A sick brown skua tested positive for H5N1 near Esperance, Western Australia, with a second migratory bird (giant petrel) showing a preliminary positive result and more than a dozen other sick or dead birds reported.

There have been 16 reports of sick or dead birds in WA since the initial detection, and officials say it is unclear whether these cases are due to bird flu or other causes.

Over the weekend, at least 16 cases of dead or sickly birds were reported to the WA Department of Primary Industries and Regional Development following the discovery of H5 in a brown skua.

Authorities stress ongoing collaboration among states, industry, environmental groups, and scientists to manage the outbreak if it escalates.

The WA government and Agriculture Minister say there is no evidence of mass wildlife mortality and that containment measures are precautionary while surveillance continues.

Federal government has developed more than 100 response plans and invested about AU$100 million in preparedness for key sites and vulnerable species.

Ingham’s Group has requested permission to keep free-range chickens indoors and has suspended nonessential access to facilities as a precaution.

Inghams is seeking an exemption from the ACCC to keep free-range poultry indoors if required to protect supply and labeling, contingent on an approved exemption.

Inghams is pursuing a regional housing order from the state government to keep free-range poultry indoors across Western Australia facilities.

Australian officials warn avian influenza can affect mammals as well as birds and may spread among wild birds and mammals, with the virus circulating globally for years.

The incident raises concern among scientists, conservationists, and agricultural groups, with comparisons to mass culling seen in the United States.

Australia had been free of H5N1 on the mainland prior to these findings, marking a significant biosecurity development.