Index of Species Information

WILDLIFE SPECIES:  Urocyon cinereoargenteus


WILDLIFE SPECIES: Urocyon cinereoargenteus
AUTHORSHIP AND CITATION : Sullivan, Janet. 1996. Urocyon cinereoargenteus. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: []. Revisions: 18 July 2013: DeGraaf, Richard M.; Rudis, Deborah D. 2001 citation corrected to DeGraaf, Richard M.; Yamasaki, Mariko. 2001. ABBREVIATION : URCI COMMON NAMES : common gray fox grey fox tree fox maned fox TAXONOMY : The currently accepted scientific name of common gray fox is Urocyon cinereoargenteus Schreber. It is a member of the dog family (Canidae). There are 15 accepted subspecies; the 7 subspecies occurring north of Mexico are as follows [16]: Urocyon cinereoargenteus borealis Merriam Urocyon cinereoargenteus californicus Mearns Urocyon cinereoargenteus cinereoargenteus (Schreber) Urocyon cinereoargenteus floridanus Rhoads Urocyon cinereoargenteus ocythous Bangs Urocyon cinereoargenteus scottii Mearns Urocyon cinereoargenteus townsendi Merriam ORDER : Carnivora CLASS : Mammal FEDERAL LEGAL STATUS : Urocyon cinereoargenteus ocythous is Under Review for listing [40]. OTHER STATUS : Information on state- and province-level protection status of animals in the United States and Canada is available at NatureServe, although recent changes in status may not be included.


WILDLIFE SPECIES: Urocyon cinereoargenteus
GENERAL DISTRIBUTION : The range of common gray fox extends from extreme southern Canada to northern Venezuela and Columbia, excluding portions of the northern Rocky Mountain region, the northern Great Plains, and eastern Central America [16].  Common gray fox range has expanded in the last 50 years to areas formerly unoccupied and areas where common gray fox had been extirpated including New England, Michigan, Minnesota, Iowa, Ontario, Manitoba, North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, and Utah [9]. Ranges of subspecies follow [16]. U. c. borealis occurs in New England and southern Ontario. U. c. californicus occurs from southwestern California to northern Baja California. U. c. cinereoargenteus occurs from southern Massachusetts and Connecticut west to Lake Michigan and Illinois; south to central South Carolina; and west to the Mississippi River. U. c. floridanus occurs from southern South Carolina south to Florida and west to eastern Texas; it occurs along the Gulf Coast excluding Louisiana. U. c. ocythous occurs in Wisconsin and extreme western Illinois; from Missouri and Arkansas west to Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, and extreme southern Manitoba and Quebec. U. c. scottii occurs from western Texas north through northern Colorado and Utah to the southern half of Nevada; and from California east of the Sierra Nevada southeast in Mexico to Chihuahua. U. c. townsendi occurs in northern California and western Oregon. ECOSYSTEMS : FRES10 White-red-jack pine FRES11 Spruce-fir FRES12 Longleaf-slash pine FRES13 Loblolly-shortleaf pine FRES14 Oak-pine FRES15 Oak-hickory FRES16 Oak-gum-cypress FRES17 Elm-ash-cottonwood FRES18 Maple-beech-birch FRES19 Aspen-birch FRES20 Douglas-fir FRES21 Ponderosa pine FRES23 Fir-spruce FRES24 Hemlock-Sitka spruce FRES26 Lodgepole pine FRES27 Redwood FRES28 Western hardwoods FRES29 Sagebrush FRES30 Desert shrub FRES31 Shinnery FRES32 Texas savanna FRES33 Southwestern shrubsteppe FRES34 Chaparral-mountain shrub FRES35 Pinyon-juniper FRES36 Mountain grasslands FRES37 Mountain meadows FRES38 Plains grasslands FRES39 Prairie FRES40 Desert grasslands FRES41 Wet grasslands FRES42 Annual grasslands STATES :
BLM PHYSIOGRAPHIC REGIONS :     1  Northern Pacific Border     2  Cascade Mountains     3  Southern Pacific Border     4  Sierra Mountains     6  Upper Basin and Range     7  Lower Basin and Range     9  Middle Rocky Mountains    10  Wyoming Basin    11  Southern Rocky Mountains    12  Colorado Plateau    13  Rocky Mountain Piedmont    14  Great Plains KUCHLER PLANT ASSOCIATIONS :    The common gray fox occurs in nearly every Kuchler plant association. SAF COVER TYPES :    The common gray fox occurs in nearly every SAF cover type. SRM (RANGELAND) COVER TYPES :    The common gray fox occurs in most SRM cover types. PLANT COMMUNITIES : Common gray foxes occur in a wide variety of forest types; they prefer woodlands and woodland-brush ecotones over open habitat.  They commonly occur in eastern and southwestern deciduous forests, but are also found in mixed and coniferous forests of the northeastern and western states [36]. Common gray foxes are ecologically important members of the oak (Quercus spp.)-hickory (Carya spp.) ecosystem.  In the Missouri Ozarks mature oak-hickory stands were the most frequently used (of six habitat types) by common gray foxes, both at night and during the day.  Old fields were least used [18].  In North Carolina common gray fox habitats include evergreen redbay (Persea borbonia) forests, deciduous forests, and streamhead forests. Common gray foxes were common in the most densely wooded habitats, including pocosins.  They are often seen running along sandy rims and ridges between bay and streamhead forests [5].  In central Louisiana common gray foxes occur in longleaf pine (Pinus palustris)-slash pine (P. elliottii) stands [25].  Common gray foxes are common in southwestern Wisconsin oak-hickory forests dominated by white oak (Q. alba), northern red oak (Q. rubra), black oak (Q. velutina), and shagbark hickory (C. ovata) with lesser amounts of white ash (Fraxinus americana), green ash (F. pennsylvanica), maples (Acer spp.), and basswood (Tilia americana) [33]. In Zion National Park, Utah, common gray foxes occur in blackbrush (Coleogyne ramosissima), shrub-grassland dominated by fourwing saltbush (Atriplex canescens), and pinyon (Pinus spp.)-juniper (Juniperus spp.) [35].  In Texas common gray foxes are found in post oak (Q. stellata) woodlands, pinyon-juniper woodlands, and wooded sections of shortgrass prairie.  In western states common gray foxes are found in brushy habitat, woods, and chaparral [36].  In Arizona common gray foxes are relatively rare; they are typically found in pine (Pinus spp.)-Gambel oak (Q. gambelii) woodlands at 5,000 to 6,000 feet (1,500-1,800 m) elevation.  They also occur in pine-fir (Abies spp.), ponderosa pine (P. ponderosa), chaparral, and desert grassland habitats [6,31].  In California common gray foxes are most common in mature chaparral at elevations of 1,000 to 3,000 feet (300-900 m) and also occur in open chaparral, riparian areas, and other plant communities [29].  In riparian zones they have been found in communities dominated by Fremont cottonwood (Populus fremontii)-northern California black walnut (Juglans californica var. hindsii), and by large willow (Salix laevigata) [17].  In northwestern California common gray foxes were present in Douglas-fir (Pseudotsuga menziesii) forests [39].


WILDLIFE SPECIES: Urocyon cinereoargenteus
TIMING OF MAJOR LIFE HISTORY EVENTS : Diurnal Activity:  Common gray foxes are more active at night and at dusk than during the day.  Activity levels decrease sharply at sunrise, and increase at sunset [17,18].  Common gray foxes usually leave their daytime rest area shortly before sunset, investigate the immediate area, and then move purposefully to a foraging area.  Close to sunrise they usually move back to a daytime resting area.  Common gray foxes usually change resting sites every day once vegetative cover is abundant in late spring; sites are reused in winter [17]. Breeding Season:  Common gray foxes usually breed from late winter to early spring; dates of mating activity vary with latitude and elevation.  In southern Illinois breeding occurs from late January to February; in Wisconsin breeding occurs from late January to March [9], and in Oregon mating occurs from mid-February to March [23].  Where common gray fox is sympatric with red fox (Vulpes vulpes), common gray foxes breed 2 to 4 weeks later than red foxes.  Common gray foxes are assumed to be monogamous, but direct evidence is lacking [9].  There is only one litter per year [35]. Gestation and Development of Young:  Gestation periods have been variously reported as ranging from 53 to 63 days; Fritzell [10] reported gestation in captivity lasted 59 days.  Mean litter size is 3.8, ranging from 1 to 7.  Development has not been well studied [9].  Young are born blind and nearly naked.  Eyes open about 9 days after birth.  The pups nurse for over 3 weeks.  Solid food is fed to the pups before they are completely weaned with the male beginning to bring food to the pups at about 2 to 3 weeks.  Pups begin to fend for themselves at about 3 months; families disperse in late summer and autumn [23]. Population Structure:  Root and Payne [33] determined that the majority of animals in a southwestern Wisconsin common gray fox population were under 1 year old.  They concluded that common gray foxes are "an annual crop."  The majority of female common gray foxes breed their first year [33]. Mortality and Longevity:  In the Central Valley of California, two of four radiotracked common gray foxes were killed by cars [11].  In east-central Alabama, a population of common gray foxes was tagged and monitored for causes of mortality.  Canine distemper was the most frequent cause of death, followed by trapping, automobile collision, and infectious canine hepatitis.  Canine distemper was probably a localized cause of mortality in this area; it is not expected that most common gray fox populations suffer the same rate of distemper deaths [27].  Maser and others [23] stated that collision with automobiles is rare in Oregon; the major causes of common gray fox mortality are hunting and trapping.  They listed a probable maximum longevity in the wild of 6 years.  The oldest captive common gray fox lived less than 8 years [23]. PREFERRED HABITAT : Common gray foxes are most closely associated with deciduous forest, particularly where it is in contact with disturbed or brushy habitat [9,23,35].  They are usually found near surface water [29].  Preferred habitat includes shrublands and brushy woodlands on hilly or rough terrain.  In areas where common gray foxes and red foxes occur together, common gray foxes prefer mixed woods with dense underbrush.  In the absence of red foxes, common gray foxes prefer other habitats [35]. In New England common gray foxes are associated with dense northern hardwood or mixed forests, thickets, and swamps.  Preferred habitat includes a mixture of fields and woods [7].  In Wisconsin common gray foxes were most abundant near brush-covered bluffs where woods and farmland were well interspersed [28].  From Virginia to southern Georgia optimal common gray fox habitat consists of woodland-farmland edge; post oak woodlands are also good common gray fox habitat [9].  In southern Georgia common gray foxes are most abundant in mixed woods and cultivated areas, less abundant in pine savanna, and least common in mixed woods with dense underbrush [35].  On the Coastal Plain most common gray fox captures occurred in tall weed-broomsedge (Andropogon virginicus)-dominated habitats and cultivated areas.  There were relatively few captures on forested sites; this difference from common gray fox preferences in the majority of its range was attributed to the absence of red foxes [24]. In the western states common gray fox habitats include rocky hillsides, mountainsides, and washes [35].  In Oregon common gray foxes prefer mixed hardwood and mixed conifer-hardwood habitats; they are present in riparian hardwood, headland prairie, headland shrub, and tanoak (Lithocarpus densiflorus) habitats [23].  In the Central Valley of California, one common gray fox spent most of its time in old fields and human-use areas, one spent most of its time in agricultural areas, and two spent most of their time in riparian areas.  None of the foxes used areas of open dirt [11].  In California common gray foxes were most abundant from 3,800 to 5,000 feet (1,150-1,525 m) elevation [15].  In northwestern California Douglas-fir forests, common gray foxes were present in similar abundances in all forest seres, but there were slightly fewer common gray foxes in mature timber [39]. Home Range:  Common gray foxes tracked from May through August, 1980 and January through August, 1981, had a monthly average home range of 740 acres (299 ha), and an average composite home range of 1,700 acres (676 ha).  Some individuals occupied the same general area for extended periods, but home ranges tended to shift from month to month.  Only a fraction of the home range is used on a given night [18].  The composite home ranges of four radio-tracked common gray foxes varied from 262 to 425 acres (106-172 ha).  Common gray foxes are apparently solitary in the nonbreeding seasons [17].  In Wisconsin common gray fox home ranges vary from 0.24 to 1.2 miles (0.40-2 km) in diameter [32].  Lord [22] estimated common gray fox home range diameter of 1.9 miles (3.2 km).  Trapp [34] reported an annual home range average of 0.2 square mile (0.52 sq km). Territoriality:  Common gray fox territoriality is not well defined. Territories are marked with urine and feces, but in many areas home ranges overlap considerably.  Family aggregates are formed so that individual territories overlap; family aggregates do not overlap [18]. COVER REQUIREMENTS : Common gray foxes tend to escape their enemies by finding cover rather than depending on speed (as do red foxes) [23].  Dense vegetation is important as diurnal resting and escape cover [18].  They climb trees for use as resting and escape cover [23].  Their climbing ability extends to saguaro (Carnegiea gigantea); one common gray fox was observed resting 15 feet (4.6 m) above ground on a saguaro limb [6]. Den sites include hollow logs and trees, rock outcrops, underground burrows (usually the abandoned den of some other species), cavities under rocks, abandoned buildings, wood or sawdust piles, and brush [9,23].  Dens have been found up to 20 feet (9.1 m) above ground in tree hollows.  Underground dens have usually been excavated by animals of other species, but common gray foxes occasionally dig dens in loose soil [35]. Den Use:  Dens are used throughout the year, but primary use is during whelping season.  Dens are usually located in brushy or wooded habitats. In Wisconsin most common gray fox dens were on east-, southeast-, or south-facing slopes [9].  Leaves, grass, fur, and other soft materials are added to dens [23]. FOOD HABITS : Common gray foxes are omnivorous, opportunistic feeders; they prey mainly on small mammals, but fruit and invertebrates form a substantial portion of the diet.  In the central United States cottontails (Sylvilagus spp.) formed the major portion of the common gray fox winter diet.  Other mammals taken in noticeable numbers include voles (Microtus spp.), mice (Peromyscus spp.), woodrats (Neotoma spp.), and cotton rats (Sigmodon spp.).  Invertebrates increase in importance in the spring.  With seasonally advancing vegetative growth and development, plant material, particularly fruit, increases in common gray fox diets, sometimes comprising up to 70 percent by volume [10].  Grasshoppers (Orthoptera), beetles (Coleoptera), and butterflies and moths (Lepidoptera) are the preferred invertebrates; plant materials include fruits, nuts, grains, and grasses.  Carrion is eaten opportunistically [35].  In some areas birds (nestlings and eggs), particularly ground-nesters, are taken by common gray foxes; in Texas wild turkey (Meleagris gallopavo) nests were broken up by common gray foxes [3]. In a riparian area in the Central Valley of California, a common gray fox ate mostly ring-necked pheasant (Phasianus colchicus), California ground squirrels (Spermophilus beecheyi), California voles (Microtus californicus), and berries [11].  In Oregon primary prey items include mice, pocket gophers (Thomomys and Geomys spp.), kangaroo rats (Dipodomys spp.), woodrats, ground squirrels (Spermophilus spp.), chipmunks (Tamias spp.), brush rabbit (Sylvilagus bachmanii), and birds including domestic poultry.  Other food items include grasshoppers, beetles, manzanita (Arctostaphylos spp.) berries, juniper cones, and cascara (Rhamnus purshiana) berries [23].  In the Sonoran Desert the fruit of the California palm (Washingtonia filifera) forms a substantial portion of the common gray fox winter diet [2].  In eastern Tennessee plant foods included persimmon (Diospyros virginiana), black cherry (Prunus serotina), blackberry (Rubus spp.) , and cancerroot (Conophilus americana).  The most common vertebrate prey determined in scat analysis (by volume) was eastern cottontail (Sylvilagus floridana), followed by white-tailed deer (Odocoileus virginiana), presumably as carrion, and rodents [14]. PREDATORS : Adult common gray foxes have few predators, but are occasionally taken by golden eagle (Aquila chrysaetos), coyote (Canis latrans), and bobcat (Lynx rufus) [35]; pups are taken by bobcat, great horned owl (Bubo virginianus), and possibly large hawks [23]. MANAGEMENT CONSIDERATIONS : Common gray fox pelts are of some value but are not as valued as those of red fox [23].  Trapping increases and decreases with pelt values; in a 1987 report it was mentioned that sales in the United States had increased dramatically in the last decade.  The common gray fox has "furbearer" management status in many states [13,38]. Population Status:  The common gray fox is characterized by widespread, healthy populations in most areas.  Habitat availability may limit its distribution, but lack of habitat does not appear to pose an immediate threat [13].  Common gray foxes are uncommon to common in New England [7]. Reported population densities range from 1 to 27 per square mile [35]. Common gray foxes are considered pests by many farmers who raise domestic poultry; biologists claim that this damage is usually overstated and that common gray foxes benefit agriculture by controlling rodent and rabbit populations [23].  In northern bobwhite (Colinus virginianus) management areas only a small number of common gray foxes (0.7%) were found to have northern bobwhite remains in their stomachs [26]. Common gray foxes commonly carry rabies, most frequently in the Appalachian states (KY, TN, VA, WV) [4].  They also carry tularemia [23] and canine distemper which is not as virulent in common gray foxes as it is in domestic dogs (Canis familiaris) [38].


WILDLIFE SPECIES: Urocyon cinereoargenteus
DIRECT FIRE EFFECTS ON ANIMALS : Death of common gray foxes due to fire has not been documented in the literature.   They are highly mobile animals and are probably only rarely caught by fast-moving or intense wildfire. HABITAT RELATED FIRE EFFECTS : Common gray foxes use brush and brushy woods in most areas.  Fire that reduces brush cover will decrease common gray fox habitat.  Fire usually increases the productivity of early successional prey species and improves predator efficiency by reducing hiding cover for prey [21].  In the Southeast fire produces immediate short-term habitat reduction for prey animals; prey is concentrated in unburned habitat islands [19].  The most important common gray fox prey in the Southeast are cottontails and cotton rats.  Cottontails and cotton rats are not usually killed by fire but prefer habitats with more cover than is found in immediate postfire environments.  Both species return to postfire habitats when there is sufficient vegetation for food and cover.  Fire often reduces fruit production in the short term, but edges of older burns are usually good regeneration sites for fruiting shrub species such as blackberries and blueberries (Vaccinium spp.); gallberry (Ilex glabra) produces the most fruit a few years after fire pruning [21]. FIRE USE : Hon [19] and Landers [21] suggest that in the Southeast, burning fields and slash pine forests on 3-year rotations would create desirable furbearer habitat; areas supporting fire-sensitive fruit-bearing plants should be protected from fire.

References for species: Urocyon cinereoargenteus

1. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. [434]
2. Bullock, Stephen H. 1980. Dispersal of a desert palm by opportunistic frugivores. Principes. 24(1): 29-32. [19703]
3. Butts, Gregory L. 1977. Aerial pursuit of red-tailed hawks (Accipitridae) by turkey (Meleagrididae) hens. The Southwestern Naturalist. 22(3): 404-405. [10482]
4. Carey, Andrew B. 1982. The ecology of red foxes, gray foxes, and rabies in the eastern United States. Wildlife Society Bulletin. 10(1): 18-26. [25970]
5. Clark, Mary K.; Lee, David S.; Funderburg, John B., Jr. 1985. The mammal fauna of Carolina bays, pocosins, and associated communities in North Carolina: an overview. Brimleyana. 11: 1-38. [13478]
6. Davis, Russell; Sidner, Ronnie. 1992. Mammals of woodland and forest habitats in the Rincon Mountains of Saguaro National Monument, Arizona. Technical Report NPS/WRUA/NRTR-92/06. Tucson, AZ: The University of Arizona, School of Renewable Natural Resources, Cooperative National Park Resources Study Unit. 62 p. [20966]
7. DeGraaf, Richard M.; Yamasaki, Mariko. 1986. New England wildlife: habitat, natural history, and distribution. Gen. Tech. Rep. NE-108. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 491 p. [21385]
8. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905]
9. Fritzell, Erik K.; Haroldson, Kurt J. 1982. Urocyon conereoargenteus. Mammalian Species. 189: 1-8. [25971]
10. Fritzell, E. K. 1987. Gray fox and island fox. In: Novak, M.; Baker, J. A.; Obbard, M. E.; Malloch, B., eds. Wild furbearer management and conservation in North America. North Bay, ON: Ontario Trappers Association: 408-420. [28236]
11. Fuller, Todd K. 1978. Variable home-range sizes of female gray foxes. Journal of Mammalogy. 59(2): 446-449. [25972]
12. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998]
13. Ginsberg, J. R.; Macdonald, D. W. 1990. Foxes, wolves, jackals, and dogs: An action plan for the conservation of canids. [Place of publication unknown]: The World Conservation Union, Gland, Switzerland. 116 p. [25761]
14. Greenberg, Cathryn H.; Pelton, Michael R. 1991. Food habits of gray foxes (Urocyon cinereoargenteus) and red foxes (Vulpes vulpes) in east Tennessee. Journal of the Tennessee Academy of Science. 66(2): 79-84. [25973]
15. Grinnell, Joseph; Dixon, Joseph S.; Linsdale, Jean M. 1937. Fur-bearing mammals of California: Their natural history, systematic status, and relations to man. Berkeley, CA: University of California Press. 2 vol. 777 p. [25979]
16. Hall, E. Raymond. 1981. The mammals of North America. 2nd ed. Vol. 2. New York: John Wiley and Sons. 1271 p. [14765]
17. Hallberg, Donald L.; Trapp, Gene R. 1984. Gray fox temporal and spatial activity in a riparian/agricultural zone in California's Central Valley. In: Warner, Richard E.; Hendrix, Kathleen M., eds. California riparian systems: Ecology, conservation, and productive management. Berkeley, CA: University of California Press: 920-928. [5881]
18. Haroldson, Kurt J.; Fritzell, Erik K. 1984. Home ranges, activity, and habitat use by gray foxes in an oak-hickory forest. Journal of Wildlife Management. 48(1): 222-227. [25991]
19. Hon, Tip. 1981. Effects of prescribed fire on furbearers in the South. In: Wood, Gene W., ed. Prescribed fire and wildlife in southern forests: Proceedings of a symposium; 1981 April 6-8; Myrtle Beach, SC. Georgetown, SC: Clemson University, Belle W. Baruch Forest Science Institute: 121-128. [14818]
20. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384]
21. Landers, J. Larry. 1987. Prescribed burning for managing wildlife in southeastern pine forests. In: Dickson, James G.; Maughan, O. Eugene, eds. Managing southern forests for wildlife and fish: a proceedings; [Date of conference unknown]; [Location of conference unknown]. Gen. Tech. Rep. SO-65. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station: 19-27. [11562]
22. Lord, Rexford D., Jr. 1961. A population study of the gray fox. The American Midland Naturalist. 66(1): 87-109. [25974]
23. Maser, Chris; Mate, Bruce R.; Franklin, Jerry F.; Dyrness, C. T. 1981. Natural history of Oregon Coast mammals. Gen. Tech. Rep. PNW-133. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 496 p. [10238]
24. McKeever, Sturgis. 1959. Relative abundance of twelve southeastern mammals in six vegetative types. The American Midland Naturalist. 62: 222-226. [25166]
25. Mullin, Keith; Williams, Kenneth L. 1987. Mammals of longleaf-slash pine stands in central Louisiana. In: Pearson, Henry A.; Smeins, Fred E.; Thill, Ronald E., compilers. Proceedings of the southern evaluation project workshop; 1987 May 26-27; Long Beach, MS. Gen. Tech. Rep. SO-68. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station: 121-124. [12473]
26. Murray, Robert W.; Frye, O. E., Jr. 1964. The bobwhite quail and its management in Florida. 2d ed. Game Publ. No. 2. [Place of publication unknown]: Florida Game and Fresh Water Fish Commission. 55 p. [15421]
27. Nicholson, W. S.; Hill, Edward P. 1984. Mortality in gray foxes from east-central Alabama. Journal of Wildlife Management. 48(4): 1429-1432. [25990]
28. Petersen, LeRoy R.; Martin, Mark A.; Pils, Charles M. 1977. Status of gray foxes in Wisconsin, 1975. Research Report 94. Madison, WI: Wisconsin Department of Natural Resources. 18 p. [25992]
29. Quinn, Ronald D. 1990. Habitat preferences and distribution of mammals in California chaparral. Res. Pap. PSW-202. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 11 p. [15761]
30. Raphael, Martin G. 1988. Long-term trends in abundance of amphibians, reptiles, and mammals in Douglas-fir forests of northwestern California. In: Szaro, Robert C.; Severson, Kieth E.; Patton, David R., technical coordinators. Management of amphibians, reptiles, and small mammals in North America: Proceedings of the symposium; 1988 July 19-21; Flagstaff, AZ. Gen. Tech. Rep. RM-166. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 23-31. [7105]
31. Reynolds, Hudson G.; Johnson, R. Roy. 1964. Habitat relations of vertebrates of the Sierra Ancha Experimental Forest. Res. Pap. RM-4. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 16 p. [13485]
32. Richards, Stephen H.; Hine, Ruth L. 1953. Wisconsin fox populations. Final Report: Pittman--Robertson Research Project 12-R. Technical Wildlife Bulletin No. 6. Madison, WI: Wisconsin Conservation Department, Game Management Division. 78 p. [25993]
33. Root, David A.; Payne, Neil F. 1985. Age-specific reproduction of gray foxes in Wisconsin. Journal of Wildlife Management. 49(4): 890-892. [25975]
34. Trapp, Gene Robert. 1973. Comparative behavioral ecology of two southwest Utah carnivores: Bassariscus astutus and Urocyon cinereoargenteus. Madison, WI: University of Wisconsin. 251 p. Dissertation. [27376]
35. Trapp, Gene R.; Hallberg, Donald L. 1975. Ecology of the gray fox (Urocyon cinereoargenteus): a review. In: Fox, M. W., ed. The wild canids: Their systematics, behavioral ecology and evolution. Behavioral Science Series. New York: Van Nostrand Reinhold Company: 164-178. [25976]
36. Sheldon, Jennifer W. 1992. Wild dogs: The natural history of the nondomestic Canidae. San Diego, CA: Academic Press, Inc. 248 p. [25760]
37. Shiflet, Thomas N., ed. 1994. Rangeland cover types of the United States. Denver, CO: Society for Range Management. 152 p. [23362]
38. Samuel, David E.; Nelson, Brad B. 1982. Foxes: Vulpes vulpes and allies. In: Chapman, Joseph A.; Feldhamer, George A., eds. Wild mammals of North America: Biology, management, and economics. Baltimore, MD: The Johns Hopkins University Press: 475-490. [25235]
39. Committee on the Status of Endangered Wildlife in Canada. 1992. Canadian species at risk. Ottawa, ON. 10 p. [26183]
40. U.S. Department of the Interior, Fish and Wildlife Service. 2013. Endangered Species Program, [Online]. Available: [86564]