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Scientists: Melting Sea Ice in Antarctica Causes Ocean Storms

Scientists know the damaging consequences of the loss of Antarctic sea ice. Juan BARRETO / AFP
Scientists know the damaging consequences of the loss of Antarctic sea ice. Juan BARRETO / AFP
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Scientists: Melting Sea Ice in Antarctica Causes Ocean Storms

Scientists know the damaging consequences of the loss of Antarctic sea ice. Juan BARRETO / AFP
Scientists know the damaging consequences of the loss of Antarctic sea ice. Juan BARRETO / AFP

The record-breaking retreat of Antarctic sea ice in 2023 has led to more frequent storms over newly exposed parts of the Southern Ocean, according to a study published Wednesday.
Scientists know that the loss of Antarctic sea ice can diminish penguin numbers, cause ice shelves to melt in warmer waters, and impede the Southern Ocean from absorbing carbon dioxide, AFP reported.
But this new research, published in the peer-reviewed journal Nature, explores another consequence: increased heat loss from the ocean to the atmosphere, and an associated rise in storms.
Since 2016 there has been a large-scale reduction in Antarctic sea ice, but nothing like 2023 when a record amount failed to reform over the winter.
For this study, Simon Josey of the UK's National Oceanography Center and colleagues focused on three regions that experienced unusually high levels of sea-ice retreat that year.
Using satellite imagery, ocean and atmospheric data, and wind and temperature measurements, they found some newly ice-free areas experienced double the heat loss compared to a stabler period before 2015.
This was accompanied by "increases in atmospheric-storm frequency" over previously ice-covered regions, the authors found.
"In the sea-ice-decline regions, the June–July storm frequency has increased by up to 7days per month in 2023 relative to 1990–2015."
The loss of heat caused by reduced sea ice could have implications for how the ocean circulates and the wider climate system, the study added.
Oceans are a crucial climate regulator and carbon sink, storing more than 90 percent of the excess heat trapped near Earth's surface by greenhouse gas emissions.
In particular, sea-ice retreat could mean changes in how a deeper layer of cold, dense Antarctic bottom water absorbs and stores heat.
The authors said further in-depth analysis of possible climate impacts were needed, including if sea-ice retreat could have even further-reaching consequences.
"Repeated low ice-cover conditions in subsequent winters will strengthen these impacts and are also likely to lead to profound changes further afield, including the tropics and the Northern Hemisphere," it said.

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Cute carnivores: Bloodthirsty California Squirrels Go Nuts for Vole Meat

This handout photo obtained from the University of California on December 18, 2024, shows ground squirrels eating voles in Davis, California. Sonja Wild / University of California, Davis/AFP
This handout photo obtained from the University of California on December 18, 2024, shows ground squirrels eating voles in Davis, California. Sonja Wild / University of California, Davis/AFP
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Cute carnivores: Bloodthirsty California Squirrels Go Nuts for Vole Meat

This handout photo obtained from the University of California on December 18, 2024, shows ground squirrels eating voles in Davis, California. Sonja Wild / University of California, Davis/AFP
This handout photo obtained from the University of California on December 18, 2024, shows ground squirrels eating voles in Davis, California. Sonja Wild / University of California, Davis/AFP

Squirrels might look like adorable, nut-hoarding furballs, but some are ruthless predators that hunt, tear apart, and devour voles.
That's the startling finding of a new study published Wednesday in the Journal of Ethology -- the first to document widespread carnivorous behavior in these seemingly innocent creatures.
"There is always something new to learn and wild animals continue to surprise us," lead author Jennifer E. Smith, an associate professor of biology at the University of Wisconsin-Eau Claire told AFP.
"In a changing world with many technological advances, there is no replacement for direct observation of natural history, including watching the squirrels and birds that often visit our backyards."
The observations were made this summer, during the 12th year of a long-term study conducted at Briones Regional Park in Contra Costa County, California.
Between June and July, researchers recorded 74 interactions involving California ground squirrels and voles, with 42 percent of them involving active hunting of their fellow rodents.
Co-author Sonja Wild, a postdoctoral researcher at the University of California, Davis, admitted she was initially skeptical of the reports brought to her by undergraduate students who first witnessed the behavior.
"I could barely believe my eyes," said Wild. But "once we started looking, we saw it everywhere."
It was previously known that as many as 30 species of squirrels opportunistically consume meat, ranging from small fish to birds. However, it was unclear whether this behavior stemmed from scavenging or active predation.
The new study is the first to confirm that hunting is, in fact, a common behavior.
Researchers observed squirrels crouching low to the ground before ambushing their prey, though more often, they chased voles, pounced, and delivered a neck bite followed by vigorous shaking.
The study also found that the squirrels' carnivorous behavior peaked during the first two weeks of July, coinciding with a surge in vole populations reported by citizen scientists on the iNaturalist app.
Other animals, such as raccoons, coyotes, and spotted hyenas, have been known to adapt their hunting strategies in response to human-induced changes in their environments.
"In a changing world, it can be daunting to consider all of the challenges that human presence, habitat loss, and climate change impose on animals," said Smith.
"Our study offers an exciting silver lining, demonstrating the incredible flexibility that some animals possess."
Several questions still remain unanswered.
Researchers hope to investigate how widespread hunting behavior is among squirrel species, whether it is passed down from parents to pups, and how it affects their broader ecosystems.