Monitoring tracks bird flu in Svalbard wildlife

Antibody tests on live animals show that bird flu is far more widespread among Svalbard's polar bears and Arctic foxes than finds in dead animals revealed, the Norwegian Veterinary Institute said on Friday 6 November.

More than 95% of the bears sampled in 2024 and 2025 had antibodies to the virus. So did 106 of 112 foxes sampled in the 2023 to 2024 trapping season, and 78 of 94 the season after. Antibodies show that an animal was infected and survived.

"No one would have known how widespread bird flu was among Arctic foxes and polar bears on Svalbard if we had only examined sick and dead animals," said Ingebjørg H. Nymo, a researcher at the institute.

Each summer millions of migratory birds arrive on Svalbard from Europe, Africa, North America and the North Atlantic, the institute said. Researchers found four variants of the virus on Svalbard and Jan Mayen from 2022 to 2025, a sign that it arrived several times with migratory birds. The institute called Svalbard an important place to detect changes in the virus early.

Several viruses found in Svalbard mammals carry genetic markers linked to adaptation to mammals. Following such changes helps to assess risk and to prepare internationally for new influenza viruses, the institute said, though little indicates that the viruses spread easily to or between people. The Norwegian Institute of Public Health rates the risk of infection as very low for the general population and low for people in contact with infected animals.

Long-term, systematic monitoring needs both tests of sick and dead animals and tests that reveal past infection in live ones, said Ragnhild Tønnessen, who coordinates the institute's bird flu work. Predators at the top of the food chain can show infection in areas where watching bird colonies directly is hard, she said.

The counts come from two studies that the institute's researchers and partners posted in July and September 2026, not yet peer reviewed. The institute presented them in an article it wrote and paid for, published on Forskning.no, a Norwegian research news site.

None of 243 bears sampled from 2014 to 2022 had the antibodies. Then 27 of 36 had them in 2023, 26 of 27 in 2024 and 37 of 38 in 2025. The bears are sampled alive between 23 March and 3 May each year, largely in the Norwegian Polar Institute's research, Nymo said.

Bird flu was first found on Svalbard in a dead glaucous gull near Longyearbyen on 13 June 2022. A peer-reviewed study in the Journal of General Virology, published on 17 August 2026, lists 27 detections up to August 2025: 21 birds of six species, one walrus and five Arctic foxes. The walrus, found in July 2023 on Hopen, an island in south-east Svalbard, was the first mammal case.

In May 2026 the institute found the H5N5 subtype in a dead walrus and a one-year-old polar bear in Raudfjorden, a fjord in north-west Spitsbergen. This was the first polar bear case in Europe. On 25 August the Governor of Svalbard (Sysselmesteren) announced a second dead bear, found on Æøya near Virgohamna, about 23 km away.

In a great skua colony on Hermansenøya, an island off the west coast of Spitsbergen, the subtypes H5N1 and H5N5 circulated together. Viruses that meet in the same bird populations can exchange genetic material and produce new variants, said Silje Granstad, who leads the institute's poultry work. She said the institute wants to follow this closely through monitoring.

Earlier: Bird flu found in second dead polar bear on Svalbard (23 October 2026)

Coverage: Forskning, Norwegian Veterinary Institute, NTB Kommunikasjon, TV 2, VG