Queensland became Australia's fourth state to confirm a case of H5N1 bird flu after authorities said on Saturday that a migratory seabird tested positive for the highly pathogenic virus.
Australia was the final continent to confirm a mainland case of H5N1 when the disease arrived in June, although it had been detected in late 2025 on the sub-Antarctic territory of Heard Island, about 4,100 km (2,600 miles) from continental Australia.
Eighteen infections have now been confirmed across four states, including in the dead petrel found by Queensland park rangers at Moreton Island, a wilderness area about 40km (24 miles) by ferry from state capital Brisbane.
"There remain no detections in poultry, nor evidence of large-scale deaths in any animals in Queensland," the authorities said in a statement, adding that the risk to human health remained low.
The virulent strain of bird flu has spread through wild bird and mammal populations since 2021, killing millions, infecting poultry and dairy farms and even some farmworkers.
Earlier this month, Australia's centre-left government confirmed the first case of the virus in a local seabird, raising concerns the disease was starting to spread more widely.
