Alaska has recorded the first case of a polar bear dying due to bird flu, alarming experts about the already stressed extant species.
The polar bear died from highly pathogenic avian influenza (HPAI), contracted by scavenging on bird carcasses infected with the deadly strain H5N1. If the infection spreads, it could be dangerous for the Arctic population which is already facing issues due to climate change.
The Division of Environmental Health officials confirmed the death in December after they found the dead polar bear in the northernmost town of Utqiagvik in October.
The case wasn’t a surprise, as black and brown bears have previously contracted the deadly virus. However, it’s more concerning as polar bears are a vulnerable species. Loss of their sea habitat has already hit their population. If the infection spreads, additional deaths could serve as another blow to the species.
Alaska’s state veterinarian, Robert Gerlach, told Live Science that the infection might have already spread among other polar bears.
First identified in 1996 in China, the H5N1 has now spread worldwide. In 2020, a new variant of the deadly virus emerged, killing unprecedented birds. It also spread to North America in 2021. The virus has impacted numerous mammals, resulting in thousands of deaths.
Douglas Clark, associate professor at the University of Saskatchewan’s School of Environment and Sustainability, said, “This is unlikely to be an isolated event. It’s just that this one led to an outcome that was detected.”
Due to their habitat, monitoring the virus among polar bears can be difficult for experts. However, the risk of transmission among polar bears is low because they are a solitary species. But, the concern remains as they have started to feed more on seabirds due to the reduced sea ice.
Pollution is another aspect which makes polar bears more vulnerable to bird flu. Anthropogenic chemicals highly affect the species as they accumulate in the high-fat diets of animals. As their fat store depletes, these stored pollutants start interfering with the immune system.
Andrew Derocher, a professor in the Department of Biological Sciences at Canada’s University of Alberta, said, “A bear fasting for longer, nutritionally stressed, may have a weakened immune system. Now expose a bear with a weakened immune system to avian influenza and the issue of surviving the exposure becomes more challenging.”
(With inputs from agencies)