Arnold bat population in danger of white nose syndrome

  • Published
  • By Janae' Daniels
  • AEDC/PA
Arnold Air Force Base, Tenn. --  Because Arnold Engineering Development Center's (AEDC) biologists are two of only a handful of experts who have experience with bat issues in the state of Tennessee, the U.S. Fish and Wildlife Service (USFWS) has asked them to help with a current and wide-spread issue. 

Aerospace Testing Alliance Conservation Biologists John Lamb and Richie Wyckoff were asked to participate in an ad hoc interagency state planning group for the arrival of white nose syndrome (WNS) in Tennessee. 

"We thought we had more time to plan for the arrival of WNS in Tennessee, but then it jumped to Virginia this past winter and is only about 20 miles from a very important gray bat hibernation cave," Lamb explained. "So we held an emergency meeting in May, one of several that is ongoing. Since that time we have stepped up our activities as cooperating agencies." 

According to Lamb, WNS has not spread to Tennessee yet, but could be expected as early as this coming winter. 

Hibernating bats that have been afflicted by WNS in the northeastern United States are dying in record numbers, according to the USFWS. WNS is named for the white fungus on the muzzles and wings of affected bats. According to the USFWS, the syndrome was first documented at four sites in eastern New York in the winter of 2006-2007 and has rapidly spread to multiple sites throughout the northeast. 

The USFWS is still learning about WNS, but they know of no risk to humans from contact with WNS-affected bats. However, officials urge outdoors men to take precautions and not be exposed unnecessarily to WNS. 

Biologists and cavers have documented WNS in bat hibernation caves in New Hampshire, Vermont, New York, Massachusetts, Connecticut, New Jersey, Pennsylvania, West Virginia and Virginia. 

The signs of WNS are usually a white fungus, especially on the bat's nose, but could also be on the wings, ears or tail; bats flying around during the day in temperatures below freezing; bats clustered near the entrance of a hibernation cave and dead or dying bats on the ground or on buildings, trees or other structures in the winter. 

"We were already doing a lot of gray bat work at AEDC," Lamb said. "Ironically it was to support taking them off the endangered species list - that won't happen now." 

For example, Lamb and Wyckoff have written sections of the Draft Tennessee White Nose Syndrome spring/summer strategy and will begin assisting with the fall/winter soon. They have also trained Tennessee Wildlife Resources Agency and USFWS biologists on techniques needed to implement parts of the plan. 

They have assisted the Nature Conservancy with trapping and banding at two of their caves in Murfreesboro and McMinnville, monitored sites to get a pre-WNS population baseline, used thermal infrared video equipment to tape gray bats emerging from caves at night to feed and have done repeated recording of bat calls with bat detectors while driving along predetermined road routes to get a baseline of species other than gray bats that may be affected by WNS. 

The bottom line for bats at AEDC, according to Lamb, is there is a good possibility that these now common species could be impacted to the point that they are listed as endangered. 

"We have eight species on base; three of these don't hibernate in caves, so they will be unaffected. Four species spend the summer in forests and hibernate in caves," he explained. "Gray bats, our eighth species, hibernate and spend the summer in caves and they travel long distances between caves. I think it is possible they will be extinct within five years." 

Why should we care? 

"In addition to the possibility of increased restrictions because of additional species being added to the Endangered Species act, bats are the primary predators of night-flying insects, and many such insects rank among North America's most costly agricultural and forest pests," Lamb said. "These include cucumber, potato and snout beetles; corn-earworm, cotton-bollworm and grain moths; leafhoppers and mosquitoes. 

"A single little brown bat (Myotis lucifugus) can catch more than 1,200 mosquito-
sized insects in an hour. A colony of just 150 big brown bats (Eptesicus fuscus) can eat sufficient cucumber beetles each summer to protect farmers from 33 million of these beetles' root worm larvae, pests that cost American farmers an estimated billion dollars annually." 

In 1976, the gray bat was listed as endangered due to dramatic declines and habitat loss. 

According to Lamb, AEDC's work with gray bats was initially to maintain compliance with the Endangered Species Act. In the 1990s they began mist netting at various areas on base to see where they gray bats occur to learn where consultation with the USFWS might be required. 

"We also knew that all the gray bats we were catching couldn't have all come from the Woods Dam where we know there is a colony," Lamb said. "So, FWS [the Fish and Wildlife Service] asked us to go to area caves and trap them, at which time we placed uniquely numbered forearm bands [on each bat] so if we caught them on base we would know where they came from." 

Lamb said, "About six years ago it was my opinion, and that of most bat biologists, that their numbers had recovered sufficiently that they no longer needed to be listed. 

"Like the Bald Eagle, we thought it was a great success story due to recovery efforts over the last 30 years. This would reduce the restriction and consultation requirements; then white nose syndrome changed everything." 

In a press release sent by the Nature Conservancy July 6, the USFWS agreed to close caves located on state lands in Tennessee. The caves will be closed for a year in an effort to prevent the spread of WNS. 

The closures were effective July 1 and will temporarily close public access to all caves, sinkholes, tunnels and abandoned mines on state land managed by the Tennessee Wildlife Resources Agency, the Tennessee Department of Environment and Conservation and the Tennessee Department of Agriculture Division of Forestry. These lands include state parks, forests, and wildlife management areas. The closure extends through May 2010.