An isolated island near Antarctica is no longer home to the world's largest penguin colony, as their population has likely been wiped out due to changes in the food chain caused by global warming, AFP reported, citing a new study published in the journal „Current Biology".
Photos taken with a drone and from a satellite show that more than 680,000 Antarctic penguins have disappeared from the volcanic Zavodovsky Island between 2011 and 2025, according to the British Antarctic Survey, BTA reports.
„This is an extremely rapid rate of extinction," he told AFP lead author of the study Norman Ratcliffe.
These observations raise concerns about a decline in the populations of the Antarctic penguins in the South Sandwich Islands region - an archipelago that includes Zavodovsky Island and is home to 38 percent of the species' population.
The researchers believe that this „alarming decline" should prompt the International Union for Conservation of Nature (IUCN) to reclassify the species as „endangered".
Antarctic penguins are currently classified as „least threatened", meaning that they are not in danger of extinction.
Research conducted in 2011 concluded that the populations of chinstrap penguins throughout the South Sandwich Islands archipelago are stable. However, their numbers on Zavodovsky Island have dropped from about 1.09 million breeding individuals in January 2011 to 402,000 in 2025, a decline of 63 percent.
The island is also home to another species, the golden-headed penguin (Gorfou macaroni), whose population has grown from about 338,000 individuals in 2011 to 433,000 in 2025 and which is now more numerous than that of the Antarctic penguins.
The total number of Antarctic and golden-headed penguins on Zavodovsky Island now exceeds 835,000 individuals.
The researchers note that Adélie penguins from Cape Ader, located on the other side of Antarctica, now the world's largest colony of penguins, with over a million penguins in 2018.
The Mount Curry volcano on Zavodovsky Island erupted in 2016, raising fears it would wipe out the penguin population. However, researchers found that the ash cloud was blown northeast, over an area not inhabited by the flightless birds.
“The decline in the area occupied by the Antarctic penguin colony was already underway before the eruption and has continued at a steady pace since,” the study said. "We don't think the volcano is the cause or the main factor in the decline," Ratcliffe told AFP.
Scientists have instead linked the decline in the number of chinstrap penguins to the limited availability of krill, small crustaceans that are their main food source.
Warming ocean temperatures have pushed the krill further south into colder waters that the chinstrap penguins cannot tolerate.
"We think climate change, acting through interconnected food chains in an ecosystem, is probably the main factor," Ratcliffe said.
While the chinstrap penguin population on the island has been declining by 7 percent a year, the number of golden-crested penguins has been increasing over the same period, as they feed on a wider range of prey. Their survival also supports the hypothesis that the volcanic eruption did not play a role in the decline of the Antarctic penguin population.