Relationships among migratory whooper swan movements, the timing of H5N1 outbreaks, and the density of poultry in eastern Asia.

<p>Solid line represents mean poultry density at whooper swan locations through the annual cycle. Circles (poultry), diamonds (migratory waterbirds), and triangles (wild non-waterbirds) indicate the timing and underlying poultry density at each H5N1 outbreak event.