This map is generated based on U.S. Department of Agriculture data, and updates weekly on Tuesdays. It draws on USDA data for both commercial and backyard flocks. Each bubble represents the scale of "Birds Affected" for a given calendar year; hovering over the bubble provides the total for that year at the county level. Zoom in using the "+" button for better resolution at the county-by-county level. Toggle off years to hone in on particular years of interest.

Map courtesy Brice Hutchings.