Bug-Eating Bats Bite the Dust, Endangering U.S. Soy, Corn Crops

Bug-Eating Bats Endangering Soy, Corn Crops
A little brown bat showing symptoms of White Nose Syndrome. Photographer: Greg Thompson/ U.S. Fish & Wildlife Service via Bloomberg

Hikers may be locked out of hundreds of caves and 30,000 abandoned mines in the U.S. West and Midwest in a government plan to protect bat from man.

The cave closings may come “as early as this week,” according to U.S. Forest Service spokeswoman Janelle Smith, and are the latest efforts to combat a disease called White Nose Syndrome that decimated bat communities in 13 states and two Canadian provinces. The disease, perhaps caused by a fungus, may spread to more states as hikers and tourists inadvertently carry spores on their clothing, Smith said.

The loss of swaths of the U.S. bat population may threaten corn and soybean crops and other parts of the U.S. agriculture and timber industries, said Mollie Matteson, a conservation advocate at the Center for Biological Diversity in Tucson, Arizona, in an interview. Bats help control insect pests, eating as much as two-thirds of their body weight per night, said Holly K. Ober, assistant professor at the University of Florida in Quincy, Florida, in a 2008 Department of Wildlife Ecology and Conservation document.

“It’s a catastrophic situation for bats,” said Jeremy Coleman, a biologist with the U.S. Fish and Wildlife Service who studies White Nose Syndrome in Cortland, New York. “We don’t have any tools at our ready to treat them or to control the spread, other than closing access to humans,” he said in a July 16 telephone interview.

“There are just too many unknowns” until research uncovers more information showing how to thwart the disease, Coleman said.

Insect Feast

The big brown bat, a species widely distributed in North America, feasts on insects that destroy corn, soybean and cotton crops, according to the report by University of Florida’s Ober.

The fungus thought to cause the disease was first detected in New York in 2006 and may have killed more than one million bats, according to a May report from the U.S. Fish and Wildlife Service. The agency called the disease “the worst wildlife health crisis in memory.”

The disease only affects hibernating bat species, which account for a little over half of the 45 varieties in North America, said Matteson. So far nine species, including the big brown bat, are known to be affected. Some of them are now threatened with extinction, the May report said.

“It’s a huge loss in the natural pest control system,” said Ober in a telephone interview yesterday. “There has never been anything like this before in terms of a pest control population dying.”

‘Bat Death Zone’

Federally managed mines and bat caves in Colorado, Kansas, Nebraska, South Dakota and parts of Wyoming will be closed, according to Smith, a spokeswoman for the Rocky Mountain Regional Office of the Forest Service in Denver, Colorado. Thousands of caves and mines on federal land have already been closed to “cavers,” or cave hikers, across the country.

The new closures were proposed in May when the disease appeared to be traveling into the Southwest after a case was confirmed in Western Oklahoma. The disease spread from New York into Ontario, as well as into the Midwest and the South along the Appalachian chain, Coleman said. The wildlife service now refers to this extended area as “the bat death zone.”

“We want to take action soon but we haven’t made the decision final yet,” Smith said in a July 19 telephone interview. The delay is caused by the Forest Service’s need to coordinate with the National Park Service and the Bureau of Land Management. All three must close sites at the same time in order to slow the rate of infection in the region, she said.

Hikers Help

Individual caves that are not home to hibernating species might be closed for one year or less, Smith said. Limiting the closures in this way is a priority for the American cave-hiking community, which has been instrumental in identifying afflicted bat populations, she said. While supportive of state efforts, cavers are reluctant to curtail their explorations.

Cavers are angry about the closures because they say it’s not proven that humans transmit the disease, according to Alan Hicks, a wildlife biologist directing a White Nose Syndrome investigation for the New York State Department of Environmental Conservation.

Bats, not people, are mainly responsible for spreading the disease, Hicks said in an interview. The animals fly several hundred miles over their lives so they’re capable of spreading the fungus, he said.

‘Pursuing Their Passion’

“You need to have a good reason to prevent people from pursuing their passion,” said Hicks. “You have this natural constituency of cavers that’s pro-conservation. If you start making decisions about not letting people into these caves for reasons that don’t make sense, you risk alienating these folks, who are your natural allies.”

Coleman, the federal biologist, said people travel much greater distances than bats and have the ability to infect bat populations that would otherwise never encounter the fungus.

“I know several cavers who’ve put their gear away and say they may never go caving again, but it’s their hobby versus the bats’ survival,” said Matteson. “All we can do now is to buy some time for bats in areas that are not affected, so that researchers can find out more about the disease.”

Research and monitoring of White Nose Syndrome is funded by five organizations at the national level, said Marc Bosch, the leader of the National Threatened, Endangered & Sensitive Species Program in Washington, in an interview. They are the U.S. Forest Service, an agency of the U.S. Department of Agriculture; the U.S. Fish and Wildlife Service; the U.S. Bureau of Land Management; the U.S. National Parks Service, and the U.S. Geological Survey, which is the research arm of Department of the Interior.

$1.9 Million for Study

In October, President Obama signed a law awarding the Fish and Wildlife Service’s White Nose Syndrome research effort $1.9 million, according to the service. Several states and universities are also backing studies, Bosch said, partly in recognition of the potentially dire consequences of bat extinctions for agriculture.

Corn futures for December delivery fell 3.25 cents, or 0.8 percent, to $3.9025 a bushel on the Chicago Board of Trade. The most-active contract has gained 13 percent since June 29, the day before the government said that U.S. farmers planted less this year than they had planned.

Soybean futures for November delivery rose 1 cent, or 0.1 percent, to $9.795 a bushel on the Chicago Board of Trade, after dropping as much as 0.6 percent. The most-active futures have risen 8.5 this month on speculation that too much rain in June will reduce the U.S. harvest.

Difficult to Study

Complicating government countermeasures is the fact that bats are difficult to study, said Matteson, the conservation advocate. The first challenge is figuring out how many of them there are and where they live. Many inhabit caves that can only be entered through passages too narrow for humans to access. An untallied number of the caves are on private estates that don’t welcome the researchers, she said.

Unable to count either the total population or the number of bats that have perished, researchers can’t pin down the severity of the crisis. In spite of the hurdles, New York investigator Allan Hicks estimated that the disease has wiped out 95 percent of the bats in his state.

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