Inside the race to save our native taonga from bird flu

Sunday, 1 December 2024

As avian influenza creeps ever closer to Aotearoa’s shores, scientists warn our already-endangered species are sitting ducks for extinction. Virginia Fallon reports.

James Russell says it was a beautiful day for a stroll along Scotland’s Stonehaven beach.

It was an afternoon at the end of 2023’s summer and Russell was there with his family; wandering along looking for interesting bits and pieces tossed up amongst the flotsam on the high-tide line.

“My daughter said ‘oh look it’s a feather’ and then there was another one, another; another, all from the sheer number of birds that had died at sea.

“There weren’t any bodies, just all these feathers.”

While the scene sounds like the start of a horror movie, it’s one that experts are warning will inevitably be seen on Aotearoa’s shores, heralding the arrival of a virus that could decimate the country’s already critically endangered native birds.

Russell, now back in New Zealand where he’s a professor of conservation biology at the University of Auckland, says its a matter of when, not if, the H5N1 2.3.4.4b virus washes up here: one of the few places in the world that has so far evaded it.

When it does, we’ll quickly know when it arrives because waterfowl and sea birds will be seen dying in large groups, he says; then after that: who knows?

“When it’s gone from a sea bird to a waterfowl, a duck to a seagull, that’s like something jumping from a goat to an ape: a massive jump across the bird world,” says Russell.

“Now its been detected in cows… and occasionally getting into humans.”

But just as it’s almost sure to arrive, the fact that it hasn’t yet has given NZ and its Oceania neighbours the gift of time: something Russell likens to what happened with the Covid pandemic.

“Our strongest lessons come from the locations which were first impacted and now have the longest history of observations of mortality, virus behaviour, and recovery.”

These locations were unprepared, under-prepared or could not realistically prepare, he says, and have allowed NZ to learn the worst-case scenario.

“Like us, our neighbours in Australia will have had the opportunity to prepare. From these locations we will learn the best-case scenario of how and which types of preparations most reduce impact.

“The threat of HPAI [high pathogenicity avian influenza] for our valued avian biodiversity is high, but we can take hope that we can prepare and learn from others.”

But what other countries are dealing with is a virus that’s jumping, adapting and spreading. Transmission occurs primarily through direct contact with secretions from infected birds, especially through faeces, or indirectly through contaminated feed and surface water.

And despite its name, the avian flu is now wiping out mammals, either because of culls to stop the disease - like the millions of mink in Denmark fur farms - or striking at wild populations.

Among them are more than 20,000 South American sea lions that have died in Chile and Peru - 9% of the regional population - while an estimated 17,000 southern elephant seal pups died in Argentina: equivalent to 96% of those born in the country in 2023.

That amounted to the loss of nearly an entire generation of seals, which take at least three years to reach maturity, The Guardian reported.

Bird-wise, at least 280 million poultry birds have died due to the virus since October 2021, while in November alone more than 6m egg-laying chickens were slaughtered on US farms to limit the spread of the disease. There is no total figure for wild bird deaths, though it is estimated to be in the millions.

In March, the disease started spreading among US cattle; the first time a bird flu virus had been found in cows. Barn cats and mice have also tested positive, leading to fears they could spread it out of farms and into the wider environment.

And on Monday, just a few days after a California child was diagnosed with the virus - the first reported case in a US minor - it was detected in a sample of raw milk sold in the state.

The US has now recorded 55 human cases of bird flu this year, including 29 in California, with most linked to farm workers who have been in contact with sick animals. The risk to humans is still considered low.

Although forms of avian influenza have been recorded since as long ago as 1878, Russell says the current outbreak emerged in South East Asia in the mid to late 90s.

“But only in the past three years it’s transformed to being highly pathogenic - which means it’s spreading across a lot of species and causing high mortality rates.”

“We are as prepared as we can be, but the caveat to that is there’s just not much we can prepare for. We can’t vaccinate wild birds.”

But Kent Deitemeyer, co-founder of Pacificvet and one of NZ’s leading veterinary immunologists and wildlife conservationists, says we can - and must - vaccinate as many of our endangered ones as possible.

For more than 20 years Deitemeyer has worked with the Department of Conservation (DOC) to vaccinate native species, and is now at the leading edge of its defence against HPAI.

“If the virus gets into our taonga, our treasured wildlife in our captive breeding flocks it would be ruinous.

“We have 245 kākāpō, 300 takahē, and that’s it. It’s taken years and years to bring the numbers up; we cannot lose them.”

Right now though, they’re sitting ducks. Deitemeyer says while scientists were initially heartened both by NZ’s distance from other countries and lack of migratory birds, those hopes were crushed when the virus moved into the already fragile ecosystem of Antarctica.

“That starts to get into our territory, where we have sea birds and mammals floating around the Southern Ocean, so suddenly our back door was open.

“A lot of our endangered species programmes are focused in the south: kākāpō flocks have spread out a little but are mainly still in Fiordland and Whenua Hou/Codfish Island; the takahē programme is all focused in Fiordland.”

Dietemeyer’s business has been supplying vaccines and immunology products to the poultry industries in New Zealand and the South Pacific for more than 30 years, though this current work with DOC is being done for free.

No more than a total of 50 critically endangered birds from five native species have now received an HPAI vaccine, the Poulvac Flufend RG, in a trial to test its efficacy and safety.

The kakī (black stilt), takahē, kākāpō, tūturuatu (shore plover) and kākāriki (red-crowned parakeet) have all passed the first phase of the trial - receiving two doses of the vaccine at least one month apart.

The second phase, involving antibody tests and health assessments, is expected to be finished by July 2025.

But although the trial is looking promising, Dietemeyer says the country is falling behind the rest of the world in its regulation of vaccinations, including getting in those developed overseas, to protect animals and birds.

“Biotechnology has changed dramatically. Vaccines are now much safer, and, in many cases, there is now a reduced need to vaccinate as frequently.

“I am all for tough regulations, but they have to be fair, transparent, science-based and balance all the risks. The real risk around veterinary vaccines for New Zealand is not having them.”

That’s a concern shared by University of Otago virologist Professor Jemma Geoghegan who last month said the vaccination trial was “hugely limited” due to MPI regulations around vaccines - meaning DOC was tremendously restricted on the numbers and species they could vaccinate.

“For the species that will be vaccinated, obviously, it’s a great thing, but use of wider vaccination, not just in wildlife, but in poultry and other animals would help us prepare.”

Dr Mary van Andel is the chief veterinary officer for the Ministry for Primary Industries (MPI), which will be leading the response if, or when, HPAI is detected in New Zealand and/or its territories.

Overseas experience has shown that a “one health” approach to the disease is essential, she says, so MPI, DOC and the Ministry of Health and Health New Zealand “are working together with industry groups and other stakeholders to prepare for HPAI if it arrives here”.

Andel says MPI has been closely monitoring the virus’s global movement for more than 20 years and, if it gets here, a key goal is ensuring early detection to limit its impact.

“Our response will be focused primarily on reducing the impact on threatened species and on the poultry sector, maintaining supply of poultry meat and eggs to the domestic market and access to overseas markets where possible, and protecting human health.”

MPI is also working on a “detailed operational plan” with the poultry industry that includes “jointly understanding how to rapidly respond to depopulate, dispose of deceased poultry and decontaminate commercial facilities”; how movement controls would be applied to limit the spread; whether vaccination would be an option in commercial facilities, and what surveillance and tracing programmes will be required.

Vaccination-wise, she says NZ has two avian influenza vaccines registered for emergency use in the event of an outbreak.

Eradication won’t be possible in wild bird populations should the virus become established but “we can focus on those endangered species which are at risk of extinction and where the full two doses of vaccine can be given.”

“We are monitoring international vaccine development to ensure we are making sure we will have the most effective vaccine possible to manage an outbreak if it happens.”

Professor Dianne Brunton, from the University of Auckland’s School of Biological Sciences, says with Aotearoa having more sea-bird species in our waters and islands than anywhere else in the world, it’s likely that’s how the virus will arrive.

“It will probably first impact the bigger colonial species - like gannets - that nest in big colonies.

“But if it hits the South Island where you’re more likely to have some of these pelagic sea birds touching down, we also have birds moving up and down the country: wintering in the south before heading north.”

Brunton says although there are so many species at stake, it’s one of the littlest and most endangered that’s at the forefront of her concerns.

“Fairy terns/tara iti are already in such a precarious state because these are ony 10 breeding pairs left, fewer than 40 individuals.”

Tara iti are about the size of a blackbird, and are only found in Auckland and Northland, nesting mostly on the east coast in summer before roosting together with other bird species around the Kaipara Harbour in winter.

“The fairy terns don’t nest together which is a bonus, though they would if there were more them.”

Ultimately, Brunton says although Aotearoa is buffeted a bit by its isolation, that won’t keep the virus out forever, and we’ll only know how prepared we were in retrospect.

“In the meantime, we wait.”

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