Brisbane. First there were individual sick migratory birds on Australia's coasts. Then there were more and more of them. It is now clear: Bird flu has not only arrived Down Under, the last continent in the world. Pure “bird flu” is increasingly becoming a problem for wild animals as a whole. At the beginning of September, according to the authorities, more than 460 positive cases of the highly pathogenic H5 virus had already been registered.
Endemic bird species are also affected, including common terns and silver-headed gulls. And now there is also the first evidence of mammals: a red fox, a long-nosed fur seal and a common dolphin. The big question is: What other species of Australia's unique wildlife could the virus reach?
“Our wildlife has not been exposed to this virus at all,” explains Galit Tzipori, head veterinarian at the well-known Lone Pine Koala Sanctuary in Brisbane. In addition to koalas, many birds, dingoes and other Australian species live in the protected park. “We will only learn more about what this means for the various endemic species over time,” emphasizes the expert in an interview with the German Press Agency.
The fear that the disease could reach the last continent free of bird flu has long been circulating among experts. Millions of migratory birds reach Australia's coast via the ocean every year, especially from regions in Antarctica.
In June, two of them brought the dangerous cargo with them: Avian influenza, as the disease is also called, was detected for the first time in the state of Western Australia in a brown skua and a giant petrel. At first it looked like isolated cases in birds that had traveled far. But it soon became clear: the virus wasn’t just visiting – it was here to stay.
Because then an Australian silver-headed gull got it. On August 1st, a specimen tested positive for H5N1 for the first time in Robe, South Australia - not good news. The species is not a rare coastal bird, it is an everyday Australian bird that visits beaches, cities, garbage dumps and freshwater areas. It could be like a kind of taxi for the virus - from the coast to new habitats and to other bird species.
The first mammals became infected at the end of August. First it hit a seal, more specifically a long-nosed fur seal (Arctocephalus forsteri), also known as a New Zealand fur seal. Shortly afterwards, the pathogen was discovered in a fox and a dolphin.
“Generally speaking, animals become infected through direct contact with infected birds,” explained Tzipori. According to the expert, this is good news for the already endangered koalas, because the cute marsupials feed almost exclusively on eucalyptus leaves. But what about other iconic species of the Fifth Continent?
"The main threats are carnivores and predators, like everywhere else in the world. In other words, species that would eat dead birds," explained Tzipori. “It could affect dingoes in coastal areas, especially on K'gari.” Hundreds of the dog-like predators live on the island, which was formerly called Fraser Island.
But marsupials that eat meat and carrion, such as Tasmanian devils or omnivores such as spotted quolls, could also potentially become infected, according to Tzipori. A new pathogen would be particularly problematic for the Tasmanian devils: the population of nocturnal predators has already suffered enormous losses in recent decades due to an infectious facial tumor disease (Devil Facial Tumor Disease, DFTD). Bird flu could put additional pressure on the species.
In the worst case scenario, five species could disappear completely. These include the white-bellied frigatebird, which breeds on Christmas Island, and the herald's petrel, which only lives on a small coral island in Australia. Mammals that are particularly at risk include various species of dolphins, whales and seals.
Meanwhile, the authorities are trying to buy time. In Tasmania, among other things, the rare golden-bellied parakeet is protected: around 350 animals in protection centers and breeding stations are to be vaccinated against H5N1. There is only a tiny population of the species left in the wild.
Little penguins are also said to have immunity to the disease. Vaccinations have begun on Phillip Island near Melbourne and on Barunguba Island in New South Wales, among others. This is possible because the flightless animals return to their colony every evening and usually even to the same breeding holes. In this way, helpers can capture them specifically and reach them again a few weeks later for the important second vaccination - this would hardly be possible with most wild bird species.
The Lone Pine Koala Sanctuary, with its dozens of iconic species, has also been preparing for the threat for weeks with a comprehensive protection and action plan. "Many wild waterfowl and migratory birds come here. So we have to be particularly careful wherever our animals come into contact with these birds," said Tzipori, who has been providing medical care to the center's residents for over 30 years. However, most of the park's birds live in aviaries, which reduces the risk.
Meanwhile, Australia is trying to learn from the experiences of other countries. “We are working with various zoos, some of them international, to see how the virus is being handled in other countries,” explained Tzipori. Many zoos around the world have long had experience with the virus. “They can give us valuable recommendations on how Australia should deal with bird flu.”
