Counts at the John Guilday Caves Nature Preserve
County, West Virginia
The National Speleological Society purchased 40 acres containing the
entrances to Trout, Hamilton, and New Trout caves in 1983.
Since that time there has been an annual bat count in each
cave to document the change in populations over time.
bat counts were also done before the NSS purchased the caves.
Finding the actual records of those old counts is difficult,
as they are uncovered they will be posted on this page.
and newer) Bat Count Reports
the bat counts done since 1999 have been published in various caving
newsletters. These reports are available below.
Reports of some of the earlier counts were also published,
but they are not available in electronic format.
the annual counts no attempt is made to count in the entire
cave, but the same area in each cave is counted each year.
This methodology should provide comparable statistics each
You can see the recent counts by clicking the link to
each year's count. The files are all PDF files.
Syndrome found in Hamilton Cave (2009) (detailed report about
finding WNS in Hamilton Cave in January, 2009).
2010 Trout Rock Bat Count
(Report on the 2010 bat count when Hamilton Cave's population crashed
to 30 bats. Includes graphs showing historical counts in all
Data for Recent Bat Counts
raw data for the "modern era" of bat counts is available below.
The data is in PDF files, but the raw data is also available
Excel format if desired. Contact Bob Hoke for more
information or to get the Excel files.
Cave raw data 1983-2019
Cave raw data 1984-2020
Cave raw data 1982-2020
section contains documentation about historical (pre-1980) bat counts
in the Trout Rock caves. There are many sources
to several early counts, but the intent is to provide the actual data
here rather than merely references to it All of the links
below are to PDF files.
document and text
copy of an article in the May, 1941, issue of the Bulletin of the
National Speleological Society by James Fowler. The article
covers many topics, but page 38 briefly describes counting 1,600-2,400
Myotis sodalis bats in one room in Trout’s [sic] Cave on February 23,
1941. [Article was supplied by the NSS Library in Huntsville,
very poor scanned image of Life History and Taxonomic Study of the
Indiana Bat, Myotis sodalis, by John S. Hall (Reading, Pennsylvania,
Reading Public Museum and Art Gallery Scientific Publication Number 12,
1962, 59 pages) [Scanned image was supplied by Barbara
the U.S. Fish & Wildlife Service].
letter from Wayne Davis (Univ. of Kentucky, Lexington, KY) to Dr.
Virginia Tipton (Radford University, Radford, VA) saying that he did
not have his notebook with banding statistics from the 1950s.
did provide some estimates of the number pf bats banded in Trout and
several other caves in the 1950s. [Letter was supplied by
Douglas of the U.S. Fish & Wildlife Service].
document and text
1984 letter from Brother Nicolas Sullivan (Manhattan College,
Riverdale, NY) to Janet McCormick (National Speleological Society)
saying that he had seen an estimated 1,000 Myotis Sodalis bats in Trout
on several winter visits from 1955-1957. These bats were
in what he called “the roost”, but he doesn’t specify where it
He also reported seeing six clusters of 10-20 bats in the main passage
toward the entrance from the roost passage. [Letter was
by Barbara Douglas of the U.S. Fish & Wildlife Service].
1984 letter from John Hall (Albright College, Reading, PA) to Leonard
Walker (U.S. Fish and Wildlife Service, Elkins, WV) giving detailed
statistics of counts done in Trout Cave in 1951-53 by Wayne
Davis. Davis banded 238 Myotis sodalis in Trout in 1951, 232
1952, and 565 in 1953. The letter also reports finding 5
sodalis bats in Trout in 1960, 13 in 1961, and none in 1965 and later.
[Letter was in correspondence file supplied by Paul Stevens].
1984 letter from Robert Miles (WV Department of Natural Resources,
Charleston, WV) to Paul Stevens (NSS President) reiterating Fowler’s
1941 Trout Cave count and stating that it is encouraging that a small
colony of Myotis sodalis bats again find Trout a suitable hibernation
site. [Letter was in correspondence file supplied by Paul
1984 letter to Rane Curl (NSS Board of Governors member) from James
Fowler (Cranbrook Institute of Science, Bloomfield Hills, MI) giving
information about the counts that Fowler did in Trout cave in
1941. [Letter was in correspondence file supplied by Paul
and comments about this page are welcome. Send them to Bob
Hoke at email@example.com.
last updated or verified on March 11, 2020