In a first, a polar bear has died of avian flu in the Arctic, confirms Alaska

Subject: Environment

Section: Species in news

In the news:

The Arctic region recorded the first case of a polar bear death due to Highly Pathogenic Avian Influenza (HPAI), confirming a concerning development.

Details:

The polar bear, found deceased near Utqiagvik in Alaska, highlights the vulnerability of these bears, listed as “vulnerable” due to habitat loss—specifically, diminishing sea ice—on the IUCN Red List.
The death of the polar bear was confirmed in December 2023 after samples collected in October tested positive for the virus.
Although polar bears primarily hunt seals, scavenging on dead birds likely exposed this bear to the influenza virus, this case emphasizes the virus’s survival on deceased animals in cold conditions.

Highly pathogenic Avian Influenza (HPAI):

The viral disease HPIA or avian influenza, especially the H5 and H7 strains, mostly affects birds.
These strains are highly pathogenic and have been reported in domestic poultry, resulting in high mortality if they manage to reach wild bird populations.
It spreads among birds and mammals due to predators and scavengers feeding on infected birds. Marine mammals have also been found to be infected.
Threatened species from HPAI:
- Avian groups like gulls and skuas, birds of prey such as hawks and caracaras, terns and shorebirds.
- Among marine mammals, fur seals, sea lions, southern elephant seals and dolphins.

HPAI in the polar region:

The HPAI strain 2.3.4.4b, causing widespread mortality among birds and mammals worldwide, emerged in the Arctic in April 2023.
Initially detected among birds and a fox, it quickly spread, infecting chickens, ducks, and various bird species in different regions, including bald eagles and Canada geese.
HPAI, initially reported in poultry in 2021, spread rapidly among wild birds and reached the Antarctic region by October 2023, infecting brown skuas.
Scientists fear the virus could spread among dense penguin populations during the Southern Hemisphere’s spring, potentially causing a significant ecological disaster.

About the Polar bear:

Native to the Arctic, is the largest bear species and land carnivore.
Close relative to the brown bear, they’re sexually dimorphic, with males significantly larger than females.
Their white or yellowish fur, black skin, and fat layer help adapt to Arctic conditions.
They have specialized teeth and large paws for walking on ice and swimming.
They’re terrestrial and ice-dependent, considered marine mammals due to their reliance on marine ecosystems.
Prefer annual sea ice but live on land when it melts; primarily carnivorous, specializing in preying on seals.
Classified as a “vulnerable” species due to threats like climate change, pollution, habitat loss and energy development.
Increased time on land raises conflicts with humans; historically hunted for their coats and other items.