Research · The World's Largest Penguin Colony Is Gone: Zavodovski's Chinstraps Fall 63% in 14 Years

Research · The World's Largest Penguin Colony Is Gone: Zavodovski's Chinstraps Fall 63% in 14 Years

A new British Antarctic Survey study published this week in *Current Biology* finds that Zavodovski Island — once home to the world's largest penguin colony — has lost more than 680,000 chinstrap penguins, roughly two-thirds of its population, between 2011 and 2025.

Drone and satellite surveys counted about 1.09 million breeding individuals in January 2011 and just 402,000 in 2025, a decline running at about 7% per year. The island's 2016 volcanic eruption was ruled out as the cause: the decline was linear, before and after, and neighboring macaroni penguins actually rose from ~338,000 to ~433,000 over the same period.

Scientists attribute the collapse to warming oceans pushing krill — the chinstraps' main food — south toward waters too cold for them to tolerate, a climate-driven regime shift through the food web. The authors call for the chinstrap penguin to be redesignated from IUCN "least concern" to "endangered," while the Adélie colony at Cape Adare (over 1 million, as of 2018) takes the title of the world's largest.

Original: read here