As authorities work to restrict the spread of the deadly H7 strain of bird flu affecting chickens and eggs across Australia, ecologists and advocates warn a different strain of the virus could lead to an environmental disaster in some wild birds.
The H5N1 avian influenza has caused mass mortality events in wildlife on every other continent on Earth, particularly among birds and animals that eat infected birds.
As the yearly migration of birds to Australia in spring approaches, experts say more communication and planning is needed, with unique species most at risk.
Federation University ecologist Meagan Dewar has tracked the spread of H5N1 throughout Antarctica since February and witnessed mass casualties among many species including Adélie penguins and southern elephant seals.
"Unfortunately our wildlife is integrated and interconnected so [remote ecosystems] aren't as safe as we think," she said.
But Dr Dewar said it would be migrating birds from Asia that would "most likely" bring H5N1 to Australia in spring.
"The virus is coming closer, and it is on our doorstep," she said.
Global mass mortalities
More than 650,000 seabirds are known to have died from H5N1 in South America since 2022, Dr Dewar said.
Animals that prey on dead infected birds also contract the virus. It killed 95 per cent of southern elephant seal pups in Argentina in 2023.
It has killed more than 30,000 South American sea lions. Australia's population is only 12,000.
Dr Dewar said Australia's unique ecosystems with small animal populations were most at risk of collateral damage.
"If it gets into our highly endangered or critically endangered bird species that could have very severe consequences for them and their survival," she said.
"We can get alterations in our ecosystems because we are losing large proportions of animals and birds."
Dr Dewar said her greatest concern was animals like threatened sea lions or vulnerable little penguin colonies with "small population numbers that really can't afford to be hit by a large-scale virus".
Fears for unique ecosystems
On the NSW south coast, Barunguba Montague Island (Barunguba) is culturally significant for the Yuin people and an ecological epicentre for almost 100 bird species.
It is the northernmost breeding colony for Australian fur seals, long nose fur seals and sea lions and is home to NSW's largest little penguin colony during breeding season.
According to a study published in the journalGenome Biology, the H5N1 virus could make the black swan, a culturally significant species to the Yuin people, locally extinct.
However, Dr Dewar said species such as seals, sea lions, seabirds and little penguins could also be at threat if susceptible to the virus.
Narooma-based seal-diving and tourism operator Francois Van Zyl said the effects of the virus on the island would be horrific.
"The seals play a big part in our small-town community," Mr Van Zyl said.
"Yes it will have catastrophic financial issues on small coastal towns, however I think the larger concern is: 'What's going to happen to the wildlife?'"
Need for rapid response
While there are reports of mammal-to-mammal transmission in North American cattle and South American sea mammals, virus ecologist Michelle Wille said those were two context-specific cases and those strains were unlikely to threaten Australia.
“This is still very much an avian virus,” she said.
But like any virus, Dr Wille said managing the spread would reduce the risk of mammal-to-mammal variations occurring because there would be less chance of mutations developing.
“It’s important we focus on what’s happening in birds because that’s where everything jumps out of,” she said.
“The more dead birds there are in the landscape, the higher the likelihood that some mammal is going to be infected over and over until you get that right combination of the exactly right genetic make up and exactly the right mammal that allows for [mammal to mammal transmission].”
Protecting the home front
In the Netherlands and Belgium, collecting dead birds before predators can feed on them reduced mammal fatalities by 80 per cent.
It is one strategy in Phillip Island Nature Parks' site-specific contingency plan for the virus. However not all similar ecosystems across the country have such a plan.
Invasive Species Council advocacy director Jack Gough wants the federal government to establish a national task force and help develop similar, localised strategies for ecosystems right across Australia.
"Right now, Australia is not prepared in terms of our wildlife if the deadly H5 strain turns up," he said.
"If it turns up here, it will cause damage and that there are opportunities with isolated populations to make sure that we can respond quickly."
Early detection critical
Biosecurity PhD candidate at UNSW Hayley Stone said the virus arriving in Australia was inevitable and early detection was critical to managing its spread.
"You want to catch it as quickly as possible," she said.
"It needs to be on a federal level. There needs to be federal policy that everyone can follow.
"America didn't realise they were having an outbreak until it had already hit poultry."
She said there could be more testing under the National Avian Influenza Wild Bird surveillance program, which tests sick wild birds for diseases.
The Department of Agriculture, Fisheries and Forestry (DAFF) declined an interview, but in a statement, said the department would coordinate a national approach in the event of a large outbreak.
In April 2024, DAFF and Wildlife Health Australia published guidelines helping wildlife managers to deal with high-risk bird flu virus, such as the H5N1 strain.
It includes prevention measures, and tips for creating a site-specific plan, which it says is the responsibility of individual jurisdictions.
The guidelines recommend dead birds be reported to the Emergency Animal Disease Hotline (1800 675 888).
"There is no way to prevent new strains of avian influenza viruses — including this H5 strain — entering Australia through migratory birds," a department spokesperson said in a statement.
Mr Gough said part of the solution was improving local awareness that dead birds washing up on a beach in Tasmania or Far North Queensland, for example, was a sign the virus had arrived.
He said the federal government had more to do in bringing people together and creating localised plans to manage the virus.
"That involves tourism operators, local fishers – people who are out seeing these environments – that they know what bird flu is, that they're checking for it and that if they see any signs of it, they're able to really quickly notify the authorities and get on top of it," he said.
"Bring wildlife carers, zoos, veterinarians, tourism operators, fishers — everyone — together. Make sure that everyone is aware, knows what to look for if this turns up and that we can respond quickly."
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