Emperor penguins as climate migrants

Climate change is a major problem influencing several atmospheric and oceanic climate processes leading to climate warming, already affecting the abundance and distribution of wildlife around the world. The Antarctic marine ecosystem is no exception and physical drivers of ecosystem functioning are also being affected by climate change, influencing the wildlife population dynamics, including several seabirds such as penguins.

Emperor penguins (Aptenodytes forsteri) are the few species to breed during the harsh winter in Antarctica, being an important environmental bioindicator. Unfortunately, they are an iconic example of a species whose numbers may decrease significantly in future decades due to climate change. Furthermore, climate warming has already been attributed to the declining of some emperor penguin colonies.

The Halley Bay (75°33′S, 27°32′W) emperor penguin colony is one of the largest in Antarctica. Using satellite imagery technology, scientists from British Antarctic Survey (BAS) showed this colony suffered three years of breeding failure (2016, 2017 and 2018) due to an early breakup of the fast ice associated with a stormy period in September 2015 (strongest El Niño in the last 60 years).

At the same time, Dawson-Lambton colony (55 km more south) had the biggest increase in the last years. Scientists suggested this could be associated with immigration of penguins from the Halley Bay colony to the Dawson-Lambton colony due to changes in sea-ice conditions and early breakup of fast ice.

Due to projected climatic conditions for the coming century, the authors concluded it is crucial to forecast the future of this iconic species by identifying the drivers of their distribution. This information will be relevant to modelling penguin movement under climate warming scenarios, as northerly emperor colonies (above 70ºS) are predicted to completely disappear in the near future.ximo.


Source: Fretwell PT, Trathan PN (2019). Emperors on thin ice: three years of breeding failure at Halley Bay. Antarctic Science 31 (3), 133-138. doi:10.1017/S0954102019000099

Author: Hugo Guímaro


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