A new census from space shows that Antarctica is home to twice as many emperor penguins than the scientific world previously thought.
The new 595,000-bird count was coauthored by researchers from the University of Minnesota Polar Geospatial Center. Using very high-resolution images from satellites, Michelle LaRue, a research fellow and co-author, analyzed the continent's far reaches from the comfort of campus.
Before, to estimate emperor penguin populations, "you had to literally go to each colony and take aerial photographs or be on the ground and count them," LaRue said. That was labor intensive, expensive and, for the most remote colonies in weather that reaches 50-below, downright impossible.
In fact, the new study found four colonies previously unknown to scientists and confirmed the existence of three "suspected" sites, bringing the total to 46. Spotting the new ones within image after image of expansive white was thrilling, LaRue said.
"It's a frantic feeling," she said. "You zoom in and try to look at the best resolution possible. Is it a colony? Or a rock outcrop?"
Zooming in, the researchers, with the help of a computer algorithm, distinguished between penguins, their shadows and their poo.
Now, with an accurate count, scientists will be able to better monitor the penguin population over time, analyzing how this essential species is being affected by global warming, LaRue said.
"We already know that one colony has been lost due to lack of sea ice," LaRue said. "Now we will be able to start to see fluctuations in certain locations and ask, 'Why is that population going up or down?'
"It will inform what kinds of questions we should be asking."
Since the study's publication in the journal PLoS ONE, LaRue has been inundated with calls.
"If I've learned anything in the last week and a half," she said, "it's that people love penguins."
Jenna Ross • 612-673-7168