think of for all this is that we are dealing with a community acting more on faith and emotion than reason. For them, birds are, by definition, innately pure and transcendent - too pure to carry anything as mundane or dirty as a virus. Given this attitude you can understand their denial, but they are doing neither wild birds nor humans any favours.
http://www.newscientist.com/channel/health/mg19025523.700-bird-lovers-in-denial.html
