Saving the world’s fattest parrot: can New Zealand vaccinate its rare species before bird flu gets to them?
In the last continent to remain untouched by the virus, hopes are being pinned on immunisation as migration season approaches
It is easy to imagine how it could happen. A petrel, flying east from the Indian Ocean at the end of the Austral winter, makes landfall at New Zealand’s southern Codfish Island/Whenua Hou. Tired from its long journey, the petrel seeks refuge in the burrow of a green kākāpō: a critically endangered flightless species that is the world’s fattest parrot.
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If the seabird intrudes when the kākāpō is primed to breed, the male parrot may attempt to mate with the smaller petrel, accidentally smothering it in the process.
In this case, there are two unwitting victims. The petrel harbours a deadly agent: H5 avian influenza. Soon after, bird flu begins to rip through the imperilled parrot population, pushing the waddling bird – which numbers fewer than 250 individuals – to extinction.
This is the kind of scenario that New Zealand’s conservationists are considering before the arrival of the spring migration season – as they have done for the past two years since a highly pathogenic strain of bird flu known as H5N1 began burning through global wildlife, spurring the largest sudden drop in the world’s bird population in decades.
Tens of millions of wild birds have succumbed to H5 worldwide, but so far Oceania has managed to keep the virus out – buying time for New Zealand to add another weapon to its arsenal before thousands of birds arrive from distant shores.
In August, the country’s Department of Conservation announced the completion of a world-first research trial showing that some of its rarest birds could be successfully and safely vaccinated against bird flu.
The effort is the latest in a global push to protect wildlife – not just farmed poultry – from the virus, which has also inflicted dramatic mass deaths among elephant seal, fur seal and seabird populations across the world. For those species already teetering on the brink of extinction, vaccination could be a gamechanger.
New Zealand is home to nearly 100 bird species found nowhere else in the world. Over the past year, the department has vaccinated up to 10 captive birds from five critically endangered species that have 500 or fewer individuals left – the kākāpō, takahē, kakī (black stilt), tūturuatu (shore plover) and one type of kākāriki.
The programme, using the H5N3 poultry vaccine, is the first to vaccinate so many species at the same time. After receiving two doses, a month apart, of the licensed poultry vaccine, scientists found that four species had built up a strong antibody response to the virus that lasted for at least six months.
“These species are dependent on captive breeding,” says Kate McInnes, a wildlife veterinarian and the department’s senior science adviser. Vaccination, she says, could protect core breeding populations in aviaries used for restocking wild populations on the knife-edge of survival, as well as managed kākāpō populations on offshore islands.
The next step is building a deployment strategy before spring migration, when travelling seabirds could introduce the virus. “You can’t just run around the forest and catch everything and jab it,” McInnes says. “You’ve got to have a really carefully planned programme in place.”
Other countries are watching the attempt closely. Australia is in close contact with officials in New Zealand about the vaccine results, and is running its own trials using stand-in species – animals similar to the critically endangered species but not endangered themselves – according to Fiona Fraser, Australia’s commissioner for threatened species.
“There is increasing concern now that the migratory bird season is just on our doorstep,” she says. Tens of millions of birds are expected to arrive in Australia in the coming weeks.
The Australian government last year announced it would allocate A$100m (£48m) to prepare for bird flu, including A$2.8m specifically to protect captive populations of threatened species.
“Having that extra time for our region to understand what the overseas impacts have been, and to get better prepared for Australian species, has been enormously important,” says Fraser. “We expect it’s not a matter of if, but when bird flu arrives in Australia. Because now that it is circulating in Antarctica, we are essentially surrounded.”
Vaccination, she says, makes up only a small part of the strategy. The country is focused on planning for species considered particularly vulnerable to avian influenza, such as the native Australian sea lion and Tasmanian devil, an endangered scavenger that could feed on the carcasses of infected birds.
Boosting the overall health of wild populations to help them withstand the eventual arrival of avian influenza is the priority, she says.
“Vaccinations can be stressful for wild animals and it cannot be as feasible as taking other measures such as improving their habitat,” Fraser says.
Australia’s policy on vaccination echoes the broader global view. Jabbing animals for conservation purposes is rare, although some programmes have been established to immunise koalas against chlamydia; vaccinate Ethiopian wolves against canine distemper; and develop a West Nile vaccine to protect endangered birds in Hawaii. Guardian.
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