98 
Christopher S. Hobson and J. Nathaniel Holland 
RESULTS AND DISCUSSION 
In winter 1992, 38 M. sodalis and 1,686 bats were hibernating 
in the cave (Leffler et al. 1993). Few individuals left the cave in 
early April, with most bats departing by early May. Trapping at the 
cave entrance resulted in 56 captures (all adults), including 19 Myotis 
lucifugus, 17 M. septentrionalis, 5 M. leibii, 4 Eptesicus fnscus , and 
11 Pipistrellus subflavus. M. sodalis were not captured during this 
period. The 56 bats captured account for only 4% of the hibernating 
population of bats in the cave. Assuming that no M. sodalis had left 
the cave before our first census, the M. sodalis population in the 
cave declined from 31 to 18, 8, 6, and 0 individuals on 3, 17, 24, 
28 April and 1 May, respectively. By mid-April the single cluster 
of M. sodalis had broken into several small clusters within a 2-m 2 
area. Cope and Humphrey (1977) reported similar trends in departure 
patterns of M. sodalis, where females left the hibernaculum before 
males, and most bats departed by late April and early May. 
Two radio-tagged male M. sodalis were tracked for approximately 
one hour after release near the cave, at which time signals of both 
individuals were lost. Bat #440 was never located from the ground 
after release, but its signal was detected by an aircraft in the cave 
area on 8 and 10 May. Bat #458 was relocated by ground in the 
George Washington National Forest on 1 May, approximately 16 km 
SW of the hibernaculum. Bat #458 roosted and foraged in George 
Washington National Forest until 20 May when the transmitter battery 
failed. For 19 nights, bat #458 roosted on a north facing slope (0° 
to 5° east of north) at 700 m elevation, beneath the bark of a mature 
shagbark hickory (ca. 30 m in height, 61 cm DBH). The bat roosted 
at a height >8 m in the shagbark hickory. Other tree species within 
a 10-m radius of the roost tree included basswood (Tilia spp.), red 
maple (Acer rubrum), eastern hophornbeam (Ostrya virginiana), tulip 
poplar (Liriodendron tulipifera), and pignut hickory (Carya glabra ). 
Bat #458 was not the only bat using the shagbark hickory for a roost; 
on separate occasions at dusk 5, 10, and 3 bats emerged from the 
roost tree. Leaving the roost tree around 2030 hours nightly, bat #458 
was one of the first bats to emerge, with the other bats emerging 
by 2100 hours. Bat #458 immediately left the area of the roost tree 
upon emergence and flew to foraging habitat, located within 1 km 
of the roost tree. Mist netting the roost site and foraging habitat resulted 
in capture of 2 Lasionycteris noctivagans, 3 Lasiurus borealis, 4 Eptesicus 
fuscus, 6 Pipistrellus subflavus, 6 Myotis lucifugus, and 3 M. septentrionalis', 
but, no M. sodalis were captured. 
After emerging from the roost tree, bat #458 foraged persistently 
