Deadly avian flu strain could enter Australia via thieving migratory birds, scientists warn

Great frigatebirds harass a white-tailed tropicbird on Christmas Island. Conservationists fear the arrival in Australia of the H5N1 strain of bird flu known as 2.3.4.4b would have grave consequences for wildlife. Photograph: Claire Greenwell

Scientists have identified a new way for an aggressive strain of bird flu to enter Australia, via the habit of some migratory birds of harassing other birds and stealing their food and potentially their viruses.

Australia is the only continent to have so far escaped a virulent H5N1 strain of avian flu – known as 2.3.4.4b and discovered in Europe in 2021– that has devastated bird populations in other parts of the world.