English (Original)
The unique features of penguin poop have allowed scientists to make a remarkable discovery. The faeces of Adelie penguins, which live along the Antarctic coast and its islands, have a unique colour. They are bright pink due to the penguins’ diet, which consists largely of pink creatures called krill. They eat so much of it that their plentiful poop stains the ground on which they live, as well as their own bodies. Moreover, they produce so much poop that the pink stains can be seen from space.
This attribute has been useful for scientists studying these birds, as it has allowed them to locate colonies of penguins using satellite images. It isn’t possible to see individual penguins in satellite photos, but the pink stains are easy to identify. Scientists can even estimate the size of the colony from the size of the pink area.
Researchers using this method were, until recently, reasonably certain that they knew the whereabouts of all the Adelie penguin colonies on the continent. However, a colleague at NASA then developed an algorithm which automatically detected these stains, rather than finding them by human eye. The computer programme identified many more pink patches that the researchers had previously overlooked, particularly in the Danger Islands.
Researcher Heather Lynch admitted that the researchers had probably missed these colonies because they never expected to find them there. As the name suggests, the Danger Islands are difficult to get to and are almost always covered in sea ice. They are so small that they don’t even appear on many maps of Antarctica. However, once the researchers were aware of the colonies, they completed a full survey. They discovered 1.5 million penguins in this small area, more than in the rest of Antarctica.
Although this seems a large number, research findings suggest that it is lower than previous years. By studying satellite images from the past, which date back to 1982, the team were able to deduce that penguin numbers peaked in the late 1990s, and have since declined by 10-20%. Krill fishing is one of the main causes for the population decline of penguins in Antarctica, but because the Danger Islands are normally surrounded by sea ice, there is less human activity here than in other parts of the continent. This leads researchers to believe that the recent decline is due to other factors, such as climate change.
The scientists are now conducting research in the area to better understand the species and the long-term health of the colonies. One team, for example, is analysing the colour and content of the poop to investigate changes in the birds’ diet. This can show the extent to which penguins are affected by commercial fishing. Another is digging holes to learn more about the penguins’ past. By radiocarbon dating the bones and eggshells found in these holes, the team have discovered that the penguins have been inhabiting these islands since 2,800 years ago. By learning more about the penguin population of Antarctica, the team hopes to understand more about the impact of human activity on the natural world.