 New penguin super-colony spotted from space Washington (UPI) Mar 2, 2018 - Scientists have found another 1.5 million penguins living in Antarctica. Ecologists had grown concerned in recent years as they counted fewer and fewer Adélie penguins, once the most abundant species in Antarctica. It turns out, population surveys were ignoring a super-colony just off the coast of the Antarctic Peninsula's northern tip. With the help of satellite images, scientists were able to locate 1.5 million Adélie penguins congregating on a remote, jagged outcropping of islands known as the Danger Islands. "Until recently, the Danger Islands weren't known to be an important penguin habitat," Heather Lynch, an associate professor of ecology and evolution at Stony Brook University, said in a news release. Satellite images of the island chain didn't reveal penguins themselves, but researchers were able to pick out the telltale signs of a large colony, large guano stains. Inspired by their discovery of seabird excrement, researchers set off in search of the birds themselves. In 2015, a research ship delivered a team of scientists to the islands. The team used a drone to help them survey the islands. "The drone lets you fly in a grid over the island, taking pictures once per second. You can then stitch them together into a huge collage that shows the entire landmass in 2D and 3D," said Hanumant Singh, professor of mechanical and industrial engineering at Northeastern University. Singh helped scientists developed the imaging software. He also designed algorithms to scan the collected images and identify the location of penguin nesting sites. Ice loss and rising temperatures are a threat to penguins in both the Arctic and Antarctica, but the latest discovery suggests some colonies and their habitats remain resilient. "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, a researcher at Louisiana State University. Additional surveys of the Danger Islands and the penguins that live there could help scientists better understand what makes the habitat there more desirable. "The population of Adélies on the east side of the Antarctic Peninsula is different from what we see on the west side, for example," said Stephanie Jenouvrier, a seabird ecologist at Woods Hole Oceanographic Institute. "We want to understand why. Is it linked to the extended sea ice condition over there? Food availability? That's something we don't know." Scientists detailed their discovery of the new super-colony in a new paper published this week in the journal Scientific Reports.
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A thriving "hotspot" of 1.5 million Adelie penguins, a species fast declining in parts of the world, has been discovered on remote islands off the Antarctic Peninsula, surprised scientists said Friday.
The first bird census of the Danger Islands unearthed over 750,000 Adelie breeding pairs, more than the rest of the area combined, the team reported in the journal Scientific Reports.
The group of nine rocky islands, which lie off the northern tip nearest South America, in the northwest Weddell Sea, housed the third- and fourth-largest Adelie penguin colonies in the world, they found.
"It is certainly surprising and it has real consequences for how we manage this region," study co-author Heather Lynch of Stony Brook University told AFP.
Just 160 kilometres (100 miles) away on the west of the peninsula -- a thin limb jutting out of West Antarctica -- Adelie numbers have dropped about 70 percent in recent decades due to sea ice melt blamed on global warming.
"One of the ways in which this is good news is that other studies have shown this area (the eastern side of the Antarctic Peninsula) is likely to remain more stable under climate change than the western Antarctic Peninsula," said Lynch.
"So we end up with a large population of Adelie penguins in a region likely to remain suitable to them for some time."
Adelies are one of five penguin species that live in and around the Antarctic continent.
A medium-sized penguin, they grow to about 70 centimetres (almost 28 inches) tall, and weigh three to six kilogrammes (about seven to 13 pounds). They are identified by a white ring around the eye.
They are carnivores, and krill -- shrimp-like creatures that are commercially fished in the area -- is an Adelie staple.
The Danger Islands group was discovered thanks to Earth-monitoring satellites, said the research team from America, Britain and France.
"This is called the Danger Islands for a reason," said Lynch.
"The area is covered by heavy sea ice most of the year, and even in the height of summer it is difficult to get into this region to do surveys."
- 'Very lucky' -
Even the most visited of the isles, Heroina Island at the chain's northeastern tip, receives only about one ship landing per year.
Evidence of the previously-unknown penguin colony first emerged in data from the Landsat Earth-monitoring satellites run by NASA and the US Geological Survey.
Lynch and her team "then went and looked at higher resolution commercial imagery to confirm the guano staining that our algorithms had picked up in the Landsat imagery," she said.
When the Landsat data originally suggested the presence of hundreds of thousands of penguins on the islands, she thought it "was a mistake".
"We were surprised to find so many penguins on these islands, especially because some of these islands were not known to have penguins."
Then followed a field expedition for a census using a combination of drone footage, pictures taken on the ground, and an old fashioned walk-about headcount.
"We were... very lucky to have a window of time where the sea ice moved out and we could get a yacht in," said Lynch.
The Danger Islands, said the team, has felt the ravages of climate change less than the western peninsula, and knew very little human activity.
Now it turns out, the area may need stronger protection from overfishing.
"The most important implication of this work is related to the design of Marine Protected Areas in the region," said Lynch.
"Now that we know this tiny island group is so important, it can be considered for further protection from fishing."
In addition to Adelies, the team also found about 100 nests of gentoo penguins, and about 27 nests of chinstrap penguins.
The polar regions are warming more rapidly than the rest of Earth as heat-trapping greenhouse gasses from fossil fuel-burning build up in the atmosphere.
Related Links
Beyond the Ice Age
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