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Wing damage kills bats in white-nose syndrome
Science Fair: Science and Space News – USATODAY.com
Dec 15, 2010
Wing damage kills bats in white-nose syndrome

Recommend Wing damage may be the most lethal effect of a fungal infection ravaging bat populations across many states, federal biologists said Wednesday.

In a report in the journal, BMC Biology, a team led by Paul Cruan of the U.S. Geological Survey, assesses the “unprecedented” drop in bat numbers caused by “White-Nose” syndrome afflicting all six cave-hibernating species nationwide.

“Biologists estimate that more than 1 million bats have died, which far exceeds the rate and magnitude of any previously known natural or anthropogenic mortality events in bats, and possibly in any mammalian group,” says the report.

“The characteristic lesions associated with (White-Nose Syndrome) are caused by a newly described psychrophilic (cold-loving) fungus, Geomyces destructans, which also occurs on bats in Europe, but without the associated mortality.”

Although fungal spores invading the snouts of the bats remains the best known symptom of the syndrome,researchers suggest the infection causes bats to use up winter stores of fat, leading to their famished demise before Spring.

However Cruan and colleagues suggest that the damage it inflicts on wings may be the key to its 75% mortality rate.

“Healthy wing membranes are critical for maintaining water balance in bats. Bats are especially susceptible to dehydration during winter hibernation,” they write. “We hypothesize that wing damage caused by G. destructans could sufficiently disrupt water balance to trigger frequent thirst-associated arousals with excessive winter flight, and subsequent premature depletion of fat stores resulting in the emaciation associated with P(White Nose Syndrome).”

Afflicted bats are sometimes seen repeatedly eating snow and drinking from puddles, they note. And wing damage would hinder efforts to find food, due to impaired flight, they note.

The team compares the fungal disease to similar B. dendrobatidis infections in amphibians, linked to drops in frog populations:

“It took researchers decades to establish the causal link between skin infection by B. dendrobatidis and mortality in amphibians. A contributing factor to this delay was the challenge of demonstrating the potential significance of what appeared to be a superficial infection, and then documenting the magnitude of its physiological consequences. In addition, this novel fungal pathogen of amphibians belonged to a genus that was previously known only as a saprophyte that did not infect vertebrates – it was a new disease paradigm.

Infection of bat wings by G. destructans, also a member of a genus typically defined as saprophytes, may similarly represent a completely
new disease paradigm for mammals.”

By Dan Vergano

Source: http://content.usatoday.com/communities/sciencefair/post/2010/12/wing-damage-kills-bats-in-white-nose-syndrome/1