Species-Specific Management (SSM)

Red and Gray Fox

Red (Vulpes fulva) and gray foxes are similar. The gray fox has a black-tipped tail; the red has a white-tipped tail. Their colors vary widely but the red fox typically is uniformly light rufous, reddish, or "orange" in color. The fur of the gray fox is much less valuable than that of the red fox, and sport hunting them is not as challenging as hunting the red fox (Vulpes vulpes).

The gray fox is a valuable component of our natural ecosystem and, in spite of modern land use practices, has remained a part of the landscape. Both gray and red foxes seem to be stable throughout the state but no studies are conducted, and data are merely those from trappers. Trapping is very much a function of fur market prices and so pelt sales as a population index are very limited.

Both gray and red foxes inhabit many different types of areas or habitats. Red foxes are most abundant when there is great variety of types of vegetation (forests, grasslands, cropland, rocky areas, etc.). The rolling pastures and farmlands that are interspersed with sparse woodlands and wet areas are where most red fox are seen. The gray fox is most likely abundant in the woodlands ...interspersed with farmland, pasture, and wet areas. Grays do well where a mixture of age classes of timber occur. Both species use dens, often made by groundhogs or woodchucks. They will dig them for themselves and the site is often under hollow logs or debris piles. The gray fox eats more rabbits and fruit than the red, but that is likely due to what is available in the areas where they typically occur.

Objectives

Managers need to assist leaders, adjacent landowners and others in specifying objectives for the gray fox resource. Should they be increased, decreased, maintained as stable? Is the number the desired unit? Perhaps sightings, or pelt sales, or financial returns are the unit. Perhaps hours of high-quality-score hunting are desired? Perhaps number of people seeing foxes and learning a little about them is the system performance measure? Perhaps generally enhancing a huntclub's activities and worth? If an increase is desired, then how much? (What is the demand?) Without a clear statement, there is no limit to the amount of money, time, energy, and risk that can be expended on the gray fox resource. The manager's dilemma: opposing objectives of increasing game and furbearers and reducing predation and disease.

Management Concepts

A resource manager desiring a viable gray fox population within a particular area must provide the habitat preferences of the species.

The gray fox is adaptable and is considered to be a habitat generalists. It needs well-distributed shrub cover, and in particular, dense tangled cover. They hunt in brushy meadows, but mature oak-hickory forests are prime living sites. Food availability influences both the diet and seasonal use of habitats. The needs are for:

1. Desirable management area with a minimum of 500 acres is recommended, since foxes have an average home range diameter of approximately 2 miles, which is a little over 3 square miles in area.
2. Primary choice in habitat for gray foxes is for woodlands in the early successional stages of forest development. Efforts should be made to ensure the occurrence of such areas by clear cutting in managed rotations of approximately 20-25 acres.

   The red fox is omnivorous and its diet, like the gray's, varies by season. Vegetation including acorns, corn, grasses, berries, and succulent fruits is the food of summer. The winter diet is of meat...small mammals. They also eat birds.

3. Denning sites, in order of preference, include earthen holes, hollow logs, cavities under rock ledges, and sometimes hollow tree cavities, since, unlike other foxed, the gray fox can readily climb trees. Wood piles and abandoned buildings are occasionally used. They particularly prefer earthen holes (groundhog holes) under roots of wind-thrown oaks and hickories.
4. Den locations need to be well screened with surrounding vegetation within a 20-yard distance on all sides. Plant a patch of dense shrubs near possible denning sites, because foxes often use the same den year after year. In Scotland, breeding dens are 3 time more numerous on agricultural land than in hill country, and twice as numerous as on land managed for red grouse. Occupied dens there are evenly spaced, not clumped or randomly. There, killing foxes in winter did not lead to fewer breeding dens in the following spring.
5. Favor forests and brush near cliffs and bluffs.
6. Retain large snags in the forest for their future denning possibilities and for their rich food supply of insects.
7. Create dense thickets of honeysuckle, blackberry, or similar vegetation greater than or equal to one-half acre in size; such areas are important in fox pup survival. They provide a hiding location and food source.
8. Prevent wild fires that result in loss of denning sites and food resources. Prescribed fires on a 3-year rotation should be considered.
9. Increase important native wildlife food items, such as rabbits, ground squirrels, mice and other rodents, birds, fish, crabs, and insects. For mice, provide rich dense meadows near a forest. A brushy, rich edge of a multi-layered forest near water is a superior site.
10. Encourage fruiting vines, shrubs, and trees through opening forest canopies to sunlight. Add fertilizer to improve soil nutrients, and transplant when necessary. Plant fruit trees and shrubs. Key species, especially in the summer, for gray foxes are:

    blackberries, huckleberries, raspberries, pokeberries, elderberries, hackberries, blueberries, greenbriar, honeysuckle, grapes, viburnum, wild strawberries, cherries, crabapples, persimmons, serviceberries.

11. Encourage nut-producing trees (hard mast) including: oaks, walnuts, hickories, and chestnuts.
12. Favor stands more than 70 acres in size. (They seem to prefer larger stands; they hardly ever stay in smaller areas.) Avoid creating small solitary forest islands.
13. Protect all streams and sources of ground water within the management area; the gray fox diet is known to include fish, unlike other foxes. Leave a zone of at least a 50-foot (17 m) area within streams where cutting trees is prohibited.
14. Protect gray foxes from the following: ground fires; firewood removal; polluted water sources; grazing; free-ranging dog disturbances; and high raccoon populations.
15. Disease is a major mortality factor in adult foxes. Gray foxes are highly susceptible to canine distemper, with 50 percent mortality rates or higher having been recorded. High raccoon population within the management area should be avoided if possible, since large numbers often exhibit a distemper-like epizootic.
16. All individuals handling gray foxes should get cheap, painless insurance in the form of a rabies vaccination.
17. Monitor population trends and adjust annual harvests when necessary. Since males roam more than female foxes, an even sex ration in capture may indicate that the population is being over harvested.
18. Reproductiveness and age ratios of female gray foxes taken from December through February can be estimated by the appearance of the reproductive teats and organs. Teats of subadults are unpigmented and between 1mm to 2mm in height. Yearlings near estrus also lack pigment with increased nipples to approximately 3mm in height; adults have pigmented teats measuring from 4mm to 6mm.
19. The reproductive status of male gray foxes can be determined by the prostate gland. A fully developed adult will have a light colored swollen prostate measuring about 12mm x 14mm in greatest length and breadth, while the gland in a regressed state is dark and shrunken with a measurement of approximately 9mm x 7mm.
20. Gray foxes cannot be stockpiled since they rarely reach a life span potential of 10-12 years. Efforts to stock them should be avoided at all cost. Introducing disease can be the result of stocking this species. Long-term harmful effects are possible.
21. Follow known game harvest laws to ensure a maintained population in the future. Never take more than one-half of the animals.
22. Use the most effective trapping techniques available.
23. Take care of the hides (attend and promote schools to improve care and reduce waste and spoilage) and sell them at fair market prices.
24. Try using the meat of foxes captured in animal foods.
25. Gain full returns of the forest investment by leasing trapping and hunting rights.
26. Work with local people who experience poultry raids and crop damage.
27. Contribute to gray fox research by way of money or action. Discuss options with the staff and see the section below.
28. Share your successes in fox resource management with others (e.g., in a blind and using a call).
29. Take notes on successes and failures and share them with others to allow improvements.
30. Make projections of future land use (10 to 100 years) and estimate the probable fox populations. Make similar estimates for human attitudes toward the fox and for wildlife agency activities. Adjust current activities on the land to be in line with those projections.

The Knowledge Base

While much is known about the gray fox, there are key pieces of information needed. While it is not the mission of the base, the DoD, or private land owners to study the fox in order to gain these missing pieces, there are strategies for supporting such work. Strategies exist for encouraging advances to be made by others, to join in cooperative studies that will serve many bases and society in general, and for forming cooperatives with nature and sportsperson groups to add to a knowledge base. The knowledge base is a phrase for research but, importantly, it includes surveys, inventories, and collections of observations made by experts and by almost any reasonable person in the field. The vast number of person-hours spent by instructors, trainees, and other observers in the area can produce invaluable observations that are never called "research" but add to knowledge about the fox.

The following are suggested as priority areas for studies and efforts (and not exclusive) to add to the knowledge base:

Title:Baseline Studies: The Gray Fox

Objectives:

1. To describe ecological baseline studies, their meaning, use, and relevance.
2. To describe baseline gray fox population abundance estimates and a system for continual studies.
3. To determine maximum population density limit and the reasons for that limit.
4. To develop an estimator for probable gray fox occurrence by Alpha Unit.
5. To list the area-specific zoonoses of the gray fox.
6. To determine the role of land snails, crayfish, and early succession fauna in the fox diet.
7. To determine the effects of fox observation (by tourists, nature observers, and researchers, e.g., using electronic calls) on fox population distributions and densities.
8. To determine the effects of rodent management (increasing, stabilizing, and decreasing) on fox population densities.
9. To determine the effects of dens and den structures on population densities.
10. To determine the effects of wildfire on fox populations.
11. To determine the relations of deer population density to fox population density.
12. To develop models that may relate fox population changes to global warming, to increases in coyote populations, and to changes in the intensity of using the firing range.
13. To develop theory of ecological energetics of the omnivore, the fox being a paradigmatic animal.

John J. Cobb, a student of Professor Robert H. Giles, Jr. in a class library-use assignment at Virginia Tech (1992), developed the above concepts. They were later further developed by Kevin Cox, A. Nicole Bryant (1997), Christine A. Tedrow and Dr. Giles for Fauna01 and SSM

References

Hewson, R. 1986. Distribution and density of fox breeding dens and the effects of management, J. Applied Ecology 23: 531-538

This Web site is maintained by R. H. Giles, Jr.
Last revision May 26, 2006.