BAT report I:
by Heather of thebluewindmill
Big-eared Townsend Bat © thebluewindmill
"It's a horror story -- but it's all too real. White-nose syndrome has devastated bat populations along the East Coast -- and this lethal infection is spreading. Biologists estimate that more than 1 million bats have fallen victim to this deadly fungal disease” Defenders of Wildlife
Madeline Bodin, a writer from Vermont who specializes in natural sciences, reports the spread of the disease in her article for Defenders Magazine, Fall 2010, titled Flying in the Dark. She reports that regional director of the U.S. Fish and Wildlife Service’s northeast region, Marvin Moriarty, has seen the disease first hand. The most prominent symptom is the fuzzy white mustache that the infected victims wear. In 2006, it started with New York, Vermont, Massachusetts, and New Hampshire, then encompassed New Jersey, Pennsylvania, Virginia, and West Virginia. In the spring of 2010, the disease spread to “Maryland, Tennessee, Missouri, Oklahoma and the Canadian provinces of Quebec and Ontario”.
“More than a million bats in the eastern United States are estimated to have died since white-nose syndrome was first detected in 2006”. The white fungus is the most obvious symptom but it is not the cause.
Microbiologist, David Blehert, at the U.S. Geological Survey’s National Wildlife Health Center in Madison, Wisconsin, noticed a pattern in 10 out of a 100 bats that were analyzed, and found “the same unusual, unknown fungus growing in their skin. Further tests showed that the fungus was found everywhere white-nose syndrome was found, but not where the syndrome wasn’t present.”
"It’s very unusual for a fungal infection to make a warm-blooded animal sick" Blehert says. Fungi that live on the skin of warm-blooded animals are called dermatophytes. A typical dermatophyte is athlete’s foot. Generally these fungi stay in the top-most layer of skin, and while itchy, rarely kill their hosts.
Little Brown Bat with White-nose © USFWS
This fungus Blehert discovered, however, is different. It grows right through the dead skin cells of the epidermis into the living cells of the dermis below. Further, this fungus loves the cold. It grows best in temperatures between about 41 to 50 degrees F and doesn’t grow at all at temperatures above 70 degrees. This fungus would never grow on human skin. It’s too warm. But, Blehert notes, during hibernation: "bats’ body temperatures drop to within a degree or two of the temperature of the cave they are hibernating in, a temperature range that brings them within the fungi’s growth range.”
When Marvin Moriarty investigated Greeley Mine in Stockbridge, Vermont he found that the bats did not have the white fuzzy fungus above their noses; instead he found bats that were “nailed to the side of the cave with the mycelium of the fungus attaching them to the cave wall. It was on their abdomens, on their wings, it was everywhere.”
“What Jonathan Wood, secretary of the Vermont Agency of Natural Resources remembers most is the pile of tiny, toothpick-like bat bones that littered the cave floor. Trained as a forester, Wood knew bones like that don’t last long in the wild. This was a fresh tragedy. As much as he knew about white-nose syndrome before visiting the mine: "It doesn’t sink home until you see the results right there in front of you" Wood said".
"Every bat eats up to half its body weight in insects each night. The loss of a million bats means that billions of flying insects—mostly moths and beetles, but also mosquitoes—have gone uneaten. Some of those moths and beetles are crop pests, meaning that farmers will have to use more pesticides or grow less food. As the syndrome spreads south, entire bat species are at risk of extinction.”
"White-nose syndrome is causing one of the most precipitous wildlife declines in North America in the last century" says Nina Fascione, former vice-president for field conservation programs at Defenders of Wildlife. "I can’t overstate how huge it is. There will be significant environmental and economic consequences."
To read this article in full and to discover what scientists are doing to slow the spread of the disease, check it out on the Defenders of Wildlife website HERE.