Climate change could cause 90% of emperor penguin colonies to disappear from Antarctica

Sudden reduction in size Sea ice can have profound effects on Environmental systems and species that depend on it for breeding, molting or feeding. One of these Emperor Penguin (Optenodides forsteri)It depends on these vast frozen expanses for all stages of its life cycle.

Almost all emperor penguin colonies depend on stable, firm sea ice that they use for breeding and molting, while also using the fringing ice zone as a feeding ground. They arrive at their preferred breeding grounds in late March and April and lay eggs from May to June until they hatch after 65 days and hatch in December and January.

Therefore, the The ground snow on which the entire process is based must be stable between April and January to guarantee successful breeding.

Now, a study has been published Communications Earth and Environment A region of Antarctica with complete loss of sea ice by 2022 warns that emperor penguin colonies have suffered an unprecedented breeding crash. This finding supports the predictions According to current global statistics, more than 90% of emperor penguin colonies will be virtually extinct by the end of the century.

British Antarctic Survey researchers The study found a high probability that no chicks survived in four of five emperor penguin colonies. Central and eastern Bellingshausen are known in the sea. They analyzed satellite images showing the loss of sea ice on breeding grounds, long before chicks develop waterproof feathers.

By early December 2022, Antarctic sea ice extent equaled the previous record set in 2021. The most intense loss was observed in the central and eastern Bellingshausen Sea west of the Antarctic Peninsula. 100% loss occurred in November 2022.

Emperor penguins have never failed to reproduce at this scale in a single season.. Loss of sea ice in this region during the Antarctic summer makes migrating chicks less likely to survive. We know that emperor penguins are more vulnerable in warmer climates, and current scientific evidence says so Such extreme sea ice loss events will become more frequent and widespread.

Since 2016, Antarctica has experienced four of the lowest sea ice extents in the 45-year satellite record, with the two lowest seasons in 2021/22 and 2022/23. Between 2018 and 2022, 30% of the 62 known emperor penguin colonies in Antarctica are affected by partial or complete loss of sea ice. Although it is difficult to immediately link specific extreme seasons to climate change, A long-term decline in sea ice extent is expected from current generation climate models.

Emperor penguins respond to incidents of sea ice loss by moving to more stable locations the following year. However, this strategy may not work if sea ice habitats are affected across an area.

These populations have not been subject to large-scale hunting, habitat loss, overfishing, or other local anthropogenic interactions in the modern era. Unusually for this vertebrate species, climate change is considered is the only important factor influencing long-term population change.

Recent attempts to predict emperor penguin population trends from forecasts of sea ice loss have painted a bleak picture that, if current rates of warming continue, By the end of this century, more than 90% of colonies will be virtually extinct.

Five penguin colonies — Rothschild Island, Verdi Inlet, Smiley Island, Bryan Peninsula and Pfrogner Point — have been discovered using satellite images over the past 14 years. All five colonies were shown to return to the same location to breed each year, with only one breeding failure on the Bryan Peninsula in 2010.

Scientists now routinely use satellite images to locate and track colonies, as the brown flecks of the birds’ guano stand out against the pure white of snow and ice. The team used images from the European Commission’s Copernicus Sentinel-2 satellite mission, which has been monitoring the Antarctic since 2018.

*Peter Freedwell, lead author of this study, is an award-winning cartographer and lead scientist on the British Antarctic Survey. He pioneered the use of satellite imagery to detect and monitor polar wildlife, leading to the discovery of nearly half of the world’s emperor penguin colonies. He is a Fellow of the Royal Geographical Society and has completed four field seasons in Antarctica.