The impact of climate change is becoming more visible in Antarctica. At the turn of the year, Antarctic birds such as the arctic skua, snowbird, and other seabird species begin their nesting season, laying eggs and starting to raise chicks. In the region of Svarthamaren, researchers did not find a single skua nest during December 2021 and January 2022, and nests of snowbirds and Antarctic birds dropped to nearly zero in that period.
In these areas, heavy snowfall and deeper snow accumulation have become more common than in previous years. A recent study published in Current Biology shows that these unusually intense blizzards are hindering the birds reproductive success.
“In a seabird colony, storms can lead to the loss of some chicks and eggs and reduce overall reproductive success,” explains the study’s lead author, Sebastien Descamps of the Norwegian Polar Institute. The researchers emphasize that this is not a matter of a few birds but a broad impact across breeding colonies. It is surprising to observe zero reproductive success in some cases.”
Since Svarthamaren and nearby Jutulsessen host two of the largest Antarctic bird colonies, they play a key role for snowbirds and south arctic skuas. Between 1985 and 2020, Svarthamaren hosted a wide range of nests each year, sometimes tens of thousands of snowbird nests and over a hundred skua nests, with numbers fluctuating seasonally.
mass disappearance
During the 2021-2022 season, only a handful of breeding Antarctic birds were observed, and snowbirds showed a sparse presence with no skua nests recorded in that period. Jutulsessen also saw virtually zero nests in the summer of 2021-2022, in contrast to earlier years when tens of thousands of active nests were documented.
Descamps notes that the impact is not confined to a single colony but spans hundreds of kilometers. He emphasizes that the stormy conditions affected a substantial portion of the Antarctic seabird population, reducing breeding success across large areas.
These seabirds lay their eggs on bare ground, and when heavy snow covers the ice-free ground, it becomes inaccessible for nesting and chick-rearing. Storms also demand extra energy as birds shield themselves from the cold and conserve resources for thermoregulation.
The problem is accelerating in Antarctica
Until recently, there were no obvious signs of warming in most of Antarctica, with notable exceptions on the peninsula. In recent years, new research and extreme weather events are shifting the scientific view on climate change impacts in Antarctica.
Descamps hopes the predictive models used to estimate future storm severity can be refined to improve accuracy. He notes that storm intensity depends not just on wind but also on the snowpack, and there are limited stations measuring snow across many regions. Better data will help explain the reproductive success of these birds.
The study presents a clear message: extreme weather events have a strong effect on seabird populations, and climate models anticipate that the severity of such events will rise in the future.
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