Emperor penguins live in colonies along the entire coast of Antarctica and are the only animal that breeds there during winter.
On April 9, their status was officially changed from near threatened to endangered on the global Red List, which tracks species at risk of extinction. This list is maintained by the IUCN.
Emperor penguins depend on stable sea ice to raise their chicks. But the sea ice is changing.
Climate change is causing problems
Annonse
Andrew Lowther is a researcher at the Norwegian Polar Institute and an expert on marine mammals and seabirds.
He has been to Antarctica several times and worked with penguins, especially on the Antarctic Peninsula.
Although he hasn’t physically handled an emperor penguin yet, he closely follows developments affecting these iconic animals.
"For quite some time now, we've had enough evidence suggesting that climate change is a problem for emperor penguins," he says.
Andrew Lowther on an expedition to Deception Island to study penguins.(Photo: Andrew Lowther)
Incubate eggs in extreme cold
Emperor penguins lay their eggs on solid sea ice in early May, which corresponds to autumn in Antarctica.
During winter, males incubate the eggs for about two months without eating, enduring extreme weather. They huddle together to keep warm, according to the Great Norwegian Encyclopedia.
The females return once the eggs have hatched, and the males head out to sea to feed. After that, both parents care for the chicks until they are ready to enter the water around December.
Have not developed feathers
"In the middle of winter, there's a lot of sea ice. Adults come ashore to lay eggs and rely on that ice staying intact until the chicks lose their down and grow proper feathers," says Andrew Lowther.
The chicks' down feathers are not waterproof.
"It's similar to wearing a down jacket. If it gets wet, it's useless," he says.
Because of this, the chicks cannot enter the water until they develop their first proper feathers.
"This has worked well throughout history. The penguins have timed it well so that the chicks' primary feathers have grown and developed by the beginning of summer, when the sea ice breaks up. Then they can jump into the water and leave," he says.
Annonse
What researchers are now seeing is that the sea ice forms later and breaks up earlier. In some cases, before the penguin chicks have finished developing their feathers.
"This means that the chicks are forced into the water and drown," he says.
Emperor penguins with chicks.(Photo: vladsilver / Shutterstock / NTB)
Colonies disappeared
Using satellite images, researchers have observed colonies vanishing as the ice breaks apart.
In 2022, researchers found that four out of five colonies were lost in the central and eastern Bellingshausen Sea. The ice disappeared before the chicks had developed proper feathers.
"I was shocked. It's very hard to think of these cute fluffy chicks dying in large numbers," Peter Fretwell, who led the study, told The Guardian.
More variation in sea ice
Another factor causing problems for emperor penguins is increased variation in sea ice concentration, says Lowther.
If the sea ice behaves predictably from year to year, adult penguins can plan more effectively. They know how far they can travel to find food and how long it will take to return.
As conditions become less predictable, it becomes harder for them to time their journeys and decide when to lay eggs.
This increased variability is especially noticeable in Queen Maud Land, though Lowther says the problem affects the entire Antarctic coastline.
Look for droppings on the snow
The reason emperor penguins are now classified as endangered is based on estimates suggesting the population could be cut in half by the 2080s.
Satellite data suggests their numbers declined by about 10 per cent between 2009 and 2018, which amounts to 20,000 fewer penguins.
Researchers, particularly those from the British Antarctic Survey, have monitored the situation using satellite images, according to Lowther.
"The challenge with satellite images is that the animals breed during winter. It's dark, and the weather is terrible. It's not easy to actually see the animals in the images," he says.
Instead, researchers look for traces of droppings on the snow and try to estimate the number of penguins from that. It's difficult, says Lowther, but the overall pattern is clear.
"The numbers are declining," he says.
Hope for more support for research
Lowther believes that the new endangered status could make a difference.
"We've known about this trend and have been raising the alarm for some time," he says.
Lowther says researchers have been seeking funding to fill knowledge gaps about the population. For example, to determine whether colonies are truly disappearing or possibly relocating elsewhere.
"We know how to go into the field and collect this information. But funding and politcal support have been lacking," he says.
He is hopeful that this could now change.
It's not only the emperor penguin whose status has changed on the Red List.
The Antarctic fur seal has gone from being listed as least concern to endangered. Its population has declined by more than 50 per cent between 1999 and 2025. Rising sea temperatures are pushing their main food source, krill, deeper into the ocean.
The southern elephant seal has had its status changed from least concern to vulnerable. These seals have been heavily affected by avian influenza.
