Scientists from Stony Brook University have discovered gentoo penguin colonies on Antarctica’s Andersson Island and on an unexplored archipelago off the Antarctic Peninsula’s northern tip. These are some of the southernmost records for gentoo breeding in the region, per a Greenpeace statement.
Until recently, these areas were too icy for the penguins, which prefer warmer temperatures to raise their chicks. But as climate change melts Antarctic ice, the penguins are expanding their habitat, a phenomenon some scientists refer to as “gentoofication.”
“It’s may be a cliché at this point, but they’re the canary in the coal mine for climate change because they’re so closely tied to those sea ice conditions,” Heather Lynch, an Antarctic penguin expert at Stony Brook University in New York and the remote leader of the expedition, tells Mongabay.
Stony Brook researchers were sailing on a Greenpeace expedition, carrying out counts of penguin colonies in remote islands of the eastern Antarctic Peninsula, when they spotted a colony with 75 chicks living on Andersson Island, per Mongabay. The researchers are surveying parts of the peninsula where satellites had spotted penguin colonies but had never before been explored on foot.
"As expected, we're finding gentoo penguins nearly everywhere we look — more evidence that climate change is drastically changing the mix of species here on the Antarctic Peninsula,” says Lynch in a statement.
Gentoos are the only penguin species along the Antarctic Peninsula that is expanding its distribution and growing in numbers, per the Oceanwide Expeditions website.
“This is the climate crisis happening right in front of our eyes,” says Louisa Casson, who was aboard the vessel and is from Greenpeace’s Protect the Oceans campaign, in a statement. “In the Antarctic, one of the most remote places on Earth, we are seeing a process where this species of penguin is spreading into new habitat and breeding further south: a biological manifestation of sea ice loss.”
Temperatures on the Antarctic Peninsula are rising five times more than the global average annually, per Discovering Antarctica. In 2020, the continent hit a record high temperature of 64.9 degrees Fahrenheit.
While gentoos thrive under the warmer temperatures, Adélie penguins, which rely on sea ice, do not.
“When we find Adélie penguins, we typically know that sea ice is nearby,” Michael Wethington, a quantative ecologist at Stony Brook, tells Reuters’ Gloria Dickie and Natalie Thomas. “And whenever we’ve seen sea ice declining or disappearing altogether, then we’re seeing corresponding Adelie penguin populations decline substantially.”
But during the expedition, scientists found that Adélie penguin numbers in the Weddell Sea have remained stable in the last decade, per a Stony Brook statement. The Weddell sea is the site of a proposed Marine Protected Area, and this discovery provides more evidence that the Weddell Sea might be an important shelter for wildlife as climate change impacts increase.
“The Weddell Sea is hardly immune from climate change, but it appears that Adélie penguins breeding in this area remain buffered from the worst of the threats posed to those populations declining so rapidly on the warming western side of the Antarctic Peninsula,” Lynch says in a statement. “Our understanding of the biology in this inhospitable landscape continues to grow every year, but everything we learn points toward its value for conservation.”