Skunk

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For other uses, see Skunk (disambiguation).
Skunks
Striped skunk
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Suborder: Caniformia
Superfamily: Musteloidea
Family: Mephitidae
Bonaparte, 1845
Genera

Conepatus
Mydaus
Mephitis (type)
Spilogale

Skunks (sometimes referred to as polecats) are mammals, usually with black-and-white fur, that are best known for their ability to excrete a strong, foul-smelling odor. They belong to the family Mephitidae[1][2] and to the order Carnivora. There are 11 species of skunks, which are divided into four genera: Mephitis (hooded and striped skunks, two species), Spilogale (spotted skunks, two species), Mydaus (stink badgers, two species), and Conepatus (hog-nosed skunks, five species). The two skunk species in the Mydaus genus inhabit Indonesia and the Philippines; all other skunks inhabit the Americas from Canada to central South America.

Skunks were formerly considered to be a subfamily of the Mustelidae family of weasels and related animals (where some taxonomists still place them), but recent genetic evidence shows that they are not as closely related to the Mustelidae as formerly thought.[2]

Skunks are sometimes called polecats because of their visual similarity to the European polecat (Mustela putorius), a member of the Mustelidae family.[3]

Contents

[edit] Physical description

Skunk species vary in size from about 15.6 inches (40 cm) to 37 in. (70 cm) and in weight from about 1.1 lb. (0.5 kg) (the spotted skunks) to 18 lb. (8.2 kg) (the hog-nosed skunks). They have a moderately elongated body with reasonably short, well-muscled legs, and long front claws for digging.

Although the most common fur color is black and white, some skunks are brown or gray, and a few are cream-colored. All skunks are striped, even from birth. They may have a single thick stripe across back and tail, two thinner stripes, or a series of white spots and broken stripes (in the case of the spotted skunk). Some also have stripes on their legs.

Skunks also have a very long tail.

[edit] Diet

Skunks are omnivorous, eating both plant and animal material and changing their diet as the seasons change. They eat insects and larvae, earthworms, small rodents, lizards, salamanders, frogs, snakes, birds, moles, and eggs. They also commonly eat berries, roots, leaves, grasses, fungi, and nuts.

In settled areas, skunks also seek human garbage. Less often, skunks may be found acting as scavengers, eating bird and rodent carcasses left by cats or other animals. Pet owners, particularly those of cats, may experience a skunk finding its way into a garage or basement where pet food is kept.

Skunks are one of the primary predators of the honeybee, relying on their thick fur to protect them from stings. The skunk scratches at the front of the beehive and eats the guard bees that come out to investigate. Mother skunks are known to teach this to their young. A skunk family can virtually depopulate a healthy hive in just a few days.

Skunks tend to be gluttonous feeders. They gain weight quickly if their diet becomes too fatty.

[edit] Behavior

Skunks are crepuscular, and are solitary animals when not breeding, though in the colder parts of their range they may gather in communal dens for warmth. During the day they shelter in burrows that they dig with their powerful front claws, or in other man-made or natural hollows as the opportunity arises. Both sexes occupy overlapping home ranges through the greater part of the year; typically 2 to 4 km² for females, up to 20 km² for males.

Unlike the fictional "Flower" in the movie Bambi, real skunks do not hibernate in the winter. However they do remain generally inactive and feed rarely. They often overwinter in a huddle of one male and multiple (as many as twelve) females. The same winter den is often repeatedly used whether under a house or in a tree.

Although they have excellent senses of smell and hearing — vital attributes in a crepuscular omnivore — they have poor vision. They cannot see objects more than about 3 metres away with any clarity, which makes them very vulnerable to road traffic. Roughly half of all skunk deaths are caused by humans, as roadkill, or as a result of shooting and poisoning.[citation needed] They are short-lived animals: fewer than 10% survive for longer than three years.

[edit] Reproduction

Breeding usually takes place in early spring. The males are polygynous, which means that there are more females than males. Females excavate a den for between one and four young to be born in May. Skunks are placental, and their gestation period is around 66 days. Four to seven kits are born. When born, the kits are blind, deaf, and covered in a soft layer of fur. After three weeks, the kit's eyes open, and they are covered in a soft, glossy, thick fur. The male plays no part in raising the young and may even kill them. A common and amusing scene in late spring and summer is a mother skunk followed by a line of her kits. The kits are weaned after around two months. The kits generally stay with their mother for around one year, when they will be ready to mate. The mother is very protective, and will often spray at any sign of danger.

[edit] Anal scent glands

The best-known, most distinctive, and often most notorious feature of skunks is their anal scent glands, which they can use as a defensive weapon. They are similar to, though much more developed than, the glands found in species of the Mustelidae family. Skunks have two glands, one on either side of the anus, that produce a mixture of sulfur-containing chemicals (methyl and butyl thiols(mercaptans)) that has a highly offensive smell that can be described as a combination of the odors of rotten eggs, garlic and burnt rubber. The odor of the fluid is strong enough to ward off bears and other potential attackers, and can be difficult to remove from clothing. Muscles located next to the scent glands allow them to spray with high accuracy as far as 2 to 5 metres (7 to 15 ft). The smell aside, the spray can cause irritation and even temporary blindness, and is sufficiently powerful to be detected by even an insensitive human nose anywhere up to a mile downwind. Their chemical defense, though unusual, is effective, as illustrated by this extract from Charles Darwin's Voyage of the Beagle:

We saw also a couple of Zorrillos, or skunks,—odious animals, which are far from uncommon. In general appearance the Zorrillo resembles a polecat, but it is rather larger, and much thicker in proportion. Conscious of its power, it roams by day about the open plain, and fears neither dog nor man. If a dog is urged to the attack, its courage is instantly checked by a few drops of the fetid oil, which brings on violent sickness and running at the nose. Whatever is once polluted by it, is for ever useless. Azara says the smell can be perceived at a league distant; more than once, when entering the harbour of Monte Video, the wind being off shore, we have perceived the odour on board the Beagle. Certain it is, that every animal most willingly makes room for the Zorrillo.[4]

Skunks are reluctant to use their smelly weapon, as they carry just enough of the chemical for five or six uses—about 15 cc—and require some ten days to produce another supply. Their bold black and white colouring however serves to make the skunk's appearance memorable. Where practical, it is to a skunk's advantage to simply warn a threatening creature off without expending scent: the black and white warning colour aside, threatened skunks will go through an elaborate routine of hisses and foot stamping and tail-high threat postures before resorting to the spray. Interestingly, skunks will not spray other skunks (with the exception of males in the mating season); though they fight over den space in autumn, they do so with tooth and claw.

The singular musk-spraying ability of the skunk has not escaped the attention of biologists: the names of the family and the most common genus (Mephitidae, Mephitis) mean "stench", and Spilogale putorius means "stinking spotted weasel". The word skunk is a corruption of an Abenaki name for them, segongw or segonku, which means "one who squirts" in the Algonquian dialect.

Most predatory animals of the Americas, such as wolves, foxes and badgers, seldom attack skunks—presumably out of fear of being sprayed. The exception is the great horned owl, the animal's only serious predator, which, like most birds, has a poor-to-nonexistent sense of smell.

Skunk spray is composed mainly of low molecular weight thiol compounds,[5] namely (E)-2-butene-1-thiol, 3-methyl-1-butanethiol, and 2-quinolinemethanethiol, as well as acetate thioesters of each of these.[6][7] These compounds are detectable at concentrations of about 2 parts per million.

[edit] Bites

The Centers for Disease Control and Prevention recorded 2,223 cases of rabies in skunks in the United States for the year 2000—about 31% of reported cases in all species. Skunks trail raccoons as vectors of rabies, although this varies regionally (raccoons dominate along the Atlantic coast and eastern Gulf of Mexico, skunks throughout the Midwest and down to the western Gulf, and in California). Despite this prevalence, all recorded cases of human rabies from 1990–2002 are attributed by the CDC to dogs or bats.

In case of a skunk bite, follow these directions as a precaution against rabies or other infection. (If a situation with a biting animal is out of control, call emergency services immediately.) If possible without further injury, retain the skunk, dead or alive, to assess and prevent the risk of spreading disease—if the animal is dead, place on ice or refrigerate. Wash the wound thoroughly with antibacterial soap and water. Place pressure to stop any bleeding. See your doctor or emergency medical services as soon as possible—within no more than 72 hours, and sooner depending on the severity of the wound or any difficulties in stopping bleeding. Call your local animal control agency to take the skunk away. Ask to have it tested for rabies. Once a doctor has looked over the wound, ask if a tetanus shot is necessary or recommended (tetanus vaccinations are typically good for ten years). When the test results are finished on the skunk, you will be told if you should get the post-exposure rabies vaccine series or not.

[edit] Domestication

Main article: Pet skunk
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Domesticated skunks can legally be kept as pets in the UK but they are legal only in certain U.S. states. Mephitis mephitis, the striped skunk species, is the most social skunk and the one most commonly domesticated. When the skunk is kept as a pet, the scent gland is removed. Typical life spans for domesticated skunks are considerably longer than for wild skunks, often reaching 10 years, though it is not unusual for a well cared skunk to live well past 20 years. One problem with U.S. skunks kept as pets is genetic problems due to a lack of genetic diversity. The few breeders of skunks are using the same genetic stock (as none are allowed to be taken from the wild) that was available many decades ago, when skunks were bred for the fur trade instead of the pet trade. Many problems such as undescended testicles, epileptic seizures, etc. are often found with the domestic stock. Some skunks were reported by European settlers in America as being kept as pets by certain Native Americans. The Pilgrims are said to have kept skunks as pets.[8]

[edit] Classification

[edit] See also

[edit] References

  1. ^ Don E. Wilson & DeeAnn M. Reeder (2005). Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed). John Hopkins University Press. 
  2. ^ a b Dragoo and Honeycutt (1997). "Systematics of Mustelid-like Carnvores". Journal of Mammalology 78 (2): 426-443. 
  3. ^ Why are skunks called pole cats? - Yahoo! Answers
  4. ^ Darwin, Charles (1839). Voyage of the Beagle. ISBN 0-14-043268-X. Retrieved on 2006-06-27. 
  5. ^ "Skunk spray is composed mainly of low molecular weight thiol compounds." Note: Sure Fire Method for De-Scenting Pets Who've had a Close Encounter with a Skunk
  6. ^ Wood W. F., Sollers B. G., Dragoo G. A., Dragoo J. W. (2002). "Volatile Components in Defensive Spray of the Hooked Skunk, Mephitis macroura". Journal of Chemical Ecology 28: 1865. doi:10.1023/A:1020573404341. 
  7. ^ William F. Wood. Chemistry of Skunk Spray. Dept. of Chemistry, Humboldt State University. Retrieved on 2008-01-02.
  8. ^ Skunk

[edit] External links

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Extant Carnivora families by suborder
Kingdom: Animalia · Phylum: Chordata · Class: Mammalia · Infraclass: Eutheria · Superorder: Laurasiatheria
Feliformia
Caniformia
Canidae · Ursidae · Ailuridae · Mephitidae · Mustelidae · Procyonidae · Odobenidae · Otariidae · Phocidae