Earth’s second-largest colony of emperor penguins is no more.

Peter Fretwell and Philip Trathan at the British Antarctic Survey in Cambridge, UK, use satellite images to keep tabs on Antarctica’s colonies of emperor penguins (Aptenodytes forsteri Gray). They watched through their eyes in the sky as the brown spots that marked the breeding colony in Halley Bay disappeared between 2015 and 2018.

The colony’s collapse stemmed from early break-up of the sea ice in that location, which is linked to El Niño weather patterns, and perhaps also to climate change. The birds are resourceful, however: the scientists report that, during the same 3-year period, there was a more than 1,000% increase in penguin numbers at the Dawson–Lambton colony, 55 kilometres to the south. This suggests that many adult birds had moved after experiencing one or more breeding failures.

The colony collapse and mass migration should be studied by those who want to learn how the species will react to changing conditions as the world warms, the researchers say.

Correction﻿: an earlier version of this story appeared with a picture of king penguins instead of emperor penguins.