Four polar bears in Greenland have tested positive for the highly pathogenic H5N1 strain of avian influenza, according to research published in Emerging Infectious Diseases. The finding marks an unusual spillover of the virus into Arctic marine mammals and signals that the outbreak is reaching new ecosystems.
The researchers said the infections heighten the chance of the virus spreading between species and reassorting along bird migration routes. Such reassortment could allow influenza strains to swap genetic material, potentially creating new variants with unpredictable behavior.
In a separate incident, a bald eagle named Jackie, known through an internet nest cam and seen as a symbol of species recovery in California, died from bird flu. Together, the cases illustrate the broad and growing impact of H5N1 on wildlife beyond domestic poultry.