Seasonal Home Range and Diurnal Movements of Sylvilagus obscurus (Appalachian Cottontail) at Dolly Sods, West Virginia
Kelly A. Boyce and Ronald E. Barry
Northeastern Naturalist, Volume 14, Issue 1 (2007): 99–110
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2007 NORTHEASTERN NATURALIST 14(1):99–110
Seasonal Home Range and Diurnal Movements of
Sylvilagus obscurus (Appalachian Cottontail) at Dolly
Sods, West Virginia
Kelly A. Boyce1,* and Ronald E. Barry1
Abstract - The purpose of the study was to estimate seasonal home ranges of
Sylvilagus obscurus (Appalachian cottontail) within dense ericaceous and coniferous
cover at its type locality, the Dolly Sods Scenic Area in West Virginia.
Ninety-five percent adaptive kernel (AK) home ranges of rabbits ranged from
5.7–13.3 ha during the leaf-on season (May–September; n = 5) and 1.5–9.0 ha
during the leaf-off season (October–April; n = 14). Fifty-percent AK core areas
ranged from 0.9–2.5 ha during the leaf-on season and 0.1–2.5 ha during the leafoff
season. Males occupied larger home ranges during the leaf-on than leaf-off
season, but female ranges did not differ seasonally. These results demonstrate
seasonal differences in spatial and associated resource requirements of Appalachian
cottontails and the need for large tracts of appropriate habitat for travel
lanes to maintain viable populations of this species.
The historical range of Sylvilagus transitionalis (Bangs) (New England
cottontail) extends from northern New England southward along the Appalachian
Mountains to northern Georgia and Alabama (Fig. 1; Chapman 1975,
Hall 1981). Because of their distinct cytotype (Ruedas et al. 1989) and different
craniometrics, Chapman et al. (1992) accorded the southern populations of this
taxon specific distinction as Sylvilagus obscurus (Chapman) (Appalachian
cottontail). However, the status of S. obscurus as a specific entity is inconclusive
based on mitochondrial DNA evidence (Litvaitis et al. 1997).
Sylvilagus obscurus is confined to higher elevations in the Appalachian
Mountains south and west of the Hudson River and ranges from northeastern
Pennsylvania south. Its status in West Virginia is currently identified by the
West Virginia Wildlife Diversity Program (2003) as a species “… somewhat
vulnerable to extirpation,” and recently has been under consideration for
listing on the IUCN Red List (Smith 2004).
The Appalachian cottontail, similar to S. transitionalis to the north, has
experienced a decline throughout its range over the last half century
(Chapman et al. 1992). Populations presumably have been reduced by:
1) gradual climatic changes since the last glaciation; 2) habitat maturation,
destruction, and fragmentation; and 3) the reinvasion of lowland areas by S.
floridanus (J.A. Allen) (eastern cottontail) (Chapman and Morgan 1973;
Chapman et al. 1977, 1992; Merritt 1987).
1Department of Biology, Frostburg State University, Frostburg, MD 21532. *Corresponding
author - email@example.com.
100 Northeastern Naturalist Vol. 14, No. 1
Sylvilagus obscurus occupies high elevations in a mosaic of habitat
refugia throughout its range (Chapman and Stauffer 1981, Chapman et al.
1982). In the central Appalachians, this species is typically found at elevations
> 570 m in conifer stands, mixed-oak forest, or 6- to 9-year-old
clearcuts, with extensive underlying ericaceous (heathlike) or Rubus
allegheniensis (Porter) (blackberry) cover (Blymyer 1976, Boyce 2001,
Chapman and Morgan 1973, Chapman and Paradiso 1972, Chapman and
Stauffer 1981, Stevens and Barry 2002). Home-range size for S.
transitionalis in Connecticut was reported as 0.2–0.7 ha (Dalke 1937). These
estimates were made from live trapping in the fall months using comparatively
few observations. Stevens and Barry (2002) reported comparatively
large (1.4–9.0 ha) 95% adaptive kernel (AK) home ranges of radio-tracked
S. obscurus in western Maryland.
We initiated a study to examine the ecological parameters of S. obscurus
in the type locality, the Dolly Sods Scenic Area of the Monongahela National
Forest in West Virginia. This site of historical abundance (Chapman
and Morgan 1973), characterized by extensive ericaceous (heathlike) and
low-lying coniferous cover (Boyce 2001), has remained largely unchanged
since the last systematic investigation in the 1970s (Chapman and Stauffer
1981, Venable 1996) due to high elevation and harsh climatic conditions that
have arrested succession. The objectives of the study were to describe
seasonal home ranges of S. obscurus at this site, determine any differences in
home-range size between sexes, and compare sizes of ranges to those of
western Maryland rabbits (Stevens and Barry 2002).
Figure 1. Historical and present distribution of S. transitionalis/S. obscurus (after
Chapman and Stauffer 1981).
2007 K.A. Boyce and R.E. Barry 101
We expected to find smaller home ranges than were reported for the
Appalachian cottontail in western Maryland because of the greater density
of cover and other resources at Dolly Sods (Boyce 2001, Sommer 1997,
Stevens and Barry 2002). Further, we predicted both seasonal and sex
differences in home-range size, with larger ranges expected during the
breeding season and among males. The information gathered indicates the
spatial resources necessary for the survival of individuals and perpetuation
of local populations, and thus permits preliminary suggestions for strategies
to effect management and conservation of the Appalachian cottontail in
West Virginia and throughout its range.
The study was conducted at the 970-ha Dolly Sods Scenic Area in Tucker
County, WV (39º01'N, 79º19'W; Fig. 2). This windswept plateau of the
Monongahela National Forest ranges in elevation from approximately 790 to
> 1200 m. The biota of the area is characteristic of northern US and Canadian
regions (Venable 1996). Conifers are abundant and include Picea
rubens Sarg. (red spruce), Pinus resinosa Ait. (red pine), P. rigida Mill.
(pitch pine), Tsuga canadensis L. (eastern hemlock), and Abies balsamea
Mill. (balsam fir). Heaths (Ericaceae spp.) provide extensive cover, especially
in the form of Kalmia latifolia L. (mountain laurel), Rhododendron
maximum L. (rhododendron), and Vaccinium spp. (blueberries). High-mountain
bogs are present. The weather is cool and wet, with > 140 cm annual
precipitation, and yearly snowfall can reach 380 cm (Venable 1996).
From October 1997 to April 1999, wooden box traps (18 x 22 x 60 cm;
Sommer 1997) were used to live-trap rabbits in 19 areas throughout the
study site. Rabbits were identified initially by a discriminant function model
(Litvaitis et al. 1991) developed to distinguish S. transitionalis and S.
Figure 2. Location of the
Dolly Sods Scenic Area in
102 Northeastern Naturalist Vol. 14, No. 1
floridanus. Species identification was later confirmed by electrophoretic
analysis of blood serum proteins (Chapman and Morgan 1973, Stevens and
Barry 2002). After sex was determined, rabbits were ear-tagged and radiocollared
so individuals could be tracked to their daytime locations. In our
study, all rabbits were opportunistically tracked from dawn to dusk 0–5
times per week, depending on weather and/or travel constraints. Subjects
usually were in view prior to flushing, but if not, a form or depression
marked their exact locations. Night-time surveillance was logistically impractical
due to extremely dense, low-lying ericaceous vegetation (Boyce
2001) that precluded us from confirming rabbits’ exact locations in the dark.
Universal-Transverse-Mercator (UTM) grid coordinates were determined at
radiolocations using a global positioning system (GPS) differentially corrected
with PATHFINDER software (Trimble Navigation Ltd., Sunnyvale,
CA) for improved accuracy (using GPS base-station data from the Soil
Conservation Service office at Morgantown, WV).
Successive locations for each individual were separated by > 24 h in an
attempt to ensure independence of observations because White and Garrott
(1990) suggested a sampling interval that allows an animal to move from one
end of its home range to another. However, no consensus exists on the
importance of autocorrelation in the estimation of home ranges. Hansteen et
al. (1997) indicated that the degree of autocorrelation decreases normally
with increasing time intervals between observations. However, Swihart and
Slade (1997) suggested that autocorrelated data will not invalidate common
estimators of home-range size as long as the study encompasses an adequate
period of time. Otis and White (1999) agreed with this assessment, but
suggested that the length of the sampling interval should be adequate so that
autocorrelation does not affect home-range estimates and hypothesis tests
involving them. DeSolla et al. (1999) concluded that accuracy and precision
of home-range size estimates from simulated data improved with shorter
time intervals despite the complication of autocorrelation. All rabbits were
tracked until they died, transmitters failed, or radio signals were lost. Homerange
estimates were generated by plotting locations for each individual
using the program CALHOME (Kie et al. 1996) and were considered stabilized
if a plot of home-range size against cumulative number of locations
became asymptotic (Bowyer et al. 1995, Hansteen et al. 1997, Stickel 1954).
Home ranges were estimated with the 95% adaptive kernel (AK) estimator
(Worton 1989), which computes a probability density (kernel) over each
location and then totals these kernels. In comparison to the minimum convex
polygon, which is extremely sensitive to sample size and positively biased at
small sample sizes (Seaman et al. 1999), the AK reduces the probability of
including areas not occupied. Also, use of the AK estimator permitted
comparisons with a study (Sommer 1997, Stevens and Barry 2002) in nearby
Maryland. The AK bandwidth or smoothing parameters were reduced to the
appropriate percentage of the selected optimum to obtain a balance between
lowering least-squares cross-validation (LSCV) scores and minimizing
2007 K.A. Boyce and R.E. Barry 103
home-range fracture into many small, isolated areas (Kie et. al 1996,
Sommer 1997). Seaman et al. (1999) recommended the use of LSCV methods
to determine the amount of smoothing for kernel estimators. If efforts at
smoothing to minimize fracture of the home range still produced additional,
isolated regions, these multiple areas of activity were included in an
individual’s home range. Home ranges were estimated for leaf-on (May–
September) and leaf-off (October–April) seasons, the former corresponding
roughly with the Appalachian cottontail breeding season (Chapman et al.
1977). A 50% AK estimate was used to describe areas of concentrated use,
or the individual’s core area (Samuel et al. 1985).
Comparisons of home-range size by sex and season, and with home
ranges of S. obscurus in western Maryland, were evaluated with the Mann-
Whitney test (Mann and Whitney 1947, Zar 1999). Statistical analyses were
conducted with MINITAB 13 (Minitab, Inc., State College, PA). Based on
their temporal segregation, 2 home ranges derived from a single individual
in different seasons or years were considered independent for the purpose of
statistical analysis; no individual generated > 2 home-range estimates. The
criterion for statistical significance for all analyses was P < 0.05.
Thirty-eight cottontails (37 S. obscurus, 1 S. floridanus) were captured at
17 of 19 sites sampled. Day home ranges of 14 individual (7 males, 7
females) S. obscurus reached asymptotes after a minimum of 18 locations
(leaf-on season: 33–47 locations, mean ± 1 SD = 41 ± 6; leaf-off season: 18–
33 locations, mean ± 1 SD = 25 ± 5) and were included in the analysis. Five
individuals (3 males, 2 females) provided 95% AK home-range estimates
that ranged from 5.7–13.3 ha during the leaf-on season (Fig. 3). These
ranges were larger (W = 76.5, P < 0.05) than the 14 home ranges (range =
1.5–9.0 ha) estimated from 13 individuals (6 males, 7 females, with 1 female
generating estimates in both 1997–1998 and 1998–1999) during both leafoff
seasons combined, and the 12 estimates (6 males, 6 females) from the
1998–1999 leaf-off season only (W = 70.5, P < 0.05). Home ranges of males
in the leaf-on season were significantly larger (W = 24.0, P < 0.05) than
those of males in the leaf-off season. Home ranges of females did not differ
seasonally (W = 12.5, P > 0.05). Male home ranges did not differ from those
of females in the leaf-on (W = 12.0, P > 0.05) or leaf-off (W = 43.0, P > 0.05)
seasons. One male died from predation during the leaf-on season before his
home range stabilized (not included in the analysis). His 95% AK home
range was 30.7 ha after only 17 locations. On 2 occasions, this male was
tracked to the locations of other radiocollared females whose radio signals
were heard and which were seen. This male traveled a 0.84-km straight-line
distance between successive locations in one 24-h period.
Core areas (50% AK estimates) showed considerable individual variation
with no discernible difference between sexes. During the leaf-on
season, 4 of 5 rabbits concentrated their activity in 2 distinct regions of
104 Northeastern Naturalist Vol. 14, No. 1
the home range (Fig. 4), with recognizable areas of concentrated use
(50% AK core areas) within each of these regions. During the leaf-off
Figure 3. Ranges of sex-specific 95% adaptive kernel (AK) home ranges (ha) for the
leaf-on (clear) and leaf-off (shaded) seasons at Dolly Sods Scenic Area in West
Virginia, 1997–1999. Medians are indicated by lines within the bars. Sample size is
to the right of the bar.
Figure 4. CALHOME
home ranges of
a female Appalachian
based on 33
locations in the
at Dolly Sods
Scenic Area in
2007 K.A. Boyce and R.E. Barry 105
season, 8 of 14 rabbits used a single major region of activity with 1–3
core areas. The other 6 rabbits used 2 distinct regions of the home range
with 1 or 2 smaller core areas.
Core areas (50% AK estimates) ranged from 0.9–2.5 ha in the leaf-on
season (n = 5) and 0.1–2.5 ha in the leaf-off season (n = 14; Fig. 5). Core
areas in the leaf-on season were significantly larger than those in the leaf-off
season (W = 75.5, P < 0.05). The difference between the core areas of males
in the leaf-on (n = 3) and leaf-off (n = 6) season was marginally nonsignificant
(W = 23.0, 0.05 < P < 0.10); female areas (leaf -on: n = 2; leaf-off:
n = 8) did not differ seasonally (W = 15.0, P > 0.05). Core areas did not differ
between male and female rabbits in the leaf-on (W = 11.0, P > 0.05) or leafoff
(W = 37.5, P > 0.05) seasons.
Appalachian cottontails were distributed widely within the Dolly Sods
Scenic Area and were captured at 17 of 19 trap sites. Appalachian cottontails
occupied home ranges at elevations of 790–1200 m in patches of dense
ericaceous vegetation and coniferous stands (Boyce 2001, Sucke 2002),
consistent with what Chapman and Stauffer (1981) and Sommer (1997)
Figure 5. Ranges of sex-specific 50% adaptive kernel (AK) home ranges (core areas–
ha) for the leaf-on (clear) and leaf-off (shaded) seasons at Dolly Sods Scenic Area in
West Virginia, 1997–1999. Medians are indicated by lines within the bars. Sample
size is to the right of the bar.
106 Northeastern Naturalist Vol. 14, No. 1
found in western Maryland. This species appears to be locally widespread
and abundant in this habitat (Boyce 2001, Sucke 2002), as it was in the
1970s (Chapman and Morgan 1973), indicating that Dolly Sods continues to
support a viable population. The eastern cottontail apparently has not displaced
the Appalachian cottontail at higher elevations at this location.
Appalachian cottontails at Dolly Sods selected home ranges in
macrohabitat characterized by dense, ericaceous vegetation, such as mountain
laurel, rhododendron, and blueberries, and stands of conifers, especially
red spruce. Rabbits used microhabitats with > 80% vegetative cover to a
height of 1.5 m above the substrate (Boyce 2001). Ranges of S. obscurus in
our study were considerably larger than those of 0.2–0.7 ha reported by
Dalke (1937) for S. transitionalis in Connecticut, although the methodologies
between the studies differed greatly. The hypothesis that the quality and
quantity of habitat present at Dolly Sods might reduce the sizes of home
ranges of Appalachian cottontails relative to those in western Maryland is
not supported by our results. Home ranges of rabbits during the leaf-on
season at Dolly Sods (n = 5; Fig. 3) were significantly larger (W = 83.0, P <
0.05) than those in the comparable season in western Maryland where
similar data collection methods were used (range = 1.4–8.3 ha, median = 4.7
ha, n = 8; Stevens and Barry 2002), even though available resources appear
to be more concentrated at the former location (Boyce 2001). Larger home
ranges of Appalachian cottontails at Dolly Sods could be attributable to
lower densities (Sucke 2002) when compared to those in other parts of the
species’ distribution (Laseter 1999). However, in both Maryland and West
Virginia studies, considerable individual and seasonal variation was observed,
and larger sample sizes could provide further clarification.
Seasonal differences in home-range size were expected and realized.
Larger home ranges in the leaf-on season may have resulted from the
comparative abundance of resources and cover, specifically, greater availability
of food, reduced metabolic cost of exposure to ambient conditions,
and reduced risk of predation (Brown and Litvaitis 1995, Litvaitis et al.
1985). Smaller ranges in the leaf-off season could be the result of limited
resources during this physiologically stressful period. During the winter
months, 3 radio-collared rabbits were found intact beneath the snow, having
died presumably from exposure. It seems likely that harsh conditions in
winter (i.e., low temperatures, heavy snowfall, high winds) restrict rabbit
movement and thus home-range size; in winter rabbits spend more time in
dense, evergreen vegetation that provides thermal cover (Boyce 2001).
Home ranges were determined based on daytime locations only and may
not reflect movements made throughout the night when rabbits are most
active. However, Trent and Rongstad (1974) found little difference between
day- and nighttime home ranges of S. floridanus, although they monitored
only 4 rabbits over a 9-day period.
We expected that male Appalachian cottontails would have had larger
home ranges than females during the leaf-on or breeding season. However,
2007 K.A. Boyce and R.E. Barry 107
we found no difference between sexes in home-range size, largely because
of the low power (small sample size) of our statistical test and our exclusion
from analysis of the male with the largest home range because of
insufficient number of data points. Home ranges of male eastern cottontails
were reported by Althoff and Storm (1989) to be larger than those of
females for all seasons except winter, with differences most notable in the
summer. Trent and Rongstad (1974) found that the smaller home-range
size of females was likely attributed to restricted movements near the nest
and greater availability of food and cover during spring and summer,
although cover also could influence male home-range size. Althoff and
Storm (1989) found that some males had home ranges that were considerably
larger than other males because these males bred with more than one
female. This finding is consistent with the idea that dominant males have
larger home ranges as a result of a dominance hierarchy (Trent and
Rongstad 1974) and with our observation that the male whose range was
30.7 ha and still had not stabilized was spatially associated with 2 radiocollared
females during the breeding season.
Leaf-on core areas were larger than leaf-off core areas presumably
because core area is relative to the size of seasonal home range. The correspondence
of sizes of core areas with sizes of home ranges of individuals is
consistent with the individual differences we observed among rabbits in
their use of space.
Based on the sizes of home ranges in our study, and the spatial and other
resource requirements (i.e., food, cover) of Appalachian cottontails reflected
by such ranges, it is evident that expansive, unfragmented (or at least
connected) areas of appropriate habitat are necessary for the maintenance of
viable populations of Appalachian cottontails. New England cottontails
occupying large patches (> 5.0 ha) had higher survival rates than individuals
occupying small patches (< 2.5 ha) because of quality of habitat and forage
(Barbour and Litvaitis 1993, Villafuerte et al. 1997). Fragmentation of
habitat and prevention of natural fires and succession (Chapman and Morgan
1973) may reduce the suitability of areas for this species in West Virginia.
Fragmentation and loss of habitat are cited as leading causes of species
extinctions (Soule 1991). On a landscape scale, New England cottontails had
lower survival rates in fragmented landscapes than in more even landscapes
(Brown and Litvaitis 1995). If large patches are not maintained and properly
managed, the Appalachian cottontail will become vulnerable to local extinctions.
Efforts to conserve expansive areas of appropriate habitat are essential
for the conservation of this species.
We thank the West Virginia Division of Natural Resources and Frostburg State
University for the funding of this project and the US Forest Service for permission to
use the Dolly Sods area for the study and for use of one of their nearby cabins. Alana
Sucke, Nancy Bensley, Jeff Peters, and Michael Boyce contributed much time and
108 Northeastern Naturalist Vol. 14, No. 1
effort in the field. Mitch Spear loaned his snowmobile to the project. Drs. J. Edward
Gates and Ray Morgan of the Center for Estuarine and Environmental Studies
Appalachian Laboratory (University of Maryland) loaned us GPS and electrophoretic
equipment and provided the use of their labs. The manuscript benefited
considerably from the evaluation of 2 anonymous reviewers.
Althoff, D.P., and G.L. Storm. 1989. Daytime spatial characteristics of cottontail
rabbits in central Pennsylvania. Journal of Mammalogy 70:820–824.
Barbour, M.S., and J.A. Litvaitis. 1993. Niche dimensions of New England cottontails
in relation to habitat patch size. Oecologia 95:321–327.
Blymyer, M.J. 1976. A new record for the New England cottontail (Sylvilagus
transitionalis) in Virginia. Chesapeake Science 17:220–221.
Bowyer, R.T., J.W. Testa, and J.B. Faro. 1995. Habitat selection and home ranges of
river otters in a marine environment: Effects of the Exxon Valdez oil spill.
Journal of Mammalogy 76:1–11.
Boyce, K.A. 2001. Distribution, seasonal home range, movements, and habitat of the
Appalachian cottontail, Sylvilagus obscurus, at Dolly Sods, West Virginia. M.Sc.
Thesis. Frostburg State University, Frostburg, MD. 134 pp.
Brown, A.L., and J.A. Litvaitis. 1995. Habitat features associated with predation of
New England cottontails: What scale is appropriate? Canadian Journal of Zoology
Chapman, J.A. 1975. Sylvilagus transitionalis. Mammalian Species No. 55:1–4.
Chapman, J.A., and R.P. Morgan. 1973. Systematic status of the cottontail complex
in western Maryland and nearby West Virginia. Wildlife Monographs 36:1–54.
Chapman, J.A., and J.L. Paradiso. 1972. First records of the New England cottontail
(Sylvilagus transitionalis) from Maryland. Chesapeake Science 13:148–149.
Chapman, J.A., and J.R. Stauffer. 1981. The status and distribution of the New
England cottontail. Pp. 973–983, In K. Meyers and C.D. MacInnes (Eds.). Proceedings
of the World Lagomorph Conference. University of Guelph, Guelph,
ON, Canada. 983 pp.
Chapman, J.A., A.L. Harman, and D.E. Samuel. 1977. Reproductive and physiological
cycles in the cottontail complex in western Maryland and nearby West
Virginia. Wildlife Monographs 56:1–73.
Chapman, J.A., J.G. Hockman, and W.R. Edwards. 1982. Cottontails. Pp. 83–123, In
J.A. Chapman and G.A. Feldhamer (Eds.). Wild Mammals of North America.
Johns Hopkins University Press, Baltimore, MD. 1147 pp.
Chapman, J.A., K.L. Cramer, N.J. Dipperaar, and T.J. Robinson. 1992. Systematics
and biogeography of the New England cottontail, Sylvilagus transitionalis
(Bangs, 1895), with the description of a new species from the Appalachian
mountains. Proceedings of the Biological Society of Washington 105:841–866.
Dalke, P.D. 1937. A preliminary report of the New England cottontail studies.
Transactions of the North American Wildlife Conference 2:542–548.
DeSolla, S.R., R. Bonduriansky, and R.J. Brooks. 1999. Eliminating autocorrelation
reduces biological relevance of home range estimates. Journal of Animal Ecology
Hall, E.R. 1981. The Mammals of North America. Volume I. Second Edition. John
Wiley and Sons, New York, NY. 1386 pp.
Hansteen, T.L., H.P. Andreassen, and R.A. Ims. 1997. Effects of spatiotemporal
scale on autocorrelation and home range estimators. Journal of Wildlife Management
2007 K.A. Boyce and R.E. Barry 109
Kie, J.G., J.A. Baldwin, and C.J. Evans. 1996. CALHOME: A program for estimating
animal home ranges. Wildlife Society Bulletin 24:342–344.
Laseter, B.R. 1999. Estimates of population density for the Appalachian cottontail
(Sylvilagus obscurus) in eastern Tennessee. M.Sc. Thesis, University of Memphis,
Memphis TN. 99 pp.
Litvaitis, J.A., J.S. Sherburne, and J.A. Bissonette. 1985. Influence of understory
characteristics on snowshoe hare habitat use and density. Journal of Wildlife
Litvaitis, J.A., D.L. Verbyla, and M.K. Litvaitis. 1991. A field method to differentiate
New England and eastern cottontails. Transactions of the Northeast Section
of the Wildlife Society 48:11–14.
Litvaitis, M.K., J.A. Litvaitis, W.J. Lee, and T.D. Kocher. 1997. Variation in the
mitochondrial DNA of the Sylvilagus complex occupying the northeastern
United States. Canadian Journal of Zoology 75:795–605.
Mann, H.B., and D.R. Whitney. 1947. On a test of whether one or two random
variables is stochastically larger than the other. The Annals of Mathematical
Merritt, J.F. 1987. Guide to the Mammals of Pennsylvania. University of Pittsburgh
Press, Pittsburgh, PA. 408 pp.
Otis, D.L., and G.C. White. 1999. Autocorrelation of location estimates and the
analysis of radiotracking data. Journal of Wildlife Management 63:1039–1044.
Ruedas, L.A., R.C. Dowler, and E. Aita. 1989. Chromosomal variation in the
New England cottontail, Sylvilagus transitionalis. Journal of Mammalogy
Samuel, M.D., D.J. Pierce, and E.O. Garton. 1985. Identifying areas of concentrated
use within the home range. Journal of Animal Ecology 54:711–719.
Seaman, D.E., J.J. Millspaugh, B.J. Kernohan, G.C. Brundige, K.J. Raedeke, and
R.A. Gitzen. 1999. Effects of sample size on kernel home range estimates.
Journal of Wildlife Management 63:739–747.
Smith, A.T. 2004. Red list assessment: Sylvilagus obscurus. IUCN Global Mammal
Assessment. 21 pp.
Sommer, M.A. 1997. Distribution, habitat, and home range of the New England
cottontail (Sylvilagus transitionalis) in western Maryland. M.Sc. Thesis.
Frostburg State University, Frostburg, MD. 98 pp.
Soule, M.E. 1991. Conservation: Tactics for a constant crisis. Science 253:744–750.
Stevens, M.A., and R.E. Barry. 2002. Selection, size, and use of home range of the
Appalachian cottontail, Sylvilagus obscurus. Canadian Field-Naturalist
Stickel, L.F. 1954. A comparison of certain methods of measuring ranges of small
mammals. Journal of Mammalogy 35:1–15.
Sucke, A. 2002. Survival, winter diet, density and macrohabitat of the Appalachian
cottontail, Sylvilagus obscurus, in West Virginia. M.Sc. Thesis. Frostburg State
University, Frostburg, MD. 89 pp.
Swihart, R.K., and N.A. Slade. 1997. On testing for independence of animal movements.
Journal of Agricultural, Biological, and Environmental Statistics 2:48–63.
Trent, T.T., and O.J. Rongstad. 1974. Home range and survival of cottontail rabbits
in southwestern Wisconsin. Journal of Wildlife Management 38:459–472.
Venable, N.J. 1996. Dolly Sods. West Virginia University Extension Service,
Morgantown, WV. 24 pp.
110 Northeastern Naturalist Vol. 14, No. 1
Villafuerte, R., J.A. Litvaitis, and D.F. Smith. 1997. Physiological responses by
lagomorphs to resource limitations imposed by habitat fragmentation: Implications
to condition-sensitive predation. Canadian Journal of Zoology 75:148–151.
West Virginia Wildlife Diversity Program. 2003. Rare, threatened and endangered
species in West Virginia. West Virginia Division of Natural Resources, Elkins,
WV. Available on-line at: http// www.wvdnr.gov/Wildlife/RareSpecLists.htm.
Accessed January 17, 2007.
White, G.C., and R.A. Garrott. 1990. Analysis of Wildlife Radio-tracking Data.
Academic Press, San Diego, CA. 383 pp.
Worton, B.J. 1989. Kernel methods for estimating the utilization distribution in
home-range studies. Ecology 70:164–168.
Zar, J.H. 1999. Biostatistical Analysis. Fourth Edition. Prentice Hall, Upper Saddle
River, NJ. 929 pp.