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Holy battered bats! Double menace threatens farmers' helpers

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Student researcher Janelle Bowcock holds a very cranky evening bat during a bat survey near a proposed wind facility. Wind companies survey for the presence of the endangered Indiana bat before constructing a new wind farm. (Photo by Tim Lloyd/Harvest Pubic Media)
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Multimedia Editor
Tim Lloyd is an education reporter at St. Louis Public Radio. He previously served as Harvest Public Media’s multimedia editor.

Farmer Shelly Cox and her husband rely on the mainstays of Midwest agriculture: John Deere tractor, genetically modified seeds and rich soil.  

They also get extra help from what you might call nature’s pest control crew – migrating bats.

“They’re huge at insect control,” Cox said while walking toward a small wetland where bats cluster during the summer months.“How much money do you want to spend on pesticides? Or do you want to be saving money and using what Mother Nature gives us?”

Cox credits the bats that visit her family’s 86-acre farm outside Savannah, Mo. as a big reason why they’ve only used pesticides twice in the last 15 years.

But that could change soon.

Wildlife experts in the heartland are preparing for a serious one-two punch to the bat population: a mysterious fungus spreading from the northeast, and the proliferation of wind power. 

“There are large bat populations in the Midwest,” said Thomas Kunz, a Boston University bat researcher.  “There’s going to be some pretty massive die offs there in I would say three years.”

The conservative estimate of economic impact is $3.7 billion a year — but could reach as high as $53 billion, according to research Kunz published in the Journal Science. 

 “Farmers would have to spend that much more on pesticides,” he said.

Kunz found that just one colony of 150 big brown bats can gobble up 1.3 million pests a year.

A bat with White Nose Syndrome, a fungus that is deadly for bats.(Photo courtesy the U.S. Fish and Wildlife Service)
 
Learn more about White Nose Syndrome by clicking HERE.
 
The benefits of bats
 
Researcher Thomas Kunz found that bats are most likely worth around $74 per acre to ag producers. Combining that estimate with crop data from the U.S. Department of Agriculture puts Iowa at the top of the list nationally, with a benefit of bats to agriculture topping more than $1.7 billion. Below are numbers for other Midwestern states.   
 

Source: The Journal Science, online supplement for the article: "Economic Importance of Bats in Agriculture"
Credit: Tim Lloyd/Harvest Public Media
  • Click HERE to read the article published in Journal Science on the economic importance of bats in agriculture.
  • Click HERE for the data shown in the above chart.
 
Interactive: The value of bats in the continental US
 

Click HERE for an interactive map showing the estimated economic value of bats to agriculture across the country.

Fungus spreads westward

There’s not much Kunz and other researchers can do about what’s projected to contribute most to the demise of cave-dwelling bats in the Midwest, a nasty fungus that ultimately spawns into something dubbed White Nose Syndrome.

The syndrome gets its name from the white face it gives infected bats and takes around three years to develop.  In parts of the northeastern U.S., bats have been decimated by White Nose and have all but disappeared in some areas, according to the U.S. Geological Survey. 

“That fungus manifests itself in several ways: Loss of body fat in mid-winter, abnormal winter behavior, suppressed immune system,” Kunz said. 

Once White Nose Syndrome is full blown, the fungus grows down into the hair follicles on their faces.

Itchy and irritated from the discomfort, hibernating bats wake up often, fly around and burn up their fat reserves.   Deaths are mostly caused by simple exhaustion, but White Nose also can lead to fatal dehydration because it scars the thin membrane of wings where bats absorb moisture. 

The fungus has been spotted as far west as Oklahoma.  Though experts are keeping their fingers crossed that somehow in the Midwest the fungus won’t turn into the syndrome, Kunz isn’t optimistic. 

“Mass mortality wasn’t observed until the third year,” he said.  “This is the third year it’s appeared in Pennsylvania … we have a massive mortality going on.”

To date, there is no cure for the syndrome and conservationists are hustling to slow its spread.  Further complicating the problem is head scratching nature of the fungus itself, which grows on living tissue.    

“I really have not seen anything of this magnitude,” said Sunni Carr, wildlife diversity coordinator with the Kentucky Department of Wildlife Resources.  In addition to her day-to-day work in Kentucky, she also works with federal and state agencies to coordinate a national response to White Nose. 

“I am confident that this is the most significant and dire wildlife issue that I will deal with in my career,” Carr said.   

Geomyces destructans, the scientific name for the fungus, primarily affects cave bats and is suspected to be transmitted on the clothing of spelunkers. 

In June, Missouri’s Mark Twain National Forest went so far as to close its caves through 2016.  Similar efforts have been taken at other state parks in the Midwest.     

Wind turbines rise up

As bad as White Nose Syndrome is for cave-dwelling bats, to a lesser extent the proliferation of wind power across the Midwest poses a danger to their counterparts, tree bats. 

For reasons that remain unknown, bats are attracted to turbines that tower above tree lines.  Once the migratory species is close, the pressure drop can crush their fragile lungs or they can simply get smacked by the spinning blades. 

Watch how bat researchers survey for the presence of the endangered Indiana bat near a proposed wind facility. (Video by Tim Lloyd/Harvest Public Media)

While no nationwide programs track how many bats are killed by wind energy each year, estimates have the number reaching as high as 111,000 annually by 2020.  

That’s based on the premise that wind turbines will continue spouting across the country at a rapid clip.

In the second quarter of 2011 alone, the U.S. wind industry installed 1,033 megawatts, according to a report by the American Wind Energy Association. And Iowa, an epicenter for corn and soybean production, comes in second in the nation for the number of megawatts produced by wind power and has 3,675 facilities, according to the report.

That’s good news for wind proponents but has bat experts feeling anxious because federal protections only cover the endangered Indiana bat.  To avoid killing that species, wind companies hire experts like Lynn Robbins, a bat researcher from Missouri State University in Springfield, Mo.

On a recent summer day, Robbins stood next to a creek in northwest Missouri while a team of student workers hung nets and placed bat detectors just miles from the first town in nation to be completely powered by wind energy, Rockford, Mo.

“What the student workers are doing today is doing a survey to determine if the endangered Indiana Bat is present in area that’s slated to become a wind energy facility,” Robbins said.  

Robbins couldn’t give the exact location of the proposed wind facility or the name of the company due to contractual obligations. 

Infrared video showing the problems some turbines pose for tree bat populations.

 “If they’re here then the wind company must take the next step in being more careful as to where they put the turbines, or determine even if they’re going to put the turbines in the area,” he said.   

Though finding an Indiana bat might slam the brakes on a proposed wind farm, the presence of other bat species isn’t likely to impede development.

 “There’s a gradient of contribution and acceptance of wildlife impacts and what companies are doing about it,” said Ed Arnett, a researcher participating in the Bats Wind Energy Cooperative.  

The cooperative, founded in 2003, brings together the American Wind Energy Association, Bat Conservation International and federal agencies for the purpose of researching how bat fatalities can be prevented.  (It’s not just bats, either; wind power has also been shown to kill migratory birds.)   

Tech solutions?

Most wind companies, Arnett said, have at least some level of interest in minimizing the negative impacts a facility has on bats, but currently the best way to avoid fatalities takes a chip out of company profits. 

“Many bat species don’t fly at higher wind speeds,” Robbins said.

So, the idea is to set the turbines so they won’t spin at lower wind speeds when bats are more likely to be flying around. 

 “It would typically cost a company about 1 percent of its revenue,” said John Anderson, director of sitting policy for the American Wind Energy Association.  “But it depends on the location and the company.”  

The best technological solution, placing devices on the top of wind towers that jam bats internal radar, works great in the lab, but not so great in the field. 

With that in mind, Arnett pegs his hopes on generating the kind of research wind companies can use on future projects.   

 “Proactively, in planning to the future, there’s no reason why those costs can’t be factored into the implementation and operations plan of a project,” Arnett said. 

And every little effort helps.

Bats are long lived, some species routinely make it to 30 years, and they don’t reproduce quickly.  All of that adds up and makes them particularly susceptible to dramatic population declines. 

Back at Cox’s family farm, tucked in the rolling hills of northwest Missouri, she’s noticed a change.

“Maybe in a given evening we were seeing a dozen or so swooping around the light, and now, last year we were seeing maybe four or five,” she said. 

She’s not ready to push the panic button, at the same time she can’t help feeling a little uneasy. 

“If you don’t really know what’s going on you hate to kind of be a catastrofier,” Cox said.   “But, yes, I have notice a difference in the number that we would typically see around the lights at night.”