April 15, 2012
Researchers Track Emperor Penguins From Space
Thanks to new technology, a study reveals there to be twice as many emperor penguins in Antarctica than had previously been estimated. The study will be used as a benchmark to understand the effects climate change is having on these flightless birds.
Published this week in the journal PLoS ONE, an international team of scientists reports how they used a Very High Resolution (VHR) satellite images to estimate the size of the emperor penguin communities.In order to distinguish the birds from shadows on the ice the researchers actually tracked the bird´s poo, using a technique known as pan sharpening which increased the resolution of the images. Then, they combined counts of the penguin population done on the ground as well as other images shot from the air to calibrate their VHR images.
Since penguins live in some very difficult regions to study within, with temps as low as –50 Celsius, the chilly scientists are excited about the possibility to be able to monitor their population remotely via VHR.
The scientists were also quite pleased to discover a healthy and thriving population of penguins.
Geographer Peter Fretwell at British Antarctic Survey (BAS) was the lead author of this study. Speaking to the UK´s Natural Environment Research Counsel (NERC), Fretwell said, “We are delighted to be able to locate and identify such a large number of emperor penguins. We counted 595,000 birds, which is almost double the previous estimates of 270,000 - 350,000 birds. This is the first comprehensive census of a species taken from space.”
Decked in black and white dress, the penguins were easy to distinguish amidst the ice, thanks to pan-sharpening and the VHR. The team was able to distinguish separate colonies, analyzing up to 44 emperor penguin colonies around the coast of Antarctica. The team even found 7 colonies which were previously unknown.
Co-author Michelle LaRue from the University of Minnesota expressed her excitement over the findings, saying this study advances the level of study conducted in her field. “The methods we used are an enormous step forward in Antarctic ecology because we can conduct research safely and efficiently with little environmental impact, and determine estimates of an entire penguin population,” said LaRue.
“The implications of this study are far-reaching: we now have a cost-effective way to apply our methods to other poorly understood species in the Antarctic, to strengthen on-going field research, and to provide accurate information for international conservation efforts.”
Scientists had been concerned an early spring warming could lead to the loss of sea ice, thus pushing the southern colonies further north and leaving them more vulnerable to any further climate change.
BAS biologist Dr. Phil Trathan expects to see the emperor penguin colonies affected by climate change. By taking frequent consensus of the penguins, the international team will be able to see in what way these birds are being affected.
Says Dr. Trathan, “Whilst current research leads us to expect important declines in the number of emperor penguins over the next century, the effects of warming around Antarctica are regional and uneven. In the future we anticipate that the more southerly colonies should remain, making these important sites for further research and protection.”
Image Caption: On the ice, emperor penguins with their black and white plumage stand out against the snow and colonies are clearly visible on satellite imagery. Credit: Paul Ponganis, National Science Foundation