Breeding patterns among Antarctic penguins shifting at record speed due to climate change

The researchers found that penguins are advancing the timing of their breeding settlement by between 10 and 13 days per decade on average, with some colonies showing shifts of as much as 24 days per decade.

The study says these changes represent some of the fastest phenological — or seasonal timing — shifts ever recorded in animals and are likely to increase competition for food and nesting space, as well as competition between species.

Scientists analysed breeding timings over a ten-year period, from 2012 to 2022, among three penguin species, Adélie, chinstrap and gentoo, across 37 colonies in the Antarctic Peninsula and nearby sub-Antarctic islands.

Settlement is defined as the first day penguins continuously occupy their nesting area. Colony sizes ranged from a few dozen birds to several hundred thousand.

Gentoo penguins showed the most rapid changes, with average settlement advancing by 13 days per decade. In some colonies, the shift was as large as 24 days per decade. The researchers said this variability is consistent with previous findings showing gentoo penguins have greater flexibility in incubation and hatching behaviour.

“These shifts were some of the fastest phenological changes ever observed in any animal,” The study said. “Relative to global review of animal phenological responses to climate change, our data indicate Gentoos have undergone the fastest phenological shift on record for all bird species while Adélies and Chinstraps are respectively fourth and fifth.”