VIRGINIA OPOSSUM: (Didelphis virginiana)

The Virginia Opossum definitely suffers from an image problem — it is frequently perceived as a giant, dirty, scavenging rat rather than one of God’s fascinating creatures of the wild. But whether you love them or hate them, North America’s only marsupial has a set of unique characteristics. The opossum is common throughout Missouri, including in urban and suburban areas. Although they rarely cause significant damage, they can become a nuisance near homes where they may get into garbage, bird feeders, or pet food. They also occasionally kill poultry.

 

Health and Safety Concerns

Opossums often harbor parasites such as fleas and ticks, and are more resistant to rabies than any other mammal, although they are not completely immune. Opossum can carry the microorganism that causes Equine Protozoan Myeloencephalitis (EPM), which kills horses.

 

Identification

The opossum is a whitish or grayish mammal about the size of a house cat. Under-fur is dense with sparse guard hairs. Its face is long and pointed, its ears rounded and hairless. Maximum length is 40 inches (102 cm); the rat like tail is slightly less than half the total length. The tail may be unusually short in northern opossums due to loss by frostbite. Opossums may weigh as much as 14 pounds (6.3 kg); males average 6 to 7 pounds (2.7 to 3.2 kg) and females average 4 pounds (6.3 kg). The skull is usually 3 to 4 inches (8 to 10 cm) long and contains 50 teeth — more than are found in any other North American mammal. Canine teeth (fangs) are prominent. Tracks of both front and hind feet look as if they were made by little hands with widely spread fingers. They may be distinguished from raccoon tracks, in which hind prints appear to be made by little feet. The hind foot of an opossum looks like a distorted hand.

 

Range

Opossums are found in eastern, central, and west coast states. Since 1900 they have expanded their range northward in the eastern United States. They are absent from the Rockies, most western plains states, and parts of the northern United States.HabitatHabitats are diverse, ranging from arid to moist, wooded to open fields. Opossums prefer environments near streams or swamps. They take shelter in burrows of other animals, tree cavities, brush piles, and other cover. They sometimes den in attics and garages where they may make a messy nest.Food HabitsFoods preferred by opossums are animal matter, mainly insects or carrion. Opossums also eat considerable amounts of vegetable matter, especially fruits and grains. Opossums living near people may visit compost piles, garbage cans, or food dishes intended for dogs, cats, and other pets.

 

General Biology, Reproduction, and Behavior

Opossums usually live alone, having a home range of 10 to 50 acres (4 to 20 ha). Young appear to roam randomly until they find a suitable home range. Usually they are active only at night. The mating season is January to July in warmer parts of the range but may start a month later and end a month earlier in northern areas. Opossums may raise 2, rarely 3, litters per year. The opossum is the only marsupial in North America. Like other marsupials, the blind, helpless young develop in a pouch. They are born 13 days after mating. The young, only ½ inch (1.3 cm) long, find their way into the female’s pouch where they each attach to one of 13 teats. An average of 7 young are born. They remain in the pouch for 7 to 8 weeks. The young remain with the mother another 6 to 7 weeks until weaned. Most young die during their first year. Those surviving until spring will breed in that first year. The maximum age in the wild is about 7 years. Although opossums have a top running speed of only 7 miles per hour (11.3 km/hr), they are well equipped to escape enemies. They readily enter burrows and climb trees. When threatened, an opossum may bare its teeth, growl, hiss, bite, screech, and exude a smelly, greenish fluid from its anal glands. If these defenses are not successful, an opossum may play dead. When captured or surprised during daylight, opossums appear stupid and inhibited. They are surprisingly intelligent, however. They rank above dogs in some learning and discrimination tests.

 

Damage and Damage Identification

Signs of opossum damage are often confused with those of skunks or raccoons. Often, seeing an opossum is the only way to confirm its presence. Opossums consume garden produce and tree fruits. They may also feed on food scraps in compost piles. Opossums generally do not cause crop losses. Also, they typically avoid pets and livestock. Opossums may prey on chickens, ducks, pigeons, and eggs. Opossum can carry the microorganism that causes Equine Protozoan Myeloencephalitis (EPM), which kills horses. The protozoan is shed in feces, so an opossum that is denning or feeding in stable areas may contaminate feed and water used for horses. Opossums may enter trailer houses and climb into insulation under the floor. They often are encountered moving about the ductwork of mobile homes. Opossums are not destructive or strong, so typically they enter areas where an opening already exists. They commonly enter living quarters through large gaps around pipes and drains under sinks. In contrast, raccoons are powerful and often create openings. Although opossums may be considered desirable as game animals, certain individuals may be a nuisance near homes where they may get into garbage, bird feeders, or pet food. They may also destroy poultry, game birds, and their nests.

 

Damage Prevention and Control Methods

In Missouri, opossums are classified as furbearers and protected by regulated trapping seasons. Taking opossums during the prescribed season can help control their numbers. Damage causing opossums may be controlled to prevent further damage. Control methods can include exclusion, habitat modification, trapping and removal. Our technicians will help you determine the best options for your situation.

• Exclusion - Prevent nuisance animals from entering or taking refuge under buildings by closing any openings. Install sunken perimeter fences around crawl spaces below decks or buildings. Cover structure openings with hardware cloth. Use wire mesh to secure pens that house poultry. Prevent opossums from climbing over wire mesh fences by installing a tightly stretched electric fence wire near the top of the fence 3 inches out from the mesh. Deter opossums by making pet food, garbage, and animal feed unavailable. Store garbage, birdseed, and animal feed in metal or tough plastic containers with tight-fitting lids, or secure lids with bungee cords.

• Habitat Modification - Remove pet food, fruits, and other foods that might attract opossums. Opossums eat birdseed, so hang a bird feeder on a wire between trees, or on a baffled pole to prevent raiding. Reduce the amount of seed that falls to the ground by using one type of seed per feeder and using feeders that recapture fallen seed. Secure lids on trash cans and enclose compost piles in bins. Only place non-food plant materials (e.g., leaves and grass clippings) in compost piles to avoid attracting opossums, skunks, raccoons, and other scavengers.

• Trapping - Opossums are not wary of traps and may be easily trapped. Cage-type traps are generally the most effective option for trapping opossums. For best and quickest results, have an experienced professional perform trapping. There are many effective methods for trapping opossums, however, a great deal of experience is required to effectively trap opossums. Body-gripping traps are not allowed for dry-land sets in Missouri. Foothold traps are effective but require special skill and experience. Many people oppose trapping with foothold traps, especially in urban situations. The most common objections to foothold traps include the perception that traps are cruel and inhumane, and concern over catching non-target animals, especially pets. When used properly, traps are effective, selective, and safe, especially when used by an experienced trapper. Restrictions on use apply and our technicians will determine the best option for your situation while following all applicable laws and regulations.

• Shooting - Opossums can be controlled by shooting. However, in most situations it is not a practical solution. Opossums are largely nocturnal and spotlighting is illegal in Missouri. Safety is a critical factor that in some circumstances may preclude the use of firearms (for example, local laws may prohibit shooting, or neighbors may be too close). Shooting is best left to professionals. In many urban areas, firearms may not be discharged, in most situations local authorities have regulations and restrictions regarding the use of firearms.

 

Economics of Damage and Control

There are few studies available on the damage caused by Opossums. The damage they do is localized and is usually more of a nuisance than an economic loss.