A deadly strain of H5 bird flu has been confirmed on the Australian mainland for the first time, ending the continent's status as the only continent free of the virus. Federal Agriculture Minister Julie Collins confirmed that a brown skua found sick in Western Australia died from the H5N1 virus. A second bird, a giant petrel found nearby, is also likely infected.
What is H5 Bird Flu?
H5 bird flu is a highly pathogenic virus, meaning it is highly contagious and causes serious illness, including death. Dr. Ariful Islam, a veterinary epidemiologist at Charles Sturt University, describes it as a "panzootic" that has spread across multiple continents and affected many species. According to Wildlife Health Australia, more than 560 wild bird species and over 100 mammal species have been affected globally.
Origin and Global Spread
The strain (H5N1 clade 2.3.4.4b) originated in Asia and has been spreading globally since 2021, reaching Antarctica during the 2023-24 summer. Australian researchers estimate it arrived on Heard Island in August 2025, killing over 13,000 southern elephant seal pups and hundreds of king penguins.
Arrival in Australia
The brown skua was found sick at Cape Le Grand National Park near Esperance on June 14 and later died. Initial tests in WA were confirmed by the CSIRO's Australian Centre for Disease Preparedness. A giant petrel from the same area tested positive at a WA government lab, with confirmation pending at CSIRO. The two birds likely migrated from the subantarctic, according to BirdLife Australia.
Impact on Agriculture
Unlike the H7 bird flu that caused outbreaks in Australian poultry farms in 2024-2025, H5 has devastated poultry industries elsewhere. Dr. Michelle Wille from the University of Melbourne notes that since H5 arrived in the US, over 200 million chickens have been culled. There is no evidence yet of infection in Australian poultry, but authorities are monitoring closely.
Human Health Risks
Bird flu infections in humans are rare but can be severe. The Australian Centre for Disease Control states that risk to the general public remains low, with limited human-to-human transmission. From 2003 to early 2026, there were 997 reported human H5 infections globally, with 478 deaths (WHO). In the US, two deaths occurred out of 71 cases (CDC). Most cases involve exposure to infected poultry or, in the US, dairy cattle.
Threat to Native Wildlife
Dr. Fiona Fraser, Australia's threatened species commissioner, warns that if H5 becomes established in wildlife, little can be done to stop its spread. At-risk species include the Tasmanian devil, orange-bellied parrot, and Australian fur seal. Jack Gough of the Invasive Species Council calls it "a genuine wildlife emergency" and urges emergency funding. The Australian Marine Conservation Society fears the virus poses a "real extinction risk" for the endangered Australian sea lion, with only 12,000 remaining.
What to Do
The public should avoid contact with dead or sick birds or animals and report sightings to the emergency animal disease hotline (1800 675 888) or birdflu.gov.au.
