Satellite Tracks Penguins From Space
Now, a new study has used technology to overcome the barriers of the Antarctic cold. Using a commercial satellite with Very High Resolution (VHR) images, scientists from the British Antarctic Survey have analyzed photos that show emperor penguin colonies across the remote regions of the Antarctic. With this satellite data, they are better able to estimate emperor penguin populations.
Lead author Peter Fretwell tells Decoded Science that this technology allows scientists to estimate population while avoiding the costs, complications, and invasiveness of a count on the ground. At the moment, the technology is best used in places where the animals contrast with their surrounding environment, since a computer is trained to recognize the difference between pixels with penguins and pixels without. However, the satellites do recognize wavelengths of light beyond the visual spectrum, and they could be used to examine ultraviolet to thermal images, potentially opening the use of the technology to a larger variety of habitats and animal populations.
Emperor Penguin Populations Are Larger Than Expected
The good news? The satellite photos show that emperor penguin populations are much larger than originally anticipated, with a population estimate of 595,000 birds. This reflects the fact that previous studies were done in the summer months, when penguins are more dispersed and harder to count, but temperatures and light make conditions more bearable for human researchers.
The Penguin in the Coal Mine: Emperor Penguins Are an Indicator Species
The bad news? Emperor penguins are interesting, not just for themselves, but for what they represent in the Antarctic ecosystem. The emperor penguin is an indicator of the overall health of the Antarctic sea ice. As the sea ice changes in response to climate change, the penguins’ environment is changing with it. If there is less sea ice for breeding, there will be potential competition from predators. Most importantly, there could be less food available to Antarctic animals. Fretwell explains that the penguins feed on fish, krill, and squid. As the sea ice cover changes, the krill are in particular danger, since they feed around the edges of the sea ice. Fretwell says that “Krill are the basis of much of the food web in Antarctica, and the penguin is the top of a broad food chain.”
Emperor Penguins: Iconic and Remote
The emperor penguin is a rare thing in this modern world. Unlike the tiger, the elephant, and other iconic animals that capture our imagination, these animals have never been hunted. They breed in a remote place in an extreme environment, and many have never seen a human being. Yet, their future will change as the planet’s climate changes, and since they are relatively unaffected by other human actions, the emperor penguin can act as an indicator species for the health of the Antarctic.
Fretwell, P., LaRue, M., Morin, P., Kooyman, G., Wienecke, B., Ratcliffe, N., Fox, A., Fleming, A., Porter, C., Trathan, P. An emperor penguin population estimate: the first global, synoptic survey of a species from space. (2012). PLoS ONE. Accessed April 15, 2012.
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