Penguin poop stains on Antarctic can be seen by SATELLITES
Researchers are tracking penguins in Antarctica with the help of their poop stains.
Adélie penguins in Antarctica nest in big colonies, leaving behind large poop stains (known as guano) on surface ice that can be seen by satellites in space.
Researchers are using these NASA satellite observations, along with field studies, to compile an online database that tracks Adélie penguin populations in Antarctica.
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This true-color image, acquired by the Enhanced Thematic Mapper Plus on NASA’s Landsat 7 satellite on December 4, 2002, shows part of Antarctica’s Luitpold Coast, with penguin poop (guano) stained ice visible
Researchers have been tracking these penguin guano stains for more than 30 years using NASA's Landsat satellites, allowing them to find previously unknown colonies.
Areas with guano stains tend to have a pinker color than exposed rock without guano.
Researchers based at Stony Brook University developed an algorithm which works by sampling the rocks at known penguin colonies and then flagging the same colors in parts of Antarctica where researchers haven't been.
ADÉLIE PENGUINS Adélie penguins find their meals in the sea, feasting on krill and fish. They live in colonies, and breed between October and February. In 2010, the arrival of an iceberg called B09B disrupted the hunting habits of Adélie penguins at Cape Denison in Commonwealth Bay, East Antarctica. Pictured is a young Adelie penguin standing on a rock in the Antarctic Peninsula Expansion of ice as a result of the iceberg cut off access to the sea by more than 59.5 kilometers (37 miles). This forced the penguins to have to travel much farther for food, which the research team suggests has led to a dramatic collapse in the population. Others, however, speculate that the colony may have moved somewhere else.
The data from the NASA satellites, along with finer resolution commercial satellite imagery and information collected from field expeditions, have helped create an online database to track the penguins.
Some of the biggest colonies discovered with the satellite data are in Antarctica's Danger Islands, which are small, remote islands off the northern tip of the Antarctic peninsula which have rarely or never been surveyed because sea ice cover makes them difficult to travel to.
Pictured is a satellite image of the Islands off the north Antarctic Peninsula. Penguin poop (guano) stains are outlined in yellow. Adélies need exposed, relatively flat rock to nest, which may explain why the stains on the jagged landscape of Darwin Island are smaller than others
Researchers have been tracking these penguin guano stains for more than 30 years using NASA's Landsat satellites, allowing them to find dozens of previously unknown colonies. Pictured is a natural color satellite image of the north Antarctic Peninsula
The researchers used their algorithm-based technique to identify 166,000 penguins on Brash Island, 23,000 on Earle Island, and 7,000 on Darwin Island that were not previously accounted for.
Adélie penguins need exposed, mostly flat rock to nest, which could explain why the strains on the landscape of Darwin Island are smaller than others.
While Adélie penguins are mostly responsible for the stains, there may be guano stains from other species of penguin as well - such as Chinstrap and Gentoo penguins.
Stretches of excrement-stained ice that are so large they are visible from space have helped researchers locate Adelie penguin populations. This particular guano stain belongs to emperor penguins. The guano tends to have a a pinker colour than exposed rock without guano
Since Adélie penguins cannot survive without sea ice, many researchers see them as a sensitive species that could face rapid population changes if Antarctic sea ice retreats because of climate change
Since the size of each pixel in a Landsat satellite image is equivalent to a 30 meter by 30 meter square (322.9 by 322.9 square feet), the technique isn't always able to detect small colonies.
Therefore, by comparing the satellite algorithm images with field observations, along with commercial satellite images (usually one meter by one meter squares, or 10.7 by 10.7 square feet) the researchers can detect smaller colonies, with fewer than 3,000 breeding pairs.
The researchers used their algorithm-based technique, which focuses in on penguin guano, to identify 166,000 penguins on Brash Island, 23,000 on Earle Island, and 7,000 on Darwin Island that were not previously accounted for. These Islands belong to the Danger Islands
Most penguins live in large colonies, and the algorithm is able to detect 97 per cent of penguins.
'We’re far from a point where satellites are going to make field work irrelevant,' said Dr Heather Lynch, an ecologist at Stony Brook University who works on the penguin research.
A recent satellite-based study of Adélie penguins found that populations have decreased near the Antarctic Peninsula but have increased in East Antarctica
'Instead, it has made fieldwork more efficient.
'We can plan expeditions to target colonies of high interest, and satellites have made expeditions much safer because we know so much more about what to expect.
'There is a nice synergy between satellite-based surveys and field surveys that I expect will be the status quo for a long time.'
Since Adélie penguins cannot survive without sea ice, many researchers see them as a sensitive species that could face rapid population changes if Antarctic sea ice retreats because of climate change.
A recent satellite-based study of Adélie penguins found that populations have decreased near the Antarctic Peninsula but have increased in East Antarctica.
The Antarctic Peninsula lost a large amount of ice over the past three decades, while the opposite happened in East Antarctica.