The highly pathogenic H5 bird flu strain, which has affected wildlife globally since 2021, is now circulating within Australian bird populations. Federal and state authorities have initiated vaccination programs targeting both captive native bird species and wild populations, with Victoria’s government focusing on little penguins following confirmed detections in terns on Phillip Island. The death of a little penguin on the island represents the first documented case of H5 infection in that species.
A government risk assessment has identified multiple Australian bird species facing heightened vulnerability to the virus. Silver gulls have been classified as high-risk due to their mobility, abundance across diverse habitats, tendency to gather in large flocks, and scavenging behavior—all factors that facilitate disease transmission. The discovery of infected seagulls in South Australia in late July marked a concerning new phase of viral spread, particularly given their proximity to urban centers and regular interaction with human populations.
Other species of concern include white-bellied sea eagles, whose feeding habits expose them to potentially infected prey, and several tern species. The Australian fairy tern, already designated as vulnerable under national conservation laws, faces particular risk due to concentrated breeding populations and shared habitat with infected greater crested terns. Greater crested terns have already experienced mass mortality events in South Australia and Victoria.
Waterbird species including Australian pelicans and black swans present additional challenges. Pelicans gather in breeding rookeries of tens of thousands and migrate across vast distances, amplifying transmission risks. Black swans lack certain immune genes necessary to combat the virus and demonstrate heightened inflammatory responses upon infection, making them likely to experience significant mortality if exposed. Research indicates black swans may serve as sentinel species indicating H5N1 presence in affected areas.
Experts emphasize substantial uncertainty regarding how native species will respond to the virus as they encounter it for the first time, with potential for severe population declines across multiple species.
Article Attribution | Read More at Article Source
Article summary produced by Claude AI