According to a study published in Global Ecology and Biogeography, reddish-brown patches of guano on the ice are visible in satellite images and provide a reliable indication of the colonies’ locations. British Antarctic Survey (BAS) scientists surveyed imagery of the sea ice surrounding 90 per cent of Antarctica’s coast and identified a total of 38 colonies, ten of which were previously undocumented. Of the previously known colonies, six had relocated and six weren’t found.

These missing colonies had previously been located at the same latitude as a colony studied in depth by French scientists whose research (also published this year) concluded that the penguin population there was at significant risk from a changing climate.

Emperor penguins spend a large part of their lives at sea, returning to their colonies during the Antarctic winter to breed on sea ice. Knowing their location provides a baseline for monitoring their response to environmental change. But gaining access to these remote colonies, where winter temperatures can drop to –50°C, is extremely difficult for researchers.

‘This is a very exciting development,’ said BAS ecologist Phil Trathan. ‘Now we know exactly where the penguins are, the next step will be to count [the population at] each colony so we can get a much better picture of population size. Using satellite images combined with counts of penguin numbers puts us in a much better position to monitor future population changes.’

November 2009