Fighting bird flu: Can New Zealand's vaccination trial protect the World's fattest and most endangered parrots?

A kākāpō parrot receives a vaccine as part of New Zealand’s trial. (Image: Lydia Uddstrom/DOC)

On a quiet southern island, a tired seabird lands. It searches for shelter and slips into a kākāpō burrow. One encounter could spread avian flu and push the world’s fattest parrot towards extinction. This is the scenario New Zealand scientists are preparing for as the spring migration season nears.

Why bird flu poses a serious threat
Tens of millions of wild birds have already died worldwide. Since 2021, the H5N1 strain has devastated colonies of seabirds and marine mammals. New Zealand, however, has remained free from infection. Conservationists know the risk grows each year, especially now the virus circulates in Antarctica. Fiona Fraser, Australia’s threatened species commissioner, said the region was “virtually encircled,” according to The Guardian.

In August, New Zealand’s Department of Conservation confirmed a research trial with promising results. Using the H5N3 poultry vaccine, scientists gave two doses to ten birds across five species, all with fewer than 500 individuals left. These included the kākāpō, takahē, kakī, tūturuatu and a species of kākāriki. Four species developed strong antibody responses lasting at least six months. Wildlife veterinarian Kate McInnes said vaccination could shield captive breeding populations that are vital for species recovery.

A kakī (black stilt), a bird unique to New Zealand, receives vaccination. (Image: Carla Smit/DOC)

What comes next for endangered species

Officials are now planning how and when to deploy vaccines. Timing is critical, McInnes warned, since starting too early could reduce protection before the virus arrives. Australia is closely following New Zealand’s work while also testing vaccines on stand-in species. Its government has pledged A$100 million to prepare for avian influenza.

Elsewhere, conservationists are divided over vaccinating endangered wildlife. In the United States, condors were recently vaccinated after H5 killed 21 birds. The programme safeguarded more than 200 condors, but experts caution that outdated vaccines and partial coverage could spur viral evolution. Habitat protection will be more useful than mass vaccination, some ecologists claim.

Beneath the adversity, New Zealand's progress is garnering global attention. With fewer than 250 kākāpō remaining in the wild, scientists recognize preparation could equal survival. The arrival of migratory seabirds in the coming weeks will test whether their precautionary work is enough.