Scientific Name: Urocyon cinereoargenteus
The gray fox is easily distinguishable from the red fox in that they have a mane of short, stiff black hairs along the back leading to a black-tipped tail. Coloration of their upper-parts appears grizzled as a result of multi-colored guard hairs. The remainder of their pelage is usually a variation of reds and browns with buff or gray underfur. Their face is distinctly marked with white, black, and rufous coloration. Total length, including the tail ranges from 31-44 inches and weight ranges from 7-13 pounds, with little difference between males and females.
The claws on the front paws have a greater curvature and they have a greater ability to rotate their forearm more than that of the red fox. These are two morphological features that may serve as adaptations for tree climbing. One classic postmortem means of identification lies in the temporal ridges along the top of the skull. When viewed from above they form the shape of a U and do not contact the sagittal crest along the back of the skull.
Distribution and Habitat
Ranging across New York State, gray fox inhabit a mixture of deciduous woodlands, brushy and rocky areas. Old fields bordering extensive forested areas and interspersed with farmlands may serve as ideal foraging grounds.
Food and Feeding
Small mammals make up the majority of the food base of the gray fox. Mice, voles, and cottontail rabbits serve as staples but they have been known to eat birds, amphibians and reptiles, various arthropods, and carrion. They will also forage for a variety of hard and soft mast such as acorns, grapes, apples and in farm country, corn.
Breeding occurs between mid-January and May. The gestation period may range between 51-63 days. Pups are usually born in a den in March or April, nearly hairless, blind and helpless. Single litters contain 2-7 pups. Weaning occurs between 8-10 weeks of age, at which time they venture out of the den, and begin hunting with the parents by 3 months. Families disperse in the autumn when young are nearly full-grown. Males reach sexual maturity sooner than females, but both are capable of reproducing in their first year.
Gray fox dens may be in use any time of year, but the majority of use comes during the whelping season, or the time of year when birthing occurs. Dens are usually located in wooded or brushy habitats, and are generally less obvious than that of a red fox. They do not excavate their own den and infrequently use abandoned dens of woodchucks or other small mammals. They prefer to use hollow logs or trees, rocky outcrops, or thick brush. They will also use abandoned houses or beneath manmade structures such as sheds or abandoned woodpiles as both temporary dens and a place to rear their young.
Tree climbing is one of the most notable adaptations in the gray fox. Gray fox have been reported to den several yards above the ground. This is not only advantageous in escaping predators such as coyotes, it may also improve their ability to find food. By gripping the bole of the tree with their front paws, and as they push off with their hind feet, they will let go with their front and re-grip the bole of the tree higher up. Once they're up in the crown they tend to jump from branch to branch. Descent is backwards or if the tree is leaning they will run down the trunk of the tree.
Due to their more aggressive behavior, Gray fox prefer to hunt thicker cover than the more timid red fox. The gray fox's preference for thicker cover, aggressive behavior, and the ability to climb trees minimizes the effect that eastern coyotes have on their population. The red foxes preference for open terrain where they are more visible and farther away from cover allow coyotes to suppress red fox populations where coyotes are abundant.
Predators, Parasites, and Disease
Across its range the gray fox serves as a host to over thirty different external parasites that includes lice, ticks, mites, chiggers and fleas. Internal parasites include roundworms, flatworms, tapeworms and acanthocephalans.
Unlike the red fox, the gray fox exhibits a natural resistance to sarcoptic mange, a mite that causes irritation resulting in a thickening of the skin, loss of hair, and eventual death due to either malnourishment or hypothermia. Rabies has been reported in New York specimens, but canine distemper appears to be the leading mortality factor, in terms of diseases, affecting wild gray fox populations.
In terms of predators, humans are likely the primary cause of mortality in this species through trapping and automobile collisions. Where encounters occur, the Eastern coyote will undoubtedly predate gray fox, as may bobcat and some of the larger raptors such as great horned owls.