Penguin poo stains expose emperors' icy homes
BONN, Germany (Reuters) - Ten new colonies of emperor penguins have been found in Antarctica after satellite photos showing brownish stains on the ice turned out to be the excrement of thousands of birds.
The findings, revealed by the British Antarctic Survey (BAS) on Tuesday, will help understand penguin populations and the vulnerability to global warming of the breeding colonies which are on sea ice.
"We now reckon there are 38 colonies in Antarctica, 10 of them previously unknown," Phil Trathan, a BAS penguin ecologist, told Reuters of the study in the journal Global Ecology and Biogeography.
"That's potentially a massive change in the 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.
Experts had previously listed 34 colonies of emperor penguins -- the discovery of 10 new colonies was offset by the fact that experts failed to find six colonies previously listed.
It was unclear if those colonies had vanished or if they were wrongly plotted on old maps. Six other colonies had also moved locations since they were first recorded.
"We can't see actual penguins on the satellite maps because the resolution isn't good enough. But during the breeding season the birds stay at a colony for eight months. The ice gets pretty dirty and it's the guano stains that we can see," BAS mapping expert Peter Fretwell said in a statement.
Trathan said British, U.S., French and Australian experts were using more powerful imagery to try to count emperor penguins -- perhaps the only species of bird that never puts feet on land.
Until now, estimates have been of about 200,000 to 400,000 breeding pairs of emperor penguins, plus thousands of juveniles and non-breeders.
Emperors breed on ice in the depths of the Antarctic winter laying their eggs in late May and early June when temperatures plunge to about -50 Celsius (-58.00F).
The males incubate the eggs in the dark, huddling together without food, their backs to the bone-chilling winds. The females trek around 100 km (60 miles) to the sea and return with food in the spring to take over care of the chicks.
Emperors may be vulnerable to climate change with sea ice breaking up earlier in spring, exposing chicks to water before they can fend for themselves.
More ice could also be damaging, making the penguins' treks to the sea longer. About 180 governments are meeting in Bonn from June 1 to 12 to work on a new U.N. climate treaty.
(Editing by Jonathon Burch)