April 13 - The population of emperor penguins living in Antarctica is twice that of previous estimates, according to scientists using high-resolution satellite technology to track penguin colonies. Jim Drury reports.
A colony of emperor penguins in Antarctica. There are thousands of them..far too many to count by hand..... Which is why a team of international scientists have come up with a different, hi-tech approach - using high-resolution satellite imaging to track colonies across the difficult-to-navigate, ice-covered, continent. Using a technique known as pan-sharpening to increase image resolution, they were able to differentiate between birds, ice, shadow and guano - penguin faeces. Peter Fretwell of the British Antartic Survey led the team which spent an entire year mapping the penguin population. SOUNDBITE (English) PETER FRETWELL, GEOGRAPHIC INFORMATION OFFICER AT BRITISH ANTARCTIC SURVEY AND LEAD AUTHOR OF STUDY, SAYING: "We started by looking for the emperor colonies at locations. You can do this with course satellite image because the emperor penguins leave brown stains on the ice. They stay in one place for many months of the year and the ice around them gets rather dirty with their guano. Once we've found the locations we can send very high resolution satellites, spy satellites, to go and check the numbers. " The satellite images helped the team provide accurate estimates for each penguin colony around the Antarctic coastline. Ground counts and aerial photography were used to calibrate the analysis. The results were unexpected. SOUNDBITE (English) PETER FRETWELL, GEOGRAPHIC INFORMATION OFFICER AT BRITISH ANTARCTIC SURVEY AND LEAD AUTHOR OF STUDY, SAYING: "Our previous estimates suggested that there were about 300,000 adults on the continent and now we believe that there are about double that, about 600,000 emperor penguins in the world. So it's very important and it's a very significant increase." The explorers previously thought just 37 colonies existed in Antarctica, but found seven others that were previously unknown. The study should provide an important benchmark for monitoring the impact of climate change on the bird's population. Experts like Tom Hart, penguinologist for the Zoological Society of London, say the study's implications are far-reaching. SOUNDBITE (English) TOM HART, PENGUINOLOGIST FOR ZOOLOGICAL SOCIETY OF LONDON (ZSL), SAYING: "Currently we've had worrying trends about what penguins are doing in Antarctica, but really no large scale way of looking at them, so for the first time we can actually detail what is changing. As far as threats to penguins we're very concerned about climate change, fisheries, and the potential for introduced species that might introduce disease and things like that into Antarctica." Though delighted to discover that twice the number of emperor penguins roam the world's coldest continent, the team believes the species is still under threat. They say climate change will inevitably lead to a population decline...and that the satellite technology will merely allow scientists a clearer window through which to to observe it. Jim Drury, Reuters