Small Mammal Survey of National Capital Region Parks -

Final Report

by

William J. McShea and Carrie O'Brien

National Zoological Park's

Conservation and Research Center

Front Royal, VA 22630

For the:

National Park Service

Inventory and Monitoring Program

National Capital Region Network

19 Dec. 2003

TIC #: NCRO D-50

The purpose of the survey is to describe the distribution and relative
abundance of small mammals species in eight parks in the National
Capital Region. Our survey protocol was not designed to detect every
species that might reside or passage through the park, but rather to
test the utility of using small mammals as a monitoring tool for park
biodiversity. Our results can provide guidance to individual parks and
to the region with regards to the relative abundance and distribution of
small mammals, as the protocol was maintained across sites and the sites
were sampled over what was essentially the same period of time.

**Study area**

The parks sampled for small mammals included: Antietam National
Battlefield (ANTI), Catoctin Mountain Park (CATO), Chesapeake and Ohio
Canal National Historical Park (CHOH), George Washington Memorial
Parkway (GWMP), Harpers Ferry National Historical Park (HAFE), National
Capital Parks-East (NACE), and Rock Creek Park (ROCR). Several parks had
a particular interest in specific mammals and received additional
monitoring for gray foxes and flying squirrels (ANTI, CHOH, GWMP, HAFE,
ROCR), or woodrats (CHOH). All the parks were within the drainage of the
Potomac River (Figure 1). Three parks (CHOH, HAFE, GWMP) were wholly
confined to the Potomac's floodplain and adjoining hills; one park
(NACE) was confined to the floodplain of both the Potomac and a major
tributary (Anacostia); and one park (ROCR) was confined to the
floodplain of a tributary (Rock Creek) (Figure 1).

**Methods**

Selecting survey points based on landcover classes for each park was
dependent on the development of the park's GIS coverage. For CATO, ROCR,
and HAFE there were landcover layers within their GIS that were readily
usable. We did have to combine habitat classes prior to point selection.
For NACE, and GWMP we used a base map the USGS national landcover
project (<http://landcover.usgs.gov/natllandcover.asp>). Their
classification system has only 3 forest classes, so no reduction of
classes was necessary.

Determining sample locations did vary between the parks. CHOH is linear
with few access points and contains many historical sites that would not
allow disturbance, so we divided the park into 9 equal sections and
located 4 sample areas within each section. Each sample area consisted
of 6 survey points that were spaced \> 200 apart along the canal road.
For sections where the park property expanded beyond the canal zone, we
made an effort to select points outside the floodplain. So little forest
cover was available for WOTR and ANTI that we were limited in the
location of points and relied on field crews to select points. For
remainder of the parks with existing habitat coverages, we used a GIS
(Arc-View 3.2) to create broad habitat classes for the parks; within
each habitat class we used a random number algorithm within ERDAS
Imagine to create one survey point for every 37 hectares. The sample
points were a minimum of 200 m apart, with additional points (10% of
total) were chosen in habitats of special concern to each park. An
example of the final survey point distribution is given for ANTI (Figure
2). The geocoordinates of each point were entered into a GIS once the
survey points were located by the field team. This selection process
resulted in each park being sampled relative to the size of the park
(Table 1), with 2.5-3.0 samples for every 100 hectares within the park.
Smaller parks were sampled beyond this level and HAFE received
additional sampling after examination of its species accumulation curve.

Each sample point was composed of eight 9" Sherman traps, one 16"
Tomahawk trap, and one pitfall array. The traps were live-capture and
baited with a mixture of oats and sunflower seeds. The pitfall array
consisted of four water-filled containers placed 6" deep and flush with
the ground surface and 1-m from each other. The containers were linked
to each other by a wire mesh screening, such that there was a central
container and three "arms". The Sherman traps were placed in pairs at
the most likely capture sites within an 11-m radius of the pitfall
array. The Tomahawk trap was attached to a tree using a wooden platform.
If the site was not wooded, the Tomahawk trap was placed on the ground.
If there was any evidence of subterranean mole activity, we set Victor
mole traps within active tunnels. The live-traps were pre-baited for two
days, followed by five days of trapping. The traps were checked twice a
day and all animals captured were marked and released. The pitfall array
was operated for the entire seven-day period and all animals captured
were returned to the laboratory for species identification. During the
first winter of the study (2000/2001) a Tomahawk trap was placed on a
tree platform at each wooded survey point to survey for squirrels. These
traps were pre-baited for two days and checked twice daily for five
days, as with the summer survey. An abundance estimate was created for
each species based on the number of animals captured per trap night.

For those parks surveyed for gray fox, infrared trip cameras were placed
at a subset of the sample points. An object within three--m in front of
the camera was baited with commercial fox lure, and the camera was
operated for one week during the winter. An abundance index for the
predators detected was created using the number of pictures per night of
camera coverage.

Our criteria for adequate sampling of a park was to construct species
accumulation curves for each trapping effort and to detect evidence that
the capture of new species using our capture protocol has leveled off.
This is not to infer that all species are captured, but can be used to
gauge when this combination of live- and pitfall traps has surveyed the
mammals "available" to it. We present the species accumulation curves
for each park at the end of this report (Appendix 1). At a single park
(HAFE) we returned to the park a second time to trap eight additional
survey points after examining the species accumulation curves. For the
remaining seven parks the graphs did not indicate a need for additional
trapping using this protocol.

##### Results and Discussion

We captured 2,081 small mammals during the survey, with all but 34 of
these coming during the summer survey period (Table 2). The most
abundant species were *Peromyscus leucopus, Sciurus carolinensis*, and
*Blarina brevicauda*. Some parks contained individual species that were
not detected in other parks, such as *Microsorex hoyi* in CATO and
*Neotoma magister* in HAFE. It is difficult to make much of the
comparisons between species because each species differs in their
propensity to be captured using our protocol. We are confident that the
3 abundant species are the most common, but the relative ranking of the
remaining species is questionable. An example of this is our inability
to capture species that we observed at some parks. *Sciurus
carolinensis* was observed at CATO, but captured during neither the
winter or summer survey. Signs of activity by *Scalopus aquaticus* were
observed at NACE and GWMP, but the animal was not captured in either
park. We can explain some of the missing species by assuming they are
not abundant and the trapping effort was insufficient to sample rare
species. Rare species are usually confined to small microhabitats, which
may not be sampled suing this broad approach*.* The *Neotoma* at HAFE
was not captured during the first survey, but only at a single
supplemental point during 2002. We have no explanation for our failure
to capture *Sciurus* at CATO.

It is not valid to compare the number of mammals captured at each park
because the sampling effort was different at each park. We strived to
keep the effort relative to the number of hectares in each park (Table
1). We had 2 exceptions to this: One was the small size of WOTR resulted
in our oversampling of that habitat. The second was the size of CATO
includes a large area that is inaccessible due to security concerns. The
sampling effort at CATO was in line with the amount of forest available
to the research team. As to be expected, the number of species captured
was positively correlated with the size of the park (Pearson's R = 0.74,
P = 0.036; Figure 3). Of interest for future study, and a focus of our
subsequent analysis of these data, were the parks whose species richness
was significantly above or below the regression line. HAFE was
particularly rich for its size and ROCR and GWMP were noticeably lacking
in species richness. Whether these differences can be related to
landscape or habitat features is still to be determined.

Our usage of remote-trip cameras to detect mesopredators would follow
the same observations (Table 3). Some species, such as *Procyon lotor*,
*Vulpes vulpes*, and *Odocoileus virginianus* were commonly photographed
and probably occur in each park, even though no photographs of *Vulpes
vulpes* was obtained at ANTI (it was observed during subsequent
surveys). The less photographed species may be either: 1) truly rare (or
absent); 2) less attracted to the lure used, or 3) possess larger
homeranges and not encounter the cameras on a weekly basis. We would
suggest that future camera surveys extend the period for each camera to
\>15 days to account for the last possibility. There was a single
detection of a gray fox at CHOH and detection of *Canis latrans* at
CATO. An additional problem with the camera surveys is that, for most
species, individuals cannot be determined. Unlike the live-trapping,
where animals are marked before release, we have no way of counting
individuals with the camera survey. For example, we do not know how many
individuals are represented in the 32 photos of *Vulpes vulpes* at
ROCR*.*

During the first year we conducted both winter and summer squirrel
surveys at ANTI, CATO, and HAFE. After comparing the two survey periods
(Table 4), we concluded that the summer squirrel survey alone is
adequate for the needs of the project. With the exception of a single
red squirrel at CATO, we captured the same species during the summer
survey period. Several species (*Tamias striatus, Sciurus niger,
Glaucomys volans*) were more abundant during the summer survey. At the
remainder of the parks we surveyed squirrels in the summer only.

There was an effort to identify sites for *Neotoma magister* and
*Urocyon cinereoargenteus.* We did detect one location for each species
within the park complex, with *Neotoma* captured in HAFE and *Urocyon*
photographed in CHOH. Both sites are located in the western half of the
survey area and probably represent the persistence of populations in
these more rural settings. We examined multiple "suitable" sites for
*Neotoma* in CHOH and CATO without success. As *Vulpes vuples* was one
of the most abundant species photographed during the survey, it is not
surprising that the shyer *Urocyon* was absent from most parks.

There are always concerns about species identification. Soricids are
difficult in the field and all specimens collected in the pitfalls were
cleaned and examined with reference to collections at the Smithsonian
Museum of Natural History and Virginia Commonwealth University. The
specimens of *Neotoma magister* were compared to the same reference
collections, yet only *Neotoma floridana* resides in the 2 museums. The
characteristics and the capture location of our specimens match those of
*N. magister,* but it cannot be verified at this time. Field
identification of a marsh rat (*Oryzoms palustris*) at NACE proved to be
a Norway rat (*Rattus norvegicus*), once the entire morphological range
of the species was examined at the museum. A second source of potential
error is that initial identifications are given at the field site, but
not all specimens were brought into the laboratory. In 2001 there was a
field identification of a golden mouse (*Ochrotomys nuttalli*) at ANTI,
but no specimen was returned to the lab. We returned to the survey point
and surrounding area in 2002 for an additional week of trapping but only
*Peromyscus* were captured. We therefore changed the initial
identification to a *Peromyscus leucopus*. A single *Peromyscus
maniculatus* was identified at CHOH, the speciman was not returned to
the laboratory, but morphological measurements taken of this individual
at the field site lead us to conclude the identification was accurate. A
single individual of *Tamiasciurus hudsonicus* was captured during the
winter trapping at CATO. The field measurements and habitat (high
elevation pine forest) were concurrent with expectations for this
species.

Both *Peromyscus leucopus* and *P. maniculatus* are known from this
region, but are difficult to distinguish correctly in the field. Field
identifications recorded all captures as *Peromyscus leucopus*, with the
exception of one animal. A recent article in the Journal of Mammalogy
distinguished the two species on the basis of detailed skull
measurements. Fifty-five field-identified *Peromyscus* were prepared as
specimens from a wide range of parks and 12 cranial measurements
obtained for each animal. At first analysis, the cranial measurements
match *Peromyscus leucopus*, but we still need to obtain cranial
measurements on known individuals to conduct statistical tests.

##### Conclusions

There is a suite of species that are common to all parks (Table 5). From
small to large body-size these species are *Blarina brevicauda,
Peromyscus leucopus, Sciurus carolinensis, Vulpes vulpes, Procyon
lotor,* and *Odocoileus virginianus*. The common species showed no
obvious patterns with habitat or landuse and should be avoided as
candidates for monitoring programs, except possibly as a negative
indicator of disturbance. There is some discussion of using body
condition for the more common species as a management indicator. It is
difficult for us to evaluate this because our sampling was conducted
over a broad period and captures in April cannot be compared to those in
September. However, there are recent concerns in the literature that
weight in small mammals is very sensitive to trapping activities and any
use of mass as a management indicator is suspect (Pearson et al. 2003,
JWM 67:684-691).

Other species were relatively abundant and constitute a potential suite
of species from which park can select monitoring species. Of this second
tier of species *Glaucomys volans* and *Sorex* sp. seem sufficiently
abundant to monitor and have suitable habitat requirements. *Glaucomys*
are associated almost entirely with mature deciduous forest; for *Sorex*
species, a diverse and undisturbed ground cover in preferred habitat.
Possible inclusion in this group would be *Clethrionomys gapperi*, which
should have been more abundant in the study area given the location of
the sample points. There are several species that were absent or rare
from our sampling and we would not recommend for a monitoring protocol.

Table 1. Sampling effort for each park included in the survey, Winter
2000 -- Summer 2003.

+------------+------+------+-----+------+-------+------+------+------+
| Attributes | ###  |      |     |      |       |      |      |      |
|            | # Pa |      |     |      |       |      |      |      |
|            | rks  |      |     |      |       |      |      |      |
|            | surv |      |     |      |       |      |      |      |
|            | eyed |      |     |      |       |      |      |      |
+------------+------+------+-----+------+-------+------+------+------+
|            | WOTR | ROCR | A   | HAFE | GWMP  | CATO | NACE | CHOH |
|            |      |      | NTI |      |       |      |      |      |
+------------+------+------+-----+------+-------+------+------+------+
| Number of  | 10   | 30   | 37  | 38   | 43    | 53   | 98   | 204  |
| sample     |      |      |     |      |       |      |      |      |
| sites      |      |      |     |      |       |      |      |      |
+------------+------+------+-----+------+-------+------+------+------+
| Size of    | 52   | 710  | 1,  | 926  | 1,706 | 2    | 3    | 7    |
| park       |      |      | 318 |      |       | ,335 | ,299 | ,785 |
| (hectares) |      |      |     |      |       |      |      |      |
+------------+------+------+-----+------+-------+------+------+------+
| Sample     | \    | 4.2  | 2.8 | 4.1  | 2.5   | 2.3  | 3.0  | 2.6  |
| sites/ 100 | -\-\ |      |     |      |       |      |      |      |
| hectares   | -\-- |      |     |      |       |      |      |      |
+------------+------+------+-----+------+-------+------+------+------+
| Total      | 520  | 1    | 1,  | 1    | 2,236 | 2    | 5    | 10   |
| t          |      | ,580 | 924 | ,976 |       | ,226 | ,096 | ,608 |
| rap-nights |      |      |     |      |       |      |      |      |
+------------+------+------+-----+------+-------+------+------+------+
| Trap       | \    | 222  | 146 | 216  | 131   | 94   | 154  | 136  |
| nights/    | -\-\ |      |     |      |       |      |      |      |
|            | -\-\ |      |     |      |       |      |      |      |
| 100        | -\-- |      |     |      |       |      |      |      |
| hectares   |      |      |     |      |       |      |      |      |
+------------+------+------+-----+------+-------+------+------+------+

Table 2. The number of animals for each species captured in pit-fall and
live-traps at eight parks in the National Capital Region during the
summers of 2001 and 2002. Sample effort in each park was determined by
the size of the park.

<table>
<colgroup>
<col style="width: 19%" />
<col style="width: 14%" />
<col style="width: 8%" />
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 8%" />
<col style="width: 7%" />
<col style="width: 8%" />
<col style="width: 9%" />
<col style="width: 0%" />
</colgroup>
<thead>
<tr class="header">
<th>Scientific name</th>
<th>Common name</th>
<th colspan="8"><h4
id="number-of-animals-trapped-in-each-park-surveyed">Number of animals
trapped in each park surveyed</h4></th>
<th></th>
</tr>
<tr class="odd">
<th></th>
<th></th>
<th>WOTR</th>
<th>ROCR</th>
<th>ANTI</th>
<th>HAFE</th>
<th>GWMP</th>
<th>CATO</th>
<th>NACE</th>
<th colspan="2">CHOH</th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td>Blarina brevicauda</td>
<td>Northern short-tailed shrew</td>
<td>1</td>
<td>7</td>
<td>21</td>
<td>3</td>
<td>20</td>
<td>43</td>
<td>48</td>
<td colspan="2">109</td>
</tr>
<tr class="even">
<td>Cryptotis parva</td>
<td>Least shrew</td>
<td>0</td>
<td>0</td>
<td>1</td>
<td>1</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td colspan="2">0</td>
</tr>
<tr class="odd">
<td>Sorex cinereus</td>
<td>Masked shrew</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>2</td>
<td colspan="2">10</td>
</tr>
<tr class="even">
<td>Sorex fumeus</td>
<td>Smoky shrew</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>2</td>
<td>0</td>
<td>5</td>
<td>0</td>
<td colspan="2">1</td>
</tr>
<tr class="odd">
<td>Sorex longirostris</td>
<td>Southeastern shrew</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>1</td>
<td>1</td>
<td>0</td>
<td>4</td>
<td colspan="2">1</td>
</tr>
<tr class="even">
<td>Microsorex hoyi</td>
<td>Pygmy shrew</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>1</td>
<td>0</td>
<td colspan="2">0</td>
</tr>
<tr class="odd">
<td>Glaucomys volans</td>
<td>Southern flying squirrel</td>
<td>1</td>
<td>0</td>
<td>2</td>
<td>5</td>
<td>0</td>
<td>1</td>
<td>0</td>
<td colspan="2">10</td>
</tr>
<tr class="even">
<td>Clethrionomys gapperi</td>
<td>Red-backed vole</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>1</td>
<td>0</td>
<td>3</td>
<td>0</td>
<td colspan="2">0</td>
</tr>
<tr class="odd">
<td>Microtus pennsylvanicus</td>
<td>Meadow vole</td>
<td>0</td>
<td>0</td>
<td>9</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>9</td>
<td colspan="2">4</td>
</tr>
<tr class="even">
<td>Microtus pinetorum</td>
<td>Pine vole</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>1</td>
<td>1</td>
<td>0</td>
<td>0</td>
<td colspan="2">6</td>
</tr>
<tr class="odd">
<td>Mus musculus</td>
<td>House mouse</td>
<td>0</td>
<td>0</td>
<td>2</td>
<td>3</td>
<td>0</td>
<td>0</td>
<td>12</td>
<td colspan="2">1</td>
</tr>
<tr class="even">
<td>Peromyscus leucopus</td>
<td>White-footed mouse</td>
<td>16</td>
<td>33</td>
<td>96</td>
<td>109</td>
<td>64</td>
<td>100</td>
<td>130</td>
<td colspan="2">604</td>
</tr>
<tr class="odd">
<td>Peromyscus maniculatus</td>
<td>Deer mouse</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td colspan="2">1</td>
</tr>
<tr class="even">
<td>Sciurus carolinensis</td>
<td>Eastern gray squirrel</td>
<td>40</td>
<td>90</td>
<td>9</td>
<td>16</td>
<td>47</td>
<td>0</td>
<td>89</td>
<td colspan="2">149</td>
</tr>
<tr class="odd">
<td>Sciurus niger</td>
<td>Eastern fox squirrel</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>1</td>
<td>0</td>
<td colspan="2">13</td>
</tr>
<tr class="even">
<td>Tamias striatus</td>
<td>Eastern chipmunk</td>
<td>0</td>
<td>3</td>
<td>7</td>
<td>23</td>
<td>0</td>
<td>7</td>
<td>1</td>
<td colspan="2">20</td>
</tr>
<tr class="odd">
<td>Zapus hudsonius</td>
<td>Meadow jumping mouse</td>
<td>0</td>
<td>0</td>
<td>3</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>1</td>
<td colspan="2">5</td>
</tr>
<tr class="even">
<td>Scalopus aquaticus</td>
<td>Eastern mole</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td colspan="2">3</td>
</tr>
<tr class="odd">
<td>Rattus norvegicus</td>
<td>Norway rat</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>3</td>
<td colspan="2">0</td>
</tr>
<tr class="even">
<td>Neotoma magister</td>
<td>Eastern woodrat</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>5</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td colspan="2">0</td>
</tr>
</tbody>
</table>

Table 3. Trip camera survey conducted during winter months in 2000 and
2001. Number of photographs does not necessarily represent individuals.
NACE was not sampled as part of this study.

+--------------+-------------+----+-----+----+-----+----+----+----+
| Scientific   | Common name | #  |     |    |     |    |    |    |
|              |             | ## |     |    |     |    |    |    |
| Name         |             | #  |     |    |     |    |    |    |
|              |             | Nu |     |    |     |    |    |    |
|              |             | mb |     |    |     |    |    |    |
|              |             | er |     |    |     |    |    |    |
|              |             |  o |     |    |     |    |    |    |
|              |             | f  |     |    |     |    |    |    |
|              |             | ph |     |    |     |    |    |    |
|              |             | ot |     |    |     |    |    |    |
|              |             | os |     |    |     |    |    |    |
|              |             |  i |     |    |     |    |    |    |
|              |             | n  |     |    |     |    |    |    |
|              |             | ea |     |    |     |    |    |    |
|              |             | ch |     |    |     |    |    |    |
|              |             |  p |     |    |     |    |    |    |
|              |             | ar |     |    |     |    |    |    |
|              |             | k  |     |    |     |    |    |    |
|              |             | su |     |    |     |    |    |    |
|              |             | rv |     |    |     |    |    |    |
|              |             | ey |     |    |     |    |    |    |
|              |             | ed |     |    |     |    |    |    |
+--------------+-------------+----+-----+----+-----+----+----+----+
|              |             | AN | W   | RO | G   | HA | CH | CA |
|              |             | TI | OTR | CR | WMP | FE | OH | TO |
+--------------+-------------+----+-----+----+-----+----+----+----+
| Sciurus      | Eastern     | 0  | 0   | 5  | 2   | 2  | 4  | 0  |
| carolinensis | gray        |    |     |    |     |    |    |    |
|              | squirrel    |    |     |    |     |    |    |    |
+--------------+-------------+----+-----+----+-----+----+----+----+
| Sylvilagus   | Eastern     | 5  | 0   | 0  | 0   | 0  | 3  | 0  |
| floridanus   | cottontail  |    |     |    |     |    |    |    |
|              | rabbit      |    |     |    |     |    |    |    |
+--------------+-------------+----+-----+----+-----+----+----+----+
| Procyon      | Raccoon     | 20 | 6   | 15 | 9   | 3  | 14 | 4  |
| lotor        |             |    |     |    |     |    |    |    |
+--------------+-------------+----+-----+----+-----+----+----+----+
| Urocyon      | Gray fox    | 0  | 0   | 0  | 0   | 0  | 1  | 0  |
| cine         |             |    |     |    |     |    |    |    |
| reoargenteus |             |    |     |    |     |    |    |    |
+--------------+-------------+----+-----+----+-----+----+----+----+
| Vulpes       | Red fox     | 0  | 9   | 32 | 6   | 11 | 13 | 3  |
| vulpes       |             |    |     |    |     |    |    |    |
+--------------+-------------+----+-----+----+-----+----+----+----+
| Didelphis    | Virginia    | 1  | 0   | 0  | 0   | 0  | 2  | 0  |
| virginiana   | opossum     |    |     |    |     |    |    |    |
+--------------+-------------+----+-----+----+-----+----+----+----+
| Mephitis     | Striped     | 2  | 0   | 0  | 0   | 0  | 0  | 0  |
| mephitis     | skunk       |    |     |    |     |    |    |    |
+--------------+-------------+----+-----+----+-----+----+----+----+
| Canis        | Coyote      | 0  | 0   | 0  | 0   | 0  | 0  | 1  |
| latrans      |             |    |     |    |     |    |    |    |
+--------------+-------------+----+-----+----+-----+----+----+----+
| Odocoileus   | W           | 9  | 3   | 20 | 17  | 1  | 81 | 6  |
| virginianus  | hite-tailed |    |     |    |     |    |    |    |
|              | deer        |    |     |    |     |    |    |    |
+--------------+-------------+----+-----+----+-----+----+----+----+
| Number of    |             | 6  | 6   | 14 | 16  | 6  | 25 | 9  |
| sites        |             |    |     |    |     |    |    |    |
+--------------+-------------+----+-----+----+-----+----+----+----+
| Number of    |             | 42 | 42  | 98 | 112 | 55 | 1  | 69 |
| camera       |             |    |     |    |     |    | 75 |    |
| nights       |             |    |     |    |     |    |    |    |
+--------------+-------------+----+-----+----+-----+----+----+----+

Table 4. Winter trapping at select parks during 2001. All trapping was
with Tomahawk live-traps placed on tree platforms. In parentheses is the
number of animals captured for that species during the summer trapping
session (2001 and 2002).

+---------------------+---------------------+--------+-------+-------+
| Scientific name     | Common name         | #### P |       |       |
|                     |                     | ark su |       |       |
|                     |                     | rveyed |       |       |
+---------------------+---------------------+--------+-------+-------+
|                     |                     | ANTI   | HAFE  | CATO  |
+---------------------+---------------------+--------+-------+-------+
| Sciurus             | Eastern gray        | 6 (9)  | 26    | 0 (0) |
| carolinensis        | squirrel            |        | (16)  |       |
+---------------------+---------------------+--------+-------+-------+
| Sciurus niger       | Eastern fox         | 0      | 0     | 0 (1) |
|                     | squirrel            |        |       |       |
+---------------------+---------------------+--------+-------+-------+
| Tamiasciurus        | Red squirrel        | 0      | 0     | 1 (0) |
| hudsonicus          |                     |        |       |       |
+---------------------+---------------------+--------+-------+-------+
| Tamias sciurus      | Eastern chipmunk    | 1 (7)  | 0     | 0 (7) |
|                     |                     |        | (23)  |       |
+---------------------+---------------------+--------+-------+-------+
| Glaucomys volans    | Southern flying     | 0 (2)  | 0 (5) | 0 (1) |
|                     | squirrel            |        |       |       |
+---------------------+---------------------+--------+-------+-------+
| Trap stations       |                     | 11     | 30    | 60    |
+---------------------+---------------------+--------+-------+-------+
| Trap nights         |                     | 44     | 139   | 240   |
+---------------------+---------------------+--------+-------+-------+

# 

Table 5. List of potential small mammal species in the region
encompassed by the study area. The letter following each species denotes
the species abundance relative to our sampling protocol: C- common; LA-
locally abundant ; R -- rare; A -- absent.

###### Species Abundance

Sorex cinereus LA

Sorex fumeus LA

Sorex longirostris LA

Microsorex hoyi R

Blarina brevicauda C

Crytotis parva R

Scalopus aquaticus LA

Condylura cristata A

Tamias striatus LA

Sciurus carolinensis C

Sciurus niger LA

Tamiasciurus hudsonicus R

Glaucomys volans LA

Oryzomys palustris A

Reithrodontomys humulis A

Peromyscus maniculatus R

Peormyscus leucopus C

Neotoma magister R

Clethrionomys gapperi R

Microtus pennsylvanicus LA

Microtus pinetorum LA

Synaptomys cooperi A

Rattus rattus A

Rattus norvegicus R

Mus musculus LA

###### Zapus hudsonicus LA . 

> Figure 1. Arrangement of National Parks included in this survey.
> Landcover classification based on USGS Landover Classification
> Project.

![](media/image1.png){width="8.25in" height="5.6375in"}

![](media/image2.png){width="5.104861111111111in" height="6.0in"}Figure
2. Example of survey site selection at Antietam National Battlefield
Park, located outside of Sharpsburg, Maryland. The park is 1,318
hectares of primarily farmland and woodlots. We sampled 37 locations
within the park during summer 2001. Sample points are \>200 m apart and
include all major habitat types found within the park.

Figure 3. Number of species captured during survey with respect to the
size of the park sampled. For park codes see text.

![](media/image3.wmf){width="5.672047244094488in"
height="5.731889763779527in"}

Appendix 1: Species accumulation curves for each park sampled. The
number of points sampled daily at each park varied depending on park
size. Since the relative effort was constant across parks we can compare
the number of species captured / trap day of effort.

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