RED FOX
PHYSICAL DESCRIPTION:
The red fox is the size of a small dog, with prominent, erect ears, a pointed nose, and a long, bushy tail (warms face during sleep) with white tip. The fur is long, soft, with the upper part reddish-yellow, black-tipped on the shoulders. The middle of the back, and feet are black, and the underparts, cheeks and inside the ear are whitish. The color varies with the season (relatively paler, shorter in summer). Various color phases includ- ing silver fox, cross fox, may occur in a litter with normal reds. The adult average length is 1000 mm, the tail vertebrae 360 mm, and the hindfoot 165 mm, with a weight from 6-12 pounds.
REPRODUCTION:
The breeding season is from December to February, with a peak in late January. The female is monoestrous, and the male has yearly cycle fecundicity. The female comes into estrus for 1-6 days. The gestation period is 51 days and the litter size is 4-10 with an average of about 5, born from March-April (one Virginia litter was noted in late February) in natal dens. They usually use an old woodchuck burrow, usually with 2 or more entrances. The dens in a Virginia study were an average of 2-4 feet deep, and 10-14 feet in total length. There is a high degree of intraspecific tolerance during denning season (several vixen with litters may occupy the same den). Denning was noted early as late November. They weigh an average of 71-119 grams at birth, and have fine gray-brown fur. The female may, but not always, breed at 10 months (year-lings litters are smaller). Most males can breed the 1st year.
BEHAVIOR:
The young’s eyes open in 9 days, and they walk in 3 weeks. They come to the den entrance around 5 weeks, and are weaned in 8-10 weeks. There are many changes in the pelage until they are reddish-brown at about 14 weeks. The juvenile male is larger, and the pups are full size in about 6 months. The male may bring food to the den until the female can leave the pups for a short time, then they both hunt. They remain with the pups until dispersal. The pups are often moved to at least one alternate site from the natal den. The young explore the parents home range by 2 weeks, with dispersal from late August- October, males first and farther. They move greater distances in the fall, and winter. They are generally (not exclusively) nocturnal, especially in the summer (relatively more diurnal in winter) with a tendency toward crepuscular peaks. It exhibits synchrony with prey species’ patterns. Winter activity is inversely related to snow depth, and summer activity is inversely related to precipitation. The home ranges tend toward linearity, and may be associated with habitat features. There is a tendency to overlap but there is also some evidence of non-overlapping suggesting seasonal territorial behavior among females. The size is influenced by food abundance, habitat diversity, and natural barriers. They are non-migratory, and usually use the same area for life. Density ranges from 2-8/square mile, and in good fox range: 12-20/square mile. Overall, the male is more solitary than the female. They hunt in fields and along their edges where the highest densities of their principal prey are (field mice and rabbits). They readily eat other foods that are abumdant and available such as plants, birds, and insects. Any fox that is active during the day, especially if it is acting strangely, should be avoided (may be diseased).
ORIGIN:
This species is a hybrid or ‘stocked’ animal, which was introduced around 1750 for recreational purposes.
POPULATION PARAMETERS:
There is much conflicting data on sex ratios, but overall they are relatively equal for fetuses but numerous unexplained variations are noted for different age groups, and seasons. There is a change toward a higher proportion of females from fall to spring, which may reflect a greater susceptibility of males to shooting and trapping. There are some reports of the population being made up of over 70% young. There is little mortality from spring to fall in the 1st year. There are 3 major mortality causes: hunting, trapping, and road kills. The latter increases toward the end of the summer as dispersal begins, and more juveniles are killed by autos and farm machines. Longevity is variously given as about 5 years, with the average life span under 1 year with few over 3-4 years.
AQUATIC/TERRESTRIAL ASSOCIATIONS:
There is a high degree of tolerance between red fox and woodchuck, which may occupy the same dens. They are an important control for rodent populations. They can also carry a number of diseases including mange, canine distemper and rabies.
LIFE HISTORY COMMENTS:
The weight of this species in Virginia, west of the Blue Ridge, is 8-10 pounds, and east of the Blue Ridge 8 pounds. The pups are born in the first two weeks of March. When food availability is reduced in an area, they will kill woodchucks (while rearing young). Thirty groundhog carcasses have been found at one den site. They will prey on gray foxes in its home range. They will prey on lambs when first born (gray foxes do not) and on turkeys (especially on turkey producing farms). They are detrimental to a rabbit population while rearing young.
GREY FOX
PHYSICAL DESCRIPTION:
This species is slightly smaller than the red fox, and the fur is grizzled gray above, white to ashy below, and lighter gray to reddish on the neck and sides. It has a long bushy tail with a median black stripe, and a black tip. The weight is from 7-13 pounds or more, with an average of about 8 pounds. Virginia adults have a total length from 868-965 mm, tail vertebrae 280-430 mm, and hind foot 130-140 mm.
REPRODUCTION:
This species is monoestrous, and the breeding season is from January-April with peaks in February. The gestation period is uncertain but it is between 51 and 63 days. They have 2 to 7 (average 3-5) blind, nearly hairless young which are born from March-May in a whelping den which may have grass, leaves or bark as nesting material. They are often in dense cover within 1/4 mile of water. They are sexually mature 1 year after birth, and many but not all females breed their first year.
BEHAVIOR:
The eyes of the young open in 10-12 days, and they stay in the den for the 1st month. Both parents bring food and they forage with the parents at first. Family ties begin to weaken in July, but they remain within the parents range until winter. Daily periodicity is primarily nocturnal, crepuscular. The home range varies with many factors. They are 1.6 km wide in the denning season
to 8 km wide in the fall. There is some range overlap. Mobility is greatest in the fall or winter. Foraging paths are erratic, and they speed over a short distance to 28 mph. They are an adept climber, and use trees to escape enemies. They make less use of underground burrows than the red fox. They will often use the burrows of woodchucks as dens, but they also use hollow trees, rocky crevices, brush piles, and banks. They pounce their prey and use a quick bite-and-toss motion. They forage over an area from 1-5 miles. If the prey is small it is eaten immediately but a rabbit or a squirrel will be taken to a protected site to be eaten. They can run up to 25 mph if they are disturbed. Barks, yaps and yips are the frequent vocalizations. Foxes that do not run when approached should be avoided as they may be rabid.
ORIGIN:
This species is native to Virginia.
POPULATION PARAMETERS:
This species has high fertility and mortality, one study of natal mortality showed 32%, and another study showed the pup death probability the 1st summer as 0.5, the 1st winter 0.9, and for succeedings years 0.5. Populations are ‘annual crops’. Population fluctuations have a positive correlation with wetter, warmer Augusts and late winters. Rabies may be a density dependent control mechanism. Longevity may be approximately 4 years in the wild. They have lived 10 years in captivity.
AQUATIC/TERRESTRIAL ASSOCIATIONS:
Larger hawks occasionally take pups. Adults may be preyed upon by eagle, bobcat and coyote. They may also be killed by dogs. They are very closely associated with deciduous forests. They are beneficial because they eat insects and a large number of rodents.
LIFE HISTORY COMMENTS:
The voice is heard mostly in February (breeding season) and late summer (pups learn hunting). The pups are born from April-May in Virginia. Occasionally, red foxes will kill gray foxes.