The red fox is the most widespread carnivore species in the world ranging across the entire Northern Hemisphere. They measure about 35–40 inches from the tip of the nose to the tip of the tail. Adults typically weigh 7–15 pounds, but may appear heavier. They are recognized by their reddish coat and black “leg-stockings.” Red is the most common coat color, but individuals may vary from light yellow to a deep auburn red to a frosted black. The white tip on the tail distinguishes this fox from other species at any age. Similar to cats, red foxes have vertical pupils which help to enhance night vision for hunting. The gray fox is often confused with the red fox because of the rusty-red fur on its ears, ruff, and neck. The overall coloration is gray, with the darkest color extending in a stripe along the top of the back down to the end of the tail. The belly, throat, and chest are whitish. The gray fox appears smaller than the red fox, but the shorter legs and stockier body are deceptive. Compared to the red fox, the gray fox has a shorter muzzle and shorter ears, as well as oval pupils. They measure about 31–44 inches in total length and weigh 7–13 pounds. Gray foxes are one of only two canid species in the world that can climb trees thanks to their hook-shaped claws. They will climb trees to escape predators and to access arboreal food sources.
Both species of foxes breed mid-January to late February and begin to prepare dens during this time. A den is typically a burrow in the earth, 15 to 20 feet long, and usually located on the side of a knoll, but foxes may also set up dens in or under outbuildings, in rock crevices, or, in the case of the gray, even in trees. Dens may have several entrances. Sometimes foxes dig their own dens, but more often they will enlarge the tunnels of small burrowing animals such as woodchucks and skunks. The single, annual litter is born after a gestation period of 53 days. A litter of 4 pups is common. The young leave the den for the first time about a month after birth. The mother gradually weans them, and by 3 months of age, they are learning to hunt on their own. The family unit endures until autumn, at which time it breaks up and each animal becomes independent.
Both the red fox and gray fox are omnivorous. They are opportunistic feeders and their primary foods include small rodents, squirrels, rabbits, birds, eggs, insects, vegetation, fruit, and dead animals. Foxes cache excess food when hunting and foraging are good. They return to these storage sites and have been observed digging up a cache, inspecting it, and reburying it in another spot. Foxes are quite vocal, having a large repertoire of howls, barks, and whines. Foxes are usually shy and wary, but they are also curious. Activity is variable; foxes may be active night or day, and sightings at dusk or dawn are common. They remain active all year and do not hibernate. Foxes actively maintain territories that may vary in size from 2 to 7 square miles. Territories are shared by mated pairs and their immature pups, but are actively defended from non-related foxes. Red foxes can be found in a variety of habitat types, but prefer areas where different habitats—forests, fields, orchards and brush lands—blend together. Gray foxes also prefer a landscape mosaic, but will thrive in dense northern hardwood and mixed forests where they often inhabit thickets and swamps. Foxes typically use the transitional areas between habitat types for most of their activities.