The discovery follows recent reports of dead and distressed seabirds, including prions and various petrel species, washing ashore or being found stranded inland elsewhere in New Zealand.
H5N1 has been found in eight migratory seabirds across three Australian states in recent weeks.
Van Andel said MPI was watching developments in Australia closely and remained in regular contact with authorities there.
“At the moment, the positive and suspected cases of H5N1 in Australia are all in individual ocean-going seabirds, and there are no reports that it is being transmitted among birds there,” she said.
“These ocean-going birds can travel very long distances.”
Birds New Zealand Auckland branch and regional representative Ian McLean reiterated that the discovery of multiple dead seabirds on a beach at this time of year was not, in itself, unusual.
However, he said the threat posed by H5N1 should be taken seriously, and that while New Zealand’s isolation had delayed its arrival, detections in Australia highlighted the need for vigilance.
He also cautioned against alarmist reactions to the discovery of single dead birds, saying such deaths should be assessed sensibly and reported through the proper channels.
McLean said so-called “beach wrecks” of multiple dead seabirds occurred regularly and were often linked to severe weather or food shortages.
He pointed to a major wreck in 2011, when an estimated 350,000 prions died along parts of New Zealand’s western coastlines.
Concern about the arrival of H5N1 in New Zealand was justified, but reports of dead birds needed careful assessment, McLean said.
He said Birds New Zealand was closely monitoring the situation through its Beach Patrol Scheme, which had operated since 1951.
People should be aware of the signs of possible infection in birds.
“Birds can be contorted and twisted up. If they’re still alive, they can show neurological problems, like they can walk around in circles, they can nod their head,” he said.
“They can also be suffering from diarrhoea,” he said.
Species such as albatrosses, penguins and shags could be especially vulnerable because they breed in dense colonies where disease can spread rapidly, he said.
Birds such as penguins that breed in dense colonies are especially prone to the spread of disease. Photo / Craig McKenzie.
The strandings have also coincided with an unusual influx of sub-Antarctic and Antarctic seabirds into New Zealand and Australian waters, which a recent report in Melbourne-based newspaper the Age described as a “once in a lifetime event” possibly caused by a marine heatwave in the Southern Ocean and south Tasman Sea.
McLean said Northland birdwatchers had recently witnessed the phenomenon firsthand.
A pelagic birding trip by Tutukākā charter business The Petrel Station recently recorded about 60 blue petrels, a species that normally breeds in the sub-Antarctic on Australia’s Macquarie Island.
“At the moment there’s a lot of birds coming up from the deep south,” McLean said.
“There’s been a lot of bad weather in the last couple of weeks and at the moment lots of southerly winds, so pushing up birds from the sub-Antarctic, from the Antarctic.”
Scientists suspect the unusual marine conditions may be disrupting food supplies and pushing seabirds beyond their normal range in search of prey, although the exact cause remained uncertain, the Age reported.
Rare birds including Kerguelen petrels, blue petrels, southern fulmars and Antarctic prions have been recorded far north of their normal range, while giant petrels and several albatross species have also appeared in unusually large numbers, the Age stated.
Australia last month became the final continent to confirm a mainland case of H5N1, although the virus had been detected in late 2025 on the sub-Antarctic territory of Heard Island, where thousands of seal pups have died from the disease.
People who find three or more dead birds, or sick birds displaying unusual symptoms, should report them to MPI’s Exotic Pest and Disease Hotline on 0800 80 99 66.
Avian influenza can spread to other animals and, in rare cases, humans, so people should avoid handling dead or distressed birds, wear gloves if necessary and wash their hands thoroughly afterwards.
Sarah Curtis is a news reporter for the Northern Advocate, focusing on a wide range of issues. She has nearly 20 years’ experience in journalism, most of which she spent reporting on the courts in Gisborne and the East Coast.