Spotted Skunk
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S. gracilis Merriam, 1890 |
The Spotted Skunks are three species of Skunk in the genus 'Spilogale.
The Eastern Spotted Skunk (Spilogale putorius) is smaller and more weasel-like than the striped skunk. Both species are nocturnal and crepuscular. The spotted skunk is faster and more agile than the striped skunk and it has a better pelt. For the last 100 years, the Easter Spotted Skunk was bred for its fine silky fur. The furs and pelts were sold as "Martin Fur."
Jerry Dragoo, in a 1997 paper co-authored by Rodney L. Honeycutt of Texas, named the new family classification Mephitidae after mephitis, the Latin word for a foul gas or smell.
The spotted skunk weighs between 1 and 3 pounds. It is black with a white spot on the forehead and interrupted white stripes over its back and sides that give the appearance of spots.
It is often incorrectly called a "civet cat"—a member of the genet family (Viverridae) with a long banded tail similar to a raccoon's—the two are not closely related.
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Location
The spotted skunk lives in central states of the US between Mexico and Canada and Southern states on the East Coast through Pennsylvania. It can adapt to varied terrains. In rocky areas they live in cracks and crevices in the rocks or a burrow under a large rock. They are expert climbers and can live in hollow trees or in the attics of buildings as well as under buildings, in drain pipes and in underground dens.
Defenses
The spotted skunk protects itself by spraying a strong and unpleasant scent. Two glands on the sides of the anus release the odorous oil through nipples. When threatened, the skunk turns its body into a U-shape with the head and anus facing the attacker. Muscles around the nipples of the scent gland aim them, giving the skunk great accuracy on targets up to 15 feet away. As a warning before spraying, the skunk stamps its front feet, raising its tail, and hissing. They may warn with a unique "hand stand"—the back vertical and the tail waving.
Skunks store about 1 tablespoon (15 g) of the oderous oil and can quickly spray five times in row. It takes about one week to replenish the oil.
The secretion of the spotted skunk differs from that of the striped skunk. The two major thiols of the striped skunk, (E)-2-butene-1-thiol and 3-methyl-1-butanethiol are the major components in the secretion of the spotted skunk along with a third thiol, 2-phenylethanethiol.
Thioacetate derivatives of the three thiols are present in the spray of the striped skunk but not the spotted skunk. They are not as odoriferous as the thiols. Water hydrolysis converts them to the more potent thiols. This chemical conversion may be why pets that have been sprayed by skunks will have a faint "skunky" odor on damp evenings.
Deodorizing
Changing the thiols into compounds that have little or no odor can be done by oxidizing the thiols to sulfonic acids. Hydrogen peroxide and baking soda (sodium bicarbonate) are mild enough to be used on people and animals but changes hair color.
Stronger oxidizing agents, like sodium hypochlorite solutions—liquid laundry bleach—are cheap and effective for deodorizing other materials.
Growth
The female gives birth to between two and six young and she may have two litters per year.
The newborn skunks are covered with fine hair that shows the adult color pattern. The eyes open between 30 and 32 days. The kits start solid food at about 42 days and are weaned at about two months. They are full grown and reach adult size at about four months.
The males do not help in raising the young.
When grown, skunks live a solitary life. During the winter months, they may share dens. Skunks squabble and fight with each other, scratching and biting, but, interestingly, they do not spray each other.
Diet
Skunks are omnivorous and will eat small rodents, fruits, berries, birds, eggs, insects and larvae, lizards, snakes, and carrion. They have a keen sense of smell that helps them find grubs and other food. Their hearing is acute but they have poor vision.
Life expectancy
Spotted skunks can live 6 years in captivity, but in the wild, about half the skunks die after 1 or 2 years. Swooping down from the sky, the great horned owl is the main predator. Others are the coyote and the dog.
Humans kill the greatest number of skunks—running over them with automobiles.
Skunks as pets
Skunks can be kept as pets. The owners stress bonding early with the skunk and not keeping the pet in a cage.
For more information on skunk ownership, see Pet skunk.
Rabies
Skunks, like other wild mammals can contract and carry rabies. Fears of a skunk walking about in daylight being rabid are not justified since they are crepuscular and will sometimes come out during daylight for food.
Rabies surveillance report for 2001 finds an increase in the number of rabid skunks over raccoons. Yet most human infections do not come from skunks.
- "Since 1990 [until 2001], 24 of 26 human cases of indigenously acquired rabies were associated, by genetic analysis, with variants of the rabies virus maintained by bats. Only 2 of these cases involved a report of a definite history of animal bite. The most likely route of infection remains transmission by bite during contact with a bat that either was ignored or unnoticed and subsequently forgotten." (Rabies surveillance in the United States during 2001, John W. Krebs, MS, Heather R. Noll, MPH, Charles E. Rupprecht, VMD, PhD, James E. Childs, ScD)
A skunk who bites a person, even a pet, will be killed and an autopsy performed to determine if the animal is rabid. If the animal is not caught the patient will undergo a series of preventative rabies shots.
Rabies vaccines for exposed humans were made from nerve tissue and had frequent serious adverse reactions. The cost of the vaccine was low but potency was inconsistent.
In 1983, a vaccinia-rabies glycoprotein (V-RG) recombinant virus vaccine was developed that has proved effective in raccoons and other reservoir species. In 1992, Cornell University experimented with aerial distribution of oral vaccine to raccoons and found it extremely effective.
Vaccination programs have eliminated rabies in domestic dogs in the US. Skunks in the US remain a reservoir for the disease. Iceland, Japan and the United Kingdom, Belgium, Finland, France, Greece, Norway, Portugal, Spain, Sweden and Switzerland, are now considered free of rabies. Until 1995, Australia was considered to be rabies-free, but in 1996 a rabies-related lyssavirus (type 7) was discovered in flying foxes, a bat species.
References
- "Mammals: A Guide to Familiar American Species" Herbert S. Zim, Donald F. Hoffmeister. Golden Press, NY, 1955
- All Taxa Biodiversity Inventory [1] (http://www.dlia.org/atbi/species/animals/vertebrates/mammals/mephitidae/Spilogale_putorius.html)
- CBC News [2] (http://www.cbc.ca/news/indepth/background/sars_civetcat.html)
- "Chemistry of Skunk Spray" William F. Wood, Department of Chemistry, Humboldt State University, Arcata, CA 95521 [3] (http://www.humboldt.edu/~wfw2/chemofskunkspray.html)
- "Rabies surveillance in the United States during 2001" John W. Krebs, MS; Heather R. Noll, MPH; Charles E. Rupprecht, VMD, PhD, James E. Childs, ScD JAVMA 221(12):1690-1701 (2002)
- "Airborne Rabies Vaccine Would Reach Most Raccoons" Science News. December, 1994
- "The development and use of a vaccinia-rabies recombinant oral vaccine for the control of wildlife rabies; a link between Jenner and Pasteur." Pastoret PP, Brochier B. Epidemiol Infect. 1996 Jun;116(3):235-40
- WHO [4] (http://www.who.int/vaccines/en/rabies.shtml)