ArticlePDF Available
the future of bats hangs in the balance
A fellow of The E xplorers Club since 2006, J. Judson “Jut” Wynne is a doctoral candidate at Nor thern Arizona
University (NAU) and a conservation biologist with the Colorado Plateau Biodi versity Center and Landscape
Conser vation Initiative, NAU. He has conducted speleological investigations throughout the American Southwest,
Belize, Chile, Easter Island, and Hawai’i. He has authored or coauthored numerous peer-reviewed paper s on topics
that include wildlife-habit at modeling, cave biology, and cave detection techniques for Earth, the Moon, and Mars.
He was also a coauthor on the U.S. Fish and Wildlife Ser vice’s WNS decontamination and prevention protocols,
which are used in both the United S tates and Canada. More information on his research and expeditions may be
found at w Special thanks to Jeff Foster of NAU, Jennifer Fox with the National Park Ser vice,
Ann Froschauer of the U.S. Fish and Wildlife Serv ice, and Angela McIntire with the Arizona Game and Fish
Department for insightful comment s that led to the improvement of this article. This work was funded through a
joint cooperative agreement bet ween the National Park Service and Northern Arizona Universit y.
Maligned in old wives’ tales for “getting in
your hair” and wrongly considered a primary
vector for rabies, bats are in fact among the
most important contributors to Earth’s eco-
systems. They are a keystone species in cave
ecosystems, their guano adding allochthonous
nutrients to an otherwise energy-limited envi-
ronment; they are important seed dispersers,
particularly in tropical forests; and they provide
critical ecological services to humankind. In
this latter role, insectivorous bats are one of
the most overlooked yet important animals. In
the United States alone, bats provide between
$4 and $50 billion annually in pest-control-
related ecological services to agriculture.
Other bat species are important pollinators for
agave—the plant used for making tequila.
Yet, North American bat colonies are facing
a crisis with the westward advance of white-
nose syndrome (WNS), a disease responsible
for the deaths of nearly seven million bats
since it was first detected in Howe Cave, near
Albany, New York, during the winter of 2006–
2007. Since then, WNS has been confirmed
in 23 states and 5 Canadian provinces.
WNS is a disease caused by the cold-loving
fungus, Pseudogymnoascus destructans,
which infects the skin of the ears, snout, and
wings of hibernating bats. During hibernation,
a bat’s immune response is in a suppressed
state as are other metabolic functions,
enabling the fungus to spread relatively un-
checked. When fully expressed, WNS often
presents as a prominent white fungal growth.
The fungal hyphae penetrate deeply into the
connective tissue and cause severe damage.
Researchers believe this epizootic did not
originate in New York but rather was trans-
ported to North America from Europe, where
interestingly, P. destructans and hibernating
bats seem to coexist. Hibernating bats with
signs of white fungal growth—confirmed as P.
destructans—from some 12 European coun-
tries have been examined thus far, but there is
no evidence of recent mass mortalities.
This bat-fungus interaction may also be
described as antagonistic coevolution. This
game of one-upmanship between bats and
fungus can be explained by the Red Queen
hypothesis, which was inspired by a pas-
sage in Lewis Carroll’s Through the Looking
Glass, in which the Red Queen tells Alice “…
it takes all the running you can do, to keep in
the same place.”
All organisms in the natural world must
continuously adapt and evolve, not only for
the sake of reproductive success, but for sur-
vival against constantly evolving competitors,
predators, and parasites in a continuously
changing environment. When European bats
were first exposed to P. destructans, it is
possible they suffered similar population
declines as have been observed in North
America. Like the exhausted young Alice,
European bats likely “ran” as fast as they
could to maintain their place (i.e., persistence
in the natural world). Over time, European
bats developed immunity to the fungus and
their populations rebounded.
Today, North American bats are faced with
the same ecological challenge. We do not
know whether the fungus requires bats to sur-
vive (i.e., dispersal to other caves or completion
of its life cycle). Current research indicates
that the fungus can persist in caves without
bats. Regardless, it seems, at least at the mo-
ment, that European bats have the upper hand
against the fungus, while the fungus maintains
an advantage over North American bats.
In North America, not all bats hibernate,
but those that do generally hibernate for three
to four months—from mid- to late November
through early March. During this time, these
animals have limited stored energy (fat re-
serves), enabling them to get through hiberna-
tion if they curtail activity. Essentially, bats have
a hibernation “budget.” Although they periodi-
cally arouse from hibernation to switch roost
locations within a roost, move to another roost
entirely, and seek water and/or forage when
conditions outside the cave are favorable,
these activities typically fall within their budget.
WNS forces bats to overspend. Infected bats
may arouse more often and may remain active
th e ex ploR eRs j ou R na l
W H I T E - N O S E S Y N D R O M E ( W N S )
O c c u r r e n c e i n N o r t h A m e r i c a
( a s o f 0 2 / 2 1 / 2 0 1 4 )
winter 2006–07 first deteCted in Howe Cave, ny
Conf irmed 2007-08
Conf irmed susP eC ted 200 8- 09
Conf irmed susP eC ted 200 9-10
Conf irmed susP eC ted 2010 -11
Conf irmed susP eC ted 2011-12
Conf irmed susP eC ted 2012-13
Conf irmed susP eC ted 2013-14
for longer periods of time, further reducing
their precious fat reserves. These animals may
ultimately leave their winter roost in search of
food and water when surface conditions are
unfavorable (i.e., snow-covered). Other aber-
rant behaviors associated with this disease
may include diurnal flight activity outside of the
hibernation sites (hibernacula), collisions with
large stationary objects, and increased con-
centrations of bats in hibernacula entrances
and other exposed areas during winter. Bats
who succumb to WNS often die of starvation
and dehydration, predation, or exposure.
It is unlikely that species of bats affected
by WNS will recover quickly because most
are long-lived and have only one pup per year.
Consequently, even in the absence of dis-
ease, bat populations do not fluctuate widely
over time. Many North American bat species,
which can be sensitive to human disturbance,
are already threatened by climate change and
habitat loss. The added threat of WNS further
complicates an already uncertain future for
North American bat populations.
There may be hope for bat populations in
the American Southwest, in particular, those
in Arizona. With 28 bats species, Arizona is
the second-most bat-diverse state in America.
Arizona bats fill a variety of ecological niches
ranging in elevation from deserts to montane
forests; they also have disparate habitat and
foraging requirements.
Hibernating bats, such as the Townsend’s
big-eared bat (Corynorhinus townsendii)
and most myotine species (Myotis spp.) are
among the highest at risk as conspecific and
congener populations have already dramati-
cally declined in eastern North America due to
WNS. The California leaf-nosed bat (Macrotus
californicus), on the other hand, is homeother-
mic and thus remains active within the south-
western region throughout winter. As a result,
it may not be at risk from WNS. Other species
that may escape the disease are the Mexican
free-tailed bat (Tadarida brasiliensis), Mexican
long-tongued bat (Choeronycteris mexicana),
and lesser long-nosed bat (Leptonycteris
yerbabuenae). These bats are migratory,
spending summers in the American Southwest
and winters in Mexico and points further south.
Little is known about where bats hibernate
in the southwestern United States and even
less is known about their habitat requirements.
Our goal has been to establish population esti-
mates, ascertain the health of the colonies and
monitor them for the presence of WNS, iden-
tify the baseline microbial communities within
cave sediment of hibernacula, and characterize
bat hibernacula habitat. We have embarked on
a multiyear study of two national monuments in
northern Arizona: Grand Canyon–Parashant
and Wupatki National Monuments. Initial cave
inventories were conducted for 11 Parashant
caves, while winter use of two Wupatki caves
had been confirmed by work conducted in the
1980s. At all Parashant and Wupatki caves
containing hibernating bats, we conducted
annual population counts for three and two
years, respectively. This was done to establish
a baseline against which future comparisons
can be made. During the course of our work,
we counted all bats detected and have iden-
tified each bat to the lowest taxonomic level
possible—bats were either C. townsendii or
myotine species (it is impossible to identify
most myotine bats to species without handling
them and this was not an option given their
sensitivity during the hibernation period). We
also photographed several bats from each
roost and visually inspected bats for any signs
of WNS, measured the location of each bat or
cluster of bats from the cave floor, and plotted
each observation on a cave map.
During the summers, colleagues and I re-
turned to these caves to collect sediments so
that baseline microbial communities may be
established. Samples were analyzed by Jeff
Foster at the Center for Microbial Genetics
and Genomics at Northern Arizona University.
To characterize and model hibernacula habi-
tat, we collected low-resolution 3-D map data,
obtained the aspect (or orientation) of each
cave entrance, and determined total length of
each cave, as well as collected temperature,
humidity, and barometric pressure data. For
each cave, we placed up to 40 HoboPro re-
mote data loggers on walls, ceilings, and cave
floors, collecting hourly data for two years.
We determined two Parashant caves to be
bat hibernacula and confirmed the continued
use of the two Wupatki caves as hibernacula.
One of the Parashant caves, which contained
at least 50 individuals, is the largest-known hi-
bernaculum in northern Arizona. We examined
hibernating bats and characterized the micro-
bial communities residing within the cave sedi-
ment and, as expected, P. destructans was not
detected in any of the sediment samples.
This large hibernaculum became the focus
of intensive research. We collected three-
dimensional bat roost
locations for each bat
observed during our
second hibernacula
count in 2012. The
following summer, I
returned to this cave
with a team, which
included Explorers
Club member Pete
Kelsey and his team
from AutoDesk, Inc., to collect high-resolution
(2 cm2) 3-D data using a LiDAR laser scanner.
In addition to capturing 3-D cave mapping
data, each microclimate instrument location
was plotted within the 3-D space. We are now
in the process of plotting all bat and microcli-
mate instrument locations within the 3-D model
of this cave. We will be using these data to
develop 3-D interpolative maps of cave climate.
Through this work, all hibernacula caves
in Parashant and Wupatki have been closed
to recreational use and all non-hibernacula
related research must occur when the bats
are not in residence. We collected important
baseline information to characterize the mi-
croclimate requirements of these hibernacula
roosts (which may be useful in extrapolating
microclimatic conditions required for hiber-
nating bats in northern Arizona in general),
as well as baseline information on microbial
communities of the hibernacula caves. The
3-D microclimatic models will enable us to
better understand why bats select micro-sites
for hibernation within caves and, more broadly,
which variables characterize bat hibernacula
habitat in the American Southwest.
While there is much uncertainty concerning
exactly how bats in the region will respond to
WNS and to what extent North American bats
will recover, strong collaboration between land
managers and conservation biologists will im-
prove our knowledge concerning the locations
of bat roosts (including hibernacula, maternity
and bachelor roosts) and cave-roosting bat
habitat requirements, and may enable us to find
a way to manage for WNS. Researchers and
land managers have
developed a national
response plan to help
guide collaboration
(see www.whitenose
While there is no
mighty Excalibur
sword that conserva-
tion biologists can
wield to stop WNS,
there are a few mitigation strategies available to
researchers and the general public. First, any-
one entering a cave or mine should follow the
WNS measures provided by the U.S. Fish and
Wildlife Service (www.whitenosesyndrome.
org/topics/decontamination). Also, many
caves and mines have been closed because of
WNS; so, it is always advisable to check with
landowners or managers before entering any
cave or mine. Second, we need to continue to
educate the public regarding the importance
of bats and the threats bat populations cur-
rently face. Finally, we need to improve our
knowledge, especially in areas unaffected
by WNS, concerning cave-roosting bat roost
locations, population estimates, and habitat
information (as described above) so that
science-based decisions may be made to help
protect and conserve many of North America’s
dwindling bat populations.
... One of the most detailed methods used to define cave and karst morphologies is Light Detection and Ranging (LiDAR or laser scanning) technology. It clearly identifies fine details of geologic, hydrologic and biologic features in karst terrains and caves, leading to accurate interpretations, analyses and modeling (Lyons-Baral, 2012;Wynne, 2014;McFarlane et al., 2013;Weishampel et al., 2011). Yet with all this effort, characterization, analysis and modeling combining highresolution surface and subsurface data has scarcely been conducted. ...
... The high-resolution and increasing availability of LiDAR technology is rapidly improving karst and cave investigations for the fields of engineering, geology, hydrology, biology and anthropology (Weishampel et al., 2012;Kemeny et al., 2012;Lyons-Baral, 2012;Wynne, 2014;Roncat et al., 2011;McFarlane et al., 2013;Pucci and Marambio, 2009). Laser scanning is a remote sensing method employed to measure the coordinates of surfaces in three dimensions (3D), X, Y and Z, and typically either the reflective intensity or color of each point. ...
... Terrestrial LiDAR scanning is also being utilized in subsurface mapping of natural caves, engineered tunnels and underground excavations. Present research and practices related to subsurface laser scanning are geologic interpretation, characterization and geomechanical modeling (Fekete et al., 2010; (2); Lyons- Baral, 2012;McFarlane et al., 2013;Murphy et al., 2008Murphy et al., & 2005Toomey, 2009), detailed mapping, visualizations and animations (Addison, 2011;Funk and Peter, 2014;Roncat et al., 2011), and biological and anthropological surveying and analyses (Lerma et al., 2010;McFarlane et al., 2013;Pucci and Marambio, 2009;Wynne, 2014). These subterranean LiDAR scans have produced beautiful imagery of caves in a way they have never been seen before. ...
Full-text available
Master's thesis on using lidar both above ground and below for better site characterization and analysis.
ResearchGate has not been able to resolve any references for this publication.