Bats are dying by the tens of thousands every year, they fall to sleep and end up plopping to the ground by the hundreds, littering the floors of caves nationwide with bat carcasses with noses covered in a white substance. The culprit? (no, not cocain) A fungus by the name of Geomyces Destructans, a new form of cold-loving fungus that embeds itself insides bats during hibernation, and destroys them from the inside out.
Bats have very few predators and are very resistant to disease, they can even live over 20 years in the wild because of it. Over 1,100 species of bat presently populate this earth, they accounts for about 20% of all known mammal species. But this fungus can make the bat locally extinct in just a few years time, and devastate the bat population. According to Whitenosesyndrome.org:
Bats with WNS exhibituncharacteristic behavior during cold winter months, including flying outside in the day and clustering near the entrances of hibernacula.Bats have been found sick and dying in unprecedented numbers in andaround caves and mines. WNS has killed more than 5.7 to 6.7 millionbats in eastern North America. In some hibernacula, 90 to 100 percentof bats have died.
The main vectors for the fungus to spread to neighboring caves seems to be the bats themselves. And spores that caused the infection may remain inside the cave long after the bats have died out or left, and is also moving south-west at an alarming rate. But why are they dying out? Well, according to Earth Magazine's article on White Nose Syndrome: “One possibility is that the disease interferes with the delicate physiological balance of hibernation.” which may kill bats by forcing them to move about more, using up the fat stores that would otherwise have been used for their winter hibernation. It also erodes and digests the bats skin. Bats infected with the fungus will fly about during the winter, and crawl on the floor, very atypical for a hibernating bat, this dehydrates the bats, and causes hypothermia in the process.
[Scientists] do not yet know if the bats die as a result of the fungal infection or perhaps as a result of the interaction between the fungus and some other aspect of the environment. (Schmidt-french and Butler) Although research suggests it is the the main cause. (Altringham)
The good news, is that more research is being done on the disease, and more information is being spread about this. Larger bats hibernate for a shorter period of time, and they seem to be more able to withstand the brunt of the fungal attack. Bats are a vital resource for eliminating insects, therefore protecting crops, so bats being eliminated isn't a good sign for us.
I'll leave you to pursue this fast-moving topic, since anything I write will be rapidly out of date.
Earth Magazine June 2011
National Geographic December 2010
Altringham, John. Bats: From Evolution to Conservation. Second. Oxford Biology, 2011. Print.
Schmidt-french, Barbara, and Carol Butler. Do Bats Drink Blood. Rutgers University Press, 2009. Print.