”Naked” penguin chicks baffle experts
with their feather-loss disorder
The appearance of “naked” penguin chicks, which have been afflicted with a feather-loss disorder, have left scientists puzzled as to what could be causing the condition.
Researchers from the Wildlife Conservation Society, the University of Washington, and other groups are trying to figure out what is causing the disorder in penguin colonies on both sides of the South Atlantic.
The authors of the study are Olivia J. Kane, Jeffrey R. Smith, and P. Dee Boersma of the Wildlife Conservation Society and the University of Washington, Nola J. Parsons and Vanessa Strauss of the South African Foundation for the Conservation of Coastal Birds, and Pablo Garcia-Borboroglu and Cecilia Villanueva of Centro Nacional Patagonico.
“Feather-loss disorders are uncommon in most bird species, 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,” Boersma, who has conducted studies on Magellanic penguins for more than three decades, said.
“We need to learn how to stop the spread of feather-loss disorder, as penguins already have problems with oil pollution and climate variation.
“It”s important to keep disease from being added to the list of threats they face,” Boersma stated.
The feather-loss disorder first emerged in Cape Town, South Africa in 2006, when researchers for the South African Foundation for the Conservation of Coastal Birds (SANCCOB) first observed the disorder in African (or black-footed) penguins in a rehabilitation centre.
During that year, approximately 59 percent of the penguin chicks at the facility lost their feathers, followed by 97 percent of the chicks at the facility in 2007, and 20 percent of the chicks in 2008.
Chicks with feather-loss disorder, it was discovered, took longer to grow to a size deemed suitable for release into the wild. The chicks eventually began growing new feathers.
On the other side of the South Atlantic, researchers from WCS and the University of Washington observed feather-loss disorder in the chicks of wild Magellanic penguins (closely related to African penguins) for the first time in 2007 in four different study sites along Argentina”s coastline.
Researchers also noted that while feathered chicks sought out shade in the hot midday sun, featherless chicks remained in the sun”s glare. Several of the chicks with feather-loss disorder died during the study.
In both instances, penguin chicks with feather-loss disorder grew more slowly than feathered chicks. Featherless chicks were also smaller in size and weight than feathered chicks.
Both disparities were due to the increased energy spent in thermoregulation in the absence of an insulating coat of feathers and/or down.
So far, the possible causes 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,” Mariana Varese, Acting Director of WCS”s Latin America and Caribbean Program, said.
“More study of this malady can help identify the root cause, which in turn will help illuminate possible solutions,” she added.
A study on the disorder appears in a recent edition of the journal Waterbirds.
======================================================
No comments:
Post a Comment