HOW ARE WILD WATERFOWL INVOLVED?
Wild birds, including waterfowl and other water birds, are sometimes killed by the new strain of bird flu, but most of them appear to be resistant. As a result, some can become carriers of the disease—that is, they have the disease in their bodies but are not sick and live normally. In this condition, infected birds may carry the disease to other locations and affect other wild and domestic flocks. Nevertheless, in almost every case where wild birds have died from the disease, the origin has been traced to infected flocks of domestic poultry. There are a few cases, however, where the disease arrived in remote locations where it was more likely transported by wild birds. Although Asian H5N1 can be lethal to individual wild waterfowl, only a few large die-offs have occurred in the wild. The most serious happened in western China last summer when more than 6,000 wild birds died in a nature preserve. Among these were 2,000 bar-headed geese, an endangered species in Asia. This represented a
