A Big Brown Bat, photographed roosting in a culvert. Photo courtesy of Louisiana Department of Wildlife and Fisheries.
WILDLIFE
Our Local Bats
LDWF’S BAT MONITORING PROGRAM ENSURES THIS VITAL POPULATION STAYS HEALTHY AND HAPPY IN LOUISIANA By Harriett Pooler
O
n a recent summer afternoon, I found myself on my hands and knees looking at what appeared to be a tiny, sneering Brazilian Freetailed bat. It was all a part of my mission to learn more about Louisiana’s twelve species of bats, and about the Louisiana Department of Wildlife and Fisheries’ bat monitoring program. These flying mammals are an integral part of our environment and provide critical ecosystem services. And they face many threats. One major threat facing bats in Louisiana is habitat alterations, including degradation, fragmentation, and destruction. When a bat’s habitat is altered or lost, the bat
must move to a lower-quality habitat for roosting and foraging. An even more urgent threat for our region’s bats, however, is the deadly disease known as White-nose Syndrome. Pseudogymnascus destructans or Pd for short, is a fungal infection that causes the disease known as Whitenose Syndrome. A cold loving pathogen, Pd infects bats during hibernation when their bodies’ temperature decreases. After the infection invades a bat, its wing membranes start to erode, white cotton-like fungus grows on its muzzle and wing membrane, and dehydration occurs. The pathogen awakens the bats from hibernation, using up necessary energy and depleting fat
reserves. Thus far, over six million bats have died from the disease since it was detected in Albany, New York in 2006. Over the past fifteen years, the disease has been identified in thirty-seven states and seven Canadian provinces; the fungus Pd has also been detected without the clinical presentation of White-nose Syndrome’s symptoms in three additional states. Researchers have identified twelve bat species with White-nose Syndrome, three of which can be found in Louisiana; the fungus has been detected without symptoms in eight additional species, four of which can be found in Louisiana. While White-nose Syndrome has been confirmed in bat colo-
nies in surrounding states—including Arkansas and Texas—Louisiana has yet to have a documented case of either the fungus or the disease. And the Louisiana Department of Wildlife and Fisheries would like to keep it that way. To ensure that the region’s population remains healthy, LDWF Wildlife Health and Disease Surveillance Program collects information on local bat populations, colony size, and locations, which allows LDWF to effectively monitor the potential spread of Pd. To determine if the fungus is in a colony, LDWF biologists take swabs from the wing membrane and muzzles of a number of bats for testing. All LDWF biologists involved in collecting these samples must be vaccinated against rabies prior to entering a bat colony. While Louisiana’s bat population seems to be doing well, Dr. Jim LaCour, LDWF State Wildlife Veterinarian and Wildlife Health and Disease Surveillance Monitoring Program Manager, said any significant reduction in the overall population would be detrimental to the state’s ecosystems. Bats play a critical role in our environment, aiding in maintaining genetic diversity in plantlife and in forest regeneration through pollen and seed dispersal. Mostly insectivores, bats also provide the service of controlling our insect populations, feeding on agricultural pests and mosquitos. In all, bats across the country eat hundreds to thousands of airborne insects an hour and save the U.S. Agricultural Industry over $3.7 billion annually. Dr. LaCour explained that bat migration in Louisiana is largely a mystery, even to scientists, because so many of the species are small and hard to outfit with transmitters, thus their movements go mostly undetected. They do know that in Louisiana, bats breed in the fall, prior to their winter hibernation. The LDWF bat monitoring program is conducted during the winter and summer seasons. To get up close and personal with the monitoring program, I met Brianna Upton—a technician with the LDWF Wildlife Health and Disease Surveillance Program—one evening in Denham Springs to participate in a sixteen-mile acoustic route that records bat calls if they are in the route area. Bats are nocturnal creatures, and their peak feeding time occurs in the evenings when they emerge. Bats use // O C T 2 1
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