Chinstrap penguin breeding pairs on Zavodovski Island fall 63 percent

Chinstrap penguin breeding pairs on Zavodovski Island fell by 63 percent from 2011 to 2025, according to ARY News’s account of a study in Current Biology. The count dropped from about 542,000 pairs to 201,000. ARY described the decline as the largest population change recorded at a single Antarctic site.

Smithsonian Magazine called Zavodovski home to one of the world’s largest chinstrap colonies; the New York Post described it as the world’s largest. ARY reported that six researchers visited the remote volcanic island in 2023 during the penguins’ incubation period.

The researchers paired images from that visit with satellite pictures covering 2011 to 2025, then used a computer program to count the penguins. The account presents the figures as breeding-pair estimates across that period. The researchers also used satellite tags to track where the penguins fed.

ARY said commercial fishing, humpback whales and a volcanic eruption in 2016 were not the main reasons for the decline. The account does not identify a principal cause, so it does not establish what drove the reduction in breeding pairs. The change was not uniform across the penguin species mentioned in the report.

Subantarctic macaroni penguin numbers on the island rose by more than 28 percent between 2011 and 2016, ARY reported. That increase covers a different period from the chinstrap comparison, which runs from 2011 to 2025. The headline accounts add limited context about the colony’s scale and the nature of the decline.

Smithsonian Magazine characterized the colony as among the world’s largest and said it was shrinking fast. The New York Post called it the world’s largest and attributed the loss to starvation, describing the decline as rapid.

ARY’s article text does not state starvation as the cause, instead saying the listed factors were not the main reasons; the available accounts therefore frame the cause differently. The figures and methods reported by ARY describe a substantial change in the island’s chinstrap breeding population, but its account does not name the main driver.

The reported macaroni penguin increase provides a separate species comparison, not an explanation for the chinstrap decline. Further causal conclusions are not established by the details reported here.