Who Knew? First Myotis sodalis (Indiana Bat) Maternity Colony in the Coastal Plain of Virginia
Michael J. St. Germain, Andrew B. Kniowski, Alexander Silvis, and W. Mark Ford
Northeastern Naturalist, Volume 24, Issue 1 (2017): N5–N10
Full-text pdf (Accessible only to subscribers. To subscribe click here.)
Access Journal Content
Open access browsing of table of contents and abstract pages. Full text pdfs available for download for subscribers.
Current Issue: Vol. 30 (3)
Check out NENA's latest Monograph:
Monograph 22
N5
2017 Northeastern Naturalist Notes Vol. 24, No. 1
M.J. St. Germain, A.B. Kniowski, A. Silvis, and W.M. Ford
Who Knew? First Myotis sodalis (Indiana Bat) Maternity Colony
in the Coastal Plain of Virginia
Michael J. St. Germain1, Andrew B. Kniowski1, Alexander Silvis1, and W. Mark Ford1,2,*
Abstract - We report the first confirmed Myotis sodalis (Indiana Bat) maternity colony in Virginia,
discovered at Fort A.P. Hill Military Reservation in Caroline County along the Piedmont-Coastal
Plain Fall Line. Acoustic surveys conducted in 2014 indicated likely presence of Indiana Bats on
the installation. Subsequent focal mist-netting during May–June 2015 resulted in capture of 4 lactating
females that we subsequently radio tracked to a maternity colony site containing at least 20
individuals. The core roosting-area was comprised of Pinus taeda (Loblolly Pine) snags with abundant
exfoliating bark and high solar exposure. This forest patch was adjacent to a large emergentshrub
wetland and within a larger matrix of mature, mid-Atlantic hardwood forests. The site where
we found the colony location is 140 km east of the nearest known hibernaculum and is outside of
the previously documented extent of this species’ occurrence.
Myotis sodalis (Miller and Allen) (Indiana Bat) is a federally endangered species that
is patchily distributed in the US from the Midwest and upper mid-South to the Northeast
(US Fish and Wildlife Service 2007). Within the Mid-Atlantic region, the species’ documented
range occurs primarily in the central Appalachians (Ford and Chapman 2007). In
Virginia, both sexes hibernate in caves in the winter (Powers et al. 2015). During summer,
males roost singly and often in close proximity (less than 25 km) to hibernacula (Ford et al. 2002),
whereas females sometimes migrate substantial distances (>150 km) from hibernacula to
maternity colonies (Cryan and Veilleux 2007, Gardner and Cook 2002, Kurta 2010, Rockey
et al. 2013) or they may remain relatively close (less than 10 km; Keyser and Ford 2006). Maternity
colonies generally consist of fewer than 100 individuals (Harvey 2002). Characteristic
maternity roost-trees or snags where females give birth and raise their young are taller than
the surrounding canopy or in a bole within a canopy gap with high solar exposure, have
large diameters, and have sloughing or exfoliating bark (Britzke et al. 2006, Callahan et
al.1997, Watrous et al. 2006). Indiana Bats have been observed in numerous species of
trees or snags, particularly Carya ovata (K. Koch) (Shagbark Hickory) and Acer saccharum
((Marshall) (Sugar Maple) in much of the hardwood-dominated portion of its distribution
(Jachowski et al. 2016, Menzel et al. 2001), whereas Pinus spp. (pine) snags with bark
peeling off the bole are common day-roosts in the southern Appalachians and into the mid-
South and lower Tennessee Valley (Britzke et al. 2003; D. Krusac, USDA Forest Service,
Atlanta, GA, pers. com.)
Members of the maternity colony have a non-random social-structure network and often
use multiple roost-trees throughout the season (Kurta et al. 2002, Silvis et al. 2014), within
or in close proximity (< 3 km) to riparian habitats (Bergeson et al. 2013; Carter 2006;
Kinowski and Gehrt 2014; Menzel et al. 2001, 2005). Several Indiana Bat hibernacula have
been documented in the western mountains of Virginia and neighboring West Virginia, including
US Fish and Wildlife Service Priority II hibernacula (Powers et al. 2015, US Fish
and Wildlife Service 2007); however, prior to this study, no confirmed Indiana Bat maternity
colony had been documented in Virginia (Virginia Department of Game and Inland
1Department of Fish and Wildlife Conservation, College of Natural Resources and Environment, Virginia
Tech, Blacksburg, VA 24060. 2 US Geological Survey, Virginia Cooperative Fish and Wildlife
Research Unit, Blacksburg, VA 24061. *Corresponding author - wmford@vt.edu.
Manuscript Editor: Hugh Broders
Notes of the Northeastern Naturalist, Issue 24/1, 2017
2017 Northeastern Naturalist Notes Vol. 24, No. 1
N6
M.J. St. Germain, A.B. Kniowski, A. Silvis, and W.M. Ford
Fisheries 2009), and very few had been found either in West Virginia or Maryland (Johnson
and Gates 2009, Keyser and Ford 2006).
In 2014, we initiated an extensive acoustic survey of Fort A.P. Hill, a 30,060-ha US Army
installation along the Piedmont–Coastal Plain physiographic province boundary (Fall Line)
near Bowling Green in Caroline County, VA (Fig. 1). We used Anabat II systems (Titley Scientific,
Columbia, MO) in zero-crossing format (Corben 2002) to collect acoustic data. We
analyzed call data using the USFWS-approved software program Kaleidoscope Pro v2.0.7
(Wildlife Acoustics, Maynard, MA), and Echoclass v.3.1 (US Army Engineer Research and
Development Center, Vicksburg, MS). Results of analyses using both programs indicated
the likely presence of Indiana Bats at several locations on Fort A.P. Hill. Subsequent visual
examination of calls in the Analook Version 3.7 viewer (Titley Scientific, Columbia, MO)
supported automated-identification results as having echolocation characteristics indicative
of Indiana Bats. We conducted focal mist-netting in the spring and mid-summer of 2015
at areas with acoustic detections, and captured 4 lactating female Indiana Bats. We used
surgical cement (Perma-Type Company, Inc., Plainville, CT) to attach transmitters (LB-2X,
Holohil Systems, Ltd., Carp, ON, Canada) to the dorsal surface between the scapulae of
these females (Johnson et al. 2010) and tracked them using TRX-2000 receivers (Wildlife
Materials, Inc., Murphysboro, IL). Transmitters weighed 0.27 g and were less than 5% of the body
mass of radio-tagged bats, as recommended by Aldridge and Brigham (1988).
We tracked these bats to 9 roosts. Based on 6 exit counts and daily location data, we observed
that these females were part of an active maternity colony and found that the core
roost-area consisted of 5 roosts, with 4 additional roosts ~1 km away (Fig. 2); first date of
capture was 13 May 2015. This maternity colony is ~140 km east of the nearest known hibernaculum
in Virginia (Highland County; Powers et al. 2015) and 150 km south of the Carroll
County, MD, observation of Indiana Bat maternity activity by Johnson and Gates (2009).
Although we were unable to determine the full extent of colony membership, we observed 20
individuals emerging from 3 roosts on the same evening. Individual tree exit-counts ranged
from 2 to 14 individuals. Using the minimum convex polygon method (Menzel et al. 2006)
within ArcGIS 10.3 (ESRI, Redlands, CA), we estimated that that the whole roosting area was
Figure 1. Location of Fort A.P. Hill and active Myotis sodalis (Indiana Bat) maternity colony (2015)
within the Coastal Plain physiographic province of Virginia.
N7
2017 Northeastern Naturalist Notes Vol. 24, No. 1
M.J. St. Germain, A.B. Kniowski, A. Silvis, and W.M. Ford
61 ha, although the core area was only ~1 ha. The core roosting area was comprised of standing-
dead Pinus taeda L. (Loblolly Pine) snags along a toe-slope ravine adjacent to a large
emergent-shrub wetland, and within a larger matrix of mature, mid-Atlantic hardwood forest.
All identified roost trees were Loblolly Pine snags in clusters or isolated trees. Roost trees
ranged from 15.1 m to 34.2 m in height (mean = 23.8 m); dbh range = 29.7–51.3 cm (mean
= 42.2 cm). Bats roosted in the mid–upper bole (mean = 16.6 m above the ground); 70% of
boles had full solar exposure and exfoliating bark coverage of 30–90% (mean = 54%). Snags
appeared to be insect-killed (presumably by Dendroctonus frontalis [Zimmerman] [Southern
Pine Beetle]) and/or prescribed-fire–killed individuals. We observed fire scarring to heights
of 3–4 m from the ground on most of the surrounding trees. The core roosting area was most
recently burned during a late dormant-season prescribed fire in 2014. Site occupancy with
this disturbance regime suggests that Indiana Bats at Fort A.P. Hill may be able to follow the
shifting mosaic of insect and fire mortality in pines. Prescribed burning provides suitable but
ephemeral day-roost conditions that may only persist for 2–4 seasons as observed elsewhere
in the mid-Atlantic (Johnson et al. 2010).
Stand conditions, similar to those used by the colony we identified, exist throughout
Fort A.P. Hill. It is noteworthy that all roost trees we located were readily identifiable from
high-resolution 2014 National Agriculture Imagery Program (NAIP) aerial photography
(Fig. 3a). The spectral properties of the dead trees were visible using the 1-2-3 (red-green-
Figure 2. Myotis sodalis (Indiana Bat) roost locations (filled circles) at Fort A.P. Hill, VA. Two roost
trees (within cluster) were less than 0.5 m apart and show as 1 location at this scale.
Figure 3 (following page). Myotis sodalis (Indiana Bat) roost locations (filled circles) at Fort A.P.
Hill, Virginia, with (A) National Agriculture Imagery Program (NAIP) 2014 true-color imagery and
(B). ArcGIS v10.3, 1-2-3 (red-green-blue) band combination with a histogram equalize The spectral
properties of dead vegetation show as pink with this combination and histogram stretch. Two roost
trees were less than 1 m apart and show as 1 location at this scale.
2017 Northeastern Naturalist Notes Vol. 24, No. 1
N8
M.J. St. Germain, A.B. Kniowski, A. Silvis, and W.M. Ford
Figure 3.[Caption located on previous page.]
N9
2017 Northeastern Naturalist Notes Vol. 24, No. 1
M.J. St. Germain, A.B. Kniowski, A. Silvis, and W.M. Ford
blue) band combination with a histogram-equalize stretch within ArcGIS 10.3 (Fig. 3b).
The change-detection analysis we performed between 2012 and 2014 suggests 1% annual
Loblolly Pine mortality as potential roost recruitment.
Our finding represents the first confirmed Indiana Bat maternity colony in Virginia and is
relatively novel for its occurrence in the Coastal Plain. Although this colony appears small
compared to other sites studied prior to the advent of White-nose Syndrome (Menzel et al.
2001, Silvis et al. 2014), it represents a significant expansion in the known range of the
species’ summer distribution. Additional acoustic surveys along the Fall Line in Virginia
conducted during 2014–2015 detected the probable presence of Indiana Bats at numerous
other locations (A. Silvis, unpubl. data), suggesting the species may be more widely distributed
than previously believed. The Coastal Plain of Virginia, and more broadly, much of
the Coastal Plain of the mid-Atlantic, was previously considered to be outside the known
range; thus, surveys for targeting Indiana Bats in the area have been lacking. Therefore, it
is unclear whether the colony we documented has a long-term history in the region, or if
it represents a shift in range in concert with land-use change, ongoing climate change, the
White-nose Syndrome disease dynamic, or a combination of those factors. Accordingly, we
suggest that increased monitoring and surveys in the mid-Atlantic Coastal Plain physiographic
province are warranted.
Acknowledgments. We thank Jason Applegate and Ben Fulton along with numerous others at the
Fort A.P. Hill Environmental and Natural Resources Division and Range Control staff for their assistance
throughout this effort. Our study was carried out in accordance with state requirements for
capture and handling of wildlife (Virginia Department of Game and Inland Fisheries Threatened and
Endangered Species Permit # VA53992). Capture and handling protocols followed the guidelines of
the American Society of Mammalogists for bats and was approved by the Virginia Polytechnic Institute
and State University Institutional Animal Care and Use Committee (protocol # 14-014-FIW).
Funding was provided by Fort A.P. Hill through US Geological Survey Virginia Cooperative Fish and
Wildlife Research Unit RWO 157 Grant #G14AC00124.
Literature Cited
Aldridge, H.D.J.N., and R.M. Brigham. 1988. Load carrying and maneuverability in an insectivorous
bat: A test of the 5% “rule” of radio-telemetry. Journal of Mammalogy 69:379–382.
Bergeson, S.M., T.C. Carter, and M.D. Whitby. 2013. Partitioning of foraging resources between
sympatric Indiana and Little Brown Bats. Journal of Mammalogy 94(6):1311–1320.
Britzke, E.R., M.J. Harvey, and S.C. Loeb. 2003. Indiana Bat, Myotis Sodalis, maternity roosts in the
southern United States. Southeastern Naturalist 2:235–242.
Britzke, E., A. Hicks, S. Von Oettingen, and S. Darling. 2006. Description of spring roost-trees used
by female Indiana Bats (Myotis sodalis) in the Lake Champlain Valley of Vermont and New York.
American Midland Naturalist 155:181–187.
Callahan, E.V., R.D. Drobney, and R.L. Clawson. 1997. Selection of summer roosting sites by Indiana
Bats (Myotis sodalis) in Missouri. Journal of Mammalogy 78:818–825.
Carter, T. 2006. Indiana Bats in the Midwest: The importance of hydric habitats. Journal of Wildlife
Management 70:1185–1190.
Corben C. 2002. Zero-crossings analysis for bat identification. Pp. 95–107, In R.M. Brigham. E.K.V.
Kalko, G. Jones, S. Parsons, H.J.G.A. Limpens (Eds.). Bat Echolocation Research: Tools, Techniques,
and Analysis. Bat Conservation International, Austin, TX. 171 pp.
Cryan, P.M., and J.P. Veilleux. 2007. Migration and use of autumn, winter, and spring roosts by tree
bats. Pp. 153–175, In M.J. Lacki, J.P. Hayes, and A. Kurta (Eds.). Bats in Forests. Johns Hopkins
University Press, Baltimore, MD. 329 pp.
Ford, W.M., and B.R. Chapman. 2007. Indiana Myotis. Pp. 205–211, In M. Trani-Griep, W.M. Ford,
and B.R. Chapman (Eds.). Land Manager’s Guide to Mammals of the South. The Nature Conservancy,
Durham, NC. 546 pp.
2017 Northeastern Naturalist Notes Vol. 24, No. 1
N10
M.J. St. Germain, A.B. Kniowski, A. Silvis, and W.M. Ford
Ford, W.M., J.M. Menzel, M.A. Menzel, and J.W. Edwards. 2002. Summer roost-tree selection by a
male Indiana Bat on the Fernow Experimental Forest. USDA Forest Service Research Note NE-
378. Newtown Square, PA. 7 pp.
Gardner, J.E., and E.A. Cook. 2002. Seasonal and geographic distribution and quantification of potential
summer habitat. Pp. 9–20, In A. Kurta, and J. Kennedy (Eds.). The Indiana Bat: Biology
and management of an endangered species. Bat Conservation International, Austin, TX. 253 pp.
Harvey, M.J. 2002. Status and ecology in the southern United States. Pp. 29–34, In A. Kurta and J.
Kennedy (Eds.). The Indiana Bat: Biology and Management of an Endangered Species. Bat Conservation
International, Austin, TX. 253 pp.
Jachowski, D.S., C.T. Rota, C.A. Dobony, W.M. Ford, and J.W. Edward. 2016. Seeing the forest
through the trees: Considering roost-site selection at multiple spatial scales. PLoS ONE 11(3):
e0150011. doi:10.1371/journal.pone.0150011.
Johnson, J.B., and J.E. Gates. 2009. Observations of Indiana myotis roosting and foraging behavior
in Carroll County, Maryland. Maryland Naturalist 50:11–29.
Johnson, J.B., W.M. Ford, J.L. Rodrigue, J.W. Edwards, and C.M. Johnson. 2010. Roost selection by
male Indiana Myotis following forest fires in central Appalachian hardwoods forests. Journal of
Fish and Wildlife Management 1:111–121.
Keyser, P.D., and W.M. Ford. 2006. Influence of fire on mammals in eastern oak forests. Pp. 1801–90,
In M.B. Dickinson (Ed.). Fire in Eastern Oak Forests: Delivering Science to Land Managers.
Conference proceedings. USDA Forest Service General Technical Report NRS-P-1.
Kurta, A. 2010. Reproductive timing, distribution, and sex ratios of tree bats in Lower Michigan.
Journal of Mammalogy 91:586–592.
Kurta, A., S.W. Murray, and D.H. Miller. 2002. Roost selection and movements across the summer
landscape. Pp. 118–129, In A. Kurta and J. Kennedy (Eds.). The Indiana Bat: Biology and Eanagement
of an Endangered Species. Bat Conservation International, Austin, TX. 253 pp.
Kniowski, A.B., and S.D. Gehrt, 2014. Home range and habitat selection of the Indiana Bat in an
agricultural landscape. Journal of Wildlife Management 78(3)503–512.
Menzel, J.M., W.M. Ford, M.A. Menzel, T.C. Carter, J.E. Gardner, J.D. Garner, and J.E. Hofmann.
2005. Summer habitat use and home-range analysis of the endangered Indiana Bat. Journal of
Wildlife Management 69:430–436.
Menzel, J.M., W.M. Ford, J.W. Edwards, and T.M. Terry. 2006. Home range and habitat use of the
vulnerable Virginia Northern Flying Squirrel (Glaucomsy sabrinus fuscus) in the Central Appalachian
Mountains, USA. Oryx 40:204–210
Menzel, M.A., J.M. Menzel, T.C. Carter, W.M. Ford, and J.W. Edwards. 2001. Review of the foresthabitat
relationships of the Indiana Bat (Myotis sodalis). USDA Forest Service, General Technical
Report NE-284. 21 pp.
Powers, K.E., R.J. Reynolds, W. Orndorff, W.M. Ford., and C.S. Hobson. 2015. Post-White-nose
Syndrome trends in Virginia’s cave bats, 2008–2013. Journal of Ecology and the Natural Environment
7:113–
123
Rockey, C.D., J.P. Stumpf, and A. Kurta, 2013. Additional winter recoveries of Indiana Bats (Myotis
sodalis) banded during summer in Michigan. Northeastern Naturalist 20:N8–
N13.
Silvis, A., A.B. Kniowski, S.D. Gehrt, and W.M. Ford. 2014. Roosting and foraging social structure
of the endangered Indiana Bat (Myotis sodalis). PLoS ONE 9:e96937.
US Fish and Wildlife Service. 2007. Indiana Bat (Myotis sodalis) draft recovery Plan: First Revision.
US Fish and Wildlife Service, Fort Snelling, MN. 258 pp.
Virginia Department of Game and Inland Fisheries.2009. Fish and wildlife information service. Available
online at: http://vafwis.org/fwis/?Menu=Home.Species+Information. Accessed 5 May 2016.
Watrous, K.S., T.M. Donovan, R.M. Mickey, S.R. Darling, A.C. Hicks and S.L. Von Oettingen. 2006.
Predicting minimum habitat characteristics for the Indiana Bat in the Champlain Valley. Journal
of Wildlife Management 70:1228–1237.