The World’s Second Largest Emperor Penguin Colony Is Disappearing
According to a report released on Thursday by the British Antarctic Survey (BAS), the world’s second largest emperor penguin colony has nearly disappeared. Researchers say that the emperor penguin colony at Halley Bay in the Weddell Sea of Antarctica has suffered three years of almost complete breeding failure.
Beginning in September of 2015, storms destroyed sea ice in the Weddell Sea, drowning thousands of emperor penguin chicks in 2016. The storms recurred in 2017 and 2018, decimating the population of emperor penguin chicks at the Halley Bay colony. Researchers have concluded that the emperor penguin colony at Halley Bay has faced three years of breeding failure, an occurrence that is unprecedented in the historical record.
The BAS released a statement that said “For the last 60 years, the sea-ice conditions in the Halley Bay site have been stable and reliable… But in 2016, after a period of abnormally stormy weather, the sea ice broke up in October, well before any emperor chicks would have fledged. This pattern was repeated in 2017 and again in 2018 and led to the death of almost all the chicks at the site each season."
However, during the same three year period, the nearby Dawson-Lambton colony has seen more than a tenfold increase in population, which the report attributes to the immigration of emperor penguins from the Halley Bay colony. According to the report, “it appears that many of the birds from Halley Bay have relocated to Dawson-Lambton, with the rest remaining at Halley Bay, but not breeding successfully. This number seems to be diminishing on an annual basis as more failed breeders move to the nearby colony. It is possible that some emperors could have formed a new colony elsewhere, but an exhaustive search using Sentinel2 imagery shows no new colony locations in the region.”
While the immigrant penguin population of the Dawson-Lambton colony is still lower than the population of the original Halley Bay colony, it is promising that many of the emperor penguins from the Halley Bay colony have migrated rather than remaining at the dangerous Halley Bay site.
BAS penguin expert and report co-author Dr. Phil Trahan stated that “It is impossible to say whether the changes in sea-ice conditions at Halley Bay are specifically related to climate change, but such a complete failure to breed successfully is unprecedented at this site,” going on to say that “even taking into account levels of ecological uncertainty, published models suggest that emperor penguins numbers are set to fall dramatically, losing 50-70% of their numbers before the end of this century as sea-ice conditions change as a result of climate change.”
The report’s conclusion stated that “In a warming world… Understanding how emperor penguins react to catastrophic sea-ice loss will be of crucial importance if one is to predict the fate of the species over coming decades.”