A British Antarctic Survey (BAS) study from satellite maps reveals that there are twice as many emperor penguins (Aptenodytes forsteri) in Antarctica than previously thought . According to the researchers published in the journal PLoS ONE, they have used very high resolution satellite images (VHR) to estimate the number of penguins that make up each of the 44 colonies of this species scattered along the coasts of the white continent. Using a technique called pansharpening that increases the spatial resolution of digital satellite images, they were able to distinguish between birds, their shadows, and ice. And they have counted 595,000 emperor penguins, up from 270,000-350,000 expected. The populations are clearly visible to the satellite thanks to their black and white plumage, which stands out on the ice. "It is the first census of species carried out from space", explains geographer Peter Fretweel, co-author of the work.
The milestone is important considering that, in the coming decades, these penguins could become especially sensitive to climate change , and that with this method the impact of global warming on the species could be monitored periodically and with great precision. Above all, experts are concerned about how the progressive advance of spring at Earth's poles may affect them. The technique also offers the advantage of not having a negative impact on the Antarctic environment or on birds.
