First Australian mass mortality event suspected as deadly bird flu virus rapidly escalates among native birds
The Guardian · 2026-08-01
More than 80 dead and dying greater crested terns discovered off the South Australian coast are suspected to be Australia's first mass mortality event due to the deadly H5N1 bird flu virus, merely six weeks after its initial detection in the country. Helicopter surveillance on Saturday revealed 49 dead and 35 sick greater crested terns on Baudin Rocks, near Robe, prompting South Australia’s chief vet Skye Freuan to suggest it signals the disease's first mass die-off. Additionally, three suspected positive cases in greater crested terns, including one inland at Monarto, and three suspected positive Silver gulls, follow a confirmed Silver gull case, indicating inland spread.
Jack Gough of the Invasive Species Council warns the disease is "starting to take off," mirroring rapid escalations and mass mortality events seen in South America. The escalating situation, with 20 new cases in days bringing the total to 53, underscores the challenge, as Freuan states, "nothing we can do" to stop the spread. The virus, having killed millions globally, has now reached all Australian states except Tasmania, with Victoria confirming its first cases this week. Concerns are heightened for endangered Australian sea lions on Kangaroo Island, where five confirmed bird cases could threaten the marine mammal population, given that tens of thousands of seals have died worldwide from the disease. Experts like Sean Dooley of BirdLife Australia are particularly worried about Silver gulls, which, due to their scavenging habits and widespread presence, including in urban areas and inland, could act as significant vectors, potentially spreading the virus to unique and susceptible native bird populations.
*The full article also explores the emotional toll on bird conservationists and the previous best winter season for bird watchers, now tainted by the virus's presence.*