Australia's pristine wilderness is facing an unprecedented threat as the H5N1 bird flu strain, responsible for devastating wildlife populations globally, has been detected on the continent. The recent analysis by the Australian federal government identifies over 150 native bird species and more than 10 mammal species at 'very high risk' of extinction or significant decline if they contract the deadly virus.
The assessment highlights the vulnerability of Western Australia's iconic black swans, which lack crucial immune genes to combat the virus. Other species deemed most vulnerable include the red goshawk, fairy tern, plains-wanderer, and shy albatross, alongside migratory birds like the short-tailed shearwater. Critically endangered species such as the swift parrot and orange-bellied parrot are also categorised as high risk.
Mammal species facing a similar threat include the already endangered Australian sea-lion, subantarctic fur seal, and Australian fur seal. The analysis suggests that the Tasmanian devil and eastern quoll 'may be at high risk' if the H5N1 strain spreads. A spokesperson for the federal environment department underscored the gravity of the situation, stating that many of Australia's birds and mammals are found nowhere else globally, making the potential impacts difficult to predict.
Australia had remained the only continent free of the H5N1 strain until tests confirmed its presence in a brown skua and giant petrel found near Esperance, Western Australia. While authorities in Western Australia have reported no new cases or evidence of widespread transmission into other wild populations since the initial discovery, state and federal governments have been preparing for the virus's arrival for several years. This preparation includes developing 100 response plans tailored for specific species and habitats.
Professor Kirsty Short from the University of Queensland, a lead author of research into the black swan's immune response, explained that black swans possess an 'out-of-control, pro-inflammatory response' to the virus, rather than a controlled one. She suggested that widespread mortalities among black swans could serve as a 'sentinel species' indicator, signalling significant H5N1 incursions due to their high susceptibility. Chris Purnell, wetland and migratory shorebird program manager at BirdLife Australia, who advised on the analysis, emphasised that for endemic birds, there is no possibility of repopulation from outside Australia, meaning 'if they are gone, then they are gone.'
The findings underscore the unique challenges Australia faces in protecting its biodiversity from a global threat that has already claimed millions of birds and mammals worldwide. The ongoing monitoring and implementation of response plans highlight the need for continued vigilance and collaboration between state and federal governments to mitigate the impact of H5N1 on Australian wildlife.