Big Picture Science

The worry about whether H5N1 will trigger a human pandemic has concealed a startling reality. Avian influenza has already taken an enormous toll on the lives of other animals. Since 2005, the number of wild and domesticated birds killed is greater than the combined human populations of the United States and Russia. Bird flu is burning through wild flocks, poultry farms, and mammal populations, including those of sea mammals. We look at the places where the virus can recombine and mutate, and why this version is not simply dying out as it has in years past. At a squawking live poultry market in Brooklyn, and on a Long Island duck farm, we hear about the difficult experience of euthanizing 100,000 birds and whether a farm can recover from such a devastating loss. And finally, we ask, why poultry vaccines that could curb the spread of H5N1 aren’t being used. But we begin our episode with descriptions of the soaring global migrations of birds whose feats of endurance help us understand why H5N1 is widespread in b