Australia confirms first H5N1 bird flu case in local seabird

Australia has confirmed its first case of the deadly H5N1 bird flu virus in a mainland seabird, a greater crested tern found in South Australia, bringing the total positive detections to 12.

​Australia on Friday confirmed the first case of the ​deadly H5N1 bird flu virus in a ‌local seabird, ​raising concerns that the disease is beginning to spread more widely after it landed in the country last month. Laboratory testing by Australia's national science agency confirmed the virus ‌was present 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 a mainland Australian seabird, with all other cases being found in migratory seabirds. It brings the ‌total number of positive 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 other animal populations and the poultry or agriculture sector. "Our scientists are undertaking further work to establish the potential pathway that resulted in ⁠the Australian ​seabird's infection," she said.

"What we do ⁠know is that this is a coastal seabird that has an overlapping coastal range with migratory seabirds that have previously tested positive for H5." The ⁠virus spreading to a local seabird was "very bad news," said Hamish McCallum, an infectious diseases ecologist at Griffith University.

"It's likely that this will ​be the beginning of many more cases," he said. A deceased juvenile fur seal found on New South Wales' Central ⁠Coast was also tested for possible H5N1 infection but returned a negative result, a spokesperson for the state's Department of Primary Industries and Regional Development ⁠said.

New ​South Wales was the country's third state to detect H5N1, after a migratory seabird in the Mid North Coast tested positive earlier this month. 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.

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. Scientists believe the virus has killed around 13,000 ‌seal pups on Heard ‌Island.