WASHINGTON, April 8 (UPI) -- U.S. researchers say a mysterious disorder in penguin colonies on both sides of the South Atlantic is causing chicks to lose their feathers.
Researchers from the Wildlife Conservation Society and the University of Washington say "naked" penguins, afflicted with a condition known as feather-loss disorder, were first seen in Cape Town, South Africa, in 2006 in a wildlife rehabilitation center where around 59 percent of the chicks lost their feathers, a WCS release said Friday.
On the other side of the South Atlantic, researchers observed the same disorder in the chicks of wild Magellanic penguins at four sites along Argentina's coastline in 2007.
In both instances, penguin chicks with feather-loss disorder grew more slowly than feathered chicks because of increased energy spent in regulating body temperature in the absence of an insulating coat of feathers.
Scientists say they're unsure of the cause; possible suspects include pathogens, thyroid disorders, nutrient imbalances or genetics.
"The recent emergence of feather-loss disorder in wild bird populations suggests that the disorder is something new," said Mariana Varese of WCS's Latin America and Caribbean Program.
"We need to learn how to stop the spread of feather-loss disorder, as penguins already have problems with oil pollution and climate variation," P. Dee Boersma of the WCS said. "It's important to keep disease from being added to the list of threats they face."