Goal: Declining bats- White Nose Syndrome

In the past five years there has been a major decline in the bat population of Pennsylvania. (it is also a problem across the northeast coast from New Hampshire to Tennessee) More recently, WNS is spreading to states in the Midwest; Indiana reported their first case in February 2011. It is also now being reported in Canadian provinces such as Ontario, Quebec, New Brunswick, and most recently Nova Scotia. White nose syndrome was first discovered on February 16th2006 and is the main cause of bat deaths. Over a million bats are estimated to have died already.

Spread of WNS, June 2011

The first findings of White Nose Syndrome was in Howes Cave, New York. Symptoms include white fungus over the nose, wings, and skin of bats, and erratic behavior such as leaving hibernation early and dying in the cold. The fungus replaces hair follicles and evades the skin .. In a study conducted in 2008, 69 out or 105 bats with the infection lost their fat reserves, which is crucial for hibernation. The sickness also causes bats to arouse more frequently and lose fat, which is stored during hibernation to keep them alive. With white nose syndrome, bats awake every 3-4 days, rather than the normal 10-20 days. The bats leave the cage and fly in freezing weather seemingly to seek out water sources. The fungus spreads from bat to bat, but it is also believed that humans can carry the bacteria from cave site to cave site. Bats which are more prone to WNS are species sensitive to water loss. The most common cause of death is the infection itself, but other causes related to the fungi include starvation, dehydration, and exposure to cold temperatures. (fws.gov/whitenosesyndrome/pdf/WyomingWNSStrategicPlan2011.pdf)

The bat species in Pennsylvania include the Big Brown Bats, tri-colored bats (Eastern pipistrelle), Hoary bat, Indiana bat, Little Brown bat, Northern Long Ear bat, Eastern red bat, Silver-Haired bat, and Small-footed bat. WNS has been the most destructive among the little brown bats species. There has been a 93% decline of this species (batconservation.org). The lifespan of a Little Brown bat can go up to 25 years. The Indiana bat has already been distinguished as an endangered species before WNS, only surviving in a handful of caves in the Northeast. However with WNS, the bats’ mortality rates are increasing and are close to becoming extinct.  In Pennsylvania there has been a 90% decrease in four native species. After three years there were 50 remaining bats out of 23,000 in Mifflin County PA (readingeagle.com).

Bats are an important link in the food chain as they keep insects in check. Mosquitoes, one of the most unpopular insect types, are devoured by bats. It is estimated that one bat can eat between 600-1000 insects within an hour. Bats are the most dominant predator of night insects, and also eat moths and beetles. With the bat population dwindling, the insect population will rise and become harder to control. One million fewer bats means there are between 660 and 1320 metric tons of insects that have gone uneaten per year. Bats help with agriculture by eating insects, which control crop damage. They are also important to pollination and the sowing of seeds. Lastly, bats are an important energy source for cave life. The effect it can have on the ecosystem and food chain can become a lot more serious if WNS persists.

The intensity of WNS is affected by the method and place of hibernation per species. Some bats choose warmer environments or dense clustering. Studies now reveal it will take hundreds of years to repair the damage that WNS has done to the bat population. Bats also procreate slowly which stunts the growth of the population. Each year from June to July only one baby bat is born to each female.


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