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A deadly strain of bird flu, known as H5 bird flu, has arrived on the Australian mainland.<\/p>\n
The federal agriculture minister, Julie Collins, this weekend confirmed that a brown skua \u2013 that had been found sick in Western Australia \u2013 had died from the H5N1 virus. The skua is a wild migratory bird.<\/p>\n
A second bird, a sick giant petrel found nearby, was also likely infected.<\/p>\n
Australia\u2019s run as the only continent free of the virus has now ended. H5 bird flu has killed millions of birds and thousands of marine mammals since it began spreading <\/strong>across the globe in 2021.<\/p>\n The H5 bird flu is a \u201chighly pathogenic\u201d virus, which means it is highly contagious and causes serious illness, including animal deaths.<\/p>\n Dr Ariful Islam, a veterinary epidemiologist at Charles Sturt University who researches avian influenza viruses, says the virus is a \u201cpanzootic\u201d, meaning it has spread across multiple continents and affected many species.\u00a0<\/p>\n The disease has already infected millions of wild birds, including threatened species, and has had a devastating impact on agricultural industries, particularly poultry, Islam says.<\/p>\n According to Wildlife Health Australia, more than 560 wild bird species and more than 100 different types of mammals have been affected by the virus.<\/p>\n The deadly bird flu strain (H5N1 clade 2.3.4.4b) started in Asia, but has been spreading globally across Europe and the Americas since 2021, arriving in Antarctica during the 2023-24 summer.<\/p>\n Australian researchers estimate the virus arrived on Heard Island, an Australian territory located about 4,000km south-west of Perth, in August 2025. It has spread among penguins, seals and petrels, killing more than 13,000 southern elephant seal pups<\/a> and hundreds of king penguins.<\/p>\n<\/div>\n The brown skua, a subantarctic species, was found sick at Cape Le Grand national park near Espearance on Sunday 14 June and subsequently died. An initial positive test for H5 bird flu in WA was later confirmed by the <\/strong>CSIRO\u2019s Australian Centre for Disease Preparedness.\u00a0<\/p>\n A second bird, a giant petrel found in the same area, has tested positive for the disease at a WA government laboratory. <\/strong>\u00a0That result is being confirmed by further testing at the CSIRO lab.<\/p>\n Islam says further environmental sampling and monitoring are needed to determine the extent of the outbreak. \u201cWe need to know the full spectrum of the disease ecology, and the transmission dynamics and pattern in that area of Western Australia,\u201d he says.<\/p>\n The two birds most likely migrated to Australia from the subantarctic, according to BirdLife Australia.<\/p>\n <\/gu-island><\/p>\n It is not yet known if the virus has spread further. Collins says there is no evidence to date<\/a> <\/a><\/em>of mass mortality<\/a> or of infection in poultry. She says a nationally coordinated response will initially focus on determining whether the disease has spread to other wildlife.<\/p>\n It will likely be known within days whether the disease has affected local wildlife populations.<\/p>\n<\/div>\n The virus differs from the H7 bird flu, which caused outbreaks in poultry farms across several Australian states in 2024 and 2025, and led to the euthanising of hundreds of thousands of chickens.\u00a0<\/p>\n Dr Michelle Wille, an expert in avian influenza viruses at the University of Melbourne, says H5 has had significant impacts on the poultry industry in other parts of the world.<\/p>\n \u201cFor example, since the arrival of the virus in the US, more than 200m chickens have been culled, which, of course, is bad for birds, bad for farmers and bad for consumers.\u201d<\/p>\n Wille says the virus has led to human infections, generally among people who work with infected poultry.<\/p>\n<\/div>\n Bird flu infections in people are rare, often mild, but potentially dangerous.\u00a0<\/p>\n The Australian Centre for Disease Control says bird flu in people is rare and often mild but can cause severe disease or death.<\/p>\n People can be infected<\/a> by breathing in contaminated dust or air, or by touching an infected animal. Symptoms can include fever, cough, sore throat, conjunctivitis and muscle aches and pains.<\/p>\n Dr Matt Mason, from the University of the Sunshine Coast\u2019s school of health, says the risk to the general public remains low, and there is limited evidence of human-to-human transmission.<\/p>\n \u201cAlmost all human cases recorded globally have resulted from exposure to infected poultry or, in the US, dairy cattle.\u201d<\/p>\n Australia\u2019s first reported human case in 2024 was travel-associated<\/a>, in a child who likely acquired the infection overseas and later recovered.\u00a0<\/p>\n From 2003 to early 2026, there were 997 reported cases of human H5 infection from 25 countries. Of these, 478 were fatal, the World Health Organization reports<\/a>. In the US, there have been two deaths out of 71 cases, according to the US Centers for Disease Control and Prevention<\/a>.<\/p>\n<\/div>\n Dr Fiona Fraser, Australia\u2019s threatened species commissioner, says <\/strong>if H5 bird flu becomes established in wildlife, there is little that can be done to stop its spread.<\/p>\n Governments have analysed which of Australia\u2019s birds and mammals could be most at risk, which include, for example, the Tasmanian devil, the critically endangered orange-bellied parrot and the Australian fur seal.<\/p>\n Authorities have developed more than 100 response plans for at-risk animals and important natural sites such as Ramsar wetlands and islands.<\/p>\n \u201cWe\u2019ve taken into account whether they\u2019re already threatened with extinction, but also other natural traits, such as whether they\u2019re water birds, whether they\u2019re marine species, whether they congregate, to understand which species are most susceptible,\u201d Fraser says.\u00a0<\/p>\n Jack Gough, the chief executive at the Invasive Species Council, says the risk is \u201cno longer theoretical\u201d and if the virus begins circulating among native birds, it could lead to massive declines in some species and push others closer to extinction.<\/p>\n \u201cThere is a very good chance that the impact on Australia\u2019s native wildlife will be even worse than it is in the northern hemisphere,\u201d he says. \u201cThis is a genuine wildlife emergency, and it must be treated as such with emergency funding to increase efforts to protect wildlife populations.\u201d<\/p>\n The council says Australia could help protect native species by boosting wildlife resilience, and wants the federal government to invest $200m over two years to tackle invasive species, restore habitat and reduce predators.\u00a0<\/p>\n The Australian Marine Conservation Society fears the mainland arrival of H5 bird flu could pose a \u201creal extinction risk\u201d for the endangered Australian sea lion, with only 12,000 remaining along the coasts of South Australia and WA.\u00a0<\/p>\n \u201cBird flu poses a real risk to the future of the Australian sea lion, found nowhere else in the world, potentially pushing it to extinction,\u201d the campaign director Alexia Wellbelove says.<\/p>\n \u201cThe experience worldwide demonstrates the potential for this virus to be catastrophic for Australia\u2019s unique wildlife and threatened species.<\/p>\n \u201cInvesting in boosting the resilience of our threatened species by protecting and restoring their habitat, and reducing pressures on their populations, is now essential to ensure their future.\u201d<\/p>\n<\/div>\n Members of the public are urged to avoid contact with any dead or sick birds or animals showing signs of bird flu. Report sightings to the emergency animal disease hotline 1800 675 888 or birdflu.gov.au<\/a>.<\/p>\n<\/div>\n<\/div>\n
\nWhat is H5 bird flu and why are authorities concerned?<\/h2>\n
\nWhere did it start?<\/h2>\n
\nHow did it arrive on the Australian mainland?<\/h2>\n
\nWhat does it mean for Australian agriculture?<\/h2>\n
\nWhat are the risks for human health?<\/h2>\n
\nWhat are the risks to native wildlife?<\/h2>\n
\nWhat to do if you see sick birds or marine mammals?<\/h2>\n