Two of the settlements were a particular surprise. They were found far from shore, living on sea ice anchored to anchored icebergs, a place never before seen.
The new colonies are believed to have a few hundred penguins each, which is smaller than average, so the findings increase the total emperor penguin population by a smaller proportion of around 5-10%.
Emperor penguins are the only penguins to breed on ice floes rather than on land, making them particularly vulnerable to the climate crisis. All of the new settlements are in high-risk areas and researchers say they will be the “canaries in the coal mine” as global warming increasingly affects Antarctica.
” The [new colonies] are an exciting discovery, ”said Peter Fretwell of the British Antarctic Survey (BAS), who led the research. “While this is good news, the colonies are small and therefore only number just over half a million penguins.”
Philip Trathan, also at BAS, said: “The new breeding sites are all located in places where recent model projections suggest that emperor penguins will decline. So these birds are probably the canaries of the coal mine – we need to carefully monitor these sites as climate change will affect this region.
Fretwell said one of the settlements was 180 km from the Antarctic continent: “Many penguin scientists we spoke to were in disbelief, as you would normally expect them to be on the coast. Emperor penguins require stable sea ice, usually attached to the land, for nine months a year to breed successfully.
There were only 30 known colonies ten years ago, as they are usually found in remote and inaccessible places, where temperatures can drop to -50 ° C in winter. But then Landsat satellite imagery began to be used. These have a resolution of 30 meters, which is enough to spot the largest colonies.
The European Space Agency’s Sentinel-2 satellite was launched in June 2015 and has a resolution of 10 meters. This made it possible to search for the smallest penguin colonies, as BAS scientists reported in the journal Remote Sensing in Ecology and Conservation.
Emperor penguins were expected to be present at fairly regular intervals around the Antarctic coast, so research was targeted in areas where none were known. “In every hole where we thought there might be a colony, we found one,” Thretwell said.
Three of the 11 colonies found had been suspected following sightings of penguins by boat or plane in the 1960s and 1980s, but Sentinel-2 images confirmed their presence. There are now 61 known emperor colonies around Antarctica. “There might still be a very small settlement or two to uncover, but I think we’ve filled all the gaps now,” Thretwell said.
The next step is to direct the satellites with very high resolution 30 cm cameras over the colonies to allow penguins to be counted. “It’s dark right now in Antarctica, so we can’t count them yet,” Thretwell said. “The sun will come up later this month or next month in most of these places, and then we’ll start.”
Previous studies have estimated that 90% of known colonies will be lost by the end of the century if no further action is taken to reduce the greenhouse gas emissions that cause global warming. Even in the best of cases, where deep and rapid reductions in carbon emissions limit the rise in global temperature to 1.5 ° C, the emperor penguin population is expected to drop by 30%.