kS

/

X

THE VIRGINIA JOURNAL OF SCIENCE

EDITOR

Werner Wieland
Biological Sciences Department
University of Mary Washington
Fredericksburg, VA 22401
Phone: (540)654-1426

BUSINESS MANAGER

James H. Martin
Dept, of Biology - PRC
J. S. Reynolds Comm, Coll.
P.O. Box 85622
Richmond, VA 23285-5622
Phone: (804)523-5593

©Copyright, 2005 by the Virginia Academy of Science. The Virginia Journal of Science
(ISSN:0042-658X) is published four times a year (Spring, Summer, Fall , Winter) by the
Virginia Academy of Science, 2500 W. Broad Street, Richmond, Virginia 23220-2054. The
pages are electronically mastered in the Parham Road Campus Biology Department of J.
Sargeant Reynolds Community College. The Virginia Academy of Science and the Editors
of the Virginia Journal of Science assume no responsibility for statements or opinions
advanced by contributors.

Subscription rates for 2005: $35.00 per year, U.S.A.; $35.00 per year, other countries.
All foreign remittances must be made in U.S. dollars. Most back issues are available. Prices
vary from $5.00 to $25.00 per issue postpaid. Contact the Business Manager for the price of
a specific issue.

Changes of address, including both old and new zip codes, should be sent promptly to
the following address: R. Gerald Bass, Executive Officer, Virginia Academy of Science,
2500 W. Broad Street, Richmond, Virginia 23220-2054. All correspondence relating to
remittance, subscriptions, missing issues and other business affairs should be addressed to
the Business Manager.

For instructions to authors, see inside of back cover.

VIRGINIA JOURNAL OF SCIENCE

OFFICIAL PUBLICATION OF THE VIRGINIA ACADEMY OF SCIENCE

Vol. 56

No. 2

SUMMER, 2005

TABLE OF CONTENTS PAGE

ARTICLES

Phytoplankton Development Within Tidal Freshwater Regions of
Two Virginia Rivers, U.S.A. Harold G. Marshall and Lubomira
Burchardt

The Small Mammals of Isle of Wight County, Virginia, as Revealed
by Pitfall Trapping. Robert K. Rose

Bats Of Sky dusky Hollow, Bland County, Virginia. Virgil Brack,
Jr., Richard J. Reynolds, Wil Omdorff, Joe Zokaites, and Carol
Zokaites

JEFFRESS RESEARCH GRANT AWARDS

^wthsoaTT^^

I . , . i' I I MH^X.i^’

pa' ■■ ,/■! •?i^P“'^ r ‘ (.■il'''>’' '

' "£€4" '‘Jlya?i^'itr>': «!ij ■«■'.■

%

m r.

■4 :

f,"

. r. r ' , •

i _ V 4 ^

.^«,a ■}«

' ' ;i

' 'I.

3 ■ I 1

V*’ 1 ■• JiiAfS

-V ; .».,' ;f;

■5i<^ *« ." ■

'-.: -

■>" . {4(‘' --

■ '. ‘ '7.''„v-irvV- -•' .. ■

®‘ IJ-I *“■ ' . '•■■'■•» ■■■

-♦■I ?

r, , <»'f^^j5' !,E- ■ '('■'^ I „ -.f

> ' I,:'

. . / '

■V').: "

: - ’-v ’‘i- P

A At '

M '

Virginia Journal of Science
Volume 56, Number 2
Summer 2005

Phytoplankton Development Within Tidal Freshwater
Regions of Two Virginia Rivers, U.S.A.

1 2

Harold G. Marshall and Lubomira Burchardt

^Department of Biological Sciences, Old Dominion University,
Norfolk, VA, 23529-0266, U.S.A.,

Department of Hydrobiology, Collegium Biologicum,

Adam Mickiewicz University, 61-614 Poznan, Poland

ABSTRACT

Phytoplankton composition and the range of seasonal patterns of abundance
are presented for the tidal freshwater regions in two Virginia rivers based on
data accumulated monthly from 1986 through 1999. Diatoms dominated the
flora during spring, summer, and fall, whereas, other taxonomic categories
were more representative when the river flow rates decreased, allowing for a
more stable water system and increased residency time within this tidal region
during summer and early fall. This summer/fall period was associated with
increased water temperatures, higher productivity rates and chlorophyll lev¬
els, increased total phytoplankton abundance and species diversity. The
major components of the summer flora were autotrophic picoplankton, chlo-
rophytes, and cyanobacteria. Mean, maximum, and minimum monthly abun¬
dance figures are given for the different phytoplankton categories, and total
phytoplankton biomass and abundance, over this 13 -year period. Although
one station showed considerable influx of oligohaline water into its tidal
freshwater region during sampling, no significant relationships were associ¬
ated with phytoplankton biomass or productivity to these changing salinities.

Key words: Phytoplankton, Virginia, Rappahannock, Pamunkey, tidal freshwater

INTRODUCTION

Marshall and Burchardt, 1998, have described the tidal freshwater region as a
unique component of a river system. It is daily influenced by tidal action, yet, the
location of this region in a river will move upstream or downstream, depending upon
daily or seasonal changes in the occuirence and duration of rainfall, or due to various
hydrodynamic events that would influence tidal amplification and flow within the river.
The tidal freshwater is defined as the region within a river possessing daily tidal
movements bordered upstream by freshwater (<0.5 ppt) lacking a tidal response, and
downstream by tidal waters of greater salinity. This is the tidal oligohaline region that
is characterized by salinities 0.5 to 5.0 ppt. The algae entering the tidal fresh region
upstream are dominated by chlorophytes, diatoms, and cyanobacteria in contrast to
downstream flora (e.g. in oligohaline and mesohaline regions) where estuarine diatoms
and dinoflagellates are the dominant taxa (Haertel et al., 1969; Forester, 1973; Jackson
et al., 1987; Marshall and Alden, 1990). The tidal freshwater region may also contain
a small percentage of estuarine species. These are introduced from sub-pycnocline
waters advancing upstream during periods of low river discharge and when tidal

68

VIRGINIA JOURNAL OF SCIENCE

movement advances farther upstream into normally tidal freshwater regions (Marshall
and Burchardt, 1998). Farrell, 1994 and Schmidt, 1994, have associated increased
diatom abundance with increased river discharge common during spring months.
Marshall and Burchardt ,1998, reported peak diatom development occurred in the tidal
freshwater James River (Virginia) during periods of increased river discharge, with
chlorophytes, cyanobacteria, autotrophic picoplankton, and euglenophytes having
greater abundance during summer and periods of more stable water conditions. This
study reports on the phytoplankton populations and water quality of tidal freshwater
stations in the Pamunkey River and Rappahannock River, both located in southeast
Virginia, U.S.A.

The Rappahannock River (ca. 341 km in length) is a major tributary of the
Chesapeake Bay located in the eastern coastal plain of Virginia. The river flows
southeasterly through predominantly forest, crop-land, and pasture before entering
Chesapeake Bay. The Pamunkey River (ca. 96 km long), is also located in Virginia,
just south of the Rappahannock River, flowing southeasterly through mostly forest
and land used in agriculture, or for raising live stock. The river terminates at its
confluence with the Mattoponi River, forming the York River that continues parallel
to the Rappahannock River before entering the Chesapeake Bay. The climate in this
region is moderate with an average annual temperature ca. 14‘^C and average rainfall
ca. 106-1 16 cm.

Previous phytoplankton studies in the Pamunkey/York and Rappahannock rivers
include those by Marshall and Alden, 1 990; Marshall and Affronti, 1 992; Marshall and
Nesius, 1993; and Marshall and Burchardt, 2004. Their results identify the charac¬
teristic species composition and abundance in these rivers. Spring, summer, and fall
productivity and abundance maxima were described in relation to dominant flora, with
the autotrophic picoplankters being a major component and contributor to productivity
during summer (Marshall and Nesius, 1993). Downstream studies in the York River
section are mainly in the lower reach of the river where summer dinoflagellate blooms
are common (Mackieman, 1968;Zubkoffetal., 1979). Relationships of phytoplankton
distribution and stratification to tidal cycles in the York River are discussed by Haas
etal., 1981 and Ducklow, 1982.

The objectives of this study are to identify the seasonal developmental patterns of
the phytoplankton composition within the tidal freshwater regions of two rivers. Using
a long-term data base the annual biomass patterns are described to indicate the range
of population fluctuation that may occur within these systems. Additional charac¬
teristics and environmental relationships between the phytoplankton community and
several physical and chemical factors associated with these rivers are also presented.

METHODS

Monthly water samples were taken at the tidal freshwater stations in the Rappahan-
nock River (TF3.3, 38“ 01’ 07” N; 16° 54’ 30"W) and the Pamunkey River (TF4.2,
37“ 34’ 47"N; 11° 01’ 19"W) from July 1986 through December 1999 (13.5 years)
(Figure 1 .). The mean depths at these stations were ca.6.8 m and ca.8.9 m respectively
for TF3.3 and TF4.2. At each station a vertical series of five 3 liter water samples were
taken from the upper third of the water column and placed in a carboy, mixed, and a
500 mL sample drawn off and fixed with Lugofs solution. These samples were
analyzed using a modified Utermohl technique following a series of settling and

PHYTOPLANKTON DEVELOPMENT

69

FIGURE 1 . Sampling stations: Station TF3.3 (38° 01 ’ 07” N; 76° 54’ 30” W) located in the Rappahannodc
River and Station TF4.2 (37° 34’ 47”N; 77° 01’ 19” W) in the Pamunkey River, Virginia.

siphoning steps over time to produce ca. 40 mL concentrate of the original sample for
subsequent microscopic analysis (Marshall and Alden, 1990). Identification and cell
abundance for each sample were based on a minimum microscope cell count of 200,
using a minimum of 10 random fields examined at 315X and 500X, plus including
other species observed by scanning the entire counting chamber at 125X. An additional
24 samples from 1998-1999 at these stations were examined for further species
identification. The autotrophic picoplankton cells were identified using epifluores-
cence microscopy as described in Marshall, 1995. Also determined were produc¬
tivity rates, beginning in July 1989, using protocols described by Marshall andNesius,
1 993. Biomass was determined from cell volume measurements made for the different
species and transferred to cell carbon according to Smayda, 1978. The Margalef
Diversity Index was used regarding species diversity. River water discharge rates were
provided by the U.S. Geological Survey from locations near station TF3.3 (38°19’20"
N, 77°3 r05"W), and station TF4.2 (37°46’03"N, 77''l9’57'’W). Surface water tem¬
peratures and Secchi readings were taken on station during each sampling period.
Additional water quality data from these stations were provided by the Virginia

70

VIRGINIA JOURNAL OF SCIENCE

Monthly Mean Discharge Rates

Month

FIGURE 2. Monthly mean discharge rates (1986-1999) for stations adjacent to stations TF3.3 in the
Rappaliannock River and TF4.2 in the Pamunkey River

Chesapeake Bay Monitoring Program. These included analysis of water taken on
station for total nitrogen (TN), total phosphorus (TP), total suspended solids (TSS),
and dissolved oxygen. Seasonal references are defined as winter including the months
of December, January, and February, followed by the sequential 3-month periods for
spring, summer, and fall. A Student T-test was used to determine distribution relation¬
ships of the phytoplankton and productivity to salinity differences noted during the
sampling period at the Rappahannock River station TF3.3.

RESULTS

2 2

The drainage area above the two sampling stations is 4,133 km and 1,739 km for
the Rappahannock and Pamunkey Rivers respectively, with the monthly discharge
pattern similar at both sites. Peak water flow at these stations was from winter through
early summer (December-June), with decreased flow in mid-summer that continued
into early fall (July-September), after which flow increased, from mid-fall into the
winter months (Figure 2). The summer minimum and winter-spring maximum of the
mean monthly rates of flow differed at the two stations, ranging from. 25.8 m^ sec’^
(912 sec’^) in July to 76.7 m^ sec'^ (2,71 1 ft^ sec’^) in March for the Rappahannock
River, and from 12.4 m^ sec'^ (438 ft^ sec'^) in August to 52.7 m^ sec'^ (1,863 ft^ sec'^)
in February in the Pamunkey River. The major annual influence to these seasonal flow
patterns was the amount of rainfall within these two river watersheds. U.S. Geological
Survey records of flow rates began in 1951 and are the basis for estimating average
and extreme periods of monthly and annual mean flow. Those annual rates that were
within the 25 to 75 percentile of this data set were considered average, or normal. If
the annual rate falls below the 25 percentile it would be considered a “dry” year,
whereas, flow rates above the 75 percentile would be classified as “wet” years. During
the 13 years of this study, the annual flow into these rivers varied greatly. There were
5 “wet” and 5 “dry” years, and 3 years where the flow may be considered “normal”,

PHYTOPLANKTON DEVELOPMENT

71

or “average”. As these differences in annual rainfall occur, they will have major
influence on the horizontal range and dynamics associated with the tidal fresh and
various downstream salinity regions of these rivers. Progressing into this study it
became evident that salt-water intrusion frequently occurred at TF3.3 in the Rapppa-
hannock River. Over the 13 year period, Station TF3.3 had freshwater status (<0.5 ppt)
40.6% of the collection dates, whereas, during 59.4% of the dates the salinity was >0.5
ppt. Tidal freshwater status was associated with periods of increased rainfall and
coincided with the spring diatom bloom (e.g. January-May). Periods when salinity
intrusion into this area was most common occurred during the summer and fall months
(June-October). In contrast, station TF4.2 in the Pamunkey River had freshwater status
on 97.7% of the collection dates. Overall, more water flowed through the Rappahan¬
nock station, and at a faster rate, than at the Pamunkey station.

Both stations had similar surface water temperature patterns reaching highs of ca.
28 in July, with lowest mean monthly temperatures occurring in February at TF3.3
(3.6 ®C) and in January at TF4.2 (4.8 ®C). The dissolved oxygen concentrations were
inversely related to the water temperature with lowest values during summer and
highest in winter. The mean monthly range was from 6.5 in July to 12.2 mg L'* at
TF3.3 in February, and 4.7 in August to 1 1.8 mg L"* in February at TF4.2. Monthly
periods of peak total suspended solids (TSS) varied, with greatest loads during periods
of high flow in spring (Figure 3). At station TF3.3, TSS were consistently higher than
at TF4.2, ranging from 20.6 mg L‘* in late summer (August) to 51.2 mg L^, in late
winter (February). The TSS at station TF4.2 ranged from monthly means of 13.5 (Sept.)
to 1 8.9 mg L"* (Dec.), showing a rather stable pattern throughout the seasons. The TSS
increased gradually from summer into fall, reaching highest concentrations from early
winter through spring. Maximum records of 140 and 168 mg L'^ at TF3.3 occurred in
January and May respectively. Mean monthly Secchi readings ranged from 0.3 1 m
(February- April) to 0.64 m (September) at TF3.3, and from 0.51 m (January) to 0.82
m (September) at TF4.2. The annual monthly means for TF3.3 and TF4.2 were 0.45
m and 0.70 m respectively. These results indicated an association between increased
water flow to higher TSS concentrations and reduced Secchi readings at TF3.3, in
contrast to the reverse relationships during periods of reduced flow during summer.
However, this relationship was less clear at TF4.2, where a lower and more consistent
presence of TSS was recorded. More suspended solids were carried in the Rappahan¬
nock, with the mean and range of Secchi readings less than in the Pamunkey River.

There were differences in the total nitrogen (TN) patterns at the two stations (Figure
3). At TF3.3, peak levels (monthly means) occurred in early spring (1.32 mg L'*,
March), decreasing into the summer and fall months to a low of 0.73 mg L‘* (August)
to increase through late fall and winter to the spring highs. Maximum levels occurred
from mid-winter through mid-spring. The mean range at TF4.2 showed less variability,
increasing from 0.69 mg L’’ (November) to 0.88 mg L"^ (June), resulting in the mean
total nitrogen being higher at TF3.3 than at TF4.2. The mean monthly total phosphorus
(TP) at TF3.3 ranged between 0.06 and 0. 12 mg L’* throughout the seasons, showing
a decrease from late spring into summer, before rising again in winter (Figure 3). At
TF4.2, the monthly means ranged from 0.06 mg L'* in the fall (October), to a spring
(March) high of 0.12 mg L"l Maximum TP occurred during winter-spring at TF3.3
and in summer at TF4.2 (Figure 3). Both stations had pulses that occurred in early
spring, mid-summer, and fall, with the highest monthly means at TF3.3. The mean

72

VIRGINIA JOURNAL OF SCIENCE

TN:TP ratio ranged from 7.6 to 12.6 at TF3.3, and 8.2 to 13.8 at TF4.2, with the lowest
ratios occurring May through July at TF3.3, and in July and August at TF4.2. Thus,
there were general differences in the periods of maximum levels of nitrogen and
phosphorus in these rivers. In the Rappahannock, the greatest TN concentrations
occurred in spring and the lowest in late summer, corresponding to the high and low
flow periods in this river. In the Pamunkey, the highest TN concentrations were in
early summer, and least in late fall. TP maxima occurred in winter and summer
respectively for the Rappahannock and Pamunkey. In the Pamunkey, this summer TP
high coincided with high productivity, decreased river flow, and increased concentra¬
tions of cyanobacteria, picoplankton, and other algae.

Chlorophyll a increased into summer from a winter low, with concentrations greater
at TF3.3 than at TF4.2 (Figure 4). At TF3.3, the monthly mean ranged from 2.9pg L’'
(January) to 13.9 pg L‘* (August). There was generally a late spring (May) develop¬
ment, a slight decrease in early summer, then highs from mid-summer through fall. At
TF4.2, there was chlorophyll a increase during summer, with peaks in July and August
(9.27, 8.37 pg L'*), to a January low (2.09 pg L”'). Also present were periods of
maximum chlorophyll a concentrations from spring through fall at both stations. The
mean productivity rates for both stations were lowest during mid-winter, then gradually
increased to peaks during late spring, summer, and early fall, before declining into
winter (Figure 5). The higher rates were consistently recorded at station TF3.3 and
ranged from 12.2mgcm^h‘* (Dec.) to 156.9 mg cm^ h'^ (May). Increased productivity
extended from April through August. At TF4.2, productivity ranged from 5.2 mg cm'’
h" ^ (Dec.) to highs of 43 . 1 and 46.3 mgcm^ h‘ ^ for July and August respectively. This
pattern was similar to seasonal chlorophyll a concentration differences between the
two river stations with highest mean rates of productivity during the summer months.

A total of 268 phytoplankton taxa were identified at these two stations (Marshall
and Burchardt, 2004). There were 208 and 232 phytoplankton taxa represented at the
Rappahannock River and Pamunkey stations respectively. Sixty one percent of the
taxa were present at both stations, with the general composition of the dominant species
similar. The major difference in composition was the estuarine taxa at the Rappahan¬
nock station during periods (summer/early fall) of increased salinity and upstream
advancement of tidal water from the oligohaline region. Collectively for both stations,
there were 133 Bacillariophyceae, 63 Chlorophyceae, 31 Cyanobacteria (cyano-
prokaryotes), 10 Dinophyceae, 11 Euglenophyceae, 6 Xanthophyceae, 5 Cryptophy-
ceae, and 9 Chrysophyceae. The autotrophic picoplankton was identified as a separate
and composite group from the above categories and consisted predominantly of single
celled cyanobacteria. Figures 6 and 7 show the monthly maximum and minimum
records, and means for the major phylogenetic categories. The two extremes indicated
the past ranges recorded for these categories. Variability also occurred over this time
period in taxon representation in each water sample analyzed, with maximum repre¬
sentation of taxa per water sample in the summer months and least in winter (e.g. at
TF3.3 these totals were 73 and 26 taxa; and at TF4.2, 59 and 22 taxa). The Margalef
Diversity Index maxima during this period ranged from 2.3 (January) to 4.0 (July) at
TF4.2, with the mean monthly range from 1.6 (March) to 2.4 (August). The diversity
maxima at TF3.3 ranged from 2.3 (January) to 4.0 (July), with monthly means from
1 .6 (March) to 2.4 (August). Diversity was lowest at both stations in late winter/early

PHYTOPLANKTON DEVELOPMENT

73

.

i

_

!

' 0500' .

- - . . "yfmw - -

\

imw/\

i 0403

i If

\ Ijawi

' r-

015

1 GO,

1

I g

i 0 iffiJ ,

T 7 \ ^

1

\

\ 0.TO

■ o.m

m

i F « A i* J . i A $ O « £>

FIGURE. 3 Monthly concentrations for chlorophyll a, total phytoplankton abundance, and total phyto¬
plankton biomass at TF3.3 and TF4.2, 1986-1999, indicating mean (solid line), maximum (dotted line), and
minimum (dot-dash line) records.

spring when flow in the rivers was greatest, increasing into summer during periods of
reduced flow rates.

In presenting total phytoplankton abundance and total phytoplankton biomass, the
mean monthly values, plus the cell maxima/minima amounts are indicated (Figure 4).
The seasonal patterns of phytoplankton development show seasonal abundance peaks
in mid-winter, spring, mid-summer and fall (Figure 4). The abundance figures do not
include the picoplankton, however, the picoplankton biomass was included in the total
phytoplankton biomass. The mean monthly range at TF3.3 was 6.8 x 10^ cells L'^
(February) to 35.5 x 10^ cells L'^ (July), with the highest cell concentrations as 108.8
X 10^ cells L“^ (July). At TF4.2, abundance ranged from 24.0 x 10^ cells L'^ (March)
to 12.8 X 10^ cells L'^ (July), with the maximum of 35.9 x 10^ cells L’^ (January). The
phytoplankton biomass mimics these patterns, but with greater biomass during spring
and fall, followed by winter and summer at TF3.3. In contrast, at TF4.2 the summer
biomass was greater than in the other seasons. At TF3.3 the phytoplankton biomass

74

VIRGINIA JOURNAL OF SCIENCE

j OlHUJ

50.05.

-laco.

: G OQlCO

1 s

I moo

1 QOO

JFMAMi JASO NO

FIGURE 4. Monthly concentrations of chlorophyll a, total phytoplankton abundance, and total phytoplank¬
ton biomass at TF3.3 and TF4.2, 1986-1999, indicating mean (solid line), maximum (dottedline), and
minimum (dot-dash line) records.

ranged from 279 to 979 x 10^ figcm^ (December, April), with the maximum of 4,902
X 1 0^ pgCm^ (October), and the least as 48 pgcm^ (November). Biomass peak records
were associated with the diatoms. At TF4.2, the biomass ranged from 91 to 818 x 10^

n ^ It

pgcm (December, July), with a maximum record of 3,694 10 pgcm in July. Since
there were frequent salinity differences occurring in the tidal freshwater station (TF3.3)
in the Rappahannock River, student T-tests were run to determine the degree of
phytoplankton/salinity relationships present. The results indicated there were no
significant differences between total phytoplankton biomass (p = 0.296), diatom
biomass (p = 0.1 16), cyanobacteria biomass (p = 0.399), or productivity (p = 0.823),
to salinity values <0.5 and those >0.5 ppt. at this location.

PHYTOPLANKTON DEVELOPMENT

75

Mean Productivity Rates

Month

FIGURE 5. Mean monthly carbon productivity rates for stations TF3.3 and TF4.2 from July 1989 to
December 1999.

I . Bacillariophyceae:

The diatoms had mean monthly concentration peaks occurring during win¬
ter/spring, summer, and fall at both stations, with greater abundance recorded in the
Rappahannock River (Figure 6). Diatoms represented the seasonally dominant flora
at both stations. Mean monthly minimum and maximum concentrations were 3.2 to

I I. 4x lO^cellsL’^ (December, May) at TF3. 3, and 1.0to3.5x lO^cellsL”^ (December,
July) at TF4.2. The recorded minimum and maximum concentrations over this period
were 0.5 and 53.1 x 10^ cells L'^ at TF3.3 (October, January), and 0.007 to 28.2 x 10^
cells L'^ at TF4.2 (October, April). The diatoms had a diverse assemblage of taxa that
included the major producer of the spring diatom pulse, Skeletonema potamos, and an
abundance of planktonic centrics and benthic pennates. Most common were Aste-
rionella formosa, Aulacoseira granulata, A. granulata v. angustissima, A. distans, A.
varians, Cyclotella Meneghiniana, C. striata, Navicula crytocephala, N. radiosa,
Nitzschia acicularis, Surirella ovata, and a variety of other pennates and centrics <20
microns in size. This composition and dominant freshwater taxa were similar in both
rivers. However, the summer/fall flora at TF3.3 contained ample representations of
estuarine species, specifically Skeletonema costatum. The mean abundance for the
diatoms was moderate within their maximum and minimum concentrations. However,
there existed considerable fluctuation in the year-to-year patterns that were influenced
by flow through the system and the initiation time for diatom development to occur.
The maxima depicted here also illustrates the range of the potential growth for this
community. The historic maxima during spring, summer, and fall that occurred at both
stations greatly exceeded the mean concentrations.

76

VIRGINIA JOURNAL OF SCIENCE

\ .

\

II

■

. /V . . * ^

« 10

:|

1

i

5

\ . A

i

i

? I

j

. ^ *

I

i f A u i ■$*. s o a i

>

FIGURE 6. Monthly concentrations for diatoms, cyanobacteria, and chlorophytes at stations TF3.3 and
TF4.2, 1986-1999, indicating mean (solid line), maximum (dotted line), and minimum (dot-dash line)
records.

2. Cyanobacteria:

At both stations, the predominant development of the cyanobacteria (cyano-

prokaryotes) occurred from mid-summer into mid-fall, then decreased in late fall and
winter (Figure 6). Flowever, there were sporadic seasonal highs throughout the year
with the mean monthly range from 1.2 to 22.2 x 10^ cells L” (April, July) at TF 3.3,
and at TF4.2, from 0.2 to 6.3 x 10^ cells L”^ (December, July). Maxima at the two
stations were 95.5 and 29.2 x 10^ cells L'^ respectively for TF3.3 and TF4.2, with both
occurring in July. Several filamentous taxa were common during winter and early
spring. These included Oscillatoria limnetica, O. granulata, O. irregua, O.
pseudominima, Nodularia spumigena f litorea, and Lyngbya contorta. Noted through¬
out the year was Dactylococcopsis rhapidioides . This species, plus D. rhapidioides v.
falciformis, O. granulata, O. angustissima. Microcystis aeruginosa, M. incerta, and
Merismopedia marssonii were common representatives of the summer/early fall flora.
The same tidal freshwater species occurred at both stations, with previous records of
their abundance common in downstream oligohaline and mesohaline regions of these

PHYTOPLANKTON DEVELOPMENT

77

60000

IVWW .

” tFX} Plsopiankton ■■ |

50000

TF4.2 Plc^cnkton

^ - - -

.. .* *• i

o 40000

/

: 2 fimm

/ '•'* i

*

- - , - — ^ 1

T* 30000 -

’ « 40000

• ■« i

s

; %.* \

% 20000 .

i n

20000 .

O

10000

i

1 A

0

: JFMAMJJASOND

i Marth

fFMAMJ JA50NC
Month

)

FIGURE 7. Monthly concentrations for dinoflagellates, cryptophytes, and autotrophic picoplankton at
stations TF3.3 and TF4.2, 1986-1999, indicating mean (solid line), maximum (dotted line), and minimum
(dot-dash line) records.

rivers (Marshall and Nesius, 1993). The greatest development and diversity within this
category occurred during the more stable, decreased flow periods of the year (summer,
early fall), which also coincided with warmer water temperatures and a reduced
sediment load.

3. Chlorophyceae

The chlorophytes were among the most common taxa in the tidal freshwater region.
They consisted of a diverse group of single cell, or small colonial forms in the
Pamunkey (57 taxa) and Rappahannock Rivers (52 taxa). Seasonal maxima were
greater at the Rappahannock River station, and developmental patterns also differed in
the two rivers (Figure 6). At TF3.3, several seasonal peaks occurred in late spring,
mid-summer, and early fall. The mean monthly range of cells varied frorri 0.5 to 2.7
X 10^ cells L‘^ (April, July), with a maximum of 19.6 x 10^ cells L‘^ in July. At TF4.2
lower concentrations prevailed, with the mean monthly abundance from 0.08 to 2.2 x
10^ cells L'^ (March, July), with a maximum of 1 1 .0 x 10^ cells L'^ for September. At
TF4.2 there was a single development during summer, rather than several-peak periods

78

VIRGINIA JOURNAL OF SCIENCE

present at TF3.3. Taxa most prevalent included a diverse group of Scenedesmus spp,
Ankistrodesmus falcatus, A. falcatm v. fluviatile, Pediastrum duplex, plus several
Crucigenia spp. and desmids. Scenedesmus quadricauda was recorded year round, but
also common were S. bijuga, S. dimorphus, and S. acuminatus, with the filamentous
Ulothrix variabilis also abundant. The development of these taxa favored the less
turbulent conditions in the rivers between the spring rains and the fall-winter period.

4. Dinophyceae:

Dinoflagellates were not abundant at these stations. Ten species common for this
region were recorded and included the freshwater Peridinium cinctum, P. wisconsi-
nense and Ceratium hirundinella, plus several taxa characteristic of the downstream
estuarine waters, e.g. Heterocapsa rotundata, PI. triquetra, and Prorocentrum mini¬
mum (Marshall and Affronti 1992). There were differences in their abundance,
presence, and seasonal patterns at the two stations (Figure 7). TF3.3 contained the
higher mean concentrations, exhibiting abundance peaks in spring, summer, and late
fall, with lowest concentrations during the winter months when freshwater status was
more common. The range was from 0.03 to 0.25 x 1 0^ cells L'^ (February, April), with
a maximum abundance of 3.3 x 10^ cells L’^ for April. At TF4.2 the cell maxima
occurred in early summer, with a maximum count of 1.5 x 10^ cells L"’ in June, and
monthly ranges from 0.004 to 0.14 x 10^ cells L'^ (September, June), with late winter
and mid-spring lows prevailing. These taxa were absent in numerous samples through¬
out the year and most common at TF3.3.

5. Cryptophyceae:

Although represented by a modest number (5) of species, this was a ubiquitous
group throughout the year. There were seasonal fluctuations of development at both
stations, with greater abundance at TF3.3 (Figure?). Mean monthly concentrations
ranged from 0.7 to 1.8 x 10^ cells L'^ and 0.3 to 1.2 x 10^ cells L"* at TF3.3 and TF4.2
respectively. Maximum records for these two stations were 9.4 and 3.4 x 10 cells L
in July and November for TF3.3 and TF4.2. The cryptophytes have been noted as a
common background population to other flora within Virginia tributaries (Marshall
and Alden 1990). The species recorded were Cryptomonas erosa, C. marsonni, C.
ovata, C reflexa, and Rhodomonas minuta. The major cryptomonad development was
from early spring through mid-fall, and then decreased in early winter to a mid-winter
low.

6. Autotrophic picoplankton:

Ubiquitous throughout the year, this category consisted of mainly isolated single
cells, or those in small doublets of cells. Cells in this category were less than 2.0 microns
in size and did not include species reported in the other categories. They consisted of
mainly cyanobacteria and less abundant chlorophytes, with other eucaryotes occasion¬
ally present, but not dominant. Maximum concentrations occurred during the summer
months (July-September), but these high numbers frequently extended into early fall
and were similar to patterns described in these rivers and Chesapeake Bay (Marshall
and Affronti, 1992; Marshall, 1995). The mean monthly ranges for TF3.3 were from
8.3 to 367 X 10^ cells (March, August), and for TF4.2 from 2.2 to 128.2 x 10^ cells
L'* (February, June), with maxima for these two stations at 870 and 537 x 10^ cells L'^

PHYTOPLANKTON DEVELOPMENT

79

(August, June) (Figure 7). The minimum counts were 0.31 and 0.18 x 10^ cells L’^
(December, March) at TF3.3 and TF4.3 respectively. The seasonal maxima occurred
during the summer/fall months, being associated with warmer water temperatures and
reduced river flow, in addition to being a major contributor to productivity during this
period (Marshall and Nesius, 1993).

7. Other Phytoplankton Categories:

Among other algal categories, there was a small variety of additional background
taxa that included euglenophytes, xanthophytes, and chrysophytes. These groups were
generally not abundant, with low species diversity in both rivers, and were more
common during the summer/fall months. Representative xanthophytes were Cen~
tritractus belonophorus, Ophiocytium cochlerare, Tetraedriella spinigera, Tribonema
minus, T. affine, and T. viride. The common euglenophytes were Euglena acus,
Lepocinclis sp., Phacus caudatus, P. longicauda, Strombomonas asymmetrica, S.
affinis, and Trachelomonas hispida. The chrysophytes were less abundant, but more
diverse, and included Dinobryon cylindricum, D. sertularia, D. sociale, Synura uvella,
Ochromonas minuscule, Chrysococcus ornatus, and Chromulina wislocchiana. These
taxa were noted sporadically within the samples, lacking established periods of major
development.

DISCUSSION

The tidal freshwater region of these rivers contained a diverse representation of
phytoplankton taxa dominated in abundance and biomass by a diatom flora. High
concentrations of the diatoms occurred during winter-spring, summer, and fall, with
decreasing abundance in early winter. Although representative taxa from the other algal
categories were present throughout the year, their development was most pronounced
in summer and early fall. The patterns of development coincided with periods of high
and low river flow. The maximum and minimum concentration records for the different
algal categories provide a graphic illustration of the variability that may exist in their
development. The major physical influence on water flow during these seasons was
the period of the spring rains and increased flow within these rivers, which was
followed by months of reduced flow and increased residence time for flora passing
through the tidal regions of these rivers. Although the general phytoplankton compo¬
sition and the dominant species at these stations were similar and of mainly freshwater
origin, there were differences in water quality and the abundance of the algal flora. For
instance, station TF3.3 (Rappahannock River) represented waters with a more rapid
rate of flow from a larger drainage system than TF4.2 (Pam unkey River), plus the total
suspended sediment loads were greater, and mean Secchi readings were less at station
TF3.3, in comparison to TF4.2. The total phosphorus values were somewhat similar,
in what may be considered a nitrogen limiting system for both river stations (low TN:TP
ratios predominated). The mean spring and fall chlorophyll pulses at TF3.3 corre¬
sponded to higher levels of TN and TP, with the summer chlorophyll highs associated
with increased TP levels and a decrease in TN. These periods coincided with the spring
diatom pulse, followed by increased abundance of cyanobacteria and chlorophytes
during the summer, with a resurgence of diatom concentrations in fall. These were
similar to patterns noted in the nearby James River (Marshall and Affronti, 1992;
Marshall and Burchardt, 1998). Chlorophyll concentrations typically decreased with

80

VIRGINIA JOURNAL OF SCIENCE

the lower temperatures of winter. At TF4.2, the greatest concentrations of chlorophyll
were in summer, along with increased levels of both TN and TP. The mean TN:TP
ratios increased during greater water flow within the rivers, when additional nitrogen
input occurred, and followed by increased diatom development. The decreased flow
of summer was associated with increased residency time, lower levels of TSS, deeper
Secchi readings, increased picoplankton, increased productivity, greater species diver¬
sity, greater abundance of chlorophytes and dinoflagellates, plus higher chlorophyll
concentrations. This was in contrast to the reverse status of these variables associated
with the increased flow rates during the winter/spring months.

In contrasting the flora at these stations, the Pamunkey River contained a greater
diversity of diatoms, cyanobacteria, chlorophytes, chrysophytes, cryptophytes, and
euglenophytes. Of the 268 taxa identified at these two stations, 232 (86.6%) were
recorded in the Pamunkey River, with 208 (77.6%) in the Rappahannock River, and
there were 61.9% of the taxa common to both stations. Differences in composition
were mainly noted in three algal categories (diatoms, dinoflagellates, chlorophytes),
with additional estuarine species recorded at TF3.3. There was greater phytoplankton
abundance, productivity, and biomass in the Rappahannock River (TF3.3), which also
contained higher TN and TP concentrations, with indications of less light availability
than station TF4.2, as indicated by the more shallow Secchi depths recorded.

SUMMARY

The comparison of the tidal freshwater regions of two closely located river systems
indicated both differences and similarities in the abundance, diversity, and develop¬
ment of the phytoplankton populations. These differences, which include the ranges of
seasonal and annual development among the various phytoplankton taxa, were a
product of the unique combination of conditions in the two rivers (e.g. water quality,
light and nutrient availability, seasonal flow rates). These cumulative factors, and
others, influenced the floral composition and its seasonal abundance, plus determine
the initiation and duration of development among the algal assemblages. These
conditions were further influenced by the amount, timing, and duration of river water
flow annually, when wet and dry years of water occur within these rivers. Yet, there
were similarities in algal composition and dominant species within these rivers, and in
their seasonal development transitions that extend beyond local conditions and are
characteristic of broader developmental patterns typically associated with phytoplank¬
ton in temperate regions.

ACKNOWLEDGMENTS

This study is a component of the Chesapeake Bay Monitoring Program supported
by the Virginia Department of Environmental Quality and the U.S. Environmental
Protection Agency. Special thanks are given to Dr. Kneeland Nesius of Old Dominion
University for providing the results of the productivity analysis determined during the
period of study. Both authors participated in the species identification and data analysis
of this paper.

LITERATURE CITED

Ducklow, H. W. 1982. Chesapeake Bay nutrient and plankton dynamics. 1. Bacterial
biomass and production during spring tidal destratification in the York River,
Virginia, estuary. Limnology and Oceanography 27(4);65 1-659.

PHYTOPLANKTON DEVELOPMENT

81

Farrell, I. 1994. Comparative analysis of the phytoplankton of fifteen lowland fluvial
systems of the River Plate Basin (Argentina). Hydrobiologia 289: 109-1 17.

Forester, J. W. 1973. The fate of freshwater algae entering an estuary. Pages 387-419
In L. Stevensen, and R. Colwell, R., eds. Estuarine Microbial Ecology, University
of South Carolina Press, Columbia.

Haas, L.W., S J. Jastings, and K.L. Webb. 1981. Phytoplankton response to a stratifi¬
cation mixing cycle in the York River during late summer. Pages 619-636 In J.
Neilson and L. Cronin, eds. Estuaries and Nutrients, Humana Press, Clifton, N.J.

Haertel, L., C. Osterberg, H. Curl, and P. Park. 1969. Nutrient and plankton ecology
of the Columbia River estuary. Ecology 50: 962-978.

Jackson, R., P.L. Williams, and 1. Joint. 1987. Freshwater phytoplankton in the low
salinity region of the River Tamar Estuary. Estuarine, Coastal, and Shelf Science
25:299-311.

Mackieman, G. B. 1968. Seasonal distribution of dinoflagellates in the lower York
River, Virginia. M.A. Thesis, College of William and Mary, Williamsburg, Va.,
104 pp.

Marshall, H.G. 1995. Autotrophic picoplankton distribution and abundance in the
Chesapeake Bay, U.S.A. Marine Nature 4:33-42.

Marshall, H.G. and L.F. Affronti. 1992. Seasonal phytoplankton development within
three rivers in the lower Chesapeake Bay region. Virginia Journal of Science
43:15-23.

Marshall, H.G. and R.W. Alden. 1990. A comparison of phytoplankton assemblages
and environmental relationships in three estuarine rivers of the lower Chesapeake
Bay. Estuaries 13(3):287-300.

Marshall, H.G. and L. Burchardt. 1998. Phytoplankton composition within the tidal
freshwater region of the James River, Virginia. Proceedings of the Biological
Society of Washington 1 1 1(3):720-730.

Marshall, H.G. and L. Burchardt. 2004. Phytoplankton composition within the tidal
freshwater-oligohaline regions of the Rappahannock and Pamunkey Rivers in
Virginia. Castanea 69(4):272-283.

Marshall, H.G. and K.K. Nesius. 1993. Seasonal relationships between phytoplankton
composition, abundance, and primary productivity in the three tidal rivers of the
lower Chesapeake Bay. J. Elisha Mitchell Scientific Society 109(3): 141-151.

Schmidt, A. 1 994. Main characteristics for the phytoplankton of the southern Hungar¬
ian section of the River Danube. Hydrobiologia 289:97-108.

Smayda, T. 1978. From phytoplankters to biomass. Pages 273-279 In Soumia, A.,
ed. Phytoplankton Manual, United Nations Educational, Scientific and Cultural
Organization, Paris.

Zubkoff, P., J.C. Munday, R.G. Rhodes, and J.E. Warinner. 1979. Mesoscale features
of summer (1975-1977) dinoflagellate blooms in the York River, Virginia
(Chesapeake Bay estuary). Pages 279-286 In D.L. Taylor and H. H. Seliger, eds.
Toxic Dinoflagellate Blooms. Elsevier, Inc., N.Y.

82

S’'.

VIRGINIA JOURNAL OF SCIENCE i - J / - V

-*• •■’^ t : :

ti. .».• j •■'>'/; 'i?

( M _ 'V^i'v.y ._,L

39 .

r .;.. ’

I ■ -I -

*■■*;? ■•■ ■■ t * «' t

WsllSiWflaJ.i^ ‘I'

-1 ,j»i.i;t>''i '■•■" ' **-t' '■J!^''iVi'Wj9t5Sf''

^‘-"t' '-j ■ i-V- ■

■ -- ■-' • i‘-- '

<■ ^KvniL . V^.

“ ■ ,: sJr^aifU

,vQ

J. I < * \*

■' ^ L* >

' ' A::?^-^-.^' ■’■ > ' ’:'

•. .■- -".di'CcttW '^f«»il)i>ti.'' I -ttCHfe^' ■ ? •' ..'^S'-W

. ''jiv siiyTlHf 4!«tii*irjiai^4iil^^. ' .';'>r. f- ' '. .', ■- ’• H

' ’ ^I^^D^lll^S^(^l««■ v’, ..^^• ■ f (^^■4:•-';^.^i*J;^|i^■-

|(; («■'*:, ■ ,.i: v: <• i,..* L.-.< ..jr|* J>jii{r;.M;

, .w‘' V ’0:>/n Wlaiwaalwi.i^ j

; / : , -1 - a. rij

.‘M .Kv. '" ■■ ■■

" '0 - i' n.if.4Rrifefa>Tj»ty“rtftfc^ ■,tj9ffi-iaS§BI

1^* ato.r

Wt»R# 1^

. .r:.-^- 1?. ^ *v. .f.- r, .. KvJKfirtJtt '

••r.i »w • ^ " vr .1 v*» ^ ■ fi- *

•w n/AVi';'"

t «

ii:^) .

. :< v'‘f-.V. "

. ■-. I *.■•- - *)•' l" ^,V-’ ««r ^ ^ i ■ t

\ . .ViVf i>

’. ''‘A»..,Jt.^r,jvr.iv.

■ ■ >■ I I r. ■.r‘;!^.iTrL

II& . . " ' IBf’ '. Iff',,.

e.' ■ • ;.;. ■'"i ... ■•:■ , ■...

''-. ,1 ■ ' :l. '{H- .r.|) r;.rtl.%jU.,‘r7?iK>?'‘''s

•4

Virginia Journal of Science
Volume 56 Number 2
Summer 2005

The Small Mammals of Isle of Wight County, Virginia,
as Revealed by Pitfall Trapping,

Robert K. Rose, Department of Biological Sciences,

Old Dominion University, Norfolk, Virginia 23529-0266

ABSTRACT

In a study conducted in mid-winter, pitfall traps were used to assess the small
mammal communities on 14 grids set in open habitats in Isle of Wight County
in eastern Virginia. In all, 136 shrews of three species and 103 rodents of five
species were trapped. Least shrews (n=l 10) comprised 46 percent of small
mammals and 80 percent of shrews. Eastern harvest mice (n=62) were the
most common rodents. Reproduction was detected only in pine voles and
southern bog lemmings. The majority of small mammals of the region were
trapped during this month-long study.

INTRODUCTION

As part of a study to determine the western extent of populations of the then
federally threatened Dismal Swamp southeastern shrew, Sorex longirostris fisheri, I
conducted a survey of small mammals in Isle of Wight County, located just west of the
City of Suffolk and lying approximately 40 km west of the Great Dismal Swamp
National Wildlife Refuge in eastern Virginia. Using a standard protocol to study the
Dismal Swamp southeastern shrew, an assistant and I established 14 study grids at
different locations throughout the county. Trapping between 6 January and 6 February
1 992, we collected 239 small mammals of eight species. This report relates the details
of the types of small mammals, and their associations, in a coastal plain county in
eastern Virginia.

MATERIALS AND METHODS

The southeastern shrew, the species of particular interest, is known to achieve
greatest numbers in early successional habitats, such as oldfields, recently clearcut
forests, and sites that are infrequently mowed (Rose et al. 1990). Powerline rights of
way provide excellent habitat for such small mammals because they are mowed at 3-5
year intervals to prevent excessive growth of shrubs and trees, thereby continually
setting back biological succession and promoting the persistence of perennial grasses
and other herbaceous plants. Furthermore, because powerlines cross roadways, these
habitats are easily reached, an additional benefit. Several high-voltage powerlines form
a network across Isle of Wight County (Figure 1), many radiating from the Surry
Nuclear power plant located on the south side of the James River. Thus, wherever
county roads crossed the 30 m wide powerlines, I examined the vegetative stage of the
habitat and usually was able to establish one or two study grids nearby.

The trapping grids were placed on sites with vegetation that is typical of early
succession in the region. Grasses, mostly in the genera Andropogon, Pdnicum, and
Uniola, dominated the vegetation of most grids, but sedges {Car ex spp.) and even
softrushes {Juncus spp.) were present on wetter places. Many grids had American cane
{Arundinaria gigantea) and other woody elements, such as brambles {Rubus spp.),
Japanese honeysuckle (Lonicera japonica), and tree seedlings, especially .of sweet gum

84

VIRGINIA JOURNAL OF SCIENCE

FIGURE 1. Map of Isle of Wight County, Virginia, showing the state roads and powerlines relevant to this
study. The study grids were placed near where powerlines crossed the state roads, at locations listed in

Table 1.

{Liquidambar styraciflud). The soils varied greatly among the 14 sites with grids, from
sandy loams to silty clays, and occasional patches of black or peaty loams.

The standard trapping protocol for our shrew studies used a 5 X 5 grid with 12.5
m intervals, covering an area of 0.25 ha. Near each coordinate, we dug a 1 5 cm diameter
hole, deep enough to accommodate a 15 X 23 cm #10 tin can. When partly filled with
water or formalin solution, these serve as efficient pitfall traps, a common method to

ISLE OF WIGHT COUNTY SMALL MAMMALS

85

secure some species of small mammals, especially southeastern shrews, that are
resistant to being trapped by live or snap traps. These pitfall traps were unbaited,
because early studies demonstrated that baiting did not increase their efficiency
(Hudson and Solf 1959).

Once in place, we tended these traps twice a week to remove the bodies of small
mammals that had fallen into the traps and drowned. (Drowning is considered to be a
more humane method of kill-trapping than other methods, and we sought Sorex shrews
whose body lengths we could measure). We trapped each grid for three weeks, and
then removed all pitfalls from the ground. Earlier studies (Everton 1985) had indicated
that little additional information is learned on the small mammals of a site if trapping
continued beyond three weeks. Catch rates for pitfall traps tend to be very low, often
on the order of 1 -2 captures per 1 00 nights that a trap is in the ground.

Animals were frozen until they could be measured, weighed, and examined for
reproductive status. At necropsy, each animal was weighed and then measured for total
length and lengths of tail, ear, and hind foot. Each animal was examined for evidence
of past or current reproduction (for females) or for current reproductive competency
for males (the presence of convolutions in the cauda epididymides of the testes). All
cataloged specimens were donated as skeletal material to the Mammal Division of the
Smithsonian Institution in Washington, D. C. Because the field study was conducted
in the dead of winter, I did not expect to see evidence of reproduction in most species.

RESULTS

In all, 239 small mammals of eight species were collected from the 14 grids in this
study (Table 1). The number of specimens per grid ranged from 3-5 1 and the number
of species per grid ranged from 2~6. Least shrews {Cryptotis parva) and eastern harvest
mice {Reithrodontomys humuUs) were taken on 13 of 14 grids, whereas the white¬
footed mouse {Peromyscus leucopus) and pine vole (Microtus pinetorum) were least
common, from one and two grids, respectively. The short-tailed shrew {Blarina
brevicauda), from seven grids, and southeastern shrew (Sorex iongirostris), from six
grids, also shared locations with least shrews on three grids. The microtine rodents,
meadow voles (Microtus pennsylvanicus) and southern bog lemmings (Synaptomys
cooperi), were present on seven and eight grids, respectively, and co-occurred on four
grids.

The 239 small mammals collected in this study were taken in 3,750 trap-nights (one
trap in place for one night equals one trap-night), for an overall capture rate of 3 .25
small mammals per 100 trap-nights. The catch rates among grids ranged from 0.57 to
9.75/1 00 trap-nights (Table 1), indicating great variation in the densities of populations
in the small mammal communities from location to location. There were no obvious
vegetation or soil patterns that would account for this range of variation in small
mammal abundance among the 14 grids.

Information on the number of specimens, their standard measurements, and other
details is presented in Table 2 for the six species with sufficient specim'ens to permit
calculations of standard statistics. Sex ratios of all species did not differ significantly
from 1:1, nor was there statistically significant sexual size dimorphism. The mean
number of species taken per grid was 4.07 and the mean number of individuals per grid
was 17.07, but there was no significant correlation between the number of species and

TABLE 1. Results of pitfall trapping on 14 study grids in Isle of Wight County, Virginia. Grids were placed where state highways or other state roads
intersected with high-voltage powerlines. Two grids were placed near state road 600, and three grids each were placed near state roads 621 and 626.
“# sites” denotes to the number of sites yielding individuals of that species, “total N” refers to the total individuals of that species collected during the study,
and “t-n” equals trap nights.

86

VIRGINIA JOURNAL OF SCIENCE

2^ 2

1 VO cj m

<N

^ VO m CJ

o

VO-^ CO (NVOOVVO’-^
VO

IT) CU Ov ro '
^ < VO

Ov ro to O O

oo

^ ^ OO <N
*r)

fovocj ro iiotT)

ro IT) r-

Ov

ro

Os ro —

Tt CJ CU ^ OO
—I 04

VO ro VO OV CN

^ CM »r:>

ro Cv)

O

<NO(N CU

O — ^

^ ro U'

ir» ^ CO VO

a f
& 8
Q -b
b.0

§ 8 -
U Co

, I 3

& O -b

§ 'S s

O g Q

^■3

o g

5 ~§ § g I «

g e ^ .s c/3

o

g

5 I

-ts O c 5- .

^ c^(2 f2

o o

ISLE OF WIGHT COUNTY SMALL MAMMALS

87

number of individuals across the 14 grids (r = 0.337, P = 0.24). Thus, grids that yielded
more individuals did not have more species than grids with few individuals.

Because this study was conducted in mid-winter, most of the animals collected were
full adults and exhibited little evidence of reproduction. Exceptions were seen only in
pine voles (female with five embryos and male was fertile) and southern bog lemmings,
in which 1 5 g male and 1 8 g female, both late juveniles based on body size, were taken,
plus two females were pregnant and all males of adult size were judged to be fertile.
In all other species, the minimum sizes were those of adult animals (Table 2), and no
evidence of reproduction was detected.

DISCUSSION

The three shrews and five rodents represent the majority of small mammals that are
typical for the region. The shrews are all of the common ones; only the pygmy shrew,
Sorex hoyi, was absent, and this tiny shrew has a patchy distribution, usually in
shrubbier or more forested habitats than were examined in this month-long study of
small mammals in the open habitats under powerlines. Among the rodents, only the
introduced house mouse {Mus musculus) was absent among the mammals small enough
to be contained by the 23 cm tall pitfall traps used in this study. House mice, introduced
from Europe to the Americas during colonial times, are excellent colonizers of newly
created and early successional habitats, but they tend to disappear once natural plant
communities required to sustain native mammal populations have developed. Those
conditions seemed to apply here. The hispid cotton rat, Sigmodon hispidus, likely was
present on some grids but adults are too large to be caught in pitfall traps. The only
other common small mammal in the region, the marsh rice rat (Oryzomys palustris), is
associated with wet or regularly flooded sites, and thus was unlikely to be present on
these mostly mesic sites.

The short-tailed shrew {Blarina) is perhaps the most common and widespread small
mammal, and certainly is the most common shrew, in eastern North America. Tolerant
of a wide range of conditions and thus found in habitats ranging from moderately dry
Oldfields to wet closed forests, this shrew is the largest North American shrew. The 14
collected in this study averaged 13 g (Table 2). Half the grids yielded short-tailed
shrews, but only 1-3 individuals each, indicating that they were never as numerous as
least shrews on these sites.

Short-tailed shrews have been studied extensively for their adaptations that enable
them to sustain their high metabolic rates year round (no American shrew hibernates).
For example, Merritt (1986) reports that this shrew possesses brown adipose tissue, a
special fat that, when required, produces heat under stimulation from the adrenal gland.
In effect, this is a supplementary or emergency source of heat production to that of
shivering, the normal manner by which mammals produce heat on demand to get their
sagging body temperatures back into the normal range. Their high metabolic rates also
contribute to their remarkable abilities to produce young strictly through maternal
energy sources during pregnancy and lactation. Pearson (1944) reports that an 1 1 g
Blarina produced five weaned young that collectively weighed 55 g in just 50 days:
21 days for pregnancy and the rest for lactation. Two species of shrews in the genus
Sorex, studied by Nagel (1994) in Germany, show a similar ability, producing young
during pregnancy and lactation that were equivalent to 536 and 540 percent of the initial
body weights of the mother shrews. Thus, besides an ability to mobilize sufficient

88

VIRGINIA JOURNAL OF SCIENCE

TABLE 2. The means, standard errors of means, minimal and maximal measurements for total length, tail
length, weights, and the sample sizes for six species of small mammals taken in pitfall traps in Isle of Wight
County, Virginia. Too few Microtus pinetorum and Peromyscus leucopus were caught to include in this
table.

MALES

FEMALES

Total

length

mm

Tail

length

mm

Weight

(g)

Total

length

mm

Tail

length

mm

Weigh

(g)

Blarina

Mean

115.0

25.57

14.26

114.43

26.86

12.34

brevicauda

SE

2.49

0.75

0.56

1.64

1.26

0.32

Min

109.0

22.0

11.71

110.0

23.0

11.50

Max

127.0

28.0

16.40

123.0

31.0

13.61

N

N-7

N=7

Cryptotis

Mean

78.41

17.70

3.88

77.70

18.17

3.91

parva

SE

0.71

0.21

0.07

0.48

0.20

0.08

Min

67.0

13.0

1.80

66.0

15.0

2.03

Max

97.0

21.0

5.33

87.0

21.0

5.25

N

N=56

N=64

Sorex

Mean

89.86

34.57

3.08

88.75

33.50

3.15

longirostris

SE

0.70

0.65

0.27

0.22

0.25

0.11

Min

88.0

33.0

1.74

88.0

33.0

2.80

Max

93.0

38.0

3.95

89.0

34.0

3.56

N

N=7

N=5

Reithrodontomys

Mean

122.56

58.66

8.58

118.57

56.47

7.94

humulis

SE

1.44

0.92

0.19

1.72

0.87

0.29

Min

109.0

49.0

6.21

105.0

48.0

4.19

Max

140.0

69.0

12.03

140.0

68.0

11.41

N

N=32

N=30

Microtus

Mean

147.0

43.50

31.26

148.29

41.29

31.7

pennsylvanicus

SE

6.64

2.43

3.68

3.22

1.06

2.09

Min

112.0

32.0

13.10

131.0

36.0

21.87

Max

167.0

52.0

45.08

154.0

45.0

40.12

N

N=10

N=7

Synaptomys

Mean

118.54

20.69

27.96

128.86

23.0

32.17

cooperi

SE

2.44

0.86

2.09

4.72

2.90

3.79

Min

102.0

15.0

14.63

117.0

18.0

24.05

Max

129.0

26.0

41.63

151.0

40.0

47.36

N

N=13

N=7

ISLE OF WIGHT COUNTY SMALL MAMMALS

89

energy to maintain a constant body temperature, female shrews are able to find
additional energy from food to produce young equal to five times their own body weight
in just 7-8 weeks. Because young shrews do not leave the nest to forage as Juveniles
but stay in nests until weaned at 95 percent of adult weight, their entire body weight
gain after birth must come from the milk they acquire from their mothers.

The least shrew, the only brownish short-tailed shrew in Virginia, was the most
numerous small mammal, with 56 males and 64 females (Table 2) collected from 13
of 14 grids (Table 1). Thus, they comprised 46 percent of total mammals. This shrew,
at least in eastern Virginia, is mostly restricted to dry sites with mineral soils (Everton
1985). At less than 4 g in body weight, this is one of the dozen smallest mammals in
the world. The number of least shrews per grid was highly variable, ranging from 1 or
2 to 9, 10, 1 1 , to as many as 36. Distributed throughout Virginia in appropriate habitats,
the highest densities have been reported by Adkins (1980) from tidal marshes on the
Eastern Shore, specifically of Assateague Island. Least shrews are more social than
other shrews, often forming groups. Jackson (1961) reports finding “about 25 shrews”
in a leaf nest in Virginia and McCarley (1959) describes the well-insulated nest in
which he found “at least 3 1 shrews” in early January in eastern Texas.

The southeastern shrew, the primary subject for which this study was undertaken,
was found on 6 of 14 grids, always in low numbers (1-3 per grid). All were similar in
size, weighing < 4 g and measuring nearly 90 mm in body length (Table 2). The most
common long-tailed shrew in eastern Virginia, it is slightly longer and heavier than the
pygmy shrew. Longer shrews of the Dismal Swamp subspecies, Sorex longirostris
fisheri, ranging in body length to near or slightly above 100 mm, are found mainly in
wet sites with peaty soils, whereas the upland subspecies, S. 1. longirostris, is somewhat
smaller, with lengths in the low to mid-80s mm range (Everton 1985). Three of the six
grids yielding southeastern shrews also had the other two shrew species present as well.
Before the regular use of pitfall traps, the southeastern shrew was considered to be one
of the rarest American shrews throughout its distribution in the southeastern states.
Many of the first or second state records were of specimens found dead on trails, dug
from nests in rotting logs, or found floating in water- filled stumps or receptacles at the
bottom of downspouts. However, with the systematic use of pitfall traps, initially by
French ( 1 980), southeastern shrews often are the most numerous small mammal species
of a site. This result also was found to be true in eastern Virginia (Everton 1985),
especially on wet or damp sites.

The white-footed mouse, Peromyscus leucopus, is a forest-dwelling arboreal rodent
that occasionally is present in early successional sites. The two specimens collected
on the grid near state road 603 were sub-adults in gray pelage, and likely were animals
dispersing from one nearby forest to another. The white-footed mouse is considered
the most common rodent in forests in eastern North America.

The eastern harvest mouse, Reithrodontomys humulis, was by far the most numer¬
ous rodent, with 62 being taken on 13 of the 14 grids (Table 1). These 62 harvest mice
represented 60 percent of all rodents and 25 percent of all specimens taken in the study.
The number per grid was usually small, five or less but tw'o .grids yielded 7 and 16
specimens. The smallest rodent in eastern North America (< 10 g), harvest mice eat
insects and seeds and build aerial nests in tufts of grasses. Only pregnant females exceed
10 g. This nocturnal species often is numerous on sites with tall herbaceous vegetation,
such as was present on most of the grids. Cawthom and Rose (1989), who studied the

90

VIRGINIA JOURNAL OF SCIENCE

dynamics of a population of eastern harvest mice in similar oldfield habitat in
Portsmouth, Virginia, found densities to be some of the highest of any harvest mouse
in North America, so their ubiquity and numbers are not surprising in the present study.
Harvest mice are often found in association with hispid cotton rats, a species almost
always the largest rodent in the same oldfields (Cameron 1977; Cameron et al. 1979;
Joule and Cameron 1975; Rose pers. obs. in southern Chesapeake in an on-going
study). The reasons for this association remain to be revealed.

The other three small mammals are short-eared, short-tailed animals in the sub¬
family Microtinae of the Order Rodentia. Most microtine rodents have the common
names of voles and lemmings, but the muskrat {Ondatra zibethicus) is the largest
member of this group of strict herbivores. Microtines are intennittently active day and
night, have high metabolic rates, and are exceedingly efficient at turning grass into
flesh. Sometimes microtines breed year-round (even in the arctic!) and so members of
this group had the greatest potential to exhibit reproduction during this study, con¬
ducted in mid-winter.

The meadow vole flourishes in grassy fields, wet or drier, and is considered the
most common and widespread herbivorous rodent in eastern North America. I caught
17 on seven grids, usually in low numbers (1-4 per grid). Many grids had too little
covering vegetation to support populations of meadow voles: some studies indicate
that 90 percent covering vegetation is required (review by Getz 1985). Before the
arrival of hispid cotton rats into Virginia in 1940 or slightly before (Patton 1941), the
meadow vole was the largest rodent in grassland or early successional habitats and as
such was the staple in the diets of snakes and carnivorous mammals and birds. Meadow
voles build runways through grassy vegetation, which they maintain by clipping the
vegetation that grows in their footpaths. They frequently build feeding runways off the
main trails, and there they sit on their haunches and, using their sharp incisors, cut the
grasses into 3-5 cm sections until they get to the most palatable and nutritious bits,
which they consume. Thus, their presence can often be told by the small piles of cut
vegetation in runways. In the winter, they are able to sustain themselves by eating, if
necessary, dead and dried grasses and by conserving energy during their hours of
inactivity in well-insulated subterranean nests.

The pine vole, also sometimes and more appropriately called the woodland vole,
is a smaller and shorter-tailed version that lives in early successional habitats but more
typically at low densities in woodlands. Thus, its habitat requirements or tolerances are
broader than those of the meadow vole. Unlike the brownish black and scruffy-haired
meadow vole, the pine vole has a short velvety pelage of a uniform chestnut-brown
color. Its tail is only as long as its hind foot, compared to the tail of the meadow vole,
which is twice as long as the hind foot. Pine voles, which build shallow burrow systems
3-5 cm below the surface, sometimes are economic pests, especially in orchards,
because they eat the bark off the root systems of trees and shrubs, sometimes girdling
and killing the plant. The pine vole is present in low densities in mature forests
throughout its range in eastern North America, but often reaches higher densities in
early successional habitats, such as recently clearcut forests. In the present study, only
one male and one female were collected, on separate grids. Called the pine vole because
the specimens from which the species was described and named came from pine forests
in South Carolina, we now know that pine voles are rare in pine forests and much more
abundant in deciduous forests, hence the alternative common name of woodland vole.

ISLE OF WIGHT COUNTY SMALL MAMMALS

91

Finally, perhaps the most interesting small mammal to be collected was the southern
bog lemming. Similar in size and proportions to the pine vole but with a grizzled grayish
pelage and a squarish nose with its exceedingly long and ‘busy’ nasal whiskers, this
species generally is thought to require wetter habitats than the other microtine rodents
(as the common name suggests). In Virginia, the southern bog lemming is found in
some cool wet habitats in the montane west, such as in Montgomery and Giles counties
near Blacksburg, but an isolated subspecies, Synaptomys cooper i helaletes, is known
only from the Dismal Swamp region. Until I caught several in pitfall traps in the Great
Dismal Swamp National Wildlife Refuge in early 1980 (Rose 1981), some investiga¬
tors (such as Handley 1979) speculated that this subspecies might be extinct. The
southern bog lemming is another species rarely caught in live or snap traps (Rose et al.
1990; Stankavich 1984), but pitfall trapping studies have revealed it to be widespread
and locally common in some locations. In this study, I collected 20 southern bog
lemmings on 8 of the 14 grids, making it more numerous and widespread than either
species of Microtus. Most of the grids yielded one or two specimens but two grids
yielded four and one six specimens. The results of this study show that the Dismal
Swamp southern bog lemming is flourishing beyond the bounds and habitats of the
Dismal Swamp.

Among the small mammals collected in this mid-winter study, evidence of repro¬
duction was seen only in pine voles and southern bog lemmings. The lone female pine
vole had five embryos and the male was judged to be fertile, based on the presence of
sperm in the cauda epididymides. Two southern bog lemmings were pregnant, and all
adult-sized males were judged to be fertile. That winter breeding occurred is also
supported by the two juvenile southern bog lemmings taken in the pitfall traps.
Surprisingly, no female meadow vole was pregnant and all males were judged to be
infertile. No embryos were found in any species of shrew or in harvest mice, so only
the southern bog lemming and pine vole were reproducing over the winter.

In conclusion, the small mammals of Isle of Wight County presented few surprises,
except perhaps the widespread presence and abundance of least shrews and the
presence of southern bog lemmings so great a distance from the Dismal Swamp. It
seems likely to me that southern bog lemmings will be found even farther westward
from the Dismal Swamp, provided that searches using pitfall traps are made in
appropriate habitats.

ACKNOWLEDGMENTS

1 thank John Rose for field assistance, ODU undergraduate Sharon Sockman for
help with measuring, necropsying, and tallying the small mammals, Scott Bellows for
preparing the figure, and the non-game program of the Virginia Department of Game
and Inland Fisheries for their support of my studies of southeastern shrews in eastern
Virginia.

LITERATURE CITED

Adkins, L. C. 1980. Contributions of habitat selection, interspecific competition and
tidal flooding to small mammal species diversity in an Assateague salt marsh. M.
S. thesis. University of Virginia, Charlottesville, 78 pp.

92

VIRGINIA JOURNAL OF SCIENCE

Cameron, G. N. 1977. Experimental species removal: demographic responses by
Sigmodon hispidus and Reithrodontomys fulvescens. Journal of Mammalogy.
58:488-506.

Cameron, G. N., B. W. Kincaid, andB. A. Carnes. 1979. Experimental species removal:
temporal activity patterns of Sigmodon hispidus and Reithrodontomys fulvescens.
Journal of Mammalogy. 60:195-197.

Cawthom, M. and R. K. Rose. 1989. The population ecology of the eastern harvest
mouse {Reithrodontomys humulis) in southeastern Virginia. American Midland
Naturalist. 122:1-10.

Everton, R. K. 1985. The relationship between habitat structure and small mammal
communities in southeastern Virginia and northeastern North Carolina. M. S.
thesis. Old Dominion University, Norfolk, Virginia, 76 pp.

French, T. W. 1980. Natural history of the southeastern shrew, Sorex longirostris
Bachman. American Midland Naturalist. 104:13-28.

Getz, L. L. 1985. Habitats. Pages 286-309. //7Tamarin, R. H. ed. Biology ofNew World
Microtus. Special Publication No. 8, American Society of Mammalogists. 893 pp.

Handley, C. O., Jr. 1979. Mammals of the Dismal Swamp: a historical account. Pages
297-357. In Kirk, P. W., Jr. ed. The Great Dismal Swamp. University Press of
Virginia, Charlottesville. 427 pp.

Hudson, G. E. and J. D. Solf 1 959. Control of small mammals with sunken-can pitfalls.
Journal of Mammalogy. 40:386-391.

Jackson, H. H. T. 1961. The Mammals of Wisconsin. University of Wisconsin Press,
Madison. 504 pp.

Joule, J. and G. N. Cameron. 1975. Species removal studies: 1. Dispersal strategies of
sympatric Sigmodon hispidus and Reithrodontomys fulvescens populations. Journal
of Mammalogy. 56:378-396.

McCarley, W. H. 1959. An unusually large nest of Cryptotis parva. Journal of
Mammalogy. 40:243.

Merritt, J. F. 1986. Winter survival adaptations of the short-tailed shrew {Blarina
brevicauda) in an Appalachian montane forest. Journal of Mammalogy. 67:450-
464.

Nagel, A. 1994. Metabolic rates and regulation of cardiac and respiratory function in
European shrews. Pages 421-434, In Merritt, J. F., Kirkland, G. L., Jr., and Rose,
R. K. eds. Advances in the Biology of Shrews. Carnegie Museum ofNatural History
Special Publication 18, Pittsburgh, Pennsylvania. 458 pp.

Pearson, O. P. 1944. Reproduction in the shrew {Blarina brevicauda). American
Journal of Anatomy. 75:39-93.

Rose, R. K. 1981 . Synaptomys not extinct in the Dismal Swamp of Virginia Journal of
Mammalogy. 62:844-845.

Rose, R. K., R. K. Everton, J. F. Stankavich, and J. W. Walke. 1990. Small mammals
in the Great Dismal Swamp ofVirginia and North Carolina. Brimleyana 16:87-101.

Stankavich, J. F. 1 984. Demographic analysis and microhabitat relationships of a small
mammal community in clearings of the Great Dismal Swamp. M. S. thesis. Old
Dominion University, Norfolk, Virginia, 1 15 pp.

Virginia Journal of Science
Volume 56 Number 2

Summer 2005

Bats Of Skydusky Hollow, Bland County, Virginia

Virgil Brack, Jr.\ Environmental Solutions & Innovations, Inc.,
781 Neeb Road, Cincinnati, OH 45233
Richard J. Reynolds, Virginia Department of Game and Inland
Fisheries, P.O. Box 996, Verona, VA 24482
Wil Orndorff, Virginia Department of Conservation and Recreation,
6245 University Park Drive, Suite B, Radford, VA 24141
Joe Zokaites, 2281 Lubna Dr., Christiansburg, VA 24073
Carol Zokaites, Virginia Department of Conservation and Recrea¬
tion, 6245 University Park Drive, Suite B, Radford, VA 24141

ABSTRACT

During the period 22 November 1999 - 1 1 October 2001, winter hibemacula
surveys, spring staging/autumn swarming surveys, and summer surveys for
bats were completed in caves of Skydusky Hollow, Bland County, Virginia.
During winter, 12 caves were entered and 16,185 bats counted: 235 Myotis
sodalis (Indiana bat), 14,475 Myotis lucifugus (little brown myotis), 12 Myotis
septentrionalis (northern myotis), 7 Myotis leibii (eastern small-footed
myotis), 1,441 Pipistrellus subflavus (eastern pipistrelle), and 15 Eptesicus
fuscus (big brown bat). Myotis sodalis hibernated in thermally stable areas
of 7 - 9°C. The largest concentration of M. lucifugus {n = 4,280) hibernated
in an area that was cooler (6.5°C) than areas used by M. sodalis. The
remaining 6,300 M lucifugus hibernated at temperatures similar to, or slightly
cooler than, temperatures used by M. sodalis. Intra-cave (and possibly
inter-cave) movements of M lucifugus and M sodalis during the season of
hibernation concentrated bats in cooler areas of the caves. An unusually large
concentration of P. subflavus {n = 920) hibernated in Coon Cave in a warm
(8.6 - 9.7°C), stable environment. Proportions of species of bats captured
during spring staging and autumn swarming varied from proportions found
during winter hibernation. Mating and perhaps other social functions affect
patterns of autumn use. No concentration of bats used the caves during
summer.

INTRODUCTION

The association between bats and caves is well known. Although a few species of
bats from temperate regions use caves during summer, use of caves as hibemacula is
more common. Winter ranges of many species, including federally endangered Myotis
sodalis (Indiana bat) and Cory nor hinus townsendii virginianus (Virginia big-eared

I Corresponding author: Virgil Brack, Jr., Environmental Solutions & Innovations, Inc. ,781 Neeb
Road, Cincinnati, OH 45233, (513)4514777, Fax: 513-451-3321,

E-mail: Vbrack@.Environmental SI . com

94

VIRGINIA JOURNAL OF SCIENCE

bat), are restricted to areas of well-developed karsts such as are found in western
Virginia (Barbour and Davis 1969).

Few studies have examined use of a cave or cave system by bats across seasons. In
addition to hibernation, bats use caves in other ways. Autumn swarming is a phenome¬
non exhibited by microchiropterans in North America (Cope and Humphrey 1977) and
Europe (Parsons et al. 2003). Swarming is the use and visitation of hibemacula and
nearby habitats in late summer and early autumn, and for many species swarming is
associated with the opportunity for sexes to meet and mate (Cope and Humphrey 1 977;
Thomas et al. 1979; Parsons et al. 2003). During spring staging, bats often remain near
hibemacula caves for a few days before leaving for summer maternity areas. In
summer, some species, for example C. t. virginianus and Myotis grisescens (gray
myotis), form maternity colonies in wami areas of caves (Barbour and Davis 1 969), or
caves may be used by a bachelor colony (LaVal and LaVal 1980), a loose aggregation
of males, of these species. Bats sometimes also use caves as stopovers during the spring
and autumn migration/transient period (Parsons et al. 2003), and bats visit a variety of
habitats and situations during all seasons, apparently searching for suitable habitat
(Fenton 1969; Kurta et al. 2002).

We studied bat use of caves of the Skydusky Hollow Cave System and other nearby
caves within the same karst system in Bland County, Virginia. Studies included (1)
surveys for hibernating bats, including temperatures used by concentrations of bats,
winter intra-cave movements, and a search for accumulations of guano that indicate
summer nursery use, (2) spring staging and autumn swarming, and (3) a summer survey
for nursery colonies.

Background on bat populations. — Unpublished data from previous visits to Sky-
dusky Hollow caves by several individuals influenced the design and completion of
our studies. These data (Table 1 ) provide background information that might otherwise
be lost. A group of cavers organized by authors Carol and Joe Zokaites completed a
bat count in five caves of Skydusky Hollow on 8 February 1992 when 7,470 bats were
found, providing background information on portions of caves where bats concentrate
during winter. Winter visits have been made to Newberry-Bane Cave by many
individuals. In 1986, probably from the Bane entrance, Ginny Dalton (Radford
University, personal communication) found 159 bats of 5 species, including two
endangered species: C. t. virginianus and M sodalis (Table 1). On each of four visits
(1990, 1992, 1995, and 1999) Gary Nussbaum and students (Radford University,
personal communication) reported from 120 to 4,203 bats of 1 to 6 species (Table 1).
In 1993, author Richard Reynolds, Chris Hobson (Virginia Department of Conserva¬
tion and Recreation), and colleagues surveyed from both Newberry and Bane entrances
and found six species of bats, and recorded for the second time the presence of C. t.
virginianus.

MATERIALS AND METHODS

Study area. — The Skydusky Hollow Cave System is in Walker Creek Valley
between Brushy and Big Walker mountains. Bland County, in western Virginia, about
90 km west of Roanoke. It is in the Valley and Ridge Physiographic Province, with
elevations of 649 - 1,160 m. The Skydusky Hollow Cave System includes, from west
to east, Coon, Paul Penley (and Harmans Avalanche Pit), Buddy Penley, Newberry-

BATS OF BLAND COUNTY VIRGINIA

95

TABLE 1 . Unpublished data of bats found during previous winter surveys of caves in Sky dusky Hollow,
Bland County, Virginia. Bats counted but not identified to species are recorded as Unknown. When species
identification was tentative, the name is followed by (?).

Year

Cave

Location in Cave

No. of bats by Species

1986^

Newberry-Bane

4 C. t. virginianus

90 M. sodalis

2 M leibii

1,800 M lucifugus

62 P. subflavus

1990^

Newberry-Bane

120 M sodalis

90 M. lucifugus

6 M. septentrionalis

4 E. fuscus

1 1 P. subflavus

19923

Paul Penley

Whisper Hall
Big Room
South of Big Room
Victory Room
Upper Level
Harman’s Metro

524 - Unknown

138 - Unknown

135 - Unknown

122 - Unknown

121 - Unknown

280 - Unknown

Buddy Penley

Entrance Passage

Main Pit (Pit 1)
Lower Passage

40 P. subflavus

1 1 M lucifugus

3,100 M lucifugus(7)

1 0 P. subflavus

525 M. lucifugus

Bane Spring

Main areas

Back pits

21% P. subflavus

543 M lucifugus

5 E. fuscus

3 M. sodalis{2)

1 M. leibii

21 P. subflavus

66 M. lucifugus

Spring Hollow

Entrance area

160 Unknown

Newberry-Bane

Tourist Connection
T-Intersection
Straddle Pit and
Connection area

163 Unknown

528 Unknown

90 M sodalis

553 M lucifugus

63 P. subflavus

1992^

Newberry-Bane

1 00 M sodalis

4,000 M. lucifugus

3 M. septentrionalis

1 00 E. fuscus

19934

Newberry-Bane

5 C. t. virginianus

107 M sodalis

13 M leibii

988 M lucifugus

1 0 E. fuscus

30 P. subflavus

1995^

Newberry-Bane

1 1 0 M sodalis

1 1 M leibii

8 M lucifugus

2 M. septentrionalis

6 E. fuscus

9 P. subflavus

19992

Newberry-Bane

120 M sodalist

1 Ginny Dalton (Radford University, personal communication)

2 Gary Nussbaum and students (Radford University, personal communication)

3 Data from simultaneous surveys of the caves by a group of cavers organized by Carol and Joe Zokaites

4 Richard Reynolds (Virginia Department of Game and Inland Fisheries), Chris Hobson (Virginia Depart¬
ment of Conservation and Recreation), and colleagues

96

VIRGINIA JOURNAL OF SCIENCE

Bane, Bane Spring, and Spring Hollow caves. These caves are hydrologically con¬
nected (Wright 1 995), although physical connections have not always been established.

A description and map of the Skydusky Hollow Cave System was provided by
Zokaites (1995), and maps of three caves, Newberry-Bane, Buddy Penley, and Paul
Penley, were provided by Zokaites and Zokaites (1995) and Devine (1995a, 1995b).
Newberry-Bane Cave, largest and most complex of the system, has two entrances, the
Newberry and Bane entrances. Where the two entrance passages intersect is a maze
of passages referred to as the Junction (area), with Upper and Lower Junction areas.
In addition to caves of the Skydusky system, six caves in the same karst system were
also surveyed: Munsey #1 and #2, Munsey Twins (#1 and #2 entrances), Morehead’s
Pit, and Springhouse Cave.

The Skydusky Hollow karst is part of a linear belt of karsts extending from the
northwest flank of Walker Mountain northward to Walker Creek Valley, developed in
Cambro-ordovician limestone and dolomite. Streams and talus springs draining the
north flank of Walker Mountain sink at or near the upper limestone contact, and flow
through a complex network of caves before emerging at springs along Walker Creek.
Extensive, accessible cave passages are restricted to upper limestone formations that
lie beneath or near the upper limestone contact. Sinking streams from east and west
ends of the hollow converge in the lowest section of Newberry-Bane Cave.

Hibemacula surveys.— Four caves in Skydusky Hollow were visited 22 ~ 24
November 1999, to document autumn intra-cave use and to help establish which cave
areas, as based on temperature, morphology, and concentrations of bats, were most
likely to contain endangered bats during winter hibernation. Winter surveys, 17
January - 5 March 2000, were conducted in areas of 12 caves (1) that contained
concentrations of bats, (2) where temperatures were <9°C, a range typically suitable
for hibernation by concentrations of bats, particularly M. sodalis, and (3) that had
morphology typical of caves that cool appropriately for hibernation.

Bats were tallied by species and location in the caves. Individuals and bats in small
clusters were counted directly, but large clusters of Myotis lucifugus (little brown
myotis) were estimated in groups of 5 or 10 bats. Searches were made for accumula¬
tions of guano, indicative of summer use. Temperatures were taken at cave entrances,
in twilight areas, near clusters of endangered bats, near concentrations of other species,
and at intervals along the survey route. Temperatures were taken using Raytek infrared
thermometer model ST2 or Raynger® ST20, with a range of -18 or -32 to 400°C, an
accuracy of ±2 and ±1% of reading, and a display to the nearest 1.0 and 0.2°C,
respectively. Brack et al. (2003a) discussed advantages and disadvantages of point and
shoot infrared thermometers.

Spring staging and autumn swarming.— A bat trap was used to capture bats in
spring and autumn. Bats were trapped from dusk until 0000 ~ 0200 h at Buddy Penley
Cave 17-20 April 2000. Trapping in autumn was on 8, 11, and 26 September and 1 1
October 200 1 at the Bane entrance of Newberry-Bane Cave, and ran from dusk to 0 1 00
h on 8 September and until 2300 h on the other nights.

Bats were identified to species and sexed. When time allowed, weight, right forearm
length, time of capture, and reproductive status were recorded. During autumn, the
rate of capture was so great that about 150 -■ 200 bats were released without data
collection on 8 September, and about 50 bats were released on 1 1 September. Using

BATS OF BLAND COUNTY VIRGINIA

97

Chi-Square analysis, percentages of each species in the winter survey (expected ratio)
were compared to percentages of each caught in autumn (observed ratio) for species
where the catch was sufficient to test.

Summer cave use. — To determine summer use by a maternity colony or aggrega¬
tion of male bats, most notably C t. virginianus, autumn and winter intra-cave surveys
included searches for accumulations of guano. In late May 2000, caves were searched
for concentrations of bats, including the Attic of Buddy Penley Cave where a moderate
accumulation of guano was noted during winter surveys.

RESULTS

Wintering bats.— During autumn trips in four caves, >7,000 bats of four species
were found (Table 2). Most were M. lucifugus, and most were in Newberry-Bane (5
species) and Buddy Penley (4 species) caves. Only M. lucifugus and Pipistrellus
subflavus (eastern pipistrelle) were found in Paul Penley and Coon caves. During
winter, 12 caves were searched and 16,185 bats counted (Table 2); 89% {n = 14,479)
were M. lucifugus. Newberry-Bane (6 species) and Buddy Penley (3 species) caves
again contained the greatest number of bats. More bats were in Newberry-Bane (48%
more than in autumn). Buddy Penley (197%), Paul Penley (107%) and Coon (285%)
caves in winter than in autumn. About half the increase of bats in Newberry-Bane Cave
and about a third of the increase in Buddy Penley Cave resulted from increases in areas
surveyed in those caves. Paul Penley and Coon caves again had M. lucifugus and P.
subflavus, and a single Myotis septentrionalis (northern myotis) was also found in Coon
Cave. Munsey #1, Bane Spring, and Paul Penley caves had 100 - 1,000 bats. No bats
were found in Munsey Twin #2. No endangered C. t. virginianus were found during
autumn and winter cave surveys.

Myotis sodalis was found only in Newberry-Bane Cave, with the exception of a
single individual in Buddy Penley Cave on 23 November (Table 2). On 22 November,
26% of the population was in Lower Junction with 74% in Upper Junction. The
temperature in both areas was >8.5°C. During winter, bats had changed location,
abandoning Lower Junction entirely, and Upper Junction in large part, although
temperatures in both areas had dropped (Table 3). Instead, 88% of the population was
in a new area, the Bane Entrance Passage, at a temperature that was lower than either
of the other two areas (Table 3).

Like M sodalis, Myotis leibii (small-footed myotis) was found only in Newberry-
Bane Cave (Table 2). In autumn, one individual was found in the Junction area (9°C),
and in winter, seven M. leibii were found hibernating between the Bane Entrance
Passage and the Junction area (5.7 - 6.8°C). No M. septentrionalis were found during
the autumn survey, but 12 were found in winter, 9 in Newberry-Bane Cave, scattered
throughout the survey area, most near 9°C. Autumn surveys located 9 Eptesicus fuscus
(big brown bat) and winter surveys located 15 hibernating at a wide range of tempera¬
tures (1.2° - 13.3°C).

The largest concentrations of M. lucifugus were found in Newberry-Bane and
Buddy Penley caves during both autumn and winter (Table 2). Numbers of M.
lucifugus in Newberry-Bane Cave increased by 45% {n = 1,725) between November
and February, but bats were less concentrated in the North Subway. There were three
times more bats in Buddy Penley Cave in winter than in autumn (Table 2), but about
one-third were from an area not visited in autumn. Nevertheless, the number of bats

TABLE 2. Bats found during autumn 1999 and winter 2000 visits to caves in the Sky dusky Hollow Cave System and nearby caves in the same karst system in Bland County,
Virginia. Four caves were surveyed in autumn and 12 caves in winter; refers to sample size.

98

VIRGINIA JOURNAL OF SCIENCE

I ^

Cl)

lO ^ U-

' — I

^ in

(N

o o

o©

Os

in ^ OS in r-- (N
(N so os ^ (N OO (N
os^ oo (N ^ ^

in so" (n"

p

o

O so

00 oo in
^ oo

p — ;

in o

in

(N ^

p p (N p

o in

^ ^ in
o so so

(N

p

o

pinininpcNppp

rdrdsd^cdoscnoo
^ ^ VO o

in
os U-

r- o OO
cn so in

o CO in 00

(N

OS

SO

r- so — <

rt o
o o

OS

o o
o

(N

p

r—<

OO

p

p

p

p

p

OO

p

"O-

in

in

'0-

P

rn

rn

oo

■O'

o

SO

in

Os

os

os

oo

in

os

os

os

Os

in

OO

OS

m

OO

o

s;

OS

oo

o

(N

Os

Tt

Tt

m

so

(N

'xf

in

O

so

in

m

o

rn

Os

<N

r-

oo^

p^

m

(n

ip

ip

rp

oo

CN

■Tt

p

cn

(N

so"

in"

so"

— f

'xf"

nt o
o

OS

OS

OS o

§5

o

<N

cc (n
in

<D

O
C
a

CQ ^

>. (U

c ^ g

^

Z CQ D-

b

cd

3

C

cd

TO

§

OJ

§ ^

b S -S

c ^ g

^ 3

<L)

2: CQ Cu

"o

X

on

— ^ (N
^ =}t ^

c c S

&n '> ’> c«

^ S H H ^

CO CD (D (U 1> r-!

w:i QO c« 3

(L> (— < )-H f— ( r-<

C

<o

o o o o

(U

m

o

OX)

c

BATS OF BLAND COUNTY VIRGINIA

99

at Pit 1, the area of greatest concentration in both seasons, more than doubled (Table
3). Numbers of M lucifugus in Paul Penley doubled between autumn and winter, and
the number in Coon Cave increased by four times (Table 2); in both caves, locations
used by the largest concentrations of bats changed between seasons (Table 3).

Although individual M. lucifugus were found across the range of temperatures
available (1 - 14°C), concentrations in autumn were found at higher temperatures than
were concentrations in winter (Table 3). In autumn, the largest concentrations were in
Newberry-Bane Cave in North Subway (58% of the autumn total) at 9 - 9.5°C, and Pit
1 of Buddy Penley Cave (32%) at 7.9°C (Table 3). In winter, M. lucifugus were
concentrated at Pit 1 (30% of the winter total) at 6.3 - 6.5°C and Guano Climb (10%)
at 6.9°C in Buddy Penley Cave, in North Subway (20%) at 8.2 - 8.9°C and a portion
of the Junction area (12%) at 7.4°C of Newberry-Bane Cave, and in Big Room of Coon
Cave (9%) at 8.6 - 9.TC (Table 3).

Pipistrellus subflavus used the most caves, 4 of 4 caves in autumn and 11 of 12
caves in winter (Table 2). Coon Cave contained over half the total in both autumn and
winter, but Buddy Penley held 22% of autumn and 1 1% of winter populations.
Temperatures were warmer in both caves in autumn than in winter (Table 3). In winter,
P. subflavus concentrated in Main Passage (31% of the winter total) at 7.4 - 8.2°C and
Big Room (33%); at 8.6 - 9.7°C of Coon Cave, and in Buddy Penley Cave at 6.5 -
7.4°C (Table 3). During winter, small concentrations of P. subflavus in Munsey #1,
Paul Penley, and Bane Spring caves were generally in areas >8.0°C (Table 3).

Spring staging and autumn swarming. — Trapping at the entrance to Buddy Penley
Cave for 4 nights in April 2000 produced 101 bats of four species: 63 M lucifugus,
31 M septentrionalis, 6 P. subflavus, and 1 E. fuscus. Female M. lucifugus were six
times more common than males, but there were nearly equal numbers of male and
female M. septentrionalis.

During autumn 200 1 , trapping on 4 nights at Newberry-Bane Cave, 885 bats of six
species were processed: 27 M sodalis, 603 M lucifugus, 185 M septentrionalis, 6 M.
leibii, 60 P. subflavus, and 4 E. fuscus. Proportions of M sodalis, M. lucifugus, and
P. subflavus in the catch in autumn 200 1 were different than proportions observed in
Newberry-Bane Cave during winter 2000 {X^ = 123.9; at P<0.001; df = 2). Myotis
lucifugus was over represented in the winter survey and P. subflavus in the autumn
survey. Myotis sodalis was similarly represented in samples from both seasons. In
addition, M. septentrionalis was nearly absent from the winter survey (0.2%), exclud¬
ing it from the analysis, but it was common in autumn (20.9%).

Catch of female M. sodalis, although small, was greater in mid-September than
early September and early October, whereas captures of males, relative to females,
increased through the samples (Figure la). Captures of female M. lucifugus remained
relatively constant, but captures of males, relative to females, dropped dramatically
over the autumn season (Figure lb). More male than female M. septentrionalis were
caught early and late in the sample season and the absolute catch appeared to increase
late in the season (Figure Ic). The pattern for P. subflavus similar to that of M.
lucifugus (Figure Id). Myotis leibii were caught on 8 September (2 male and 2 female),
26 September (1 male), and 1 1 October (1 male). On 26 September, owQmdXQ E. fuscus
was caught and on 1 1 October two males and one female were caught.

Summer maternity colonies. — ^No large accumulation of guano that would indicate
summer use was found during autumn and winter intra-cave surveys. There was a

100

VIRGINIA JOURNAL OF SCIENCE

TABLE 3. Temperatures at which concentrations of three species of bats were found during autumn 1999
and winter 2000 surveys in caves of the Skydusky Hollow Cave System, Bland County, Virginia. Because
not all bats were in areas of concentration, totals in this table do not necessarily match totals in Table 2.

Species

Survey

Date

Cave

Location

Bats

Temp

(“C)

M. sodalis

Autumn

22 Nov

Newberry-Bane

Lower Jet.

44

8.5

Upper Jet.

126

8.9

Winter

5 Feb

Newberry-Bane

Lower Jet

0

7.2

Upper Jet

29

8.7

Bane Ent. Passage

206

7.0

M. lucifugus

Autumn

22 Nov

Newberry-Bane

N. Subway

3,778

9.0 -9.5

23 Nov

Buddy Penley

Pit 1

2,068

7.9

23 Nov

Paul Penley

Big Room

245

11.0

Whisper Hall

67

10.0

24 Nov

Coon

Main Passage

67

11.0

Big Room

245

11.0

Winter

17 Jan

Coon

Main Passage

28

9.1

Big Room

1,268

8.6 -9.7

19 Jan

Bane Spring

Front

383

7.4-8.3

Pit

59

9.8

3 Feb

Newberry-Bane

N. Subway

2,891

8.2-8.9

5 Feb

Junction area

1,802

7.4

Junction area

255

8.7

4 Mar

Buddy Penley

Pit 1

4,280

6.3-6.5

Pit

375

7.4

Guano Climb

1,400

6.9

Attic

210

8.4

5 Mar

Paul Penley

Big Room

76

9.8

Whisper Hall

755

9.4 -9.8

P. subflavus

Autumn

22 Nov

Newberry-Bane

all

31

9.0- 11.0

23 Nov

Buddy Penley

Entrance Passage

101

9.0

Paul Penley

Whisper Hall

32

10.0

24 Nov

Coon

Main Passage

175

11.0

Big Room

90

11.0

Winter

17 Jan

Coon

Main Passage

451

7.4-8.2

Big Room

469

8.6 -9.7

19 Jan

Bane Spring

Front

41

7.4 -8.3

28 Jan

Munsey #1

all

78

7.7 -8.4

3 - 4 Feb

Newberry-Bane

various

105

8.1 -9.3

5 Feb

Junction area

29

7.4

4 Mar

Buddy Penley

all

160

6.5 - 7.4

5 Mar

Paul Penley

Whisper Hall

47

9.4- 10.2

BATS OF BLAND COUNTY VIRGINIA

lOI

(C) (d)

FIGURE 1 . Captures of male (diamond) and female (closed circle) M. sodalis (a), M. lucifugus (b), M
septentrionalis (c), and P. subjlavus (d) during autumn 2001 swarming. Note that numbers of bats are not
to the same scale.

moderate accumulation of guano in the Attic of Buddy Penley Cave. When visited on
3 1 May 2000, no bats were present and there was no new accumulation of guano. The
temperature was about 10°C.

DISCUSSION

Spring staging and autumn swarming. — Proportions of species of bats captured in
spring and autumn varied among populations hibernating in the same caves. The
greatest disparity was seen with M septentrionalis, a species ofteiF caught at entrances
to hibemacula in spring and autumn (Whitaker and Rissler 1992) but infrequently
found during winter (Brack et al. 2003b, 2004).

The change in capture of bats as autumn progressed indicated a social component
in use of the cave. Although there were disproportionately large numbers of males of
all species, M sodalis had the most dramatic shift in relative abundance of sexes during

102

VIRGINIA JOURNAL OF SCIENCE

autumn. Male M. sodalis are more common during swarming than females because
they congregate near hibemacula to mate with females that are arriving for hibernation;
females terminate autumn activities and enter hibernation before males (Cope and
Humphrey 1977; LaVal and LaVal 1980). Richter et al. (1993) found that small male
M sodalis with insufficient fat reserves to survive the winter may remain active in
hibemacula, possibly seeking an opportunity to copulate before dying.

Male M lucifugus were much more abundant than females early in autumn, but
numbers dropped precipitously over time, similar to patterns observed for this species
at caves in Indiana (Humphrey and Cope 1976). Activity of P. subflavus declined
earlier in autumn than for other species, perhaps signaling an earlier entry into
hibernation. By contrast, activity of M. septentrional is seemed to rebound late in
autumn, and perhaps is related to greater activity during winter (Whitaker and Rissler
1992).

Winter hibernation. — Cave morphology strongly affects suitability for hibernation
(Humphrey 1978) by affecting airflow and thus temperatures. Large complex systems
offer more opportunities for the combination of characteristics needed to support
hibernating bats. The Skydusky Hollow Cave System and its individual caves are
complex and extensive (Zokaites 1995). Most species of bats make relatively charac¬
teristic and recognizable use of hibemacula, including temperature regimes and spatial
associations (Brack et al. 2003b). In the caves of Skydusky Hollow, the locations within
caves used by concentrations of bats often changed between seasons, similar to studies
in Missouri (Myers 1964; Clawson et al. 1980)

Hibernating M sodalis often form dense clusters in cool areas of hibemacula.
Myotis sodalis did not use the traditional roost in the Bane Entrance Passage in autumn,
but by winter had moved there, at 7°C, from the Upper and Lower Junction areas.
About 1 2% of the population remained in Upper Junction at 8.7°C. These temperatures
are not as cold as is often considered optimal for the species during mid-winter, i.e., 4
- 8°C, or perhaps more narrowly 3 - 6°C (USFWS 1 999). Further, cooler temperatures
(6.3 - 6.5°C) were available at the bottom of Pit 1 in Buddy Penley Cave. Hall (1962)
in the Midwest, Henshaw and Folk (1966) in Kentucky, and Humphrey (1978) in
midwestem and eastern states, considered mid-winter temperatures used by M. sodalis
to be 4 - 5°C, 2 - 3°C, and 4 - 8°C, respectively, but they did not provided supporting
documentation. In contrast. Brack et al. (2003b) completed 25 years of studies in many
of the caves addressed by Hall (1962) and Humphrey (1978) in Indiana, and they
documented increasing populations of M. sodalis in these caves, hibernating in areas
with mean mid-winter temperatures of 6 - 8°C. In Missouri, Myers (1964) found M
sodalis hibernating at 4.4 - 16.7°C, but considered 7.8°C representative; mid-winter
temperatures at clusters in three caves were 5.0 - 9.2°C (/7 = 6; X = 7. 1 ; SD = 1 .4). Also
in Missouri, Clawson et al. (1980) found M. sodalis hibernating at 6 - 8°C in late
January. Thus, temperatures used by M sodalis in Skydusky caves were similar to
those reported in other studies.

Myotis lucifugus uses many caves (Dalton 1987; Brack et al. 2003b) and small
numbers often hibernate in warm areas, sometimes giving the impression that this
species prefers the warmer temperatures that are available in caves for hibernation
(Brack et al. 2003b, 2004). In Skydusky caves, the largest concentration ofM lucifugus
{n = 4,280) hibernated at 6.5°C, at the bottom of Pit 1 in Buddy Penley in an area cooler
than areas used by M sodalis. The remaining 6,300 M. lucifugus hibernated at

BATS OF BLAND COUNTY VIRGINIA

103

temperatures similar to, or slightly less than, temperatures used by M sodalis. In a
limestone mine in Ohio, M lucifugus similarly used cooler areas, which were also less
thermally stable, than did M sodalis (Brack unpublished data).

Pipistrellus subflavus is found hibernating in more caves than other species of bats,
and it typically hibernates singly and dispersed at warm, stable temperatures (Hassell
1967; Brack et al. 2003b, 2004). As in other caves, P. subflavus hung singly or
occasionally in pairs and used a stable, warm area, but the number of P. subflavus in
Coon Cave was much greater than observed in most caves. The species arouses less
frequently than other species (Brack and Twenty 1985; Twenty et al. 1985), which may
offset the cost of hibernating at warmer temperatures. This species often collects beads
of moisture on guard hairs, which increases the mass of individuals and it is an
interesting question whether this water, suspended between the bat and its environment,
may act as a heat sink, dampening fluctuations in air temperature.

Little is known about M septentrionalis and M leibii during the season of
hibernation. Myotis septentrionalis is readily caught at cave entrances in spring and
autumn, providing indirect evidence of winter use (Whitaker and Rissler 1992), but is
infrequently found in hibernation (Brack et al. 2003b). When found in winter, it is often
deep in cracks or tight crevices in warm stable areas of the cave. Myotis leibii is believed
to hibernate at cold temperatures (Best and Jennings 1997), an inference based on
limited observation.

Eptesicus fuscus, a common summer resident in western Virginia, was uncommon
in these caves in winter. In natural hibemacula, it is considered a hearty species that
hibernates near entrances where temperatures may get very cold (Brack and Twente
1985), and it moves among hibemacula during winter. However, E, fuscus commonly
hibernates in walls of old brick houses (Whitaker and Gummer 1992), where tempera¬
tures are 3 - 20°C (X= 10°C).

Intra-cave movements of bats during the season of hibernation are poorly docu¬
mented. Like Skydusky caves, Clawson et al. (1980) documented an increasing
concentration of M sodalis in areas considered traditional hibemacula roosts between
autumn and mid-winter. Similar to Skydusky, Hassell (1967) found that M sodalis
hibernated in areas that got colder through the first half of the winter and warmer during
the latter half of winter.

Because M sodalis is listed as endangered, the occurrence of even a single
individual has sometimes been used to identify a cave or mine as a hibemaculum. A
single M sodalis was found in Buddy Penley Cave in autumn; none were present in
winter. There are several similar occurrences in Indiana: (1) an individual M sodalis
was in a cave one winter, and none were present the next (Brack et al. 2004), and (2)
an M sodalis was netted at a cave entrance in autumn, but no M sodalis have been
found during several winter surveys over a 25-year period (Brack et al. 2003b). In
Ohio, a single M sodalis was caught at a mine portal, but four additional nights of
sampling during two seasons did not produce additional M sodalis (Brack, unpublished
data). These occurrences indicate that M sodalis, and likely oth^ species, visits caves
and mines that are not used as hibemacula. Bats undoubtedly explore caves or parts
of caves not suitable for hibernation, especially during the spring and autumn migration
and transient periods.

Although Hassell (1967) reported that M lucifugus occupied the same locations
within caves throughout winter, we found that numbers and proportions of M lucifugus

104

VIRGINIA JOURNAL OF SCIENCE

in specific regions of Newberry-Bane, Paul Penley, and Coon caves changed dramati¬
cally over the season of hibernation. It is probable there were also inter-cave move¬
ments; Whitaker and Rissler (1992) documented bats exiting and entering hibemacula
throughout winter. The net result of these population shifts was to concentrate
hibernating M. lucifugus in cooler areas of the cave. Similarly, there were large changes
between autumn and winter in numbers and proportions of P. subflavus in parts of Coon
Cave. It is probable that in addition to temperature, the social nature of bats affects the
locations they used for hibernation. Raesly and Gates (1987) found that the presence
of other bats, of all species, strongly influenced use of sites for hibernation.

Summer maternity colonies. — ^No concentrations of bats were found in Skydusky
caves during summer. The most likely candidate for summer use was C t. virginianus,
although there are records of bachelor colonies of M. grisescens in Lee County Virginia
(Webster et al. 1985). There was no large accumulation of guano indicative of past
use, and there were no bats in the Attic of Buddy Penley Cave in late May, The Attic
was cooler (10°C) than maternity roosts used by C t. virginianus in Kentucky (Lackie
et al. 1994) and the closely related subspecies C. t. ingens (Ozark big-eared bat) in
Oklahoma (Clark et al. 1996) at this time of year (12.8 - 16.3°C).

Summary. ^ — ^The caves of Skydusky Hollow held >16,000 bats of 6 species in
winter 2000, which is an important resource for the Commonwealth of Virginia and
the region. Most (89%) were M lucifugus, although 9% were P. subflavus and 1% the
federally endangered M sodalis. No endangered C. t. virginianus were found. Most
bats were in two caves, Newberry-Bane (37%) and Buddy Penley (40%), including
endangered M sodalis, although there was an unusually large concentration of P.
subflavus (64% of this species and 6% of the total) in Coon Cave. Of the three most
common species, the largest mid-winter concentration of M lucifugus was at the
coldest temperature (6.3-6.5°C), M sodalis at a more moderate temperature (7.0°C),
and P. subflavus at the warmest temperature (8.6-9.7°C). No concentration of bats used
the caves during summer. Proportions of species captured in spring and autumn were
not consistent with wintering populations, with the greatest disparity shown by M
septentrionalis, a species often caught at hibemacula in spring and autumn but
infrequently found in winter. Changes in proportions of males and females caught over
autumn indicate a social function to autumn swarming.

ACKNOWLEDGMENTS

All authors contributed to field and reporting efforts. American Electric Power
(AEP) and Virginia Department of Game and Inland Fisheries funded portions of these
studies. Ron Poff (AEP) played a vital role in assuring completion of the studies. We
thank landowners who allowed access to caves: Molly and Jerry Thompson, Robert
Banes, Gene Harman, Billy Dilman, Joe Bane, Ellis Morehead, Bob Munsey. Many
individuals participated in caving trips, and, without them, the surveys would not have
been as safe or as successful: Bobby Zokaites, Joe Thompson, Steve Wells, Steve
LePera, Brad Atkinson, Eileen O’Malley, Matt Burnett, Kirk Digby, Raymond Sira,
Don Anderson, Walter Pirie, Michael Malsbum, Charlie Jones, and Terri Brown. The
1992 bat count was led by Ed Devine in Paul Penley, Jerry Redder in Buddy Penley,
Barbara Graham in Bane Spring, Paul Kirchman in Spring Hollow, and Joe and Carol
Zokaites and Jean Simonds in Newberry Bane. We thank Dean Metter and Gary Finni
for inspiration.

BATS OF BLAND COUNTY VIRGINIA

105

LITERATURE CITED

Barbour, R. W. and W. H. Davis. 1969. Bats of America. University Press of

Kentucky, Lexington. 286 pp.

Best, T. L. and J. B. Jennings. 1997. Myotis leibii. Mammalian Species 547:1-6.

Brack, V., Jr., R. K. Dunlap and S. A. Johnson. 2003a. Advantages of infrared
thermometers for recording temperatures in caves. Bat Research News 44:62-63.

Brack, V., Jr., S. A. Johnson and R. K. Dunlap. 2003b. Wintering populations of bats
in Indiana, with emphasis on the endangered Indiana bat {Myotis sodalis). Pro¬
ceedings of the Indiana Academy of Science 1 12:61-74.

Brack, V., Jr. and J. W. Twente. 1985. The duration of the period of hibernation in
three species of vespertilionid bats I: field studies. Canadian Journal of Zoology
63:2952-2954.

Brack, V., Jr., J. O. Whitaker, Jr. and S. Pruitt. 2004. Bats of Hoosier National Forest.
Proceedings of the Indiana Academy of Science 1 13:76-86.

Clark, B. K., B. S. Clark, D. M. Leslie, Jr. and M. S. Gregory. 1996. Characteristics
of caves used by the endangered Ozark Big-eared bat. Wildlife Society Bulletin
24:8-14.

Clawson, R. L., R. K. LaVal, M. L. LaVal and W. Caire. 1980. Clustering behavior
of hibernating Myotis sodalis in Missouri. Journal of Mammalogy 61:245-253.

Cope, J. B. and S. R. Humphrey. 1977. Spring and autumn swarming behavior in the
Indiana bat, Myotis sodalis. Journal of Mammalogy 58:93-95.

Dalton, V. M. 1987. Distribution, abundance, and status of bats hibernating in caves
in Virginia. Virginia Journal of Science 38:369-379.

Devine, E. 1995a. Buddy Penleys Cave. Pages 30-33 In C. Zokaites, ed. Under¬
ground in the Appalachians: A Guidebook for the 1995 National Speleological
Society Convention. National Speleological Society Press, Huntsville, Alabama.

Devine, E. 1995b. Paul Penleys Cave. Pages 35-39 In C. Zokaites, ed. Underground
in the Appalachians: A Guidebook for the 1995 National Speleological Society
Convention. National Speleological Society Press, Huntsville, Alabama.

Fenton, M. B. 1969. Summer activity of Myotis lucifugus (Chiroptera: Vestertilioni-
dae) at hibemacula in Ontario and Quebec. Canadian Journal of Zoology 47:597-
602.

Hall, J. S. 1962. A life history and taxonomic study of the Indiana bat, Myotis sodalis.
Reading Public Museum Publication 12:1-68.

Hassell, M. D. 1967. Intra-cave activity of four species of bats hibernating in
Kentucky. Ph.D. Dissert., Univ. Kentucky, Lexington. 62 pp.

Henshaw, R. E. and G. E. Folk, Jr. 1966. Relation of thermoregulation to seasonally
changing microclimate of two species of bats {Myotis lucifugus and M. sodalis).
Physiological Zoology 39:223-236.

Humphrey, S. R. 1978. Status, winter habitat, and management of the endangered
Indiana bat, Myotis sodalis. Florida Scientist 41 :65-76.

Humphrey, S. R. and J. B. Cope. 1976. Population ecology of the little brown bat,
Myotis lucifugus, in Indiana and north-central Kentucky. American Society of
Mammalogists Special Publications 4:1-81.

Kurta, A., S. W. Murray and D. H. Miller. 2002. Roost selection and movements
across the summer landscape. Pages 118-129/^ A. Kurta and J. Kennedy, eds. The

106

VIRGINIA JOURNAL OF SCIENCE

Indiana Bat: Biology and Management of an Endangered Species. Bat Conserva¬
tion International, Austin, Texas.

Lacki, M. J., M. D. Adam and L. G. Shoemaker. 1 994. Observations on seasonal cycle,
population patterns and roost selection in summer colonies of Plecotus townsendii
virginianus in Kentucky. American Midland Naturalist 131:34-42.

LaVal, R. K. and M. L. LaVal. 1980. Ecological studies and management of Missouri
bats, with emphasis on cave-dwelling species. Missouri Department of Conserva¬
tion Terrestrial Series 8:1-53.

Myers, R. F. 1964. Ecology of three species of species of myotine bats in the Ozark
Plateau. Ph.D. Dissert., Univ. Missouri, Columbia. 210 pp.

Parsons, K. N., G. Jones, I. Davidson- Watts and F. Greenaway. 2003. Swarming of
bats at underground sites in Britain — implications for conservation. Biological
Conservation 1 1 1:63-70.

Raesly, R. L. and J. E. Gates. 1987. Winter habitat selection by North American
temperate cave bats, American Midland Naturalist 118:15-31.

Richter, A. R., S. R. Humphrey, J. B. Cope and V. Brack, Jr. 1993. Modified cave
entrances: thermal effect on body mass and resulting decline of endangered Indiana
bats {Myotis sodalis). Conservation Biology 7:407-415.

Thomas, D. W., M. B. Fenton and R. M. R. Barclay. 1979. Social behaviour of the
little brown bat, Myotis lucifugus. I. Mating behaviour. Behavioural Ecology and
Sociobiology 6:129-136.

Twente, J. W., J. Twente and V. Brack, Jr. 1985. The duration of the period of
hibernation of three species of vespertilionid bats II: laboratory studies. Canadian
Journal of Zoology 63:2955-2961.

USFWS (U.S. Fish and Wildlife Service). 1999. Agency draft Indiana bat {Myotis
sodalis) revised recovery plan. Fort Snelling, Minnesota. 53 pp.

Webster, W. D., J. F. Parbell and W. C. Biggs, Jr. 1985. Mammals of the Carolinas,
Virginia, and Maryland. University of North Carolina Press, Chapel Hill. 255 pp.

Whitaker, J. O., Jr. and S. L. Gummer. 1992. Hibernation of the big brown bat,
Eptesiciis fuscus, in buildings. Journal of Mammalogy 73:3 12-316.

Whitaker, J. O., Jr. and L. J. Rissler. 1992. Winter activity of bats at a mine entrance
in Venuillion County, Indiana. American Midland Naturalist 127:52-59.

Wright, W. 1995. Hydrology of the Sky dusky Hollow Cave System. Pages. 126-141
In C. Zokaites, ed. Underground in the Appalachians: A Guidebook for the 1995
National Speleological Society Convention. National Speleological Society Press,
Huntsville, Alabama.

Zokaites, C. 1995. Sky dusky Hollow Cave System. Pages 22-25 //? C. Zokaites, ed.
Underground in the Appalachians: A Guidebook for the 1995 National Speleologi¬
cal Society Convention. National Speleological Society Press, Huntsville, Ala¬
bama.

Zokaites, J. and C. Zokaites. 1995. Newberry-Banes Cave. Pages 34-35 In C.
Zokaites, ed. Underground in the Appalachians: A Guidebook for the 1995
National Speleological Society Convention. National Speleological Society Press,
Huntsville, Alabama.

JEFFRESS AWARDS

107

JEFFRESS RESEARCH GRANT AWARDS

The Allocations Committee of the Thomas F. and Kate Miller Jeffress Memorial
Trust has announced the award of Jeffress Research Grants to the institutions listed
below to support the research of the investigator whose name is given. The Jeffress
Trust, established in 1981 under the will of Robert M. Jeffress, a business executive
and philanthropist of Richmond, supports research in chemical, medical and other
natural sciences through grants to non-profit research and educational institutions in
the Commonwealth of Virginia. The Jeffress Research Grants being announced here
have been awarded in 2003 .

The Jeffress Memorial Trust is administered by Bank of America. Additional
information about the program of the Trust may be obtained by writing to: Richard B.
Brandt, Ph.D., Advisor, Thomas F. and Kate Miller Jeffress Memorial Trust, Bank of
America, Private Bank, P. 0. Box 26688, Richmond, VA 23261-6688. An unofficial
website is listed under Grants and Awards, www.vacadsci.org.

William P. Anderson, Radford University. Collection of Water Level Data to Test New
Methods for Estimating Recharge in Water-Table Aquifers. $10,000. (one year
renewal).

Todd D. Averett, The College of William and Mary. Neutron Spin Structure Studies
Using High Density Polarized ^He Targets. $10,000. (one year renewal).

Stephen F. Baron, Bridgewater College. Regulation ofExcellular Polyhydroxalkanoate
Depolymerase Synthesis in Streptomyces spp.5A. $27,320. (one year).

Deborah C. Bebout, The College of William and Mary. Investigation of Silica Sup¬
ported Copper Complexes as Biometrics of Micronuclear Monooxygenases.
$10,000. (one year renewal).

John J. Beck, Sweet Briar College. Structure-Activity Relationships of Aromatic
Analogs of (Z)-Ligustilide: A Natural Product from Ligusticum Species. $10,000.
(one year renewal).

Matthew J. Beckman, Virginia Commonwealth University/Medical College of Vir¬
ginia. Arthritis and the Importance of Ets-2 in Urokinase-Plasminogen Activator
Expression. $10,000. (one year renewal).

Wade E. Bell, Virginia Military Institute. The Role of Calcium in Paramecium
Chemoresponse: Elucidation of Mechanisms for Calcium Influx. $10,000. (one year
renewal).

Mark P. Birkenbach, Eastern Virginia Medical School. Characterization of Interleukin-
27 Function in Immune Response to Murine Cytomegalovirus (MCMV). $20,000.
(one year).

Robert A. Bloodgood, University of Virginia School of Medicine. Calciurn Regulation
of Whole Cell Locomotion. $10,000. (one year renewal).

Timothy Bos, Eastern Virginia Medical School. Regulation of Breast Cancer Gene
Targets by the AP-1 Transcription Factor. $10,000. (one year renewal).

Karen J. Brewer, Virginia Polytechnic Institute and State University.. Binding Metal
Centers to Photochemically Active Metal Sites. $10,000. (one year renewal).
Stephen G. Cessna, Eastern Mennonite University. Reactive Oxygen Production
During Salinity Tolerance Responses in Tobacco Cells: Relationship to Cytosolic
Ca^~ Fluxes. $10,000. (one year renewal).

108

VIRGINIA JOURNAL OF SCIENCE

Jennifer A. Clevinger, James Madison University. Phylogenetic Analysis of [Sil-
phium} and [Berandiera] (Asteraceae) Using DNA Sequence data. $10,000. (one
year renewal).

Stuart C. Clough, University of Richmond. The Preparation and Application of
5-chioro-5-ary!-2, 4-pentadienoates to the Regioselective Synthesis of Heterocy¬
cles and Carbocycles. $20,000. (one year).

Gary G. Cote, Radford University. Regulation of Plant Crystal-Containing Idioblast
Cells by Herbivory. $8,820. (one year renewal)

Brian Cusato, Sweet Briar College. The Pavlovian Conditioning on Sexual Behavior
and Fertility in Female Japanese Quail (Coiurnixjaponica) . $25,000. (one year).

Antonio del Castillo, Virginia Commonwealth University/Medical College of Vir¬
ginia. Role of Feto Protein Transcription Factor (FTF) in Bile Acid Synthesis.
$25,000. (one year).

Christopher Del Negro, The College of William and Mary. Do Pacemaker Neurons
Generate the Rhythum for Breathing?. $30,000. (one year).

Michael R. Deschenes, The College of William and Mary. Effects of Senescence on
Neuromuscular Adaptations to Disease. $30,000. (one year).

Anca D. Dobrian, Eastern Virginia Medical School. Vascular Reactivity and Oxidative
Balance in Large and Small Arteries in a Rat Model of Obesity-Induced Hyperten¬
sion. $10,000. (one year renewal).

James Eason, Washington and Lee University. The Mechanisms of Defibrillation
During Acute Myocardial Ischema $16,000. (one year).

Sergei A. Egorov, University of Virginia. Interactions Between Nanoparticles in
Supercritical Fluids. $10,000. (one year renewal).

Joseph J. Feher, Virginia Commonwealth University/Medical College of Virginia.
Continuous Measurement of Superoxide During Ischemia- Reperfusion Injury of
Intact Rat Hearts. $28,863. (one year).

Marcia B. France, Washington and Lee University. Chiral Schiff Base Complexes as
Catalysts for Assemetric Cyclopropanation. $10,000. (one year renewal).

Babette Fuss, Virginia Commonwealth University/Medical College of Virginia. Novel
Mechanisms in CNS Mylelination: Role of PD-lalATX. $10,000. (one year
renewal).

Ning Gao, Virginia Commonwealth University/Medical College of Virginia. Molecu¬
lar Mechanisms of the Anticarcinogenic Effects of Indole-3-Carbinol. $25,000.
(one year).

George W. Gilchrist, The College of William and Mary. The Genetic Architecture of
Rapidly Evolving Traits in Invading Populations of Drosophila subobscura.
$10,000. (one year renewal).

Glenda Gillaspy, Virginia Polytechnic Institute and State University. Inositol Synthesis
and Catabolism in Plants. $15,000. (one year).

Emma Goldman, University of Richmond. Synthesis and Characterization of a Series
of Dicopper Compounds for Use as Electro catalysts in the Reduction of Carbon
Dioxide. $16,450. (one year).

Douglas S. Graber-Neufeld, Eastern Mennonite University. Renal Transport of Or¬
ganic Anions in Insects: A Role for Handling Environmental Toxins. $ 1 0,000. (one
year renewal).

JEFFRESS AWARDS

109

Robert M. Granger, II, Sweet Briar College. What to do with the CO2? Studies of Novel
CO2 Reduction Catalysis. $10,000 (one year renewal).

Hisasha Harada, Virginia Commonwealth University /Medical College of Virginia.
The Molecular Mechanisms of Cytokine-Mediated Cell Survival. $14,000. (one

year).

Elizabeth J. Harbron, College of William and Mary. Factors Influencing the Kinetics
of Aromatic Stacking in an Azobenzene Photoswitch $25,000. (one year).

Barbara Y. Hargrave and Christopher J. Osgood, Old Dominion University. Develop¬
ment of a Mouse Model to Tnvestigate Gender Differences in the Susceptibility to
Cardiovascular Disease. $30,000. (one year).

James B. Herrick, James Madison University. Exogenous Isolation and Charac¬
terization of Antibiotic Resistance Plasmids from an Agriculturally-Impacted
Stream. $10,000. (one year renewal).

Kirdir W. Hilu, Virginia Polytechnic Institute and State University. Origin and Mo¬
lecular Differentiation of Prolamin Multigene Families in Grasses. $10,000. (one

year renewal).

Robert J. Hinkle, The College of William and Mary. Expanding the Scope of
Alkenyl(aryl)iodonium Substitutions. $10,000 (one year renewal).

Helen T Anson, Washington and Lee University. Metabolic Regulation of the Onset of
Puberty. $19,470. (one year).

Brian M. Kelley, Bridgewater College. The Influence of Adolescent Nicotine Exposure
on Adult Drug Sensitivity and Substance Abuse Risk. $10,000. (one year renewal).
Sunyoung Kim, Virginia Polytechnic Institute and State University. Spectroscopic
Investigation of DNA Binding to Photolyase. $10,000. (one year renewal).

Darius Kuciauskas, Virginia Corn monwealth University. Membrane Phase Transi¬
tions and Transport Studied by Transient Grating Spectroscopy. $10,000. (one year
renewal).

Lisa M. Landino, The College of William and Mary. Probing the Reactivity of the
Sulfhydryl Groups of Microtubule Proteins. $10,000. (one year renewal).

Timothy Larson, Virginia Polytechnic Institute and State University. Trafficking of
Sulfur in Bacteria. $10,000. (one year renewal).

Michael C. Leopold, University of Richmond. Biological Enhanced Metallic Nonopar¬
ticles: The Next Dimension of Protein Enhanced Monolayer Electrochemistry.
$10,000. (one year renewal).

Scott B. Lewis, James Madison University. Search for the Most Appropriate Precursos
of Difluorocarbene to Produce Difluoroaromatic Compounds. $10,000. (one year

renewal).

Nilanga Liyanage, University of Virginia. Construction of a Proto-Type Multi-Wire
Proportional Chamber for Jefferson Lab. Engineering. $ 1 0,000. (one year renewal).
Shirley Luckhart, Virginia Polytechnic Institute and State University. Signaling by
Transforming Growth Factor 1~ Homologs in Anopheles stephensi $10,000. (one

year renewal).

Michael Madigan, Virginia Polytechnic Institute and State University. Effects of Low
Back Fatigue on Balance. $10,000. (one year renewal).

J. Paul Mounsey, University of Virginia Medical School. Phospholemman and the
Regulation of the Cardiac Sodium Pump. $20,000. (one year).

110

VIRGINIA JOURNAL OF SCIENCE

Ramesh Natarajan, Virginia Commonwealth University/Medical College of Virginia.
Role of Hypoxia Inducible Factor-1 in Microvascular Ischemia/Reperfusion.
$30,000. (one year).

Robert D. Pike, The College of William and Mary. Bridging Caged Phosphite Ligands:
New Metal-Organic Network Formers. $10,000. (one year renewal).

Robyn A. Puffenbarger, Bridgewater College. Cannabinoid Receptor Expression in
Macrophages. $10,000. (one year renewal).

Roland N. Pittman, Virginia Commonwealth University/Medical College of Virginia.
The Role of the Microcirculation in Skeletal Muscle Dysfunction Associated with
Chronic Heart Failure. $18,000. (one year).

Joseph H. Porter, Virginia Commonwealth University. Effects of Antipshchotic Drugs
on Phencyclidine (PCD)-Induced Impairments in Reference and Working Memo¬
ries in Mice. $10,000. (one year renewal).

Jennifer Radkiewicz, Old Dominion University. An Investigation of 2-Aminoethoxy-
dipphenylborate and Analogs as Store-Operated Calcium Entry Channel Inhibitors.
$10,000. (one year renewal).

Anne C. Reilly, The College of William and Mary. Investigation of Pulsed Laser
Deposition of Magnetic Multilayer Systems. $10,000. (one year renewal).

Shunlin Ren, Virginia Commonwealth University/Medical College of Virginia. Bio¬
chemical Study of Cholesterol Transporter in Bile Acid Synthesis. $25,000. (one
year).

Terrie K. Rife, James Madison University. Understanding Transcriptional Changes of
Nitric Oxide Synthetase I in Neurons Using a PC 12 Cell Model. $10,000. (one year
renewal).

James D. Rowan, Bridgewater College. Cognitive Representation of the Rules Used
in Serial-Pattern Learning. $25,000. (one year).

Charles Rutherford, Virginia Polytechnic Institute and State University. The Role of
5 ’Nucleotidase During Cell Differentiation Diciyostelinm. $10,000. (one year
renewal).

Margaret Saha and William Cooke, The College of William and Mary. Novel Laser-
Based Strategies for the Insertion of DNA into Cells of Living Organisms. $10,000.
(one year renewal).

Carmen Sato-Bigbee, Virginia Commonwealth University/Medical College of Vir¬
ginia. Identification of Molecular Mechanisms Regulating Oligodendrocyte Pro¬
liferation. $10,000. (one year renewal).

Dorothy A. Schafer, University of Virginia. Mechanism of Anti-Capping by ENA-
IVSAP Proteins. $30,000. (one year).

Michael W. Stacey and William G. Kearns, Eastern Virginia Medical School. The
Myelodysplastic Syndrome and Genetic Instability. $10,000. (one year renewal).

Kam Tang, Virginia Institute of Marine Science. Copepods as Microbial Hotspots in
DMSP Dynamics: Effects of Host Feeding Activities on Attached DMSP-Consum-
ing Bacteria. $25,000. (one year).

Douglas R. Taylor, University of Virginia. Identifying the Genes Controlling Melanin
Production to Study the History of Selection on Melanie Mosquitofish Gambusia
hoibrooki. $25,000. (one year).

David W. Thompson, The College of William and Mary. Silver Nanowire, Nanorod,
and Nanosphere-High Performance Polymer Composites. $30,000. (one year).

JEFFRESS AWARDS

111

Julie Davis Turner, University of Virginia Medical School. Molecular Dissection of
the Synergy Between HIV and Mycohacterium luherculosis. $20,000. (one year).

Erich Uffelman, Washington and Lee University. HMBC Spectroscopy of

Complexes Relevant to Green Chemistry. $25,000. (one year).

Raphael J. Witorsch, Virginia Commonwealth University/Medical College of Virginia.
G-Screen Microassay for the Identification of Xenoglucocorticoids $25,000. (one
year).

Debra L. Wohl, University of Richmond. The Importance of Functionally Redundant
Species on an Ecosystem Process. $10,000. (one year renewal).

Fang-Sheng Wu, Virginia Commonwealth University. Direct Gene Transfer of a Intact
Plant Cells. $10,000. (one year renewal).

Judith A. Wubah, James Madison University. The Role of Mitochondrial Salvage
Enzymes During Early Mouse Development. $25,000. (one year).

Roshna Wunderlich, James Madison University. Biomechanics of Bipedal Locomo¬
tion in Propithecus verreauxi. $30,000. (one year).

Henry M. Yochum, Ill, Sweet Briar College. Optical Spectroscopy of Defects in
Undoped Yttrium Orthovanadate Crystals. $30,000. (one year).

Chetiming Zhang, Virginia Polytechnic Institute and State University. Effectiveness
of Site Selection by Molecular Modeling for Site-Directed Protein Mutagenesis.
$20,000. (one year).

Quibing Zhou, Virginia Commonwealth University. DNA Promoted Intercalating/Al¬
kylating Drugs. $30,000. (one year).

Richmond, VA 23220-2054

Instructions to Authors

All manuscripts and correspondence should be addressed to the Editor. The
Virginia Journal of Science welcomes for consideration original articles and short
notes in the various disciplines of engineering and science. Cross-disciplinary
papers dealing with advancements in science and technology and the impact of
these on man and society are particularly welcome. Submission of an article implies
that the article has not been published elsewhere while under consideration by the
Journal.

Three complete copies of each manuscript an figures are required. It is also
required that authors include a diskette in IBM compatible format containing a text
file (ASCII or acceptable word processing file) of the manuscript. Original figures
need not be sent at this. time. Authors should submit names of three potential
reviewers. All manuscripts must be double-spaced. Do not use special effects such
as bold or large print.

The title, author’s name, affiliation, and address should be placed on a cover
page. An abstract (not to exceed 200 words) summarizing the text, particularly the
results and conclusions, is required. The text should follow the general format used
byprofessionaljournals in the author’s discipline. Literature cited in the text should
follow the name-year format: (McCaffrey and Dueser, 1990) or (Williams et al.,
1990). In the Literature Cited section at the end ofthe article, each reference should
include the frill name of the author(s), year, title of article, title of journal (using
standard abbreviations), volume number and first and last page ofthe article. For
a book, include author(s), year, title, pages or number of pages, publisher and city
of publication. Examples:

McCaffrey, Cheryl A. and Raymond D. Dueser. 1990. Plant associations ofthe
Virginia barrier islands. Va. J. Sci. 41:282-299.

Spry, A. 1969. Metamorphic Textures. Pergamon Press, New York. 350 pp.

Each figure and table should be mentioned specifically in the text. All tables,
figures and figure legends should be on a separate pages at the end of the text.

Multiple author papers are required to have a statement in the acknowledg¬
ments indicating the participation and contribution of each author.

After revision and final acceptance of an article, the author will be required to
furnish two error-free copies ofthe manuscript: 1) typed copy, single spaced, with
tables and figure captions at the end ofthe document, and one set of original figures,
each identified on the back by figure number and author’s name; 2) a diskette in an
IBM compatible format containing the text file, tables and figure legends.

SMITHSONIAN INSTITUTION

LIBRARY ACQUISITIONS (SMIV) ROOM 25 NHB

WASHINGTON, DC 20560-0001

SMfTHSONIAN INSTITUTION LIBRARIES

3 9088 01180 0026

O)

K)

00

is

hO CD
O ^

<5' <9.

^ >
c 2

CO Q.

i|

2,a

< CO

<3.g-

3 3
O

0)

CD