Members of the First German South Polar Expedition (1901–1903) encountered emperor penguins (Aptenodytes forsteri) near their wintering station in the sea ice of Posadowsky Bay, East Antarctica. The penguins appeared to be generally less of scientific interest, but more of a useful resource. Despite the presence of chicks, the men were uncertain about the existence of a breeding colony, and did not record the position of the penguin aggregation they encountered. In later years, only a few sightings confirmed the existence of a colony, and the last ground visit took place in 1960. Based on satellite imagery, a colony appears to exist even now. This paper examines what impact the expedition may have had on this colony, and whether it still exists.

Satellite imagery is used to show that the world's second largest emperor penguin colony, at Halley Bay, has suffered three years of almost total breeding failure. Although, like all emperor colonies, there has been large inter-annual variability in the breeding success at this site, the prolonged period of failure is unprecedented in the historical record. The observed events followed the early breakup of the fast ice in the ice creeks that the birds habitually used for breeding. The initial breakup was associated with a particularly stormy period in September 2015, which corresponded with the strongest El Niño in over 60 years, strong winds, and a record low sea-ice year locally. Conditions have not recovered in the two years since. Meanwhile, during the same three-year period, the nearby Dawson-Lambton colony, 55 km to the south, has seen a more than tenfold increase in penguin numbers. The authors associate this with immigration from the birds previously breeding at Halley Bay. Studying this ‘tale of two cities’ provides valuable information relevant to modelling penguin movement under future climate change scenarios.