Laboratory testing by Australia's national science agency confirmed the case in a greater crested tern found in the South Australian coastal town of Robe, Agriculture Minister Julie Collins said.

It is the first confirmed infection in an Australian seabird, with all other cases being found in migratory seabirds.

It brings the total number of confirmed detections in the country to 12, after authorities on Friday also confirmed two additional infections in South Australia and one in Western Australia.

Collins said the development was "concerning" but not unexpected, adding that there was still no evidence of mass mortalities or spread to the poultry or broader agriculture sector.

"Our scientists are undertaking further work to establish the potential pathway that resulted in the Australian sea bird's infection," she said.

"What we do know is that this is a coastal seabird that has been overlapping coastal range with migratory seabirds that have previously tested positive for H5."

Australia in June became the final continent to confirm a mainland-based case of H5N1, although the virus had been detected in late 2025 on the sub-Antarctic territory of Heard Island, about 4,100 km (2,600 miles) from continental Australia.

(Reporting by Christine Chen in Sydney; Editing by Jacqueline Wong and Thomas Derpinghaus)

Posted by: Alma Angeles/NET25 News