Puzzling New Disease in Bats Has Been Identified

For spelunkers and students of nature, it is common knowledge that bats are vital to the balance of the earth's ecosystem. These carnivorous little creatures consume about half of their body weight each night in insects (except in winter when they hibernate). Bats are a very efficient and necessary form of insect pest control. And contrary to rumors, bats are no more likely to carry rabies than squirrels or other wild animals.

A new bat disease was documented in February, 2006 in a small cave near Albany, New York. The caver took photographs of the bats with the strange white fuzz on their muzzles. The US Fish and Wildlife, Bat Conservancy International, and other agencies and groups launched efforts to identify the disease. As the scope of its reach was discovered, more people became involved in trying to control the spread. The disease is a fungus, and was named White-Nose Syndrome (WNS). The most recent information from spring of 2009 estimates that over a million small insect-eating bats have died from WNS in the three years since it was found. That is 95% of the entire bat population in the New England areas where the fungus currently exists. So far, six species of bats have been affected. The impact of this loss of bats will be noticed by a greater use of pesticides in agriculture, and human issues with direct contact of the increased insect populations will no doubt follow.

The fungus was only recently identified as a new strain of fungus, Geomyces destructans. The fungus was isolated through post-mortem examinations of bats collected from infected sites. The previously unidentified genus was genetically coded and named. The fungus is not like most fungi, which require warmer temperatures for growth. Geomyces destructans reaches optimal growth in cool temperatures of around 40°-50°F. The temperature in many caves and mines is near this range, making them perfect incubators for the fungus.

WNS appears as whitish fuzz on the bats' little muzzles, and it spreads to the skin of their ears and wings. They become disoriented and display abnormal behavior patterns. WNS seems to interrupt the bats' hibernation, causing them to awaken and fly out in the dead of winter, often in daylight. These episodes may occur several times throughout the winter. The interruptions of hibernation use up a great deal of the bats' stored energy. Of course, there is no insect activity this time of year, and the bats cannot replenish their fat reserves. Bats with WNS are found to have no fat reserves when they die, indicating that they are, in essence, starving to death before springtime.

Individual cave ecosystems exist in an extremely delicate balance. Trying to eradicate the fungus by using any kind of fungicide, even an organic/natural one, would introduce all kinds of unnatural matter into the cave. This kind of treatment would certainly have an adverse affect on other life in the cave, and experts are in a quandary about how best to proceed. The focus for now is mainly on controlling the spread. As the fungus moves westward, caving clubs and state agencies are voluntarily closing caves in 2009 in an attempt to prevent the spread of WNS. Caves have been closed in Virginia, North Carolina, Tennessee, Kentucky, Indiana, and the bat populations in these states are being closely monitored. The endangered Indiana Bat, which has recently seen modest population increases, is one of the species affected by WNS.

You can check the US Fish & Wildlife website where updates of WNS information are made regularly. http://www.fws.gov/northeast/white_nose.html

Also: http://www.cavebiota.com/wns.htm