2013 Southeastern Naturalist Notes Vol. 12, No. 4
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B.D. Carver and A.E. Lereculeur
Predation on a Northern Long-eared Myotis by a Gray Rat
Snake
Brian D. Carver1,* and Anabel E. Lereculeur1
Abstract - A number of species are known to be predators of bats. In North America, the greatest number
of bat predation records is by snakes. To date, no animals have been reported preying on Myotis
septentrionalis (Northern Long-eared Bat). We report the predation of a Northern Long-eared Bat by
Pantherophis spiloides (Gray Rat Snake) in Tennessee.
Myotis septentrionalis Trouessart (Northern Long-eared Bat) are small bats (5–8 g)
found in eastern and northern North America. Like several other eastern Myotis bats, Northern
Long-eared Bats roost under exfoliating tree bark or in tree cavities during summer and
hibernate in caves during winter (Caceres and Barclay 2000, Chapman 2007).
We initiated a project in May 2012 to evaluate roost selection by Northern Long-eared
Bats on the Cumberland Plateau in Tennessee. On 18 May 2012, a pregnant female Northern
Long-eared Bat was captured in a mist net set over a forest road in Catoosa Wildlife
Management Area in Morgan County, TN. We trimmed the fur between the scapulae, affixed
a 0.35-g radio-transmitter (model LB-2N, Holohil Systems Ltd., Carp, ON, Canada)
with surgical cement (Perma-Type, Plainville, CT), and then we affixed a 2.9–mm lipped
aluminum-alloy band (Porzana Ltd., East Sussex, UK) to the left forearm. The bat was released
at the site of capture.
1Department of Biology, Box 5063, Tennessee Technological University, Cookeville, TN 38505. *Corresponding
author - bcarver@tntech.edu.
Notes of the Southeastern Naturalist, Issue 12/4, 2013
Figure 1. Gray Rat Snake that consumed a radio-transmittered Northern Long-eared Bat at Catoosa
Wildlife Management Area, Morgan County, TN. Note the distended abdomen indicating the presence
of the recently (less than 24 h) consumed bat.
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2013 Southeastern Naturalist Notes Vol. 12, No. 4
B.D. Carver and A.E. Lereculeur
On 19 May 2012, we found the bat in a live Quercus alba L. (White Oak) tree located
150 m from the site of capture. On 20 May 2012, the signal emanated from a 1-mtall
Pinus sp. (pine) snag 460 m west of the previous roost and 410 m west of the site of
capture. The pine snag was too short for standard diameter-at-breast-height (dbh) measurement,
but if the trunk were intact it would have had a dbh of approximately 30 cm.
Approximately 60 percent of the bark remained. Visual inspection of the roost structure
revealed a Pantherophis spiloides Duméril, Bilbron, and Duméril (Gray Rat Snake)
under the bark, and radio-telemetry led us to suspect that the snake had consumed the
bat. We captured and examined the snake which was 50 cm in snout–vent length (SVL),
and had an obvious distension of the abdominal wall from a recent meal (Fig. 1). Radiotelemetry
was used to confirm that the snake had indeed consumed the bat. Because two
taller, better-candidate roost trees were located less than 10 m from the pine snag, it is
possible that the bat was roosting in one of the nearby trees when it was consumed by
the snake, which then moved to the pine snag to digest the meal. However, during this
study, we found six roosts where the bats were observed under loose bark or in a cavity
located 1 m or less from the forest floor, demonstrating that Northern Long-eared bats
roost in short snags. The exact location of the bat immediately prior to its discovery by
the snake cannot be known, but consumption of large meals relative to body size are
generally assumed to impair locomotion in snakes (Blouin-Demers and Weatherhead
2001), making it more likely that the predation event took place very near to the site
where the snake was discovered.
To our knowledge, this event represents the first published predation account of a
Northern Long-eared Bat. Many species of snakes have been documented to prey on
bats, including a number of bat species that, like Northern Long-eared Bats, roost under
exfoliating bark (Sparks et al. 2000). The Gray Rat Snake was at one time considered
to be a subspecies of the Black Rat Snake (formerly Elaphe obsoleta [Say]). The Black
Rat Snake, and presumably the Gray Rat Snake in at least some instances, has been
documented as preying on 8 species of bats, including Myotis lucifugus Le Conte (Little
Brown Bat) and M. sodalis Miller and Allen (Indiana Bat), which are both very similar
in size and roosting ecology to the Northern Long-eared Bat (Sparks et al. 2000). Wilson
(1997) indicated that snakes may capture bats out of the air as they exit from their roosts.
However, in the current instance this seems unlikely given that the snake was located at
a site far distant from the roost used by the bat the previous night. It is more likely that
the snake encountered the bat in its newly-selected day roost and was able to capture and
consume it at that location. The late state of pregnancy of the bat in question may have
increased the likelihood of the bat’s capture because it may have been less mobile than a
post-parturient bat. The fact that the bat was nearly ready to give birth is supported by the
capture on the same night (18 May 2012) of a lactating, post-parturient Northern Longeared
Bat, as well as by the large distended abdomen of the bat in question.
Acknowledgments. Funding for field travel and technician support was provided by a
US Fish and Wildlife Service Section 6 Habitat Conservation Planning Assistance Grant
administered by The Nature Conservancy and Tennessee Wildlife Resources Agency
(TWRA). Additional funding was provided by TWRA and the Department of Biology and
the Center for the Management, Utilization, and Protection of Water Resources at Tennessee
Technological University. Field assistance was provided by Aubree Johnson, Caitlin
Sebok, and Sarah Vogel. We thank Hayden Mattingly for reviewing the manuscript. Special
thanks to Chris Simpson and Dustin Thames for logistical support at Catoosa Wildlife
Management Area.
2013 Southeastern Naturalist Notes Vol. 12, No. 4
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B.D. Carver and A.E. Lereculeur
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