Bats of Virginia

Of the 45 bat species living in the United States, 15 are normally present in Virginia (and two others have been recorded). They are all insect eaters, catching mosquitoes, moths, and other insects on the fly. A single little brown bat can catch 600 mosquitoes in one hour. Virginia has no nectar-feeding bats or vampire bats that feed on blood.1

In March, 2005, Governor Mark Warner signed a new state law designating an official state bat - the Virginia big-eared bat (Corynorhinus townsendii virginianus, also considered as a subspecies of Townsend's big-eared bat Plecotus townsendii). In his signing statement, Governor Warner expressed a wry sense of humor that is not always evident in elected officials:2

This bill designates the Virginia Big-Eared bat as the official bat of the Commonwealth. The Legislature previously has designated a state bird (northern cardinal), a state flower and tree (dogwood), a state dog (American fox hound), a state boat (Chesapeake Bay deadrise), a state dance (square dance), a state insect (tiger swallowtail butterfly), a state fish (brook trout), a state shell (oyster), a state fossil (Chesapecten jeffersonius), and a state beverage (Got Milk?). Therefore, I see no harm in designating a state bat, no matter how odd-looking the Virginia Big-Eared bat might be. However, I am compelled to add this:

I took some grief for my nudist park pun.
But resist I cannot on this one.
I will sign this bill,
more or less of free will.
But I can't do it without having some fun.

We have a state dog and a fish and a bird.
And of the fossil I’m sure you have heard.
So why not a bat?
What's wrong with that?
The state beverage is no more absurd.

Upon my signature now it appears,
The designation will now last for years.
I'll spare you the Latin
If you're seeking the bat in
A guidebook, it's the one with big ears.

I think our bat's up to the test.
If you doubt it, just ask Adam West.
He was TV's Bruce Wayne --
the caped crusader's real name --
and could 'Zap!' and 'Kapow!' with the best.
Virginia Big-eared Bat
Virginia Big-eared Bat
Source: US Fish and Wildlife Service
sleeping in normal position - feet at top, head down
sleeping in normal position - feet at top, head down
Source: US Fish and Wildlife Service

About half of Virginia's bat species depend upon caves as sites for sleeping and raising their young. The other half rely upon trees, old logs, and other buildings for shelter. Three species - Big Brown Bat (Eptesicus fuscus fuscus), Little Brown Bat (Myotis lucifugus lucifugus), Evening Bat (Nycticeius humeralis humeralis) - are likely to roost inside houses and trigger conflict with homeowners unwilling to share their space with flying mammals.3

Human disturbance in caves during the winter can force the bats to burn energy during their normal hibernation cycle. Just two disruptions of hibernation can cause bats to starve before insect populations re-appear in the Spring and provide a food source.4

The Virginia Big-eared Bat spends winter and summer in the same territory. In the Spring, the females join together in maternity colonies to birth their bat "pups." While there are more Virginia Big-eared Bats in West Virginia than in Virginia, the state bat of Virginia does roost in three Tazewell County caves during the Summer (in contrast to most cave-dwelling species that hibernate in caves just during the winter). Individual bats may fly as much as six miles away from their roosting site to feed in the same area, night after night. In the Winter, the population disperses to roost in additional caves in Highland and Bland counties, as well as Tazewell County.5

Virginia Big-eared Bat Summer roosting territory
Virginia Big-eared Bat Summer roosting territory

Other species of bats migrate seasonally like birds, but the winter/summer territories of bats are typically within 100 miles. (The hoary bat can migrate as much as 250 miles, and that species reached the Hawaii islands across 2,500 miles of water.) When cold weather approaches each Fall, deciduous trees drop their leaves and many ground-level plants die back. Without a food source, insects lay eggs or hide in various crevices to overwinter, leaving bats with no food source. One solution for bats is to find a cold spot to hibernate, lowering body temperature to almost the temperature of the surrounding cave and suspending most metabolic processes to reduce the need for food. Hibernating bats seek out caves where temperatures are between freezing (32°F) and 49°F. South of Virginia, many caves are too warm for hibernation, and at least one population of gray bats migrated north out of Tennessee to overwinter in cooler caves.6

Three bat species in Virginia are listed as endangered: Gray Bat, Indiana Bat, and Virginia Big-eared Bat.7 The traditional threat to the survival of the species was human disturbance inside caves, forcing bats awake and causing them to exhaust food reserves. Bat hibernation should end when food supplies, typically insects, have returned in the Spring, so bats will starve to death if hibernation is interrupted and stored energy is used up before the insects return.

A new threat is collisions with wind energy turbine blades and tall telecommunication towers. The death of over 1,000 bats at Mountaineer Wind Energy Center (West Virginia) in 2003, followed by additional deaths in 2004, triggered research efforts to determine how to minimize bat/windmill collisions. The migration season in the fall appears to be the time of greatest risk.8

Federal Register Notice proposing designation of critical habitat for Virginia Big-eared Bat, in 1979
Federal Register Notice proposing designation of
critical habitat for Virginia Big-eared Bat, in 1979
Source: US Fish and Wildlife Service
spread of white-nose syndrome, from New England into Virginia/Tennessee
spread of white-nose syndrome, from New England into Virginia/Tennessee
Source: US Fish and Wildlife Service

white-nose syndrome in 2011
white-nose syndrome in 2011
Source: US Fish and Wildlife Service, White-nose syndrome map

expansion of white-nose syndrome in 2012
expansion of white-nose syndrome in 2012
Source: US Fish and Wildlife Service, White-nose syndrome map

expansion of white-nose syndrome in 2013
expansion of white-nose syndrome in 2013
Source: US Fish and Wildlife Service, White-nose syndrome map

A disease known as white-nose syndrome, apparently caused by the Geomyces destructans fungus, threatens to eliminate some bat species in Virginia. Massive die-offs appeared first in New York/New England in 2006, and has since spread south. The first Virginia infection was identified in a Bath County cave in 2009.9

Under the assumption that white-nose syndrome was spread by cavers introducing the fungus into new locations, in 2009 the Virginia Department of Game and Inland Fisheries and the U.S. Forest Service closed all caves on state and Forest Service lands in Virginia to recreational caving. By 2012, it was clear that quarantine efforts had failed and Geomyces destructans could not been kept out of any Virginia caves. The last watershed to report the presence of white-nose syndrome was the Powell River. In February 2013, the disease was confirmed in Cumberland Gap National Historic Park.10

little brown bat affected by white-nose syndrome
little brown bat affected by white-nose syndrome
Source: US Fish and Wildlife Service, National Digital Library

In late 2009, the National Zoo started to establish a colony of Virginia Big-eared Bats. Forty bats, not yet infected by the fungus, were captured and moved to the Smithsonian Conservation Biology Institute at Front Royal, Virginia. Only eight survived the winter, reflecting the challenge of creating an artificial environment that matched the requirements of the species. There appears to be no way to conserve the official state bat species in captivity and reintroduce it to the wild, comparable to the endangered species recovery efforts with the California condor and the whooping crane.11

white-nose syndrome
white-nose syndrome
Source: US Fish and Wildlife Service
(Photo courtesy Ryan von Linden/New York Department of Environmental Conservation)

The commercial caves in Virginia, such as Luray Caverns, never closed while white-nose syndrome spread across Virginia. No commercial cave in Virginia could afford to shut down for an indefinite number of years, until some mechanism to eliminate the Geomyces destructans fungus or mitigate its impacts could be developed. Even the National Park Service kept Gap Cave open in Cumberland Gap National Historical Park, though it did ask visitors to wear clothing that have not been in other caves.12

By 2012, groups such as the Virginia Speleological Society (VSS) proposed re-opening caves to recreational exploration in the summer, based on the understanding that white-nose syndrome had already been transmitted across Virginia through bat-to-bat contacts. Scientists projected that the endangered Indiana bat species will disappear from much of its natural range, but continuing the ban on recreational caving was no longer viewed as an effective way to limit spread of the disease.13

If recreational caving was permanently banned in Virginia, some transmission of fungal spores might be avoided. However, the current community of committed cavers, organized in regional grottoes, would gradually die out if exploration of non-commercial caves was permanently banned. The loss of the caver community would reduce public support for protection of karst communities from inappropriate development, such as directing stormwater underground in limestone-rich areas. A study of the impacts on cave closures in the Monongahela National Forest in West Virginia concluded that the economic damage was minimal, but other impacts should also be considered:14

There are costs associated with the cave closures on the MNF that go beyond the economic impacts related to equipment and travel-related expenditures by caving participants... Caves and bats may be more vulnerable to human caused negative impacts, such as vandalism, because the caves are closed to the mainstream caving community.

Virginia Big-eared Bats
Virginia Big-eared Bats
Source: US Fish and Wildlife Service, National Digital Library

Links

References

1. "Bats," West Virginia University Extension Service, December 1999, http://www.wvu.edu/~agexten/wildlife/bats.pdf?; "Bats of Virginia," Virginia Department of Conservation and Recreation (DCR), http://www.dcr.virginia.gov/natural_heritage/karst_bats.shtml (last checked May 1, 2013)
2. "Virginia's gone batty," Fairfax Times, April 14, 2005, http://ww2.fairfaxtimes.com/cms/archivestory.php?id=195840 (last checked May 1, 2013)
3. "Big Brown Bat, Evening Bat, & Little Brown Bat Removal & Control Services," Blue Ridge Wildlife Management, http://www.yourwildlifepro.com/bats.html (last checked May 1, 2013)
4. "Revised Biological Assessment for Threatened and Endangered Species on the Monongahela National Forest, West Virginia," US Forest Service, September 2001, p.68, http://books.google.com/books?id=yAN7tPsZzU0C (last checked May 1, 2013)
5. "Virginia Big-Eared Bat Facts," Smithsonian Institution - National Zoological Park, http://nationalzoo.si.edu/scbi/SpeciesSurvival/VirgianiaBigEaredBats/VBEBfactsheet.cfm; Virginia Department of Game and Inland Fisheries, "Virginia big-eared bat," http://www.dgif.virginia.gov/wildlife/information/?s=050035; "Wildlife Diversity Notebook: Virginia big-eared bat," West Virginia Wildlife, Fall 2006, http://www.wvdnr.gov/wildlife/magazine/Archive/06fall/VaBEB.pdf (last checked May 1, 2013)
6. "How North America's Bats Survive the Winter," Bats Magazine, Volume 9, No. 3 (Fall 1991), http://www.batcon.org/index.php/media-and-info/bats-archives.html?task=viewArticle&magArticleID=503; Cryan, P.M., M.A. Bogan, R.O. Rye, G.P. Landis, and C.L. Kester, "Stable hydrogen isotope analysis of bat hair as evidence for seasonal molt and long-distance migration," Journal of Mammalogy, Volume 85 No. 5 (2004), http://www.fort.usgs.gov/products/publications/pub_abstract.asp?PubID=21070; "Chemistry and Migration Mysteries," Bats Magazine, Volume 22, No. 3 (Fall 2004), http://www.batcon.org/index.php/media-and-info/bats-archives.html?task=viewArticle&magArticleID=5 (last checked May 1, 2013)
7. "Species Reports - Listings and occurrences for Virginia," Environmental Conservation Online System (ECOS), US Fish and Wildlife Service, http://ecos.fws.gov/tess_public/pub/stateListingAndOccurrenceIndividual.jsp?state=VA (last checked May 1, 2013)
8. Arnett, E. B., M. D. Strickland, M. L. Morrison. 2007. "Renewable energy resources and wildlife: impacts and opportunities." Transactions of the 72nd North American Wildlife and Natural Resources Conference 72: 65-95. http://www.batsandwind.org/pdf/Arnett%20et%20al%202007.pdf (last checked May 1, 2013)
9. "Bat-killing disease hitting Virginia harder than ever," Richmond Times-Dispatch, May 1, 2013 , http://www.timesdispatch.com/news/state-regional/bat-killing-disease-hitting-virginia-harder-than-ever/article_890ae3b7-9956-5458-a054-2e35176136c5.html (last checked May 1, 2013)
10. "DGIF Revision to the Closed Cave Policy on Agency Lands," Virginia Department of Game and Inland Fisheries, November 16, 2012, http://www.dgif.virginia.gov/wildlife/bats/white-nose-syndrome/closed-cave-policy-2012-revision.pdf; "White-Nose Syndrome Found on Bats at Cumberland Gap National Historical Park," National Park Service - Cumberland Gap National Historical Park news release, February 10, 2013, http://www.nps.gov/cuga/parknews/white-nose-syndrome-found-on-bats-at-cumberland-gap-national-historical-park.htm (last checked May 1, 2013)
11. "Virginia Big-Eared Bats at the National Zoo," Smithsonian Institution - National Zoological Park, http://nationalzoo.si.edu/scbi/SpeciesSurvival/VirgianiaBigEaredBats/zooproject.cfm; "Controversy over endangered Virginia big-eared bats, Washington Post, March 15, 2010, http://www.washingtonpost.com/wp-dyn/content/article/2010/03/14/AR2010031402724.html (last checked May 1, 2013)
12. "Guided Tours," National Park Service - Cumberland Gap National Historical Park, http://www.nps.gov/cuga/planyourvisit/guidedtours.htm (last checked May 1, 2013)
13. Thogmartin, W. E., C. Sanders-Reed, J. A. Szymanski, R. A. King, L. Pruitt, P. C. McKann, M. C. Runge, and R. E. Russell, "White-nose syndrome is likely to extirpate the endangered Indiana bat over large parts of its range," Biological Conservation, Volume 160 (April 2013), http://dx.doi.org/10.1016/j.biocon.2013.01.010 (last checked May 1, 2013)
14. Neal Christensen, Cynthia Sandeno, "Social and Economic Values of Caves on National Forest Lands: The Case of the Monongahela National Forest," September 2012, http://www.caves.org/WNS/Caves_and_WNS_social_economic_final.pdf (last checked May 1, 2013)


Threatened, Endangered, Sensitive, and Other "Species of Concern" in Virginia
Habitats and Species of Virginia
Caves and Springs in Virginia
Virginia Places