Most people have no problem identifying a North American skunk by sight or smell. Skunks are of the order Carnivora, family
Mephitidae. The six species that exist in North America are the striped skunk (Mephitis mephitis), the Western spotted skunk (Spilogale gracilis), the Eastern spotted skunk (Spilogale putorious), two species of hog-nosed skunk (Conepatus mesoleucus and Conepatus leukonutus), and the hooded skunk (Mephitis macroura). Skunks are primarily crepuscular—most active during twilight, dawn, and dusk. Skunks have excellent hearing and sense of
smell but do not see well.1
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A SKUNK'S LINE OF DEFENSE
Skunks are docile but will defend themselves when threatened. A skunk's first line of defense is defensive posturing. A skunk
will hiss, stamp its feet, and raise its tail as a warning. If the warnings are ignored, a skunk will spray anal gland secretions
(referred to as either spray or musk).
Skunks have two anal glands, one on each side of the anus. The anal gland secretions contain a mixture of sulfur-containing
thiols. The odor—which has been described as similar to that of a combination of rotten eggs, garlic, and burnt rubber—tends
to drive away most predators.2 Skunks can spray these secretions 7 to 15 ft (2 to 5 meters) and are highly accurate in their aim. Getting sprayed by a
skunk is commonly called being skunked. Skunk spray has been used as a biological weapon.2
The skunk's anal gland secretions contain seven major volatile components: three major thiols, three major thioacetates, and
a methylquinoline. These are divided into thiols and acetate derivatives of the thiols. Two of these thiols, (E)-2-butene-1-thiol
and 3-methyl-1-butanethiol, are responsible for the repellent odor. These two thiols constitute 51% to 70% of the anal gland
The thioacetates are not as initially odiferous on contact but are converted to more potent thiols with the addition of water.
This chemical reaction may explain why some animals continue to smell skunky after a bath—thioacetates trapped in fur continue
to release thiols under damp conditions.
The seventh component is an alkaloid 2-methylquinoline, which is not as volatile as the thiols and has a nitrogenous base.
The chemical composition and percentages of the volatile components may vary among skunk species. Numerous minor components
differ among individual skunks and species.3,4