Mephitis mephitis (Striped Skunk)
Written by Karah Gallagher (Mammalogy Lab--Fall 2003)

Edited by Karah Gallagher and Jennifer Bailey

Map prepared by Greg T. Lewellen

The striped skunk (Mephitis mephitis) has a geographic range covering virtually all of North America (Hall 1970).  The range stretches from the southern provinces of Canada to the northern states of Mexico (Hall 1981). For Texas, the striped skunk is considered to be distributed statewide, although there is not a record to document its occurrence in every county (Davis and Schmidly 1994). Elevation for striped skunks ranges from sea level to 1,800 m (Hall 1981).

Photo courtesy Texas Parks & Wildlife © 2003

Physical Characteristics:

Striped skunks are about the size of a domestic cat (Felis catus) with small, round ears and small, black eyes. Their legs are stubby with five toes on each foot. The front feet are equipped with long, curved claws. The tail is long, bushy, and may exhibit white hairs in some areas. As a member of the family mustelidae, the striped skunk is unique in pelage coloration. Typically, the pelage is black with two white dorsal stripes extending down the sides of the tail forming a “V” when looking at the striped skunk head-on (Davis and Schmidly 1994). The tip of the tail is usually black, but patterns vary greatly from little white to almost completely white dorsally (Stains and Stuckey 1960). Mutations for pelage are common including seal brown, white, and yellow. A color of black, blue, or silver may also be produced (Detlefsen and Holbrook 1921). Males and females do not differ in pelage coloration. The dental formula for striped skunks is i 3/3, c 1/1, p 3/3, m 1/2 =34 total. For external measurements, males are often larger than females. Length (mm) measurements for males and females are as follows: total 680, tail 250, hind foot 90 and 610-225-65, respectively. Weights for males and females vary from 1.4-6.6 kg according to age and percent body fat (Davis and Schmidly 1994).

Natural History:

Food Habits: Striped skunks are regarded as nest predators (Greenwood et al. 1999). The primary prey of the striped skunk, however, is insects with bird eggs being consumed only when available. The most common insects eaten are ground beetles, noctuid moths, scarab beetles, and carrion beetles (Greenwood et al. 1999). Seasonal food analyses showed: (Fall) insects 76%, arachnids 24%; (Winter) insects 52.3%, vegetation 22%, small mammals 18.3%, arachnids 5.3%, reptiles 1.6%, birds and millipedes 5%; (Spring) insects 96%, small mammals 2%, reptiles 1.6%, vegetation and small birds .4%; (Summer) insects 88%, arachnids 4%, small birds 3.5%, centipedes, small mammals, and vegetation 3%, reptiles 1.5% (Davis and Schmidly 1994). Oddly, bees have been found in large numbers in the diet of the striped skunk. Apiaries seem to have a problem with striped skunks reducing their bee numbers. The striped skunk will scratch at the door of the hive box until the bees become angered and exit the box. The striped skunk then beats the bees with its forepaws and eats them. They will also eat the dead bees that have been removed from the hive and deposited outside the box by the colony during the day. Although the striped skunk receives many stings, this does not seem to discourage them from coming back night after night (Storer and Vansell 1935). Another strange eating habit is the dehairing of caterpillars. The striped skunk will roll the caterpillar on the ground with just enough pressure to remove the hairs. This procedure is also carried out with toads to allow the dirt and pressure to remove the poison on the toad’s skin. In both cases, the striped skunk shakes the animal to remove the dirt before eating it (Schmidt 1936).

 Reproduction:  Reproduction for the striped skunk occurs throughout February and March. But, female striped skunks can have a second litter during May (Parks 1967). The gestation period is 59-77 days (Wade-Smith and Richmond 1978). After becoming pregnant, the female builds a nest but removes part of it before parturition so that the kits do not become entangled (Verts 1967). Parturition occurs in May and June with litter sizes of 5-8. The female striped skunk has a high pregnancy rate, becomes pregnant year after year, and is reproductively active at a young age (Greenwood and Sargeant 1994). The female striped skunk plays an active role in parturition. She physically ruptures the individual embryonic sacs of her young and disconnects the umbilical cords. After each kit is born, she cleans both the kit and herself before expelling the next kit (Shadle 1956). The kits open their eyes around day 22 and their external auditory meatuses open around day 24-27. Musk is present at birth and can be emitted around day 8 but is not directed at any certain object until the eyes open. As for males, they only show interest in females that are in estrous in which they have not previously mated and provide no parental care (Verts 1967).

 Behavior: The striped skunk is known for its unusual method of self-defense, but is actually quite docile (Verts 1967). When threatened, the striped skunk emits a vile-smelling musk ejected from a nipple on each of the two anal glands. Unless surprised, the striped skunk will rarely spray without ample warning. Muscular contractions can propel the musk 3 m and because each gland can hold several ml of oil, repeated discharges are possible. This chemical spray is rich in thiols, thioethers, and disulfides (Andersen et al. 1982). Striped skunks can also produce loud vocal sounds such as growling, squealing, and hissing (Laun 1962). Jumping has been observed as a playful threat. The striped skunk will stomp with its feet, run forward 2-3 paces, stomp hard with its front feet, and throw its hind quarters straight up in the air with its tail hanging forward and down to one side (Seton 1920). Striped skunks can swim but usually avoid water (Verts 1967). Running speeds can reach 16.5 km/h (MacLulich 1936). The striped skunk is nocturnal, but may frequently be seen in late afternoon or on cloudy mornings (Cuyler 1924). For daytime retreats, striped skunks den in above ground areas such as buildings, brush piles, and culverts. The type of retreat used is different for different seasons. In the summer and spring above ground retreats were used and in the winter and fall underground dens were used such as under large boulders or in abandoned armadillo and fox burrows (Storm 1972). In the winter, a dormancy period occurs (Mutch and Aleksiuk 1977) where popular denning sites are farmsteads and buildings (Lariviere et at. 1999). Rabies is commonly found in striped skunks and is associated with abnormal behavior. Aggression and attacks are aimed at anything that comes near an infected animal and nocturnal behavior turns to diurnal, but traveling distances remain the same for infected and non-infected striped skunks (Storm and Verts 1966).

 Habitat:  Although, striped skunks exhibit non-random use of spatial elements in fragmented landscapes, they are classified as generalist species in their ability to use a variety of habitat types (Gehring and Swihart 2003). Striped skunks select undisturbed habitats where ground litter accumulates. The most preferred habitat is one in which waterfowl nest (wetlands) followed by woodland areas and lastly croplands (Lariviere and Messier 2000). The landscape context of the wetland edges influences selection also. Agricultural-wetland edges are chosen over wetland edges within planted cover (Phillips et al. 2003). Home range size is influenced by season and body weight: skunks have larger ranges in the spring than in the winter and heavier females have larger ranges (Bixler and Gittleman 2000). Movements of individuals and distribution of den sites indicates that striped skunks, irrespective of sex or size, prefer edge habitat in comparison to forest or field (Bixler and Gittleman 2000). When food abundances are high, female striped skunks show smaller space-use patterns (Lariviere and Messier 2001).

In the past, the pelt of the striped skunk had commercial value resulting in extensive trapping. Today, they can pose a threat because they are an important carrier of rabies (Verts 1967). Another potential problem of today is that the striped skunk can become infected with Streptococcus equisimilis, causing necrotizing purulent pneumonia and/or suppurative meningoencephalitis. This will cause the striped skunk to become weak and disoriented and can lead to death. If humans come into contact with an infected striped skunk, the skunk may attack (Hwang et al. 2002).

Conservation Status:

The striped skunk is in no way rare, threatened, or endangered. Management implications are of more importance. Because they can cause reduced populations in waterfowl and bees, inhabit farm buildings, expel musk when encountered by dogs or humans, and carry diseases the striped skunk is frequently poisoned, shot, or trapped for relocation. Aside from humans and automobiles, the striped skunk has no true predators.

References:

Andersen, k. k., d. t. bernstien, r. l. caret, and l. j. romanczyk  jr. 1982. Chemical constituents of the defensive secretion of the striped skunk (Mephitis mephitis). Tetrahedron 38:1965-1970.

 Bixler, a. and j. l. gittleman. 2000. Variation in home range and use of habitat in the striped skunk (Mephitis mephitis). Journal of Zoology 251:525-533.

Cuyler, w. k. 1924. Observations on the habits of the striped skunk (M. mesomelas varians). Journal of Mammalogy 5:180-189.

Davis, w. b. and d. j. schmidly. 1994. The Mammals of Texas. University of Texas Press, Austin.

Detlefsen, j. a. and f. m. holbrook. 1921. Skunk breeding. Journal of Heredity 12:242-254.

Gehring, t. m. and r. k. swihert. 2003. Body size, niche breadth, and ecologically scaled responses to habitat fragmentation: Mammalian predators in an agricultural landscape. Biological Conservation 109:283-295.

Greenwood, r. j. and a. b. sargeant. 1994. Age-related reproduction in striped skunks (Mephitis mephitis) in the upper Midwest. Journal of Mammalogy 75:657-662.

Greenwood, R. J., A. B. Sargeant, J. L. Piehl, D. A. Buhl, And B. A. Hanson. 1999. Foods and foraging of prairie striped skunks during the avian nesting season. Wildlife Society Bulletin 27:823-832.

Hall, E. R. 1970. Studies of Tertiary and Quaternary Mammals of North America. Johnson Reprints, New York.

Hall, E. R. 1981. The Mammals of North America. John Wiley and Sons Publications, New York.

Hwang, Y. T., G. Wobeser, S. Lariviere, And F. Messier. 2002. Streptococcus equisimilis infection in striped skunks (Mephitis mephitis) in Saskatchewan. Journal of Wildlife Diseases 38:641-643.

Lariviere, S. And F. Messier. 2000. Habitat selection and use of edges by striped skunks in the Canadian prairies. Canadian Journal of Zoology 78:366-372.

Lariviere, S. And F. Messier. 2001. Space-use patterns by female striped skunks exposed to aggregations of simulated duck nests. Canadian Journal of Zoology 79:1604-1608.

Lariviere, S., L. R. Walton, And F. Messier. 1999. Selection by striped skunks (Mephitis mephitis) of farmsteads and buildings as denning sites. American Midland Naturalist 142:96-101.

Laun, H. C. 1962. Loud vocal sounds produced by striped skunk. Journal of Mammalogy 43:432-433.

MacLulich, D. A. 1936. Running speeds of skunk and European hare. Canadian Field Naturalist 50:92.

Mutch, G. R. And M. Aleksiuk. 1977. Ecological aspects of winter dormancy in the striped skunk (Mephitis mephitis). Canadian Journal of Zoology 55:607-615.

Parks, E. 1967. Second litters in the striped skunk. New York Fish and Game Journal 14:208-209.

Phillips, M. L., W. R. Clark, M. A. Sovada, D. J. Horn, R. R. Koford, And R. J. Greenwood. 2003. Predator selection of prairie landscape features and its relation to duck nest success. Journal of Wildlife Management 67:104-114.

Schmidt, K. P. 1936. Dehairing of caterpillars by skunks. Journal of Mammalogy 17:287.

Seton, E. T. 1920. Acrobatic skunks. Journal of Mammalogy 1:140.

Shadle, A. R. 1956. Parturition in a skunk, Mephitis mephitis hudsonica. Journal of Mammalogy 37:112-113.

Stains, H. J. And D. Stuckey. 1960. Brachial-antebrachial stripes on a striped skunk. Journal of Mammalogy 41:139.

Storer, T. I. And G. H. Vansell. 1935. Bee-eating proclivities of the striped skunk. Journal of Mammalogy 16:118-121.

Storm, G. L. 1972. Daytime retreats and movements of skunks on farmlands in Illinois. Journal of Wildlife Management 36:31-45.

Storm, G. L. And B. J. Verts. 1966. Movements of a striped skunk infected with rabies. Journal of Mammalogy 47:705-708.

Verts, B. J. 1967. The biology of the striped skunk. University of Illinois Press, Urbana.

Wade-Smith, J. And M. E. Richmond. 1978. Reproduction in captive striped skunks (Mephitis mephitis). American Midland Naturalist 100:452-455.