Smithsonian Channel Documentary

Due to the importance of bats to their environment and the severity of White Nose Syndrome, the Smithsonian Channel has recently produced a documentary regarding White Nose Syndrome in Little Brown Bats called "Killer in the Caves". 

Below is a link to the Smithsonian Channel's website and page about the documentary as well as a schedule of when it will be aired next.

http://www.smithsonianchannel.com/site/sn/show.do?show=3374278

Here's a sneak peak at what the documentary is about:

Bat Houses!

A great way to support bat populations is to provide supplemental housing for them, especially in areas where their natural habitat is being destroyed.  Bat houses are relatively simple to make and can be placed in your backyard to encourage them to roost there instead of in your gutters, attic, or chimney.  Bats are a great asset to have in your backyard because they work as natural pest removers!  Bats like tight and warm spaces and they like it to be 80 to 100 degrees in July when they have their young with them. The bat houses should be placed in the sun and around 12 to 15 feet off the ground to prevent predators from getting them.

For plans to make your own bat house visit:
http://www.eparks.org/wildlife_protection/wildlife_facts/bats/bat_house.asp 
http://www.batcon.org/pdfs/bathouses/SingleChamberBHPlans.pdf 
http://www.batcon.org/pdfs/bathouses/FourChamberNurseryHousePlans.pdf

To order a bat house visit: 
http://www.lonestarwoodcraft.com/ 

Why are bats so important?

Very often bats are seen as disgusting, horrifying creatures that will get caught in your hair and suck out your blood.  The great thing is-none of that is true! Bats are such great flyers that there is no chance they will end up on a persons head, let alone tangled in your hair.  Only 4 species of bats drink blood and none of these species are found in the United States.  Bats are actually quite shy and very good mothers.  So, why are people so afraid of them? Is it because they are rarely seen and even less understood?  Bats are very beneficial to the environment and, as mentioned in the previous video, they even help stimulate the economy.  Here are some ways that bats work to help improve their environment. 

• Many types of bats are insect-eating and keep pests under control. It is estimated that bats save farmers over 3.7 billion dollars every years by eating crop-killing insects. Some types of bats can eat over 1,000 insects per hour!

• Among birds, bees, and other insects, bats are also pollinators and help to pollinate many important plants.

• Fruit-eating bats spread plant seeds when they eat fruits. This helps that type of plant grow more plants.

 Without bats, the country would have to spend billions of dollars to maintain the pest control that bats perform at no cost! Due to White Nose Syndrome, habitat destruction, and pest control measures bats are seeing a dramatic decline in population numbers.  There are plenty of things that can be done to encourage bats to live in harmony with human populations.  Here are a few things that you can do! 

• Purchase a bat house and put in outside your home
• Become a member of Bat Conservation International, or donate to them at www.batcon.org
• Teach others about bats and why they are so important
• Visit local caves and parks but make sure to be respectful of rules and regulations for bat species.  Waking them up during the winter can throw off their internal clock and cause damage to their bodies.  
• Encourage local parks to have "Bat Awareness Days" to help change the mindset that bats are disgusting and something to be feared

 

White Nose Syndrome and Its Impact on the Economy

Why should we care about whether or not bats go extinct in North America and Canada?
Dr. Leighton, the Executive Director of the Canadian Cooperative Wildlife Health Center, discusses in this video how bat species impact the economy and influence our food production.  While many people find bats to be scary or disgusting, there is plenty to appreciate about this unique species of mammal!  

USGS Late March Map and Bat Devastation in Pennsylvania

The US Geological Survey posted an updated map on March 21st for the progression of White Nose Syndrome throughout the United States.  Since the last posted map, on March 1st, populations have been confirmed to have WNS farther west and south along with populations further west in Canada. 

 

 An article posted on April 1st indicated that Pennsylvania's second largest bat colony, located in an abandoned mine in Buck's County, has been dealt a devastating blow.  This population of Little Brown Bats, which once numbered over 10,000 bats, has been reduced to only 23 remaining individuals due to White Nose Syndrome.  Of those 23, more than half are infected with the fungus.  The entire article may be found at  http://www.natureworldnews.com/articles/1134/20130401/cave-10-000-bats-23-survive-mysterious-disease-killing.htm.  This new finding is devastating news for biologists as the number of bats who have fallen due to WNS is now estimated to have reached 6.7 million bats. 

 

Determining bat relatedness using PCR

Within the past few years, biologists have begun to look for noninvasive techniques for studying bat genetics.  One of the methods that was considered was the use of PCR.  A study by Puechmaille et al., showed that by collecting bat droppings and extracting their DNA, PCR techniques could be used to study the genetic relatedness of individual bats within a large colony in a noninvasive matter.  One challenge with this technique is that dropping samples must be collected on a relatively clean surface.  So in their study, Puechmaille and colleagues removed a layer of soil and placed newspaper under a roosting bat colony.  In an effort to retrieve accurate data, the papers had to be checked and retrieved often so as not to become too densely populated with fecal material, thus compromising individual results.

Using PCR in soil samples

As discussed before, not only is WNS spread from one bat to the next but it is also transferred to new caves by means of human transport when individuals do not clean off their boots, equipment, and belongings.  How did biologists come to determine that humans were a means to transfer the disease further than simply speculating?  The use of PCR has helped biologists to determine this fact, with studies showing that the fungus G. destructans is present in soil samples within caves that have had confirmed cases of WNS.  From this evidence, biologists were able to determine that environmental reservoirs, such as soil, play a key role in the spread of WNS. 

Rapid Polmerase Chain Reaction and WNS

Rapid Polymerase Chain (PCR) reaction methods are quickly becoming the favored method for monitoring bat populations that have had access to WNS.  PCR was first developed by Kary Mullis in 1983 and has since been used for DNA cloning for sequencing, DNA-based phylogeny, or functional analysis of genes; the diagnosis of hereditary diseases; the identification of genetic fingerprints (used in forensic sciences and paternity testing); and the detection and diagnosis of infectious diseases.  Polymerase Chain Reaction, for detecting White Nose Syndrome, offers a fast, reliable, and economic alternative to histology and culture samples.  Apart from being used to detect WNS, it is also used to detect pathogens in humans, plans, and animal species.  This technique allows biologists to determine if a bat has WNS within a matter of hours. 

 The process of the Polymerase Chain Reaction method requires that DNA be extracted using a commercial gDNA purification kit and potassium proteinase added to the solution.  No RNase treatment is performed on the concentration.  The final DNA solution gets measured with a spectrophotometer and is then diluted until the genomic DNA can be extracted with pure cultures of Geomyces destructans.  This process takes hours as opposed to days and is diagnostically 96% accurate. According to the Center for Biotechnological Information, a majority of PCR methods use temperature cycling of a PCR sample in a defined series of steps. These steps separate the two strands in DNA double helix at a high temperature, a process referred to as DNA melting. At a lower temperature, the strands are used as a model for DNA synthesis by the DNA polymerase, which amplifies the targeted compound.  This method is considered to be more accurate than the culture method, which maintains 54% accuracy.  

PCR testing methods require a 3mm x 3mm section of wing membrane for testing and results take a matter of hours to obtain.  Larger portions of skin result in inaccurate data, likely from the presence of nucleic acid or other inhibitors on wing tissues. PCR techniques are also highly favored because testing individuals does not require that the bat be killed or euthanized.  

WNS and Culture samples

Like histology, culture samples require skin tissue for testing.  Culture samples require a 1.5cmx1.5cm piece of wing tissue from the bat.  This sample is then placed on a dextrose medium containing chloramphenicol and gentamycin.  Plates are incubated at 45°F for 10-30 days and examined every 1-3 days for traces of G. destructans.  Biologists look for curved single-celled conidia when looking at samples under a microscope.  Fungal cultures are more complicated than histology tests because of the nonsterile nature of bat wings. Tissues for culture tests may be removed from the muzzle, wing, or ear tissues, though wing tissue is preferred.  Like histology tests, results take a long time to yield conclusive data and sample sizes are so big that the bat being studied can not survive once a culture sample has been removed. The following image is what biologists look for when determining if bats have been infected with WNS.

Histology and WNS

Histology is considered to be the standard for determining White Nose Syndrome in bat species in the United States and Europe.  To determine if a bat has WNS, a 1.5cmx3.0cm piece of wing membrane must be removed from a bat then cut and prepared.  Cross sections of the rolled wing skin are then examined microscopically for the presence of the fungus associated with White Nose Syndrome, Geomyces destructans.  Biologists specifically look for conidia in conjunction with fungal hyphae, cup-like epidermal erosions, ulsers and damage to underlying connective tissues.  This method is often considered to be labor intensive and time consuming, with results taking more than a week to acquire.  A downside to histology methods is that this technique, while sensitive and reliable, requires specialized training for the interpretation of results.  The largest downfall with this method is that it is invasive to the animal being tested and requires a large amount of tissue to be removed from the bat, often a piece too large to allow the bat to remain living.  Below are a few pictures of histology test results determining if a bat has WNS.

(A) Direct lactophenol cotton blue mount prepared from skin scrape taken from the muzzle of a little brown bat from Graphite Mine on April 6, 2008 revealed fungal hyphae and curved conidia, bar 10 µm. (B) Control, [Bi] and infected muzzle tissue section [Bii] stained with PAS revealed epidermal colonization by fungal hyphae and spores; the sample was from a little brown bat from Williams Hotel Mine on March 27, 2008. Notably, a few neutrophils are present in the underlying dermis (arrows), bar 10 µm. Bacteria are also seen in this sample (C). SEM photomicrograph of muzzle sample from bat from Williams Hotel Mine showing characteristic curved conidia and septate hyphae spread over bat skin tissues. Note heavy fungal growth with profuse curved conidia covering the skin and hair shaft (Ci, muzzle, bar 100 µm; Cii, higher magnification of a portion of muzzle, bar 10 µm; Ciii & Cvi, higher magnifications, bar 10 µm).

The second picture and description were taken from an article that can be found at  http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0010783.

Detecting bats with WNS

It almost seems that White Nose Syndrome is being discovered in another state or province daily. Recent news has stated that WNS has been found in Georgia and North Carolina now. There is a lot of talk about where it is discovered, but not much on HOW. How do biologists determine if a bat has contracted this disease that is killing almost 100% of populations that it infects? The answer isn't so simple. Biologists first identified WNS from a picture from Howes cave near Albany New York. Today, a photograph isn't enough evidence to suggest an individual is infected. Biologists typically use one of 3 methods to determine if a bat has WNS. These methods include histology, culture samples, and the use of polymerase chain reaction (PCR).  Tape has been used in the past to remove fungal particles from the wings and faces of those presumed infected, however, the three aforementioned methods are considered to be the definite methods for determining infection. Depending on the method used, results can take between hours and weeks before biologists have conclusive answers. Both histology and culture methods require weeks for definitive results but PCR methods allow for rapid answers, sometimes with hours.  Over the course of the next week I intend to go into further detail regarding each of these methods for tracking and determining if populations have WNS.  I also intend to discuss how soil samples from caves have lead to knowledge about WNS. 

USGS Update

Several weeks ago I uploaded a map provided by the USGS regarding the prevalence of WNS across the country.. Today they issued a new map....

Note the section in Illinois and Canada that now have confirmed cases of WNS that were previously not on the map at all.  It also appears that confirmed cases have now been found in Kentucky and Tennessee as well. 

As White Nose Syndrome spreads across the country effecting migratory species in their hibernacula, you will see a decrease in the number of bats around your homes during the summer months once they have returned to their summer roosts.  You know what that means? More mosquitoes and pests that are eaten by bats as they feed at night.  Did you know that WNS only infects insectivorous bat species int he U.S.? This will inevitably have an impact on the number of pests around our homes and will result in the increased use of pesticides that pose other damaging issues to our environment.  

Bat Conservation International

Bat Conservation International has been working with agencies, organizations, and individuals to understand and stop WNS and begin restoring these decimated bat populations. The following photograph is an image distributed by BCI to show how White Nose Syndrome has continued to invade hibernation areas for migrating bat species across the United States. 

What's that? You haven't heard of Bat Conservation International? Their mission is "conducting and supporting science-based conservation efforts around the world. Working with many partners and colleagues, these innovative programs combine research, education and direct conservation to ensure bats will be helping to maintain healthy environments and human economies far into the future." You can view their website at http://www.batcon.org/ and learn about their organization and become a member to support their cause!

Cumberland Gap gets added to the list

On February 10, 2013 the National Parks Service released a statement reporting the presence of White Nose Syndrome in the Cumberland Gap National Historical Park located in Virginia.  Park superintendent, Mark Woods reported that histopathology tests were performed 3 deceased bats that were found in 3 of the 30 different caves found in the park.  While all three bats tested positive for White Nose Syndrome, two actually showed visible signs of the fungus growing on their bodies. 

As a precaution, the Cumberland Gap Park had implemented decontamination protocols within the park 3 years ago in an attempt to delay the onset of white nose syndrome.  In an effort to slow the onset of WNS, visitors to the Cumberland Gap were interviewed before going on cave tours to ensure that they were not bringing items into the caves that had been in other caves or mines since 2006.  Individuals were also asked to leave unnecessary items outside of the cave and decontaminate their footwear before entering caves.  Researchers and employees of the Cumberland Gap National Historical Park followed current national guidance protocols for decontamination before and after their visit to the caves. 

 With the discovery of WNS at Cumberland Gap NHP, the disease has now been
observed in all the major mountain drainage's of the state. Virginia’s focus is now on
determining the impacts of WNS on the different cave bat species and determining if individuals
can persist over time in the face of infection.      Six species of cave-dwelling bats, including the endangered Indiana bat, are found at Cumberland Gap NHP.  All six species are at risk from WNS.  Three species of tree-dwelling bats are also found in the park.  Some bats spend both the summer and winter at Cumberland Gap.  However, other bats are much more mobile, wintering at the park but spending the summer in other areas or vice-versa.  Bats play a crucial role in the environment.  Bats are the only major predator of night-flying insects.

Before and After

The following pictures show the before and after effect that White Nose Syndrome has on an infected Little Brown Bat. 

Bats in the news as WNS spreads!

Two news articles have been released since the start of the year marking the spread of White Nose Syndrome to new locations across the United States. One article noted WNS in Mammoth Cave National Park, while the other documented WNS in the Great Smokey Mountains.

Click on this link to view the article on White Nose Syndrome moves to the Great Smokey Mountains

Link to article regarding WNS in Mammoth Caves National Park

This video is from April 2012 and comments on the spread of White Nose Syndrome in the U.S. and the questions currently associated with the disease.

Where did it come from?

The cause of the sudden appearance of WNS, in New York in 2006,  is greatly debated.  While the origin of the fungus is not known, many biologists speculate that the fungus originated in Europe.  The very same fungus has been observed in Europe in healthy bat populations that have developed an immunity to the disease.  It is speculated that the transfer of the fungus from Europe to North America came on the boots or clothing of humans.

 Once the fungus entered populations in North America, it continued to spread because of people moving from one cave to another without properly cleaning their clothing, boots, or equipment.  Samples of the fungus have been found in the soil of caves, suggesting that this transmission process is possible.  It has also been discovered that bats are capable of transferring the fungus from one bat to another. A recently conducted laboratory experiment suggested that physical bat-to-bat contact is required for the spread of the disease.  The same study found that bats in mesh cages adjacent to infected bats did not contract the fungus, implying that the fungus is not airborne, or at least is not spread from bat to bat through the air. 

What can you do to prevent the transfer of White Nose Syndrome when visiting local caves?  Researchers suggest the best measure to prevent the spread of WNS is to properly disinfect boots, equipment, and clothing after leaving a cave and to limit activity in areas where WNS is prevalent.  In some areas where White Nose Syndrome is increasingly bad, caves are being closed entirely to prevent any chance of humans aiding in the transmission of fungus spores. 

What is White Nose Syndrome (WNS)?

There has been a lot of talk recently about the deadly fungus, White Nose Syndrome (WNS), negatively impacting bat populations across the United States.  But what is WNS?

According to the USGS, White Nose Syndrome (Geomyces destructans) is a fungus impacting bat populations across the north-eastern and central portions of the U.S.  First discovered in 2006, WNS has caused the death of millions of insect eating bats across 19 states and 4 Canadian provinces.  The disease infects the skin, muzzle, ears and wings of bats and appears as a white fungus. 

Bats infected with WNS  display abnormal behaviors such as hibernating close to the mouth of the cave they are hibernating in, flying during the day-time hours during winter, and an increased time spent out of hibernation.  These occurrences contribute to the bats using up their fat reserves, causing emaciation, and a portion of the bats that die as a result of WNS. Estimates have suggested that 80% of bat populations have decreased since the on-set of White Nose Syndrome and it is suggested that populations will not rebound quickly because most hibernating species are long-lived and only reproduce one pup each year. 

This map, provided by the USGS, indicates the presence of White Nose Syndrome across North America.