So how does a bird virus get into the largest predator in the Arctic?<\/p>\n
The Arctic is becoming a very different place to hunt<\/h2>\n
Most polar bears spend their lives near sea ice. That environment keeps them away from many of the places where avian influenza commonly spreads.<\/p>\n However, like everything else in the Arctic, that is rapidly disappearing as well.<\/p>\n Due to the reduction of Arctic ice, the amount of time a polar bear spends<\/strong> on land increases. As a result, polar bears now spend more time with birds, dead birds, dead eggs, and other things that could be a source of infection.<\/span><\/p>\n A virus that was once considered to be far away is now very easily accessed.<\/p>\n Each year millions of migratory birds travel to the Arctic to nest. Many of these birds come from completely different parts of the world before arriving at the same location to mate.<\/p>\n These huge colonies provide excellent opportunities for viruses to pass from host to host.<\/p>\n Some of the species in these flocks are part of the natural reservoirs of avian influenza.<\/p>\n Greenland provides a direct link between major flyways that crisscross entire continents<\/strong>.<\/p>\n By the time birds reach Arctic mating areas, they can transfer viruses across great distances. This creates a possible route of entry into such remote areas.<\/p>\n Cornell University<\/a> researchers studied 109 blood samples collected from East Greenland polar bears between 2016 and 2025.<\/p>\n It took several years for anything unusual to happen. There were no influenza A antibodies in any sample until 2023.<\/p>\n Then the trend changed. In 2024, antibodies appeared in three of fourteen bears. By 2025, that number had risen to six of fourteen<\/strong>.<\/p>\n A CDC Emerging Infectious Diseases<\/a> study found that four bears had antibodies related to H5 viruses from the globally emerging 2.3.4.4b lineage.<\/p>\n This indicated past exposure to the virus, not a current infection.<\/p>\n The antibodies showed that some of the polar bears had been exposed to the virus and lived through it.<\/p>\n It appears that exposure to the virus does not always result in immediate death<\/strong>. That finding leaves researchers with several unanswered questions.<\/p>\n Are polar bears being infected frequently enough to consider this an issue?<\/p>\n Can there be transmission between individual polar bears?<\/p>\n Will further mutation of viral proteins make it easier for viruses to infect mammals?<\/p>\n Before 2024, there was no evidence that Greenland polar bears had been<\/strong> exposed to HPAI. And now there is.<\/p>\n This goes beyond just one group of bears. Polar bears increasingly find themselves at the intersection of shrinking sea ice<\/a>, changing food sources, and migratory bird activity.<\/p>\n Those connections may become more common in the years ahead.<\/p>\n Other examples of this type of interaction can be seen in other areas of the Arctic.<\/p>\n In Svalbard, a young polar bear died after consuming an infected walrus. Researchers also detected mammalian-adapted H5N5 strains in Arctic foxes.<\/p>\n As sea ice continues to melt at alarming rates, polar bears are forced to adapt their foraging habits.<\/p>\n They are beginning to take down terrestrial reindeer and scavenge around human settlements and dumpsters for food.<\/p>\n Those new food sources provide new pathways for exposure to diseases<\/a>.<\/p>\n Combined, all these trends suggest polar bears could help track emerging pathogens<\/strong> across the region.<\/p>\n","protected":false},"excerpt":{"rendered":" There is little reason to believe that bird flu would normally be considered a polar bear disease. The virus is usually associated with migratory birds, poultry, and flyways that span entire continents. That is why the Greenland findings stood out. Polar bears have shown evidence of encountering influenza viruses. Six of fourteen bears carried influenza … Read more<\/a><\/p>\n","protected":false},"author":27,"featured_media":45098,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_focus_keyword":"polar,bear,research","rank_math_title":"","rank_math_description":"After years without detected influenza antibodies, researchers began finding signs of previous virus exposure in East Greenland polar bears during surveys.","footnotes":""},"categories":[83],"tags":[],"class_list":["post-45017","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-earth"],"_links":{"self":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/45017","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/users\/27"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/comments?post=45017"}],"version-history":[{"count":8,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/45017\/revisions"}],"predecessor-version":[{"id":45120,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/45017\/revisions\/45120"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media\/45098"}],"wp:attachment":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media?parent=45017"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/categories?post=45017"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/tags?post=45017"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/www.ecoportal.net\/en\/wp-content\/uploads\/2026\/11\/INT-Six-of-14-Greenland-polar-bears-carried-flu-antibodies-four-showing-evidence-of-H5-exposure-1-300x169.jpg\" "\\"\\"")
The route north begins far beyond Greenland<\/h3>\n
Had the virus already reached polar bears?<\/h2>\n
Finding antibodies was only the beginning<\/h3>\n
A much larger Arctic shift may be underway<\/h2>\n
Signs of this shift are already appearing elsewhere<\/h3>\n