A seabird found dead on a remote Wairarapa beach has become New Zealand’s third confirmed case of H5 bird flu, and the officials tracking the virus say it is exactly the sort of bird they expected to find it in.
Biosecurity New Zealand confirmed on Friday afternoon that testing had found H5N1 avian influenza clade 2.3.4.4b in a single northern giant petrel picked up on a stretch of coast near Cape Palliser, the southernmost point of the North Island. The bird was found by a Department of Conservation ranger, who called it in to the Ministry for Primary Industries exotic pest and disease hotline.
“This positive detection is not a surprise as these ocean-going birds can arrive on our coastlines, especially in poor weather. We expect we will continue to find more cases in wild birds,” said Dr Mary van Andel, the ministry’s chief veterinary officer.
Getting to that answer took a while. Samples reached the ministry’s Animal Health Laboratory on 14 August, and the first round of tests found only a low level of influenza virus in the carcass. It took several more rounds before the result was firm enough to announce, a full week after the samples arrived.
“Given this species is known to be affected by bird flu and the location we wanted to be thorough with our testing despite the low viral load,” van Andel said.
The species matters here. Northern giant petrels are big, heavy-billed ocean wanderers that breed on New Zealand’s subantarctic islands, with colonies on the Chatham, Antipodes, Auckland and Campbell island groups. They are scavengers of the southern seas, and they make their living picking over the carcasses of seals, penguins, albatrosses and whales. That diet is close to a perfect delivery mechanism for a virus that has been tearing through wildlife colonies in the far south, and it is why a dead giant petrel washing up on a New Zealand beach was always going to be a bird worth testing.
Speaking to RNZ, van Andel said the find was disappointing rather than alarming. “We can definitely expect to have more of these ocean-going seabirds arrive in New Zealand. We know that they come here. We know that birds in the Southern Ocean are infected with clade 2.3.4.4b,” she said.
All three New Zealand detections have been in the Wellington region, and all three have been single wild birds. The first two were announced within days of each other in the middle of July, a brown skua found on Petone Beach and a swamp harrier found near Carterton. There is a small twist in that sequence that has since been sorted out. The harrier was actually the earlier bird. It was admitted to Massey University’s Wildbase clinic on 9 July, the day before the skua turned up on the Petone shoreline, and it was picked up through routine surveillance rather than because anyone suspected the virus.
Wildlife veterinarian Professor Brett Gartrell told RNZ the harrier had been “stuck in a fence” and was brought in with suspected head trauma. “We weren’t even thinking about highly pathogenic avian influenza at the time,” he said. “It was a surprise to all of us when it came back positive.” The likeliest explanation is that the hawk fed on a sick seabird blown ashore during July’s storms, a pattern seen with birds of prey overseas.
What has not happened is just as important as what has. There have been no mass die-offs in New Zealand wildlife, and no detections in poultry anywhere in the country. “This is a single detection in an ocean-going seabird, so no spread in New Zealand wildlife detected, no detections in poultry in New Zealand, and so really not much has changed,” van Andel told RNZ. The ministry said there were no signs of other problems at the Cape Palliser site, and that precautionary checks would be run along the remote coastline the following day.
Egg and chicken producers in the Wairarapa and Wellington are being offered one-on-one advice, which is the same approach taken after the July detections. “MPI remains focused on surveillance to track the movement of bird flu so we can help protect our poultry industry and support DOC’s work with native wildlife,” van Andel said. “By building a precise picture through testing, we help egg and chicken producers make good decisions about the best biosecurity measures to protect their flocks and keep operating.” The ministry says chicken and eggs are safe to eat and the risk to human health remains low.
Behind all of this sits the work the Department of Conservation started before the virus ever arrived. In July, ahead of the first detections, the department began vaccinating about 300 core breeding birds from five of the country’s most threatened species, among them kΔkΔpΕ, takahΔ, shore plover, black stilt and orange-fronted parakeet. It is a world first, built on four years of trial work, and the timing was deliberate so the birds would have immunity before the spring breeding season. By the time the second case was announced on 17 July, 67 birds across six species and populations had received a first dose, and the list of species was left open so it could be changed as new risks emerged.
“DOC has been preparing for the arrival of bird flu for several years, with a focus on minimising the impact to wildlife populations,” Conservation Minister Tama Potaka said at the time.
The one thing officials keep asking the public for is eyes on the coast. Anyone who finds three or more sick or dead wild birds together should ring the exotic pest and disease hotline on 0800 80 99 66 or report it online at report.mpi.govt.nz, and leave the birds alone. “We don’t want people to touch them. We don’t want these animals to be moved. But we do want to hear about them, and they’ll be assessed to see if they should be sampled and tested,” van Andel said.
Writing in The Conversation in July, University of Otago virologist Jemma Geoghegan and Massey University infectious disease expert Nigel French warned that “further incursions may occur as migratory birds continue to move through the region”. A dead petrel on an empty Wairarapa beach is what that looks like in practice.
Have you come across sick or dead seabirds on your local coast this winter? Tell us what you saw in the comments below.
This article was written by AI, briefed to report the facts, hopefully without some of the bias people bring to the job π
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