A pathogenic H5 bird flu strain killed over 13,000 elephant seal pups in a sub-Antarctic breeding colony, Australian scientists reported. Researchers discovered the carcasses on the remote Heard and McDonald Islands. Genetic testing confirmed the virus also affected penguins and birds, marking its first detection in an Australian external territory. Mortality rates in some seal "harems" reached 97%, with 13,300 dead pups counted. Biologist Julie McInnes noted the virus's eastward spread, likely introduced in August 2025 by wildlife from the Crozet Islands. These wild, uninhabited islands, located 4,000 km from mainland Australia, recently gained attention after being included in US international tariff lists in April 2025. Access remains restricted by the Australian government. #climatechange #australia #antarctica #seal #birdflu