Satellites used to count Antarctic penguins

Posted by Kate Taylor

Scientists have been able to count the number of emperor penguins in Antarctica by using satellite mapping technology - and there's twice as many as previously thought, they say.

It's the first time an entire species has ever been counted from space. Carrying out a census of the species in the usual way is, for obvious reasons, rather impractical. But the black-and-white birds stand out easily from their surroundings, making a satellite survey possible.

"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," says Michelle LaRue from the University of Minnesota Polar Geospatial Center.

"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."

The British Antarctic Survey (BAS) team used Very High Resolution (VHR) satellite images to estimate the size of each colony around the coastline of Antarctica.

They then applied a technique known as pan-sharpening to increase the images' resolution, allowing the scientists to distinguish between birds, ice, shadow and guano - penguin droppings.

"We are delighted to be able to locate and identify such a large number of emperor penguins," says BAS scientist Peter Fretwell.

"We counted 595,000 birds, which is almost double the previous estimates of 270,000 to 350,000 birds. This is the first comprehensive census of a species taken from space."

Current research indicates that colonies will be seriously affected by climate change, so the findings are good news. Indeed, the team located 44 emperor penguin colonies around the coast of Antarctica, of which seven were previously unknown.