Scientific name: Mephitis mephitis
Common name: Striped skunk
"Mephitis" is Latin for "noxious vapor" and is an extremely appropriate name for this shy, unassuming member of the mustelid ("weasel") family of carnivores. The ability of the skunk to use its mercaptan rich musk as a defensive spray has been well represented in fiction and in the real life experiences of many people (not to mention their dogs).
Both adult and immature skunks have distinctive black bodies with sharply contrasting, attention getting double, white stripes down their backs which join at the head and then finish as a narrow white strip down the center of the face. Colors of individual skunks may range from all black, to the common striped pattern described above, to, in very rare individuals, all white. Males and females have identical coloration patterns. The skunk's coat coloration is designed to make individuals very conspicuous and obviously identifiable by potential predators.
Adult skunks are 20 to 31 inches long including their stout, bushy, white-tipped, 7 to 10 inch-long tail. Body and tail lengths are quite similar in both males and females, but males are typically 15% to 30% heavier. Weight ranges are between 3 to 12 pounds. Skunks reach their full growth by their second summer and will undergo regular weight fluctuations with the seasons (up to 26% weight loss over the winter). Front paws differ in appearance from the back paws and have long, sharp claws specialized for digging.
The skunk is a slow, deliberate creature that is capable under extreme need of a clumsy gallop that can reach up to 10 mph. It is a poor climber but is capable of swimming. Its sense of sight, smell and hearing are also poor but it is reported to have a very acute sense of touch. It is a nocturnal animal typically becoming active just before sunset and inactive just prior to sunrise. During this nighttime activity period it often takes a single rest period of one to two hours usually away from its sleeping den. Juveniles still residing in the maternal den are most typically active during the day while the adults are sleeping. These juveniles typically do not stray far from the den opening and probably actively feed on the milk of the sleeping mother during the day.
Skunks make a variety of vocalizations that include hisses, growls, squeals and cooings. They are solitary creatures except during the brief mating period of late winter or early spring. Adult males are especially active during this mating season and will travel widely in search of a receptive mate. During this time large numbers of male skunks are killed on roads and highways. Males fighting over females are extremely aggressive but do not use their spray as a weapon in these encounters. Skunks typically range a half-mile in all directions from its sleeping burrow, but some males have been tracked traveling up to two miles from their dens. Foraging territories apparently overlap extensively for both males and females.
The defensive spraying of musk from its anal scent glands is one of the best known behaviors of the skunk. Musk is a thick, cream to yellow colored liquid that is rich in sulferous mercaptans. The scent glands are found just beneath the skin on either side of the rectum. Each gland has a long,
nozzle-like secretory duct that runs out through the anus. The skunk is able to use its hip muscles to squeeze down on the glands to forcefully expel the musk. The spray can travel up to 12 feet and go in any direction that the skunk can point its anus. The scent glands contain enough musk for five or six jets of spray. The skunk often attempts to bluff a potential predator with foot drumming, snarling and tail raising in order to conserve the musk. Great horned owls actively take skunks and seem to be unaffected by the musk. Skunks are eaten by foxes, dogs, bobcats, coyotes, or cougars only very occasionally.
Skunks are found in all 48 contiguous states and also in northern Mexico and southern Canada in a wide variety of habitats from woods, to grasslands, to deserts, to farmlands, to suburbs. In Pennsylvania skunks are most abundant in farmlands and are not only tolerant of humans but may be dependent upon them for appropriate habitat generation. Skunks utilize dens of a variety of structures and possible locations. The dens may be above ground (as in logs, stump holes, culverts, woodpiles, or rock piles) or subterranean. Skunks may dig their dens or use abandoned woodchuck burrows. Skunks also den underneath buildings especially if the space under the building is well enclosed. The typical skunk den consists of a central chamber twelve to fifteen inches in diameter, approximately three feet underground, lined with dry grasses and leaves, connected to the surface by one or more tunnels that are five to fifteen feet in length. Winter dens tend to be either subterranean with a single entrance tunnel or underneath buildings in very well enclosed spaces. Summer dens are much more casual in their construction and may simply consist of some aboveground refuge.
Skunks do not hibernate, but do undergo a torpid state in their winter dens during the cold days and nights of the winter (see "Exploring Hibernation"). On warmer, winter days the skunks may emerge from their dens to search for food.
Skunks eat whatever foods are available. In the spring and summer, insects (both adult and larval forms), spiders, toads, frogs, lizards, snakes, mice, chipmunks, turtle eggs and bird eggs are eaten. In the fall and winter, a variety of wild and cultivated fruits, carrion, and a variety of grasses, leaves, buds, and nuts are consumed. Skunks also eat birdseed and readily raid garbage containers in urban and suburban areas.
Skunks breed in February and March (mentioned above) and after a sixty day gestation period, give birth to a litter of pups in April or May. Older females come into estrus earlier in the season than younger females and, therefore, have their litters earlier in the spring. Older females also tend to have larger litters. Females can breed in their second summer. In a typical population of skunks the great majority of the females will be pregnant or will have just had litters. Typically a litter consists of four to seven pups. These young are born blind and hairless although the black and white pattern is observable on the skin of the newborns.
Life expectancy of a skunk in the wild is two to three years. In captivity, skunks can live up to ten years. Mortality factors include disease, accidents (especially road and highway deaths), starvation, and trapping. Skunks also represent a significant wild reservoir of the rabies virus and can, through the spread of this virus, have deleterious impacts on humans.