A greater crested tern found dead on the South Australian coast has tested positive for the deadly H5 bird flu, marking the first case of the disease in local Australian wildlife. Federal Agriculture Minister Julie Collins confirmed the result on Friday, stating the bird was discovered at Robe on the Limestone Coast by a member of the public.
First Local Transmission Detected
Until now, H5 bird flu cases in Australia were limited to migratory subantarctic seabirds, mainly giant petrels, found along the coasts of South Australia, Western Australia, and New South Wales. The infected greater crested tern, a common coastal bird species that resides in Australia year-round, indicates local transmission has occurred.
Collins noted that the greater crested tern shares an overlapping coastal range with migratory seabirds that previously tested positive for H5. “While this is a concerning development, it is not unexpected and is another sign that our strong biosecurity system is working,” she said.
Response and Surveillance
The South Australian government is leading the response, conducting extra surveillance to determine if the disease has spread further in local wildlife. Earlier this week, the state completed its largest aerial survey of coastline, islands, and reefs in 40 years, finding “no widespread evidence of sick or dead seabirds or seals.”
The dead tern was reported by a member of the public to the emergency animal disease hotline on Tuesday and was collected for testing the same day.
Expert Concerns and Implications
Chris Purnell, wetland and migratory shorebird program manager at BirdLife Australia, described the detection as “very concerning” and a “paradigm shift” in the disease’s development in Australia. “All previous confirmed detections were in migratory birds that likely brought the disease from the subantarctic. This suggests transmission has occurred on or near our beaches. We consider this to be a local transmission point,” he said.
Purnell warned that greater crested terns live in large mixed flocks with other species, creating opportunities for the disease to spread. The location near a network of coastal lakes with many birds is also concerning. BirdLife Australia is particularly worried about the eastern hooded plover, a vulnerable species whose populations live close to where the tern was found.
Terns globally have been heavily affected by H5 bird flu. In France, hundreds of sandwich terns died within days of the first reports of dead birds.
Potential for Wider Spread
Jack Gough, chief executive of the Invasive Species Council, said international experience shows H5 can spread quickly and over greater distances than expected. “This is a very serious moment because it’s the first time we’ve seen local transmission of the virus rather than sick pelagic seabirds arriving on the beaches from the Southern Ocean. I’m concerned that if we get persistent spread to Australian wildlife, this could quickly turn up all over the Australian continent,” he said.
Separately, tests on a young fur seal found on the New South Wales Central Coast returned negative for H5 bird flu on Friday night. The seal was found at Blue Bay and died on Thursday, with tests undertaken as a precaution.
