Bird flu could be catastrophic for nation's vulnerable species, experts warn

The outlook could be grim for Australia's wildlife if a deadly strain of bird flu spreads to ducks, ecology experts are warning.

Species at risk include emblematic Australian animals such as the black swan, Australian sea lion and the Tasmanian devil.

The warning comes after a migratory seabird was confirmed to have the same deadly strain of bird flu, H5N1 clade 2.3.4.4b, that has killed millions of chickens, ducks, and wild animals globally since late 2021.

The bird, a brown skua, was found sick on a beach near Esperance, in WA's south, and an ailing southern great petrel was found at a nearby beach. Test results are still pending for the second bird.

The virus has been detected in more than 400 wild bird species and 40 different types of mammals since the start of the outbreak.

The panzootic — an animal equivalent of a human pandemic — made it to Heard Island (a far-flung Australian territory) last year, where it has killed thousands of elephant seals.

There is still a chance the virus does not spread any further than a few isolated cases, but if it is carried to a freshwater environment and ducks, then "we're in bad territory", Deakin University ecologist Marcel Klaassen said.

"They [ducks] have no toilets, they poo in the water. So faecal-oral transmission is very easy in freshwater," he said.

Ducks have been key spreaders of the virus in the northern hemisphere and to commercial poultry operations.

Water birds and seals are some of the most at-risk species.

Scavengers like silver gulls and raptors could be infected if more seabird carcasses carrying the bird flu wash up before authorities can collect them.

Small populations at risk

Threatened species commissioner Fiona Fraser said many species were at risk.

"Ranging from mammals such as the Tasmanian devil … to critically endangered species such as the orange-bellied parrot," she said.

"But also species which aren't already threatened but which could become so in some locations, such as the black swan."

Black swans lack some immune genes that combat viral infections found in other species of water birds, which could mean being wiped out completely if the virus takes hold, a past study has suggested.

The WA government has said it had plans in place to protect especially vulnerable species, like the black swan.

The populations of endangered western ground parrots and orange-bellied parrots are estimated to range between 100 and 200 in the wild, depending on the time of year,

Vulnerable little penguin colonies are also at risk of becoming what Federation University ecologist Meagan Dewar described as "collateral damage" to the virus.

There are also concerns for Australia's marsupials, given Virginian opossum in the US have previously been infected by the virus strain.

Tasmanian devils and common brushtail possums could be at a higher risk than other mammals as regular scavengers of dead carcasses.

Flu cases limited to seabirds so far

So far, there have been no mass casualties of any birds in Australia nor domestic poultry.

Agriculture Minister Julie Collins said she had been advised it would be days before authorities knew if the virus had spread and where it had come from.

The WA government is triaging calls to its emergency animal disease hotline reporting sick animals, and WA's chief veterinary officer, Michelle Rodan, said vets were checking the most concerning cases.

"Obviously, we don't have any intel yet on the condition of the carcasses and how suitable they are for testing. So that can be problematic, but certainly they're investigating that," Dr Rodan said.

"At this point, we don't have evidence of establishment in Australia, but I think if you look internationally … it has caused some devastating impacts.

"It's quite a sobering situation here and we do need to prepare ourselves for how it might impact our wildlife."

Anyone who sees a dead or sick bird is asked not to touch it and report it to the Emergency Animal Disease Hotline on 1800 675 888.

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