texascavers Digest 2 Sep 2008 11:18:11 -0000 Issue 600
Topics (messages 8866 through 8868):
Re: Nature Conservancy partner in Tennessee cave gate effort to protect cave
salamanders :
8866 by: Mike Flannigan
New technologies aid in bat counts :
8867 by: jerryatkin.aol.com
UT Grotto meeting â September 3, 2008
8868 by: garyfranklin2.austin.rr.com
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Pictures of the rare salamander:
http://tinyurl.com/5qwf79
Mike
jerryat...@aol.com wrote:
Rare Salamander Protected in Knoxville Cave Gating Project
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Equipment will help officials decide if bats can be removed from endangered
species list
By Morgan Simmons (Contact)
Sunday, August 31, 2008
GAINESBORO, Tenn. - A short distance from the creek was a limestone outcropping
marking the entrance to the cave.
It was 7:30 p.m., and Corey Holliday was in Jackson County, just a few miles
from the Cumberland River, to count gray bats.
A cave specialist for the Tennessee chapter of The Nature Conservancy, Holliday
had with him an infrared video camera and a laptop computer - the latest tools
for counting bats as they leave the cave at night to feed on insects.
Prior to this summer, biologists had to use night-vision goggles and hand
clickers to count gray bats during their outflights.
With the new equipment, they'll be able to feed video footage of the bats into
a computer software program that counts them individually by reading their
thermal images taken at the mouth of the cave.
Developed by the military for tracking missiles, the software was modified by
the U.S. Army Corps of Engineers specifically for counting gray bats, a
federally endangered species that has bounced back in recent years.
Holliday said the new equipment will help the U.S. Fish and Wildlife Service
decide if gray bats have recovered enough to be removed from the endangered
species list.
"The old counting method was good at showing population trends, but not at
specific numbers," Holliday said. "For gray bats to get de-listed, we're going
to need hard, accurate data."
Holliday is among a handful of biologists who has been working in cooperation
with the U.S. Fish and Wildlife Service this summer to develop protocols for
using the new counting equipment in the field.
Gray bats use caves year-round but need different caves for the winter and
summer. In winter they hibernate in caves that trap cold air and remain between
42 and 52 degrees Fahrenheit. In summer, the females form maternity colonies in
caves that are roomy and warm.
Because of the gray bat's specific habitat requirements, less than 5 percent of
the available caves suit their needs.
Tennessee has an estimated 9,000 caves, more than any state in the U.S.
The cave where Holliday made his recent gray bat count is located in the
cave-rich region of Tennessee's Highland Rim, about two hours northwest of
Knoxville. The cave is gated with slats of angle iron that allow the gray bats
to fly in and out while protecting them from intruders.
Night came early to the leafy woods. As darkness fell, Holliday set up the
infrared camera and tripod about six feet from the cave's 6-by-9-foot opening.
At 8 p.m., he hit the record button. Illuminated in the spooky green hues of
the camera's night vision was a trickling of bats that darted across the
screen, like fairies swimming on air. Holliday said they mostly likely were
gray bat pups, and were the prelude to the mass exodus that would occur in
another half-hour.
"I was using this equipment last night when I started seeing a form on the
camera screen moving back and forth," Holliday said. "It turned out to be a
wood rat."
Holliday said the out-flight would take about an hour and a half, and that the
bats would return to the cave throughout the night.
Tennessee is home to 15 species of bats, all of them insectivores. In addition
to gray bats, Tennessee has another federally listed endangered species, the
Indiana bat, that does not appear to be making a comeback.
Scientists say bats eat 50 to 100 percent of their weight each night in
insects, which translates into 1,000 bats consuming 22 pounds of bugs per night.
Gray bats weigh between 8 and 11 grams, and eat everything from moths to
mosquitoes.
"Anything they pick up on their echolocation and can fit in their mouths,
they'll eat," he said.
Holliday said the summer gray bat colony in the cave should be around 15,000
based on previous counts made without the infrared camera and computer.
After filming the bat's 1 1/2-hour out-flight, Holliday downloaded the video
into a computer, where the software read the bats' thermal images. Once the
video was captured onto the computer and the thresholds were set, it took the
computer only about 20 seconds to calculate a bat count.
On the computer screen, the bats' heads are colored red, while the cooler
sections toward the tail show up blue.
The bat count taken at the cave that night was considerably lower than those
taken in previous years. Holliday said the colony likely had been disturbed by
someone who'd managed to get through the cave gate.
"It doesn't take much human disturbance for bats to leave their summer site,"
he said. "My guess is someone was going in there repeatedly, maybe digging for
Indian artifacts,"
Holliday said counting the gray bats with the infrared camera and computer
software as they fly out of their summer caves is less invasive than counting
them in the winter when they're hibernating.
"In the old days people would spend years perfecting their methods and learning
to count bats," he said. "If they were within 1,000 to 3,000 bats, that was
considered pretty accurate. I don't know how they did it."
http://www.knoxnews.com/news/2008/aug/31/counting-bats/
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UT Grotto meeting – September 3, 2008
www.utgrotto.org
The Underground Texas Grotto will meet Wednesday from 7:45 P.M. - 9:00 P.M.
University of Texas Campus- 2.48 Painter Hall
http://www.utexas.edu/maps/main/buildings/pai.html
UT Grotto has been very active with many events and trips planned. Come check
out what this group of Texas Cavers have been doing and what is coming up next.
Join us for both the formal UT Grotto meeting where we have a fine program
planned.
Sofia Angelo who is researching caves as part of her requirements as an Antioch
University M.S. Environmental candidate will be providing a summarization
report from her recent caving research. “My Summer Of Caving: Thirty Caves in
Two Months"
Then, join us afterward at Posse East for a social of food, beverage, upcoming
trip recruitment, and tall tales of past trips
http://www.posseeast.com/location.html
Contact Gary v...@utgrotto.org if you are interested in sharing 10 - 30
minutes of adventure from your cave related event.
http://www.utgrotto.org/contacts.asp
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