Bird flu wipes out nearly half of South Georgia's breeding elephant seal population
The population of southern elephant seals in South Georgia has plummeted by 47% following an outbreak of bird flu (avian influenza), according to a new study. The remote island in the South Atlantic Ocean is home to the world's largest breeding population of the species.
Researchers estimate that approximately 53,000 breeding females died after the virus hit the island in 2023.
"It was quite a stark number," said lead author Connor Bamford from the British Antarctic Survey. The finding highlights the extensive impact of the outbreak, as many deceased animals likely returned to the sea when sick and were never accounted for onshore.
Extensive Mortality and Long-Term Impact
The research team used aerial imagery from three beaches to compare the breeding population from 2022 (before the outbreak) to 2024. The study, published in the journal Communications Biology, revealed a mortality rate far exceeding normal levels.
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Global Impact: South Georgia hosts an estimated 54% of the global breeding population of southern elephant seals.
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Pups Affected: There was a particularly high level of mortality observed among pups. Since females take three to eight years to begin breeding, this loss of young individuals suggests a "dramatic impact on the population" in the long term.
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Contributing Factors: While direct losses from the bird flu are the primary cause, researchers suggest the stress on sick females may have also led to them abandoning their pups, potentially exacerbating overall mortality.
The researcher warned that the situation is likely not over, noting that current counts in 2024 are lower than 2023, which suggests the virus is still circulating in the population. The spread of bird flu across bird and mammal species in the Antarctic region continues to be a concern.
