Gray Fox
"Urocyon Cinereoargenteus"
Order - Carnivora Family - Canidae

Gray fox are widely distributed in the United States. This fox prefers brushy or forested habitats, and is unique in that it is a skilled tree climber. Gray foxes have small ranges and commonly take advantage of whatever type of food is available at the time. Gray foxes are often more aggressive than red fox and an abundance of gray fox will prevent an abundance of red fox in the same habitat.

Description
The gray fox is often confused with the red fox because the gray has rusty-red fur on its ears, ruffs and neck. Overall coloration is gray, and the darkest color extends in a suggested stripe along the top of the back down to the end of the tail. The belly, throat, and chest areas are whitish in color.
Gray fox appear smaller than red fox. The shorter leg length and stockier body are deceptive. Many gray fox weigh about the same as red fox in the same habitat types. Males and females both weigh 8 to 11 pounds on average. Weights are often about 8 pounds in southern states, and nearer 11 in northern states. Compared to red fox, grays have shorter muzzles and shorter ears which are usually held erect and pointed forward. Many grays stand about 15 inches tall at the shoulders and overall lengths are around 40-44 inches including a tail of 12 to 15 inches.
The claws on a gray fox are strong. They are not retractable. Gray Fox have dark eyes with elliptical pupils. Teeth number 42, including 4 canine teeth. Both male and female gray foxes have a scent gland under the skin on the top of the tail.

Reproduction
Gray fox are thought to mate for life. The breeding season extends from January to May, with peak periods around the first of March. Gestation varies from 51 - 63 days.
Most gray fox breed and raise litters during their first year of life. There is one annual litter and 3 or 4 pups are a common litter size. Male gray fox bring food to the denned up female and assist in teaching the pups to hunt.

Habits
Gray fox seldom are seen because they are normally active only during the night and because of the brushy habitat they frequent.
Gray's are very territorial. These home ranges are usually one square mile or even less. Because a gray fox might spend years or even its entire life in this small range, they soon learn to know their ranges very well. Travelling habits are erratic as the gray fox seems to wander within its territory seeking foods. This species will eat a variety of foods, including whatever food is available at the time. If food is abundant, gray fox will become fatter and heavier than usual.
The tree climbing ability of gray fox is unique. Grays can climb trees that are straight up and they do not require leaning trees to climb. These fox will climb trees at times to escape predators and they also climb because they seem just to like to. At times, gray fox will climb trees to take a nap in a sunny location, and they have been known to hide or sleep in hawk and owl nests. Rarely, gray fox will also raise their litter twenty or more feet above ground in a hollow tree. Gray fox climb trees head first, and they have the ability to descend a tree either tail first or head first.
Gray fox use dens more frequently than do red fox. These dens are usually underground cavities, and the same dens are often used year afer year. Dens seem to be used more frequently by gray fox in northern locations, as compared to southern location. Cold weather and deep snow hamper gray fox, so a likely explanation is that the dens provide more warmth for the northern grays.
Dispersal distances of young gray fox are short. Most young grays relocate and select new home ranges within a mile of their birthplace. For that reason, high densities of gray fox can sometimes be found in suitable habitats.
Although gray fox have a keen sense of smell, they seldom track prey species. The preferred method of hunting is to wander this way and that until a victim is heard or smelled. The gray fox will often stalk and pounce upon the prey. Meat items frequently eaten by gray fox include rabbits, mice, squirrels, rats, and insects. Game birds are frequently eaten, including quail, turkeys and ruffed grouse. Nesting adults are frequently killed, and all ground nests are vulnerable within the territory of a gray fox. Grays will eat carrion and vegetation eaten includes virtually all fruits, nuts, and berries.

General
Gray fox contribute to the overall health of prey species by keeping the prey species controlled. They are usually very beneficial to man because of their preference for wild foods. The number of rodents eaten outweigh a very rare visit to a farmyard where a chicken might be vulnerable. In southern states, goodly numbers of cotton rats are eaten. These rats do prey upon quail nests, so the net effect might be that the grey fox also serves the quail in spite of the fact that they also eat quail and rob nests as well.
Gray fox are able to resist mange. A more important disease of grays is distemper, which is oftentimes fatal. This disease can decimate gray fox populations whenever there is opportunity for contact between individual animals. Gray fox are also susceptible to parvo enteritis, rabies, roundworms, tapeworms, lice and mites.
Some of the worst enemies of gray fox are dogs. Significant numbers of grays, particularly juveniles, are killed by dogs before they escape to a hole or are able to climb a tree for safety. Mountain lions kill grays as do golden eagles. Coyotes are also serious predators whenever the two species share the same habitat.
Gray fox are considered as old at 12 years of age.

Source: NTA Trapping Handbook by Tom Krause