For both Chen Lianfu, whose chickens were the first to die from bird flu in Hubei Province, and Zhou Lifa, a farmer who saw the epidemic hit his ducks, migratory birds seem very likely to be the source of the disease.

Although their suspicions have not yet been confirmed by scientists, it is widely believed by farmers like Chen and Zhou and their neighbours, and even local health and agriculture officials suspect that migratory birds are the source of the problems.

And the evidence they cite, mostly drawn from firsthand experience, sounds plausible.

Chen's chicken farm is surrounded by woods, including orchards and bamboo groves, and is quite far from other farms in his village, Zhanglingshang, of the city of Wuxue, in eastern Hubei close to Jiangxi and Anhui provinces.

And before the outbreak of the epidemic, which killed 1,100 chickens from January 20 to 23, no one from other epidemic areas had come to his farm.

However, the woods which surround his farm, are home to many local and migratory birds that live or sojourn there, Chen told China Daily.

"I was quite astonished by the disease, which spread so quickly and killed so many of my chickens, and I am also puzzled over what might have caused it," Chen added.

Before his chickens finally died, in about five hours, they just stood there without moving, with swollen combs and clotted blood oozing from their beaks.

"They all died outdoors on my farm, which meant they might have been in contact with things left by other birds when they flew over the area," said Chen, who said that he often sees wild birds flying by or sojourning near his farm.

Zhou Lifa's story is similar to Chen's. Zhou's 68 ducks were killed in just several hours, and he says that he believes that the deaths were caused by the visit of some hawks.

Three days before the epidemic hit, hawks, which often visit Zhou's village, carried off a duck from outside his house and tore it apart near the village.

Just like Chen, Zhou can think of no other possible source of the deadly virus on his farm.

"It must have been the 'Yaozi,' a local name for hawks, that brought the virus," said a neighbour of Zhou.

Zhou's ducks, just like Chen's chickens, all lived in open places, which exposed them to contact with wild birds and their droppings.

Local bird experts said that wild birds may carry the virus, even though they are healthy, and could spread the virus to poultry.

Zhou's village, a remote one in Yangxin County, is several hundred kilometres away from Chen's village, and there had been no contact between them at all.

Another eight bird flu outbreaks in Hubei have been on isolated farms, said officials.

So far, wild birds are widely regarded as the possible source of the virus, said Liang Xunyin, deputy director of the health bureau of Yangxin County; however, he added that "before the final results from the tests of scientists are released, it is only a guess."

Experts from WHO headquarters in Geneva have said that after two months investigation, wild water birds have been listed as most likely suspect in carrying and spreading the H5N1 virus in Asia.

Another interesting fact is that the bird flu outbreak on Chen's farm was the only one in his county. And, similarly, the other nine counties and cities struck by the virus all have only one case in their respective regions. Culling and preventative measures were immediately undertaken in all areas hit by the virus.

In accordance with the compensation standard set by local governments, which is 15 yuan (US$2) per chicken or duck, Chen was given 30,000 yuan (US$2,700) for his chickens and Zhou has also been paid for his 168 ducks. Affected farmers in other eight villages were also compensated the same way.

(China Daily February 23, 2004)