White-nose Syndrome Update - Bat Acoustic Surveys Indicate Declining Numbers of Bats

Aug. 7, 2014

Wild Ohio eNewsletter

 
 
 

White-nose Syndrome in OhiO 

By Jennifer Norris, Ohio Division of Wildlife, Wildlife Research Biologist

Published  12/4/2014

In March 2011, the first case of White-nose syndrome (WNS) was confirmed in an abandoned mine on the Wayne National Forest in Lawrence County, Ohio. The disease was first confirmed in the United States during the winter of 2006-07 when the New York Department of Environmental Conservation found dead and dying bats in caves in New York State.  Since 2006, it has been estimated that WNS has killed over 6 million bats. The disease has spread quickly and is now confirmed in 25 other states and 5 Canadian Provinces.  Ohio has also experienced the rapid spread of the disease since the winter of 2011-2012 and has now confirmed in 18 counties to include confirmations last winter (2013-2014) in Hocking and Franklin counties. Read More http://wildlife.ohiodnr.gov/stay-informed/enewsletter/wild-ohio-enewsletter-archive/post/white-nose-syndrome-in-ohio

Summary of acoustical survey data from 2011 to 2014. 

Additionally, from 2011 and 2014, the DOW and volunteers have conducted standardized acoustic surveys across the state to evaluate our breeding bat population numbers and distribution.  The acoustic summer survey results indicate a declining trend in the number of bat detections recorded, for instance from 2011 to 2014 we detected 47% less bats.  Similar to the recorded declines in Ohio hibernacula, the summer declines documented during the acoustic surveys are potentially also indicative of declining numbers of bats as a result of WNS.

This Posting from August 2014 describes the Acoustic Monitoring Survey Process.

Ten Ohio Certified Volunteer Naturalists from the SW RiverLands Chapter participated in the Statewide Bat Acoustic Monitoring Surveys sponsored by the Ohio Division of Wildlife during the month of July.  The OCVNs received training in Columbus and conducted three survey routes in Clark County, Greene/Montgomery Counties and the Warren County/Caesar Creek Lake Region. 

The Acoustic Bat Surveys are very much in need this summer to help define Ohio's Bat Populations as White Nose Syndrome (WNS) continues to spread and affect hibernating bats in their hibernacula in many areas of the state. 

Thirty-eight survey routes were able to be completed this year giving bat biologists a better picture of Bat occurences statewide. ODNR Wildlife Biologists - Jennifer Norris and Sarah Elliott are leading this very important effort to monitor Ohio's Bat Populations.

Bat Acoustic Survey Equipment - Photos by M.A.Schumacher

Background and Methods below courtesy of the ODNR - Division of Wildlife

Background: Bat populations are potentially being impacted by two relatively recent sources of mortality: White Nose Syndrome (WNS) and wind energy development.  While it is often easy for us to document the mortality of these 2 factors at a particular site, the impact of these sources of mortality on bat populations is currently unknown.  For example, a large number of bats are dying from WNS at affected hibernacula, but it is unknown if some bats are leaving the hibernacula and dying in the surrounding landscape or if the bats are relocating to other sites and surviving until typical emergence.  Additionally, since researchers are not aware of all bat hibernacula we cannot assess the impacts to all hibernating bats from a population perspective.  In the case of wind turbine mortality, we can estimate the number of bats killed but we have, at best, a poor idea of population size and the ability of these populations to sustain this rate of mortality.  Therefore, in addition to hibernacula surveys and post-construction mortality surveys at wind-power sites, the Division of Wildlife needs a supporting method to assess the impacts to multiple species on a broad geographic scale. We have chosen an active acoustic monitoring method. 

Acoustic Survey  Microphone

Methods: In 2011, the Division developed a standardized protocol for bat acoustic monitoring using 30-mile driven routes.  As part of the standardized methodology, the 30-mile routes were surveyed using Anabat SDII units, 3 times at night during July.  In 2011, the Division surveyed 4 acoustic monitoring routes in Delaware, Harrison, Shelby, and Wood counties, as well the Wayne National Forest conducted 6 routes in Lawrence County.  In 2013, the number of routes increased to 29 of which 25 were completed (Table 1).  The Division was able to increase the number because of the many individuals who agreed to volunteer their time.  All volunteers were trained on the acoustic monitoring equipment and standardized protocols. 

Anabat SD2 Montoring Equipment

Table 1.  Bat Acoustic routes (named by County) surveyed in Ohio during 2011, 2012, and 2013. Lawrence County had 6 different routes.

 

Surveyed in:

Routes

2011

2012

2013

Ashland

   

Yes

Ashtabula

   

Yes

Clark

   

Yes

Clinton

     

Cuyahoga

   

Yes

Delaware/Franklin

   

Yes

Delaware/Marion

Yes

Yes

Yes

Franklin

 

Yes

Yes

Geauga

   

Yes

Harrison

Yes

Yes

Yes

Highland

   

Yes

Hocking

   

Yes

Hocking/Fairfield

   

Yes

Kelly's Island

 

Yes

 

Lawrence (6)

Yes

Yes

Yes

Licking

     

Marion/Morrow

   

Yes

Montgomery/Greene

   

Yes

Preble

 

Yes

Yes

Shelby

Yes

Yes

Yes

Van Wert/Paulding

   

Yes

Vinton

 

Yes

Yes

Summit

   

Yes

Wood

Yes

Yes

 
Article describing the Bat Acoustic Surveying which began in 2013.

Ohio starts summer acoustic program to record sounds of bats in the wild

Published: September 2, 2013 - 10:13 PM  Ohio.com Akron Beacon Journal

http://www.ohio.com/news/local/ohio-starts-summer-acoustic-program-to-record-sounds-of-bats-in-the-wild-1.425662


Listen to several Bats Echolocating over a pond

https://www.youtube.com/watch?v=UqdZikN9r28

Published on Sep 30, 2012

Here is another brief video on a September evening Georgia where we watch the bats fly and listen to them with an ultrasonic sound detector. It's kind of cool to listen to the bats echolocating for their bug prey! The clicking sounds will start far apart then come more and more often as they locate and home in on their prey. Suddenly the clicking will stop (they caught the insect and ate it) then it will start over again. If you watch close you can see them swoop as the clicking gets very fast. You can tell a few times when they actually catch a bug by watching them.

 

Bat echolocating and capturing moths

https://www.youtube.com/watch?v=MgRh_Q_xwys

Published on Sep 23, 2013

More info at www.sonarjamming.com

A Myotis volans bat echolcates and attacks insects. The bat captures moths using its entire wing surface, bringing the prey into its tail membrane, then into its mouth. Sometimes it doesn't like what it catches and drops the moth, other times the bat misses. But when it goes right, the bat flies away, while echolcating and eating its reward.

 

High-Speed Footage of a Bat in Flight - Smithsonian Channel

https://www.youtube.com/watch?v=Upq7LyhCGXE

Published Jul 3, 2013       High-speed cameras track this bat's brilliant flight in super slowmotion.

 

Bat Biology 101 - Smithsonian Channel

https://www.youtube.com/watch?v=iPhA82ccg9E

Published Jul 3, 2013  Bat biologist Dr.DeeAnn Reeder gives a quick close up lesson on bat physiology and anatomy.