Avian influenza has already killed black bears and grizzlies. It’s the first documented case in polar bears
The polar bear’s death means all three Alaskan bear species have been impacted by the deadly virus. USFWS
Biologists from Alaska’s state veterinarian office confirmed last month that highly pathogenic avian influenza, commonly known as HPAI or H5N1, has killed a polar bear, in the first documented case of its kind. The polar bear was found dead on the North Slope in Utqiagvik in October, its death likely the result of contracting the virus after scavenging on HPAI-infected carcasses.
With the confirmation of the polar bear’s cause of death comes a disturbing reality for Alaska’s wildlife managers: all three of Alaska’s bear species have now proven susceptible to HPAI. A year and a day before the polar bear confirmation, a Kodiak bear died from HPAI on Kodiak Island. Three weeks earlier, a black bear died in Hoonah.
December marked the fifth month in a row where at least two animals were confirmed to have died from the disease in Alaska, although the polar bear was only the second of two Alaskan mammals known to have died from bird flu in 2023. The other was a red fox that died in March, according to the state HPAI database. But as mortality soars on northern California chicken farms and in Alaskan bird nests alike, predators like bears and foxes continue to be at risk of contracting the disease wherever it is present in prey species.
“Across North America, and really around the world, lots of wild birds these days – I mean, thousands of wild birds these days, tens of thousands in some cases — are dying because of these highly pathogenic avian influenza viruses,” U.S. Geological Survey wildlife geneticist Andy Ramey told the Alaska Beacon. “What we’re dealing with now is a scenario that we haven’t dealt with in the past. And so there’s no manual.”
The most recent documented bird deaths in Alaska were in the southern Kenai Fjords, roughly 800 miles south of the Utqiagvik polar bear. Still, elsewhere on the North Slope, four other bird carcasses (three short-tailed sheerwaters and one black-legged kittiwake) tested positive for bird flu since Aug. 25. As is usually the case with wildlife diseases, the animals that test positive are only the tip of the iceberg in terms of how many sick individuals are actually on the landscape.
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Since March 2022, at least 207 mammals across 21 species have died in 27 states due to HPAI, according to a federal database maintained by the USDA’s Animal and Plant Health Inspection Service. Nine of those 207 individuals are bears, including four black bears, three grizzlies, one Kodiak bear, and the latest polar bear.
