A total of 5,010 ducks at a research institution in Taiwan's Yilan County were culled due to an outbreak of the H5N1 avian influenza. The source of the infection was traced back to wild migratory birds, despite the institution's high epidemic prevention measures and the species' high biosecurity level. The institution has backup strains and breeding eggs for continued research. The local epidemic prevention agency is expanding monitoring of poultry farms and strengthening surveillance of wild migratory birds in important wetlands to prevent further spread.