Zavodovski Island loses status as world's largest penguin colony

Zavodovski Island, located in the South Sandwich Islands, has lost its status as the world’s largest penguin colony following a massive population crash. A study published in the journal Current Biology reveals that the number of occupied chinstrap penguin nests on the remote volcanic island fell by 63% between 2011 and 2025.

Researchers from the British Antarctic Survey, led by penguin ecologist Norman Ratcliffe, described the decline as “an enormous population crash.” The island is currently experiencing the fastest-declining chinstrap population globally, with annual losses of approximately 7%, which is two to three times higher than rates observed in other regions.

While the island previously hosted roughly 600,000 chinstrap pairs and 90,000 macaroni pairs, the title of the world’s largest colony has passed to the Adélie penguin colony at Cape Adare in the Ross Sea. Scientists point to climate disruption as a primary driver, noting that winter temperatures around the Antarctic Peninsula have risen significantly above preindustrial levels. The study also ruled out the 2016 eruption of Mount Curry as the cause, noting the decline began several years prior to the volcanic event.