Mass culling is expensive, but alternatives, like vaccinating chickens or luring wild birds away from domestic flocks, would also impose logistical and environmental costs. And they may be more expensive,

Although there's a low risk of an avian flu outbreak among wild songbirds, it's advisable to keep feeders and birdbaths clean, the Department of Environmental Conservation said.

With egg prices soaring, the US is considering vaccinating laying chickens, which have been hit particularly hard by the avian influenza outbreak.