Before they can grow into their full tuxedo splendor, many penguin chicks are losing their suit coats. Strangely, featherless penguins have been popping up on both sides of the Atlantic Ocean in the last few years.

But these bare birds are no laughing matter. A penguin without feathers is a cold penguin, and these lovable birds currently face numerous threats to their survival. The feather-loss disorder has already taken lives. WCS researchers and partners are working to uncover what is causing the condition and whether it is the same disorder jumping between penguin species.

“The recent emergence of feather-loss disorder in wild bird populations suggests that the disorder is something new,” said Mariana Varese, acting director of WCS’s Latin America and Caribbean program. “More study of this malady can help identify the root cause, which in turn will help illuminate possible solutions.”

Since 2006, conservationists have been finding young penguins without a feather to their name. The disorder first emerged at a wildlife rehabilitation center in Cape Town, South Africa. Among the African penguin chicks (also called black-footed penguins) at the facility, 59 percent lost their feathers. The following year, 97 percent of chicks had the disorder, and in 2008, the numbers dropped to 20 percent.

Meanwhile in South America, WCS researchers found featherless Magellanic penguin chicks at four different areas along the Argentine coast in 2007. The scientists observed how the disorder affected the birds’ behavior and their growth. They saw that while healthy, feathered chicks sought shady refuge from the hot midday sun, featherless chicks remained in the sun’s warm but harmful glare.

Unfortunately, several chicks stricken with the disorder died during the course of the study.

“Feather-loss disorders are uncommon in most bird species,” said Dee Boersma, who has conducted studies on Magellanic penguins for more than three decades. “And we need to conduct further study to determine the cause of the disorder and if this is in fact spreading to other penguin species.”

So far the possible culprits include pathogens, thyroid problems, nutrient imbalances, or genetic disorders. African and Magellanic penguins are close relatives. On both continents, the scientists have found that chicks with feather-loss disorder grow more slowly than their downy counterparts. Eventually, the chicks that survive grow new feathers.

 “We need to learn how to stop the spread of feather-loss disorder, as penguins already have problems with oil pollution and climate variation,” said Boersma. “It’s important to keep disease from being added to the list of threats they face.”  

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