Mephitis mephitis - The Striped Skunk

Skull Pictures:        
Anterior     Mandible
Dorsal       Ventral
Lateral

Physical Description:

The Striped skunk is similar in size to a normal house cat with a stout body, short legs, small head and a bushy tail.  They can weigh from around 2 ½ lbs to over 10 lbs.  They have an average overall length of between 21 and 27 inches.  The males are typically larger than females.  The tail averages between 9 and 13 inches (E-Nature).  It has a long, black fur coat with two wide white stripes that run up the back and converge at the base of the tail.  There is also a single white stripe that runs the length of the body that starts on the head and continues to the very tip of the tail.  Some striped skunks are variable in coloration.  Some maybe almost totally black with a few spots of white, while others could be mostly white. It has long nails adapted for digging, particularly in the front feet. 

There are three other skunks that belong to this subfamily.  They are the hooded skunk, spotted skunk, and the hog-nosed skunk.  The hooded skunk looks the closest to the striped skunk.  The hooded skunk has white fur on the top of the head, along the back and all over the tail.  The underside of this skunk is black.  The spotted skunk is smaller in size than the striped skunk and has elongated white spots on its back, head, and shoulders. Lastly, the hog-nosed skunk looks similar to the hooded skunk, but has a long snout with a broad nose pad.

Distribution:

The striped skunk is found throughout North America from central Canada to northern parts of Mexico.  It is also found from coast to coast, as well. It is found through the state of Wisconsin and the Midwest. The striped skunk is the most wide spread of all the skunk species.

Adults skunks have a smaller home range and travel shorter distances during the nighttime activity periods than those skunks found in rural population.  Skunks do tend to avoid high density residential, commercial, and agricultural areas, but can be found using many different types of areas.  In Stevens Point, striped skunks were found to habit woodland, low density residential, and old-field areas during the nighttime hours (Innvaer 1985).

Ontogeny and Reproduction:

Striped skunks typically breed during the months of February to early April.  The females use delayed implantation for about 19 days. There is a gestation period of about 62 to 66 days.  The young are born typically in late April or early May.  The liter size ranges from 2 to 10 babies. The babies are born blind, deaf and almost naked with very fine hairs that show their black and white colors.  They weigh, on average, about 15 grams at birth.  The babies begin to open their eyes and crawl around their burrow at around 3 weeks. The young are weaned from their mother at about 2 months of age.  They will remain with their mother for the rest of the season, until the next autumn. They will then either den with their mother for the winter or go their separate ways.

Habitat:

Striped skunks can live almost anywhere.  It can live in deserts, mixed woodlands, wetlands, grassy plains, and even in suburbs.  It also can be found along the edge of agricultural lands and along river valleys.  They are typically found never more than 2 miles from some source of water. They can dig their own burrows or will confiscate an abandoned burrow made by a groundhog or badgers.  If a skunk digs its own den it is usually simple, but one taken over from another animal may be quite elaborate. There may be from one to five well-hidden openings that lead to a system of tunnels and chambers. One of the chambers is lined with leaves and used for a nest. The leaves may also be used to plug the openings to the den in cold weather. A skunk gathers leaves by placing them under its body and then shuffling along to the den with the leaves held between its legs as it moves. Some other den sites may include stumps, caves, rock piles, old buildings, junk piles, sheds, wood piles, and dry drainage tiles or storm sewers.  There are normally 5.2 skunks per square kilometer of agricultural land.  In the Midwest skunks are said to have a one mile squared home-range (Bartelt 2001).

Food Habits:

Striped skunks are omnivorous, and will eat a variety of plant and animal matter.  Its diet includes insects, small mammals, fish, crustaceans, fruits, berries, nuts, leaves, grasses, and carrion (dead animals).  It will eat anything it can find during that part of the year.  It will also eat eggs of nesting birds, snakes and many different amphibians.  The skunks gorge themselves in the later part of the year to fatten themselves up for the winter. They will even eat wasps and bees, which they kill with their front feet. Although they annoy farmers by raids on beehives and henhouses, it has been estimated that almost 70 percent of a skunk's diet constitutes a benefit to people and only 5 percent is harmful to human property.

Behavior:

The skunk is not well adapted to get away from its predators or enemies, so they developed the most well know defense of any animal on the planet.  It sprays a foul-smelling musk from twin vents located on either side of its rectum.  When the tail comes up, the normally retracted nipples protrude, ready to spray.  Before it actually sprays, the skunk will stamp its front feet as a warning to the intruder or predator.  Then if the threat persists, it will then raise its tail and turn its body into a “U” shape with its tail facing towards its attacker.  It may also hiss as another threat.  It motions to spray before it actually sprays. A yellowish musky fluid is sprayed into its attacker’s eyes, up to four meters away.  The skunk can spray repeatedly for up to 8 times.  It sprays in an angled stance so that it can keep an eye on its target.  It can even spray over the top of its back at some danger.  The odor can be detected up to a mile away.  The musk can cause extreme irritation in the eyes and if ingested, it can cause severe internal problems and nausea.  It can cause temporary blindness, headaches, uncontrollable tearing, nasal drainage, and salivation.  The musk or spray is produced at a pace of 1.3 oz per week, so the skunk saves its spray as much as it can.  The skunks develop its ability to spray at 8 days of age.

Skunks are mostly nocturnal and sleep during the day.  They begin activity about 1 hour after sunset and return back to their dens about 1 hour before sunrise (Innvaer 1985).  They forage within about 800 m of the den, but may venture as far away as 2 km in a night. Males become more active during the breeding season, when they may travel 8 km a night.  The skunk is active year round and does not hibernate in the winter, but rather during extremely cold weather, it will become temporary dormant.  During this dormant state, the skunk will drop its temperature from 98.6 degrees to 87.8 degrees, not the temperature of its den.  Skunks may den together with as many as 20 skunks in one den, but there are usually fewer than that number in the winter.

Economic Importance:

The skunk may be a nuisance for some beekeepers and poultry men, they are important in agricultural practices.  They help keep the insect populations down and eat grubs that could be harmful for agricultural plants.  Skunks were also trapped for their pelts.  The no striped black skunk’s pelts were in high demand after World War I.  But it the skunks pelt is no longer worth very much.  Another new importance of skunks is their actual spray.  It has been collected the skunk’s spray in small bottles and are using the spray as a bear repellant.  The two bottles are actually two different compound found in skunk spray (thiol precursor and alkaline substance) that when mixed together, create the potent smell.  Also, an Alaskan inventor patented a skunk-smell “personal protector.”  Skunk extract is enclosed in capsules, which are then incorporated into a credit card.  When the card is bent, the foul liquid is squirted onto the human or animal attacker.  The also can mark the attacker and the police can identify the assailants later.

Negative Aspects:

The skunk is the primary wildlife carrier of rabies.  “According to Dr. Thomas Eng of the Centers for Disease Control in Atlanta, during the years of 1980-1988, and average of 2,814 cases of rabies in skunks were confirmed annually” (Petersen 85).  They also contribute to the some possible water foul populations because they raid the nests of these birds.  A study occurred in the Grassy and Mud Lake Wildlife Management Areas in Columbia county, Wisconsin, and in the Horicon National Wildlife Refuge in Dodge county, Wisconsin during March through May of 1984 and 1986 relating the population density of the skunks and number of nest attacked (Bartelt 2001).  Striped skunks also tend to eat garbage left out in urban and rural areas (Innvaer 1985).

Predators:

Skunks have very few predators due to their reputation of being stinkers.  Sometimes a bobcat, coyote, and some birds of prey, particularly Great-horned owls will attack them.  The owl attacks them because they have little or no sense of smell.  They are the most prevalent hunter of skunks.  Also, humans are another cause of death for skunks.  Humans sometimes trap them, but the pelts are not worth much any more.  Skunks fall victim to road kill most often.  They are not fast enough cross the road and get out of the way of vehicles and end up just spraying and getting run over.

Remarks:

The striped skunks scientific name comes from the Latin word meaning “poisonous vapor.”  Also, skunks will avoid at all costs from using their spray on one another, even in the fiercest fight.  Skunks are also resistant to snake venom. They can survive 10 times the amount of venom needed to kill another animal of similar size (Merkat Mpango).

Literature Cited:

Banfield, A.W.F.  1981.  The Mammals of Canada.  University of Toronto Press and Hinterland Who’s Who: Fact Guru: Canadian Mammals.  

Bartelt, G.A., R.E. Rolley, and L.E. Vine.  2001.  Evaluation of Abundance Indices for Striped Skunks, Common Raccons, and Virgina Opossums in Southern Wisconsin.  Research Report 185.  Wisconsin Department of Natural Resources.

Bixler, A.  2000.  Genetic variability in striped skunks (Mephitism mephitis).  The American Midland Naturalist 143:370-376.

E-Nature.com. National Geographic.  Local Wildlife Guides:  Striped Skunks.  <http://enature.nationalgeographic.com/natgeo/natgeo_showSpeciesLG.asp?curFamilyID=976&showType=5&rgnID=1035&curGroupID=5&curPageNum=1&recnum=MA0034>.  Accessed on 4 November 2003.

Forrester, P. and D. Erler.  Striped Skunk.  Nature Works.  New Hampshire Public Television and Squam Lakes Natural Science Center.  <http://www.nhptv.org/natureworks/stripedskunk.htm#1>.  Accessed 4 November 2003.

Greenwood, R.J. and A.B. Sargeant.  1994.  Age-related reproduction in striped skunks in upper midwest.  Journal of Mammology 75: 657-662.

IDNR:  Indiana Division of Fish and Wildlife.  The Striped Skunk.  <http://www.in.gov/dnr/fishwild/publications/lifeseries/sskunk.htm>.  Accessed  4 November 2003.

Innvaer, S.H.  1985.  Habitat use, movements, and population characteristics of urban striped skunks.  Published M.S. thesis, University of Wisconsin Stevens Point.

Meerkat Mpango.  Striped Skunk.  Merkat’s Mammals.    <http://www.meerkat.org/mammals/skunk.html>.  Accessed 4 November 2003.

Miller, R.S.  1994.  Canadian Wildlife Service Hinterland Who’s who.  Striped Skunk.  <http://www.cws-scf.ec.gc.ca/hww-fap/hww-fap.cfm?ID_species=74&lang=e>.  Accessed 4 November 2003.

Petersen, D.  1990.  The big stink.  Mother Earth News 121: 80-84.

Schneider, D.  1998.  No nose is good news.  Nature Canada 27: 38-42

 
Reference written by Jason Dahl, Biology 378 student.  Edited by Christopher Yahnke.
Page last updated 4- 28-04.