Site by Bennett Web & Design Co.
2012 SOUTHEASTERN NATURALIST 11(3):507–516
Observations of Gray Foxes (Urocyon cinereoargenteus) in
a Suburban Landscape in the Piedmont of North Carolina
Joshua M. Kapfer1,2,* and Ryan W. Kirk3
Abstract - Studies of Urocyon cinereoargenteus (Gray Fox) in suburban landscapes are
rare. Past work has suggested that this species will only tolerate urbanization to a certain
density of residences (50–125 residences/km2). To test this, we employed visual observations
and camera traps to monitor Gray Fox activity within a suburban and adjacent rural
property from January to July 2011. We also used a geographical information system
(GIS) to calculate the density of buildings associated with both properties. We observed
Gray Foxes and detected them with camera traps in our properties on numerous occasions.
GIS analyses revealed an estimated suburban density of 237–347 residences/km2
(depending on spatial scale) and rural density of 50 residences/km2. The number of Gray
Fox observations did not differ greatly between rural and suburban properties, although
the peak periods of Gray Fox observations varied by site. We propose that a tolerance for
high suburban building density exhibited by Gray Foxes at our site is related to the large
amount of mature wooded buffers located adjacently.
Research focused on Canids in urban and suburban landscapes has recently
become more common (see review by Gehrt et al. 2010). For example, a respectable
amount of research has been conducted in North America on urban
and suburban Canis latrans Say (Coyote; see review by Gehrt and Riley 2010).
In contrast, the ecology of Urocyon cinereoargenteus Schreber (Gray Fox)
inhabiting anthropogenic landscapes has received little attention (Riley and
White 2010). The bulk of research on urban Gray Foxes has been carried out in
the western US (e.g., California and New Mexico; Harrison 1993, 1997; Riley
2006; Riley et al. 2004). Although work has been completed on this species in
the eastern US, only a handful of these studies have dealt with individuals that
were associated with urban or suburban habitat (e.g., Rountree 2004, Temple
et al. 2010).
This past research has suggested that Gray Foxes will use anthropogenically
disturbed landscapes, but do not prefer them. For example, radio telemetry
research conducted on Gray Foxes within the Golden Gate National
Recreation Area (Marin County, CA) found that the core home ranges of
17 tracked individuals rarely involved anthropogenic habitat present within
1Departments of Environmental Studies and Biology, Elon University, Campus Box
2015, Elon, NC 27244. 2Current address - Department of Biological Sciences, University
of Wisconsin-Whitewater, Whitewater, WI 53190. 3Departments of History and Geography,
and Environmental Studies, Elon University, Campus Box 2335, Elon, NC 27244.
*Corresponding author - firstname.lastname@example.org.
508 Southeastern Naturalist Vol. 11, No. 3
the park (Riley 2006). Of the foxes tracked, only two had core home ranges
that included “stables and residences” located in park boundaries. A third
individual had a core home range that included some urban habitat outside
of park boundaries. Furthermore, Rountree (2004) reported that Gray Foxes
tracked with radio telemetry (1 M, 3 F) used areas close to or within “human
habitation”, but were found in “fields” and “mixed forests” more often than
expected. Temple et al. (2010) also used radio telemetry to monitor 23 Gray
Foxes (15 M, 8 F) with access to residential areas. They found that Gray Foxes
showed a preference for hardwood forests, although individuals made use
of residential habitat. Harrison (1997) suggested that Gray Foxes may only be
tolerant of urban or suburban landscapes to a density of 50–125 residences/
km2. Use of suburban landscapes may also be limited by factors such as interactions
with larger carnivores. For example, past studies have indicated that
Gray Foxes select habitats to reduce the potential for interaction with Coyotes
and avoid mortality due to competitive exclusion or predation (Fedriani et
al. 2000, Temple et al. 2010). Numerous studies exist that show Coyotes will
frequently use urban or suburban landscapes (see review by Gehrt and Riley
2010), which may influence Gray Fox use of associated habitats.
Herein we report numerous observations of Gray Foxes active within a
parcel of residential property over a period of roughly 6 months, which we
generally compare to an exurban/rural habitat monitored nearby during the
same period. We also compare our results, including estimates of housing density
at the suburban property, to Harrison’s (1997) estimate of the housing
density that this species will tolerate. Our observations give further insight
into the habits of urban/suburban Gray Foxes, which is a topic in need of investigation
(Riley and White 2010).
We monitored the activity of Gray Foxes within a single legal real-estate parcel
of residential property (27.4 x 29 m) located in a suburban landscape within
the town of Elon (Alamance County), which is in the Piedmont Region of North
Carolina. Monitoring included both visual observations and camera-trap surveys.
This property was 1.56 km from the nearest rural/suburban fringe, and was located
on the corner of a road intersection (one road of moderate vehicular traffic,
and the other with low vehicular traffic). The property in question included a
mostly open tree canopy and possessed a manicured lawn, with a small ornamental
fruit tree (Malus sp.) located in the center. Mature trees existed along the
property boundaries (e.g., Pinus sp., Carya sp.) and strips or parcels of mature
wooded habitat were present in several of the adjacent properties (Fig. 1). For
relative comparison, we also monitored an exurban/rural site located 3.02 km to
the northeast of the suburban site. This property consisted primarily of deciduous
woodland (65% of area based on aerial photograph interpretation), with smaller
components of old field habitat. Deciduous forests contained a mix of mesic,
2012 J.M. Kapfer and R.W. Kirk 509
alluvial, and oak-hickory plant communities, whereas old fields were dominated
by sedge species associated with disturbance. Although this property was 9.8 ha,
in total, we monitored only the small portion associated with our camera trap, and
areas we were able to visually survey.
Visual observations of foxes occurred opportunistically by either the lead
author or other residents of the suburban property being monitored. Two
observations of Gray Foxes adjacent to and within the suburban property
boundaries were made in May (ca. 1000 hrs) and December (ca. 2100 hrs) of
2010. In response to these sightings, more intense monitoring of the property
was conducted via a motion-triggered camera trap with an infrared flash (Bushnell
Trophy Cam XLT, Bushnell, Olathe, KS). This camera trap was deployed
at various locations throughout the property in question from 6 January 2011
to 18 July 2011. The camera was deployed nightly between 1800–2200 h and
removed each morning between 0600–0900 h to avoid recording excessive
pictures of vehicular traffic and human activity. Although this camera was not
active for several brief time periods due to extrinsic factors beyond our control
(e.g., researcher illness), a total of 178 camera nights occurred (92.2% of the
primary monitoring period). A similar camera was deployed at the rural property
during the same period. This camera remained at a fixed location during
this time and was operational constantly (i.e., not removed during the daylight
hours). We also recorded time and moon phase associated with all photographs
to determine if any discernible relationship existed among these variables and
fox activity. Different individuals could not be definitively identified, therefore
we recorded photographs and observations as Gray Fox “encounters” and made
no attempt to quantify the abundances of foxes present in our study sites.
We did not attempt to lure Gray Foxes to the camera traps with artificial
scent or food bait. Domestic dog scat/urine had been deposited throughout the
suburban property periodically over a roughly 1.5-y period prior to initiation of
monitoring, although scat was typically removed by the property owner within
24 hr of deposition. Furthermore, a domestic dog often accompanied the lead
investigator when he deployed the suburban camera each night. No wildlife feeders,
bird seed, brush piles, or any other cover or food that may attract wildlife
were present on the suburban site. Fruit is reported as important in the diets of
Gray Foxes (see review by Riley 2006), and fruit from a tree on the suburban site
(Malus sp.) may have provided a food source. This fruit was only available from
late May through July of our monitoring period. Human and domestic dog recreational
activity occurred throughout the monitored suburban property almost
daily from mid-March 2011 through July 2011. Recreational activity varied considerably
in length on any given day. Extremely limited human activity occurred
on the rural property, and was mostly the result of researchers visiting the site to
check camera traps.
A geographic information system (GIS; ArcMap 9.3; ESRI, Redlands, CA)
was used to estimate building density at two different scales: first within a
2.59-km2 (1-mi2) circle (radius of 908 m) centered on the monitored suburban
510 Southeastern Naturalist Vol. 11, No. 3
property, and second for the entire area of the town (Elon, NC) in which the
property was located (9.92 km2). We also estimated the building density within
a 2.59-km2 circle centered on the camera at the rural site. Buildings within these
areas were almost entirely residential, although several commercial properties
and larger private properties (i.e., religious sanctuaries, etc.) existed. Given this
residential dominance, we refer to our building density as “residential density”
when comparing it to other studies. Within each of these boundaries, we counted
the number of structures present to estimate buildings per unit area. We also
delineated contiguous suburban forest stands at least 0.25 ha in size within the
smaller suburban landscape scale analyzed (2.59 km2) to estimate the percent
The most effective method to observe Gray Foxes was via camera trap. A
total of 15 distinct encounters of Gray Fox were recorded by the camera trap
on the suburban property during the monitoring period. These occurred over 13
dates, with one of these survey dates (14 May 2011) resulting in 3 distinct passes
(Table 1). Only 11 camera-trap encounters of Gray Foxes were recorded on the
rural property during this time (Table 2). Visual observations of Gray Foxes associated
with the suburban property in 2011 occurred on 7 occasions over 5 dates
(Table 1). No visual observations of Gray Foxes were recorded at the rural site.
Two general peaks in the frequency of Gray Fox photographs occurred at the
Table 1. Summary of camera-trap encounters and visual observations of Gray Foxes (Urocyon
cinereoargenteus) monitored on a suburban property from 6 January–18 July 2011 (Elon, Alamance
County, NC). Associated date, type of observation, time, hours before sunrise of last observation
(for nocturnal encounters), and moon phase are reported.
Date Type Time Hours before sunrise Moon phase
1/24/2011 Camera trap 0522 h 1.98 Waning gibbous
1/25/2011 Camera trap 0537 h 1.21 Waning gibbous
1/26/2011 Camera trap 2309 h 8.16 Third quarter
2/8/2011 Camera trap 0220 h 4.83 Waxing crescent
2/18/2011 Visual 1800 h NA Full moon
3/9/2011 Camera trap 0251 h 4.03 Waxing crescent
3/21/2011 Camera trap 0121 h 5.96 Waning gibbous
5/14/2011 Camera trap 0245, 0258, 0505 h 1.10 Waxing gibbous
5/18/2011 Camera trap 2251 h 7.20 Full moon
5/20/2011 Camera trap 2354 h 6.18 Waning gibbous
5/26/2011 Visual 1700, 2030 h 9.53 Waning crescent
5/29/2011 Visual 1100, 2200 h 8.01 Waning crescent
6/6/2011 Camera trap 0214 h 3.75 Waxing crescent
6/14/2011 Camera trap 0447 h 1.18 Waxing gibbous
6/16/2011 Camera trap 0401 h 1.95 Full moon
6/24/2011 Camera trap 0051 h 5.13 Waning crescent
6/27/2011 Visual* 1000 h NA Waning crescent
7/7/2011 Visual* 1001 h NA Waxing crescent
*Indicates juveniles and adults observed.
2012 J.M. Kapfer and R.W. Kirk 511
suburban property: a small peak from 24 January–21 March 2011 (which may
correspond with the breeding season) and an additional peak occurring from 14
May– 7 July 2011 (Table 1). In contrast, almost all photographs of Gray Foxes at
the rural site were taken prior to 1 April 2011 (Table 2).
All Gray Fox captures on camera traps, regardless of location, were nocturnal.
At the suburban site, camera trap captures occurred between 0051–0600 h (n =
12) and between 2200–2400 h (n = 3). Similarly, rural Gray Foxes were most
often captured on camera traps between 0034–0616 h (n = 7) and 1949–2100 h
(n = 4, Table 2). Several (n = 5) visual observations at the suburban site were
made during daylight hours (Table 1). Our sample sizes are too small to make
significant inferences in regards to moon phase and fox activity, although we saw
interesting correlations. For example, we recorded no Gray Fox activity during
the “new moon” phase on the suburban property (Table 1). In addition, only one
photograph of Gray Foxes in the rural habitat was taken during this moon phase
At the smaller suburban landscape scale (i.e., within 2.59-km2 area centered
on the suburban site), we counted a total of 901 buildings which were primarily
single-family residences. This resulted in an estimate of 347 residences/km2
(Fig. 1). At the larger landscape scale (i.e., the entire town in which our observations
were made), we identified 2359 buildings with primary functions including
individual residences, multi-unit residences, and commercial uses. This resulted
in a building density estimate of 237 buildings/km2. In contrast, we estimated
only 52 residences/km2 associated with the rural site.
We have recorded conclusive evidence that Gray Foxes will repeatedly
use, or migrate through, anthropogenically disturbed areas. In some cases,
individuals were photographed less than two meters from the residential building
on-site, where substantial outdoor activity by humans had occurred several
Table 2. Summary of camera trap encounters of Gray Foxes (Urocyon cinereoargenteus) monitored
on a rural property from 6 January–18 July 2011 (Elon, Alamance County, NC). Associated date,
type of observation, time, hours before sunrise of last observation, and moon phase are reported.
Date Type Time Hours before sunrise Moon phase
1/13/2011 Camera trap 1941 h 11.85 First quarter
1/14/2011 Camera trap 2020 h 11.06 First quarter
1/21/2011 Camera trap 2100 h 10.36 Waning gibbous
2/4/2011 Camera trap 0034 h 6.65 New moon
2/15/2011 Camera trap 0125 h 5.8 Waxing gibbous
2/26/2011 Camera trap 0420 h 2.51 Waning crescent
3/9/2011 Camera trap 0616 h 0.31 Waxing crescent
3/10/2011 Camera trap 0605 h 0.48 Waxing crescent
3/15/2011 Camera trap 1954 h 11.51 Waxing gibbous
3/23/2011 Camera trap 0323 h 3.86 Waning gibbous
6/16/2011 Camera trap 0103 h 4.91 Full moon
512 Southeastern Naturalist Vol. 11, No. 3
hours prior (Fig. 1). Furthermore, this property was located in an area with
a housing density of two to three times greater than suggested as a tolerance
threshold by Harrison (1997; i.e., 50–125 residences/km2). The reasons why
Figure 1. Top: map of buildings (points), roads (lines) and wooded area (gray polygons)
within a 2.59-km2 (1-mi2) area centered on the monitored suburban property (indicated
by star). Elon, Alamance County, NC. Bottom (2 photos): Example of photographic evidence
of Gray Fox (Urocyon cinereoargenteus) visiting a suburban property in 2011.
2012 J.M. Kapfer and R.W. Kirk 513
Gray Foxes exist within higher building densities here than what Harrison
suggested are not fully understood. Harrison (1993) reported that the extent of
“original” habitat present within a rural residential area had a significant influence
on Gray Fox density. Gray Foxes prefer habitats with some element of
tree and brush cover (reviewed by Cypher 2003). The presence of this species
at the suburban site we monitored may be related to the prevalence of mature
wooded buffers and wooded parcels located adjacently. For example, 12.1%
of the 2.59-km2 suburban area analyzed was forested (Fig. 1). In addition,
this property was also located less than 1.6 km from the nearest rural/suburban fringe,
which may have given Gray Foxes easy access.
The greatest activity of Gray Foxes monitored at the rural site differed seasonally
from the suburban site. The largest number of suburban fox encounters
occurred in May and June 2011. In contrast, Gray Foxes at the rural site were
photographed most often in January and February 2011, and only one cameratrap
photograph was taken there from 1 April–18 July 2011.
We believe that the frequency of Gray Fox encounters at the suburban
property suggests that these were residents of the general area. Although
we cannot say if the property that we monitored was part of their core home
range, it at least appeared to be part of the home range they traversed during
the active season. On one occasion (26 May at 1700 h), an individual was
witnessed moving across the adjacent road with a small mammal of unknown
species in its mouth. This observation, coupled with the peak in activity observed
during late May, may be related to parturition and nursing by females,
during which males are known to forage alone and bring food to the nursing
female (Cypher 2003). In addition, an adult was seen on 27 June crossing
a road adjacent to the suburban site followed by four kits. An adult and kit
were also seen crossing the same road on 7 July (Table 1). These observations
strongly suggest that the suburban site was part of their core home range, due
to the apparent likelihood that the natal den was located nearby. The lack of
photographs captured at the rural site during the late spring/summer may also
be related to parturition. For example, fox photographs at this site would decline
in late spring/summer if the camera was not located near the natal den.
We did not record Coyote activity as commonly as Gray Fox at the sites we
monitored. Coyote activity was observed at the suburban site on two occasions
(5 May and 16 June 2011). Interestingly, all photographs of suburban Coyotes
were followed soon after by photographs of Gray Foxes (one within 20 min, and
the other within 2.25 hr). This would suggest that either these Coyotes were not
resident individuals that defended territories and excluded local Gray Foxes, or
the presence of these Coyotes did not influence the habitat selection of the suburban
Gray Foxes we monitored. In contrast, a Coyote was photographed once
on the rural property (26 February 2011), and no further Gray Fox activity was
recorded at this location for 10 days.
Our observations provide more information on the ecology of Gray Foxes in
suburban landscapes. However, we support the recommendation by Riley and
514 Southeastern Naturalist Vol. 11, No. 3
White (2010) that more research is needed on this subject. Because this species
prefers brushy cover or wooded habitat, it is possible they will persist in developed
areas if mature woody buffers are present. Therefore, we suggest that, in
addition to estimates of building density, future research include detailed landscape-
level habitat analyses. Such research should include investigations of how
the maturity and proportion of vegetation in natural buffers available to suburban
Gray Foxes influences their ecology.
It would also be valuable to relate data on fox habitat use and movement
to fox population estimates for the surrounding landscape. Such population
information for our study region does not currently exist. Annual trapping records
for Gray Fox and Coyotes in Alamance County show a general increase
in numbers harvested over the last five years (Table 3; Colleen Olfenbuttel,
North Carolina Wildlife Resources Commission, Pittsboro, NC, pers. comm.).
For example, during 2005/2006, 43 Gray Fox and 3 Coyotes were harvested.
These numbers steadily increased until 2010/2011, during which 179 Gray Fox
and 87 Coyotes were harvested (Table 3). However, this data should be viewed
cautiously. Trappers are not required to report harvest totals for these species in
North Carolina, and this increase could be indicative of greater survey participation
by trappers over time. The legal trapping season for fox and Coyote in
Alamance County was also increased by several months in 2008, which likely
influenced the total number harvested. However, the numbers of each species
harvested showed a general increase prior to 2008 (Table 3). If these data represent
an actual increase in Gray Fox and Coyote populations in the region, there
may be implications for how these species use suburban/urban habitat. For example,
higher fox and Coyote population densities, coupled with loss of habitat
due to suburban sprawl, could force individuals from preferred habitat into
areas that would otherwise be avoided. Further research on this topic is warranted,
particularly in the southeastern US.
Camera traps are a relatively new and effective tool for studying wildlife,
particularly for medium and large mammals. They provide a non-invasive
method for meeting a variety of research needs, such as species inventories,
behavioral studies, and population estimates (see multiple chapters in
O’Connell et al. 2011). Camera traps are also especially useful for studying
Table 3. Annual harvest totals for Gray Foxes (Urocyon cinereoargenteus) and Coyotes (Canis
latrans) for Alamance County, NC. Totals based on voluntary trapper reports received from
2005/2006 through 2010/2011 trapping seasons (data provided by Colleen Olfenbuttel, North
Carolina Wildlife Resources Commission, Pittsboro, NC).
Species 2005/2006 2006/2007 2007/2008* 2008/2009 2009/2010 2010/2011
Gray Fox 43 62 77 92 106 179
Coyote 3 11 23 34 58 87
*Note: after 2007/2008, the trapping season for fox and Coyote in Alamance County was lengthened
from October 1st through January 31st to June 1st through February 28th.
2012 J.M. Kapfer and R.W. Kirk 515
cryptic or wary species that are challenging to survey by other means
(O’Connell et al. 2011). As a result, camera traps are often employed in studies
focused on rare species (e.g., Janecka et al. 2011, Mohd-Azlan and Sanderson
2007). We found they are equally as effective in studying common species,
such as Gray Fox in our study areas. Camera traps can be deployed long-term
in a relatively inexpensive fashion, they survey a particular location continuously
once deployed, and they reduce the likelihood of injury to animals and
researchers that may result from traditional trapping methods.
We thank Elon University for providing the funds that purchased the camera traps
used during our study and granting us access to the rural site for monitoring. We also
thank J.J. Kapfer and V.E. Kapfer for providing information on visual observations of
Gray Foxes from the suburban site. D. Muñoz and M. Forster helped maintain rural camera
traps. The University of Wisconsin-Whitewater and Elon University provided funding
to support the publication of this manuscript.
Cypher, B.L. 2003. Foxes. Pp. 511–546, In G.A. Feldhammer, B.C. Thompson, and
J.A. Chapman (Eds.). Wild Mammals of North America: Biology, Management, and
Conservation, 2nd Edition. Johns Hopkins University Press, Baltimore, MD. 1216 pp.
Fedriani, J.M., T.K. Fuller, R.M. Sauvajot, and E.C. York. 2000. Competition and intraguild
predation among three sympatric carnivores. Oecologia 125:258–270.
Gehrt, S.D., and S.P.D. Riley. 2010. Coyotes (Canis latrans). Pp. 79–96, In S.D. Gehrt,
S.P.D. Riley, and B.L. Cypher (Eds.). Urban Carnivores: Ecology, Conflict, and Conservation.
Johns Hopkins University Press, Baltimore, MD. 304 pp.
Gehrt, S.D., S.P.D. Riley, and B.L. Cypher (Eds.). 2010. Urban Carnivores: Ecology, Confl
ict, and Conservation. Johns Hopkins University Press, Baltimore, MD. 304 pp.
Harrison, R.L. 1993. A survey of anthropogenic ecological factors potentially affecting
Gray Foxes (Urocyon cinereoargenteus) in a rural residential area. The Southwestern
Harrison, R.L. 1997. A comparison of Gray Fox ecology between residential and undeveloped
rural landscapes. Journal of Wildlife Management 61:112–122.
Janecka, J.E., B. Munkhtsog, R.M. Jackson, G. Naranbaatar, D.P. Mallon, and W.J. Murphy.
2011. Comparison of noninvasive genetic and camera-trapping techniques for
surveying Snow Leopards. Journal of Mammalogy 92:771–783.
Mohd-Azlan, J., and J. Sanderson. 2007. Geographic distribution and conservation status
of the Bay Cat, Catopuma badia, a Bornean endemic. Oryx 41:394–397.
O’Connell, A.F. J.D. Nichols, and K.U. Karranth (Eds.). 2011. Camera Traps in Animal
Ecology: Methods and Analyses. Springer Publishing, New York, NY. 280 pp.
Riley, S.P.D. 2006. Spatial ecology of Bobcats and Gray Foxes in urban and rural zones
of a national park. Journal of Wildlife Management 70:1425–1435.
Riley, S.P.D., and P.A. White. 2010. Gray Foxes (Urocyon cinereoargenteus). Pp. 197–
200, In S.D. Gehrt, S.P.D. Riley and B.L. Cypher (Eds.). Urban Carnivores: Ecology,
Conflict, and Conservation. Johns Hopkins University Press, Baltimore, MD. 304 pp.
516 Southeastern Naturalist Vol. 11, No. 3
Riley, S.P.D., J. Foley, and B. Chomel. 2004. Exposure to feline and canine pathogens in
Bobcats (Lynx rufus) and Gray Foxes (Urocyon cinereoargenteus) in urban and rural
zones of a national park in California. Journal of Wildlife Diseases 40:11–22.
Rountree, G.H., III. 2004. Comparative study of the home range and habitat usage of
Red Foxes and Gray Foxes in an urban setting: A preliminary report. Pp. 238–244, In
W.W. Shaw, L.K. Harris, and L. VanDruff (Eds.). Proceedings of the 4th International
Urban Wildlife Symposium. May 1–5, 1999, Tucson, AZ. College of Agriculture and
Life Science, Univeristy of Arizona-Tuscon, Tuscon, AZ. 368 pp.
Temple, D.L., M.J. Chamberlain, and L.M. Conner. 2010. Spatial ecology, survival, and
cause-specific mortality of Gray Foxes (Urocyon cinereoargenteus) in a Longleaf
Pine ecosystem. American Midland Naturalist 163:413–422.