population."

Experts studying images taken from space were initially baffled by reddish-brown splodges on the ice.

"It turned out they were the feces, guano stains, of the emperors," Trathan said. "There's a really good contrast between the dark poo stains and the ice."

Scientists widened the search for the tell-tale blots to 90 percent of the Antarctic coastline and found 38 colonies.