Biology and Control of Skunks

People generally relate skunks to the foul-smelling, defensive spray they discharge when scared or threatened. Many people have experienced this unpleasant odor along roadways and on dogs that have come in contact with skunks. Generally, people avoid skunks and have little tolerance for their presence.

In many parts of North America, skunks are the major carriers of rabies. Rabies is a viral disease that affects the nervous system of warm-blooded animals. This disease is normally spread by the bite of a rabies-infected animal and is fatal once symptoms develop. Rabies has been present in the skunk population of southern Alberta, at fluctuating levels, since the late 1970s. Any skunk acting abnormally, such as being tame or active during daylight hours, should be avoided and reported at once to the nearest Agriculture Agri-Food Canada veterinarian.

Identification

The striped skunk, Mephitis mephitis, is the most common of four skunk species found in North America and the only one present in Alberta.

The striped skunk (Figure 1) can be found across the province but is most common in the settled central and southern parts. It is characterized by a black body with a narrow white stripe on the forehead and wider stripes that extend from the neck along each side of the back. Some white may also be present on the top of the black bushy tail. The body size is comparable to a house cat, with most adult skunks measuring about 74 cm long and weighing about 2 to 4 kilograms.

Skunks have sharp claws on the front feet used for digging insects and worms. Their footprint and moving pattern distinguishes them from other similar-sized animals (Figure 2).

Biology, Behaviour and Reproduction

Skunks are members of the weasel family, all of which possess scent glands near the anus. However, the skunk has the most advanced scent gland development..


Figure 1. Striped skunk

The glands contain approximately 15 cc of a yellowish, oily liquid. This fluid is a sulphur compound, n-butyl mercaptan. A skunk can discharge a spray of this fluid as far as 4 to 5 m and spray up to 6 times in succession. It takes up to 10 days to replenish the supply of liquid after full discharge.

Skunks are nocturnal animals, active and feeding during night hours. Their behavior is slow and deliberate, and they appear confident in defending themselves against other animals.

Before a skunk discharges its scent glands, it will usually give a warning by stamping its feet rapidly, raising its tail straight up, clicking its teeth, and growling or hissing. A skunk generally sprays only as a last resort, preferring to retreat from danger.

Skunks eat many harmful insects and rodents but also prey on eggs and young of waterfowl and other ground- nesting birds. They sometimes cause problems in bee yards by feeding on bees as they emerge from the hive. Skunks also occasionally prey on farm poultry and eggs.



Figure 2. Skunk tracks

Several skunks, generally one mature male and several (up to 12) females, gather at and cohabitate a winter den site from fall until spring. The same winter den is generally used year after year if not disturbed. In rural areas, den sites are frequently found under old farm buildings, granaries and other structures. Skunks do not hibernate but generally remain inactive during winter, surviving on their fat stores. However, they may leave the winter den for short periods during warm weather.

Skunks mate during February and March. One male may breed several females. After mating, female skunks disperse from the winter den to a separate maternal den. Grass is usually gathered and brought into the maternal den for bedding.

Generally, 4 to 7 young are born about nine weeks after mating in May or June. The young are blind and deaf at birth with short, fine fur. Adult male skunks do not take part in rearing offspring. The young are nursed in the den for about six weeks before joining their mother on trips outside the den. By this time they are miniature replicas of adults. The young are weaned by about two months of age.

The family group breaks up in the fall, and the young move to new territory. They generally travel about six to 10 km in search of a new home; however, extremes of up to 50 km have been recorded.

Legal Status

Skunks are not protected by law in Alberta. The Agricultural Pests Act declares the skunk a nuisance. This allows landowners to destroy skunks and skunk dens on their land. The Wildlife Act classifies the skunk as a non- licenced animal. Skunks can be hunted or trapped year-round on private land by the property owner and during the fur trapping season by a licensed trapper. Some Alberta Fish and Wildlife Services and municipal Agricultural Service Board offices loan or rent out skunk live traps.

Non-Lethal Control Methods


Exclusion and habitat modification
A skunk becomes a problem when its presence and activities conflict with people. The best way to minimize skunk problems around homes and farmyards is to remove potential sources of food and living sites for skunks.

Skunks can be prevented from living or entering under buildings and other structures by closing all spaces with wood or metal screen. Ensure spaces are enclosed tightly to the ground to discourage digging. When skunks are already living under a building, they can be coerced to leave in the following manner:

• Seal all openings except the main skunk entrance.
• Sprinkle a layer of flour, chalk or other powder outside the entrance.
• After dark, inspect the powder for exiting skunk tracks.
• Once a skunk has left the building, immediately seal the entrance.
• The following evening, re-apply powder, and re-open the entrance to allow any other skunks to leave before permanently closing the opening.