White-nose syndrome could decimate Missouri bat population

It’s an unnerving sight – in the dead of winter, bats frantically fly about in broad daylight, collecting the few bugs the cold has left behind, clinging onto the little life they have left.

What comes next for these creatures is a white fungus growing at the face and wings, followed by death.

White-nose syndrome, a disease found in hibernating bats, has killed approximately 6.7 million bats across North America since it was first discovered in the winter of 2007. First found in New York, the disease has been spreading west, with the first documented case in Missouri in the spring of 2010. With such a low survival rate, there is great concern that white-nose syndrome will continue to decimate the bat population- disrupting the ecology and economy of surrounding areas.

Columbia is home to Devil’s Icebox, a cave that houses two endangered species of bats. Many scientists believe the threat of white-nose syndrome is imminent.

While no cases have been found in Columbia yet, scientists fear that if a solution to the spreading disease is not found the majority of Missouri’s hibernating bats will be dead within a few years.

Other members of the white-nose syndrome response team have expressed an it’s-only-a-matter-of-time outlook. Ann Froschauer, national white-nose syndrome communications leader for the U.S. Fish and Wildlife Service, expressed similar concerns.

“My opinion as someone who works on this disease full time is that it is likely to continue to spread, and affect additional species,” said Froschauer.

Much is unknown about the nature of the spreading, but scientists are beginning to have an understanding of the disease and the symptoms. Contaminated bats exhibit strange behaviors, or warning signs, that they have been infected before the disease takes hold. During cold winter months, those infected wake from hibernation, due to what some scientists believe is due to general discomfort of exposed skin, and fly around during the daytime collecting bugs and gathering at the entrance of the hibernacula. Many don’t survive the winter; they either starve or freeze and then begin to litter the floor of the cave.

The disease was first discovered on the east coast and is spreading west quickly, decimating bat populations in 19 states and four Canadian provinces. The U.S. Geological Survey estimates that the bat population decline in the U.S. since the emergence of white-nose syndrome is approximately 80 percent.

These devastating numbers are unprecedented in hibernating bats and experts say it’s unlikely the affected species will recover quickly. Dwindling bat populations could throw the ecology of North America completely off balance.

Bats account for approximately one-fifth of all mammal species, which makes them a key player in the ecological game. The effects of population changes ripple throughout the food chain, misshaping the chain and affecting other species. The survival and success of Missouri’s bats is crucial for the continuation of a stable environment.

U.S. Fish and Wildlife Service’s Midwest Regional White-Nose Syndrome Coordinator Richard Geboy works to understand the bat species’ place in the ecology of Missouri and how the disease could destroy the fragile structure.

“Anytime you are faced with high levels of mortality in a group of species, there will certainly be repercussions,” Geboy said in an email interview.  “As for what and how those repercussions surface many times are unknown.”

What they do know is bats have historically had an effect on cave ecology. Bat guano, or droppings, is a primary source of nutrients for the entirety of a cave. Without these nutrients many species that reside in caves alongside gray bats will suffer.

“The value of bats in Missouri (has) the potential to be even greater to cave biodiversity and ecology,” Geboy said in an email interview. “Much depends on the susceptibility of gray bats. Gray bats provide incredible inputs into a number of cave systems in a throughout Missouri. These inputs, especially the guano inputs, are crucial for the existence of a few cave invertebrates.”

Cave ecology is not the only concern surrounding the threat of diminishing bat species; rural economy is also at risk.  The U.S. Geological Survey considers bats to be one of the most economically important, yet underappreciated animals in North America. The estimated 775,000 gray bats that inhabit Missouri are said to eat more than 540 tons of insects per year, which translates into approximately 233 billion bugs.

Because of this, the U.S. Geological Survey cites a possible $3.7 billion per year of agricultural loss if North America experiences a more severe decline in the population.  Bats act as nocturnal protectors of farms by feeding off insects that damage crops and hurt sales.

A research publication by the American Association for the Advancement of Science described the economic importance of bats in agriculture and estimates the value of bats on farming to be as high as $53 billion per year.  The same publication cited the benefits of bats to agriculture in Missouri to be nearly a billion dollars.

With signs of white-nose syndrome found in Missouri last spring and hibernation season ending, the risk of the disease decimating the bat population and the agricultural economy is becoming a real threat.

In March of 2012, Missouri Department of Conservation resource scientist Tony Elliott and a team of researchers entered a cave in Lincoln County to survey the area. It was there that Elliott “came face-to-face with a little brown bat and my stomach sank.”  It had white fungal growth developing on its snout, and here Elliott had stumbled upon the first case of white-nose syndrome in Missouri.

There are a few private caves in northeastern Missouri that reported spotting the fungus, but Lincoln County was the first and only area to confirm white-nose syndrome had finally reached Missouri.

“Seeing that one little spot of fungus here was bad enough, I really do not want to see a bunch of dead and dying bats,” Elliott wrote in a blog for White-Nose Syndrome.org.

Elliott’s wishes appear to be granted for now, with no reported deaths from white-nose syndrome in Missouri as of yet.  But 12 known species of bats that have taken up residency in Missouri, and six species are known to be susceptible to the fungus- two of which reside at Rock Bridge Memorial State Park, near Columbia.

Devil’s Icebox holds the title of the second best environment in the state for the gray bats.  Rangers at the Rock Bridge Memorial State Park did not take any chances this winter in protecting the endangered creatures.  A sign at the opening of Devil’s Icebox restricts visitors who have been in a different cave within the past two months from entering. Once inside, another sign forbids hikers from exploring further into the cave for fear of spreading the fungus.

The Missouri Department of Conservation, or MDC, issued a warning last spring urging visitors to stay out of the caves.

“As a longstanding policy to protect bats and the fragile, unique cave ecosystems they depend on, MDC restricts access to caves on Department lands. We permit access to these caves only if you have an MDC Special Use Permit for research, recreation or education purposes,” issued the Missouri Department of Conservation.

Blocking access to caves is a common approach for controlling spread of this disease.

“Across much of North America, including the Midwest,” Geboy explained, “many states have focused on containment through cave closure and decontamination.”

It is unknown if humans aid in the transfer of the fungus but conservationists are not willing to take that chance.  Many public and private caves across the U.S. have blocked off cave entrances including some in Illinois, Arkansas, Tennessee and Texas.

Closing the caves is just one precaution scientists in Missouri and all across North America are taking to control the rampant spread of white-nose syndrome. Froschauer stresses the importance of research and education to protect our nation’s bats.

“The response includes research … into everything from the natural history of the fungus, disease spread and how the disease affects bats, treatment options, containment methods,” Froschauer said. “We coordinate communications, education and outreach with our partners and the public and media, including things like the website, presentations and working with print, radio, and film news outlets to educate people about bats and the disease.”

The future of these creatures is uncertain. Scientists and researchers work against nature to slow the progression of the disease. Ecological and economical repercussions have been analyzed, and Froschauer didn’t forget to take into account the human element of this issue.

“There is a real human connection with bats, very directly for some of us who have been working with bats for a few years or for our entire career,” she wrote. “Maybe not quite as directly – but just as meaningful- for the people who sit on their porches or walk down their lanes or lie on the dock and watch the amazing nightly aerial acrobatics display of bats at twilight.”