White Nose Syndrome: Formidable but Not Undefeatable

Some months ago I shared with readers information about the ecological and economical value bats provide in the widely various ecosystems in which they live. They are particularly valuable in protecting crops from destruction by insects, gobbling up so many bugs that bats are estimated to save farmers up to $53 billion in pest control each year. Bats are also very important for pollination and tropical reforestation. More than 1,331 species of bats have been discovered worldwide. But my favorite fact about bats is that they are the only mammal to evolve true flight. There are other animals that glide but bats are the only mammal that truly have wings and self-propelled flight capabilities. Such marvels!

Bats are now vulnerable to a large and rapidly increasing threat known as white-nose syndrome (WNS), named for the white fungus Pseudogymnoascus destructans that appears on the muzzle and other body parts of hibernating bats. WNS is associated with extensive deaths in eastern North America, affecting entire colonies in some cases. WNS invades the nose, mouth and wings of bats during hibernation, when bats’ immune systems are largely shut down. Research indicates that the fungus may lead to dehydration, causing them to wake more frequently and burn precious fat reserves, which leads to starvation. WNS has spread rapidly across the eastern United States and Canada, and has been detected as far west as Oklahoma. WNS has killed more than 5.7 million bats in eastern North America.

According to White-Nose Syndrome.org, at the end of the 2014-2015 hibernating season, bats with WNS were confirmed in the following 26 states and five Canadian provinces: Alabama, Arkansas, Connecticut, Delaware, Georgia, Illinois, Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, Michigan, Missouri, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Vermont, Virginia, West Virginia, Wisconsin, New Brunswick, Nova Scotia, Ontario, Prince Edward Island, and Quebec. The fungus that causes WNS has also been confirmed in Minnesota and Mississippi.

In this context, it is with cautious jubilance that I share the news that 150 bats that were part of the first field trial were released after having been successfully treated for WNS. Scientists and conservationists that are part of the large network of collaborators combating WNS gathered in the evening of Monday, May 18, 2015 at the historic Mark Twain Cave Complex in Hannibal, MO and released these bats back to the wild.

Sybill Amelon, USDA Forest Service research wildlife biologist.  Credit Katie Gillies, Bat Conservation International.

Sybill Amelon, USDA Forest Service research wildlife biologist.
Credit Katie Gillies, Bat Conservation International.

Beginning in 2012, Dr. Christopher Cornelison and other Georgia State University peers determined that the bacterium, Rhodococcus rhodochrous, can inhibit the growth of some fungi. They found in the lab that Rhodococcus rhodochrous, without even directly touching the Pseudogymnoascus destructans, could strongly inhibit its growth. Dr. Cornelison, U.S. Forest Service wildlife biologist Dr. Sybill Amelon and research plant pathologist Dr. Daniel Lindner continued to conduct laboratory research on the application of this bacterium, and in the winter of 2014 conducted field trials in Missouri and Kentucky caves, thanks to funding by many organizations including Bat Conservation International, the U.S. Forest Service and the Tennessee Chapter of The Nature Conservancy. 

Multi-agency collaboration has been integral to the search for a treatment for White Nose Syndrome. The U.S. Fish and Wildlife Service administers most of the federal funds provided by Congress to fight the disease, and many state wildlife agencies contribute staff and funds of their own in surveying for the fungus as it has traveled throughout their regions. There are also numerous private donors. This elaborate network of scientists and financial backers will continue this management-based research to control the mortality of WNS and, I believe, eventually eradicate its destruction of bats.

Here is a video produced by Texas Parks and Wildlife describing WNS and the importance of bats.

Fifty-three Billion Dollars of Organic Pest Control is not Spooky

Mexican (or Brazilian) Free-Tailed Bats, ''Tadarida brasiliensis'', emerging from Carlsbad Caverns, Carlsbad Caverns National Park, New Mexico. Source=http://www.nps.gov/cave/naturescience/images/bat_outflight_hristov_

Mexican Free-Tailed Bats. Photo courtesy of National Park Service

By Maymie Higgins

My street is a typical rural North Carolina subdivision with ecological features that influenced my home purchase.  The narrow road entering the neighborhood begins at the top of a hill and quickly descends to a valley, where trickling just beneath is a tributary of Abbott’s Creek, part of the Yadkin-Pee Dee River System.  The valley is an undisturbed riparian forest, thick with cypress, loblolly pine, dogwood and maple trees rising from a carpet of fallen leaves and pine cones.  The road then sharply ascends, cresting at my home before starting to gently descend again as it reaches the cul-de-sac that punctuates the street at four-tenths of a mile.  Because of this design and absence of thru traffic, it is an excellent street for kids to play, adults to walk and certainly for hill work in running. More importantly, the proximity to a water source provides an abundance of wildlife sightings, particularly passerines and small mammals but also raptors from time to time.  In fact, just last week a Barred Owl provided my husband a jolt with a silent fly over just above his head.  He never knew taking the garbage to the curb could be so thrilling.

In cooler months, I take my walks when the sun is high.  But in the late spring and all of summer, I brave the mosquito laden dusk for an air show like no other.  As I approach the valley, dozens of small brown darting masses appear above, moving in a way that seems sporadic to those who do not understand echolocation.  Bats are not out of control.  I stand there and giggle like a little girl as they zip towards my face and then bank right or left at the last moment.  Do they think “My!  What a big mosquito!” when they pick up the echolocation from my melon of a head?  Bats are the only major predator of night-flying insects such as lacewings, cockroaches, gnats and of course, mosquitoes.  A single big brown bat (Eptesicus fuscus) can eat between 3,000 – 7,000 mosquitoes in one night.  Insect-eating bats in the United States likely save the U.S. agricultural industry at least $3 billion a year and possibly up to $53 billion a year, gobbling up insect pests that would otherwise damage crops.  Fruit-eating bats are also pollinators and seed dispersers.  Nearly 200 plant species are pollinated by bats, including bananas, peaches, dates, and figs, making them agriculturally and economically very important.

Healthy Little Brown Bat (Myotis lucifigus) Photo Credit: U.S. Fish and Wildlife Service/Ann Froschauer USFWS Headquarters

Healthy Little Brown Bat. Photo courtesy of U.S. Fish and Wildlife Service

The mere existence of bats is a positive story of the environment.  Fossils for bats have been found on every continent except Antarctica and date as far back as 55 million years ago.  They are the only mammal that evolved true flight capabilities.  Ponder that for a moment.  Bats are the only mammal that can genuinely create lift using their own self-generated energy.  Bats are mammals with wings!  Incredible!  As if that weren’t enough, bats have the greatest degree of specialization among their 1,116 species than any of the other mammalian orders.  Most eat insects.  Some eat small vertebrates such as mice, frogs and even other bats. A few eat fish.  Many eat pollen and nectar.  Some eat fruit.  All these different diets require different physical skills.  But they are not blind and they do not bite without being provoked.  Unless injured and unable to get away, it is unlikely for a bat to purposefully attack a human.  If you find an injured bat, keep your children and pets away from it and call a certified, experienced wildlife rehabilitator.  A very small percentage of bats can be carriers of rabies, which is transmitted through saliva.

Bat populations have declined in many areas due to loss of roosting sights and water sources because of commercial development.  Insecticides can accumulate in their bodies and lead to death.  In some parts of the world, bat populations have declined because they are consumed by humans; however, in North America, the largest and rapidly increasing threat to bats is white-nose syndrome.  Named for the white fungus (Geomyces destructans), that appears on the muzzle and other body parts of hibernating bats, WNS is associated with extensive deaths in eastern North America, affecting entire colonies in some cases.  WNS has spread rapidly across the eastern United States and Canada, and has been detected as far west as Oklahoma.  WNS has killed more than 5.7 million bats in eastern North America.  The good news is that many partners have come together and created a national plan and response strategy.   There are 45 state and local organizations, 17 non-governmental organizations, 17 federal organizations and 11 universities working together to save dozens of species of bats and provide information to citizens on how they can help: http://whitenosesyndrome.org/what-can-you-do-help.

The bat story is just one of many examples of how biologists are collaborating with governmental organizations, non-governmental organizations and even corporations to conserve and preserve the natural world.

Little Brown Bat with WNS Photo Credit: U.S. Fish and Wildlife Service/Ann Froschauer USFWS Headquarters

Little Brown Bat with WNS.
Photo courtesy of the U.S. Fish and Wildlife Service