Scientists have reported the discovery of a supercolony of Adelie penguins in Antarctica which host more than 1.5 million birds.
Patches Of Guano Found In Pictures Taken From Space
Researchers located the previously unknown colony in the Danger Islands, a group of rocky islands on the most northerly point of Antarctic Peninsula. They found the penguin colony when great patches of the birds' guano, or poo, showed up in pictures taken from space.
Heather Lynch, from Stony Brook University in New York, said that prior to the discovery, the Danger Islands were not known to be an important habitat for penguins.
She said that among the reasons why these supercolonies have been undetected for decades are the remoteness of the islands and the treacherous waters surrounding them. The nearby ocean has thick sea ice even in austral summer, which makes the place difficult to access.
Lynch and NASA's Matthew Schwaller initially found telltale signs of guano in NASA satellite imagery of Danger Islands in 2014. This suggests a large number of penguins in the area, so they arranged an expedition to the island with the objective of counting the birds.
Members of the expedition team arrived at the island in December 2015. There, they found hundreds of thousands of penguins crammed in the rocky soil. They tallied up the numbers by hand and used a modified quadcopter drone to capture images of the entire island from above.
A neural network software was then used to analyze the images to search for penguin nests. The researchers also used a software to do the counting.
The survey revealed that Danger Islands is home to a total of 751,527 pairs of Adélie penguins, which include the world's third and fourth largest colonies.
"Not only do the Danger Islands hold the largest population of Adélie penguins on the Antarctic Peninsula, they also appear to have not suffered the population declines found along the western side of Antarctic Peninsula that are associated with recent climate change," said Michael Polito, from Louisiana State University.
Protection Of The Area Needed
The researchers said that the findings highlight the importance of protecting the area. These also provide evidence to support the proposed Marine Protected Areas near the Antarctic Peninsula.
"The Danger Islands appear to have avoided recent declines documented on the Western AP and, because they are large and likely to remain an important hotspot for avian abundance under projected climate change, deserve special consideration in the negotiation and design of Marine Protected Areas in the region," Lynch and colleagues wrote in the journal Scientific Reports.