On the shores of Goolwa, on South Australia's Fleurieu Peninsula, a dead dolphin has become an unexpected messenger — the first of its kind in Australia to test positive for H5N1 bird flu. The animal most likely encountered the virus through contact with an infected wild bird, a quiet transaction between species that reveals how far a pathogen can travel across the boundaries of land, air, and sea. Coming days after a red fox in Adelaide's north-west also tested positive, this detection suggests H5N1 is no longer a visitor to South Australian wildlife but something closer to a resident, quietl