Bat Conservation in Georgia
Much of this information is from the U.S. Fish and Wildlife Service. Other sources include the Georgia DNR’s Wildlife Resources Division and the U.S. Geological Survey.
What is white-nose syndrome, or WNS?
White-nose syndrome is a malady blamed for the death of at least 5.7 million to 6.7 million bats in the U.S. WNS has been called “the most precipitous wildlife decline in the past century in North America.”
The disease is named for the white fungus on the muzzles and skin of affected bats. Discovered by a caver in eastern New York’s Schoharie County in February 2006 and documented by state biologists the following winter, white-nose has rapidly spread to sites throughout the Northeast and into the Southeast, the Midwest and Canada.
WNS is caused by the fungus Geomyces destructans, which thrives in the cold and humid conditions characteristic of caves and mines used by bats.
All bats affected with WNS do not have obvious fungal growth, but they may display abnormal behavior (see below) in and outside of their hibernacula – caves and mines where bats hibernate during winter.
The fungus leads to bats being awakened too often from hibernation, or less intense periods of torpor. The bats may then use up fat reserves, which they need to survive hibernation, long before winter is over. Affected bats often leave their hibernacula during winter, searching for insects that have not yet emerged, leading to death of the bats by starvation and cold.
Death rates of 90-100 percent have been seen in some hibernacula.
Emaciation and poor body condition were common factors in bat carcasses checked by the U.S. Geological Survey’s National Wildlife Health Center. Many of the bats examined had little or no body fat.
Bat-to-bat transmission has been verified and is considered the most common pathway. Affected sites generally following bat migration routes.
Research has also shown that viable Geomyces destructans spores can be transmitted on gear, meaning white-nose may also be transmitted by people inadvertently carrying the causative agent from cave to cave on shoes, clothing and gear.
As of March 2013, white-nose has been documented in 22 and five Canadian provinces. The fungus Geomyces destructans has been found on hibernating bats as far west as Oklahoma.
The syndrome was found at five Georgia sites -- two in Dade, two in Walker County and one in Gilmer County -- during cave surveys in February and March 2013. White-nose has also been confirmed in four border states: Tennessee, Alabama and North and South Carolina.
Georgia has few known large winter hibernacula. But, 16 species of bats are found in the state, including all but one of the species affected so far by WNS (see below).
There have been no reported affects on humans or other wildlife. However, authorities urge taking precautions and not exposing yourself unnecessarily to WNS. Scientists use protective clothing when entering caves or handling bats.
According to the Fish and Wildlife Service, white-nose may be associated with some or all of the following unusual bat behaviors:
Hibernating bats may have white fungus that is not associated with WNS. If a bat with fungus is not in an affected area and has no other signs of WNS, it may not have white-nose.
Georgia’s Wildlife Resources Division has stepped up surveys to better assess bat populations, and limited scientific activities in caves. Researchers are also monitoring summer roost sites, which does not require entering caves, and working with other states and federal agencies.
The division is urging cavers and others to reduce trips to Georgia caves and follow national protocol for disinfecting clothes and gear. Wildlife Resources considered some closures – as advised by the Fish and Wildlife Service for WNS-affected and adjacent states – but chose voluntary limits after weighing research, the resource and public interests. This course of action will be reviewed and revised as needed.
Wildlife Resources has sought cavers’ help in spreading the word about white-nose and monitoring and evaluating caves on state lands. About 15 percent of Georgia’s caves are on state-managed lands.
The division has a WNS response plan. Designed to be simple and flexible, the plan outlines steps for raising awareness about the syndrome, preventing or slowing its spread, reporting and analyzing bats, and managing related natural resources such as caves. The document can help guide everyone from cavers cleaning their equipment to researchers scoring bat wing damage and animal control companies removing bats from a building.
An extensive network of state and federal agencies, universities, caving grottos and private individuals are working to investigate the source, spread and cause of bat deaths associated with WNS, and to develop management strategies to minimize the impacts. The overall investigation has three primary focus areas: research, monitoring and management, and outreach.
Research topics vary from possible control measures to decontamination protocols, infection trials and sampling to determine how widespread the fungus is in the soil.
In addition, the U.S. Forest Service closed most caves and mines on Southeastern national forests in June 2009. Groups such as the Southeastern Cave Conservancy that own caves have closed or added permit requirements for some caves.
In Georgia, contact the Wildlife Resources Division at GADNRBats@dnr.state.ga.us or (770) 918-6411.
It is important to determine the species of bat in case it is a federally protected species. If possible, photograph the potentially affected bats (including close-up shots) and send the photograph and a report to the Wildlife Resources Division.
State wildlife agencies that are members of the Southeastern Cooperative Wildlife Disease Study can submit bats to SCWDS for clinical diagnosis using the form available at http://www.vet.uga.edu/scwds/diagnosticservice.php
If you need to dispose of a dead bat found on your property, pick it up with a plastic bag over your hand or use disposable gloves. Place the bat and the bag into another plastic bag, spray with disinfectant, close the bag securely, and dispose of it with your garbage. Thoroughly wash your hands and any clothing that comes into contact with the bat.
If you see a band on the wing or a small device with an antenna on the back of a bat (living or dead), contact the DNR Wildlife Resources Division (770-918-6411) or the nearest U.S. Fish and Wildlife Service office (the Southeast Region office is in Atlanta, 404-679-4000; www.fws.gov/southeast).
These band and transmitters are tools for biologists to identify individual bats.
Georgia DNR encourages cavers to reduce their trips to caves on state-managed lands and follow U.S. Fish and Wildlife Service protocol for disinfecting clothes and gear. Cavers are asked to help spread the word about white-nose, and aid the Wildlife Resources Division in monitoring and evaluating caves on state lands.
The division encourages cavers to observe cave closures and related advisories involving other properties.
Cavers and cave visitors are also urged to stay out of caves in affected and in adjoining states to help slow the potential spread of WNS. Local and national cave groups have also posted information and cave advisories on their websites.
Species affected so far include the tri-colored bat (Perymyotis subflavus), little brown bat (Myotis lucifugus), big brown bat (Eptesicus fuscus), Northern long-eared bat (Myotis septentrionalis), Southeastern myotis (Myotis austroriparius), small-footed myotis (Myotis leibii), cave myotis (Myotis velifer), and the federally endangered Indiana bat (Myotis sodalis) and gray bat (Myotis grisescens).
All except the cave myotis are found in Georgia. The small-footed myotis is a state species of concern.
By Fish and Wildlife Service estimates, 5.7 million to 6.7 million bats have died from WNS, and there seems to be no end in sight. Bat mortality rates of 90-100 percent have been reported at several hibernacula in New York, Massachusetts, Connecticut and Vermont. There may be differences in mortality by site and by species within sites.
The endangered Indiana bat hibernates in many affected sites. Scientists are closely monitoring Indiana bat populations in many hibernacula and, to the extent possible, in their summer maternity colonies.
The impact is unknown. But, bats play a critical role in the health of natural habitats: They are the major predator of night-flying insects, eating on average half their weight in insects in a night, including agricultural pests. (One analysis estimated that the pest-control services provided by insect-eating bats save the U.S. agricultural industry at least $3 billion a year.) Bats also provide nutrients vital to some cave habitats.
In the tropics, bats that eat fruit and nectar help pollinate plants and disperse seeds.
Many bat populations are already in decline because of habitat loss. Their ability to rebound is limited by reproduction rates as low as one offspring a year.
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