Australian authorities reported on October 16 that CSIRO's Australian Centre for Disease Preparedness confirmed highly pathogenic H5 avian influenza in samples from an elephant seal and a kelp gull collected on Macquarie Island, marking the island's first H5 event. Macquarie Island is administered as part of Tasmania, and the results will enter the state's H5 reporting. Officials say there is currently no evidence of H5-related mammal-to-mammal transmission in Australia, public-health risk remains low and no infections have been detected in poultry or agricultural production. Agencies are expanding sampling, wildlife-mortality surveillance and worker precautions. Cross-species infection at a remote breeding site raises monitoring, conservation and logistics challenges, and more testing is needed to define the true extent.