The little brown bat shares the bisons' plight. This time however, the hunter is no longer human. White-nose Syndrome, Geomyces destructans, a fungus newly introduced to America, is sweeping through little brown bat colonies, and has killed more than a million bats since it was first discovered five years ago. Bats in nineteen states have been diagnosed with White-nose Syndome (WNS), and it only continues to spread. The survival rate of the disease is scarily low: less than ten percent of infected bats live. The truly scary part? We have no idea what we can do to stop it.
In February of 2006, forty miles west of Albany, N.Y., White-nose Syndrome was first observed in a single cave. The following winter, the New York Department of Environmental Conservation took interest in cases of erratic bat behavior, strange white substance on bats, and hundreds of dead bats. In January of 2007, White-nose Syndrome was documented, and it was confirmed that it was responsible for mass die off of bat populations.
White-nose Syndrome is not directly responsible for the death of the bats. When bats are hibernating, WNS disrupts them, causing them to awaken, and fly around, thinking that it’s spring again. Since the energy consumption of bats is decreased while in hibernation, waking up too many times burns too much of the bats’ fat reserves, causing them to starve before the winter is over. Unfortunately, the ideal conditions for WNS are the same conditions that bats prefer to hibernate at.
The origins of White-nose Syndrome are no secret. WNS is widespread in Europe, appearing in countries across the continent and affecting a large percentage of bats. However, the death rate of bats in Europe is significantly lower than that of bats in America, suggesting that genetic resistance has developed to the disease in Europe. However, WNS has probably been around for centuries or millennia in Europe, meaning that bats may have needed a long time to develop a resistance. Perhaps a mutation causes the immune systems of European bats to respond to WNS faster, or maybe bats that hibernate at a slightly different temperature have been naturally selected for over time.
A question of vital importance remains: why do bats matter? Of course, the loss of species is a horrible tragedy, but eradicating WNS will be a time consuming, expensive process. In a time when the economy is in a period of rapid fluctuation, investing in a species of animal that most people have never seen sounds a bit odd. To many, bats are no better than mice, invading attics and flying in through open doors. Bats fill a vital ecological niche perfectly though, and it is a task none other could take over. In a single night, little brown bats typically eat at least half of their body weight in insects. While there is no accepted method of putting a price on this service, we know that bats are the primary predator of many crop damaging insects.
So, what can we do about it? There are chemicals that kill WNS quickly, but applying these fungicides to every bat that is infected would be impossible. In addition, chemicals could disrupt other species of fungi that live in caves. Culling has been proven as ineffective; primarily because WNS can be spread by many methods, so culled bats may have already passed on the fungus. The problem is that WNS is still a mysterious organism. Little is known about the way it passes from cell to cell, and how well it will respond to changes in the climate that bats hibernate at.
Bats reproduce incredibly slowly; a little brown bat population increases at a rate of .008 percent per year. WNS is destroying the colonies because of its high death rate. We have to be careful also. If a chemical treatment that kills the fungus also kills more bats than are born, we will just be taking the place of WNS.
Federal funding for work to help the bats is scarce, but individuals still press on. Many research projects are being led to determine what can be done to help infected caves, prevent new caves from being infected, and to understand WNS better. One thing is certain: we need to work fast. It is possible, even probable, that the entire population of little brown bats will be decimated within a century, leaving only the few individuals who have a genetic mutation that allows them to withstand the fungus. The little brown bat is only the start though, there are forty-seven species of bat in the United States alone, and who knows how many will be susceptible to WNS?
The American Bison is on its way to becoming a common animal. Lets hope that bats stay that way.
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