The opossum is a medium-sized animal that measures between 15 and 20 inches long (not including the tail) and weighs between 4 and 12 pounds. It has long, coarse, grayish-white fur. Black, brown, and albino opossums have been found, but are very uncommon. Opossums have a sharp-pointed and slender muzzle, prominent thin ears, and short legs. A long (9-20 inches), scaly, scantily-haired, prehensile tail helps stabilize the opossum when climbing. The tail is well adapted for grasping and wrapping around things, but not for hanging for long periods of time. Opossums have five toes on each foot. The first toe on the hind feet is opposable, clawless, and thumb-like. These ‘thumbs’ help the opossum grasp branches when it climbs. Both sexes are similar in appearance, although males are commonly larger in size.
Habit and Diet
Opossums are adaptable and will live wherever food, water, and shelter exist. They inhabit woodland areas along streams, ponds, lakes, swamps, and marshes. Farmland and woodlots are preferred over extensively forested areas. Opossums also are commonly found living in residential areas, making their homes in backyards and under sheds and other outbuildings.
The opossum is both a scavenger and an omnivore which feeds primarily at night. It uses its keen sense of smell to find food. The diet consists mainly of insects, worms, carrion (dead animals), reptiles, amphibians, birds and their eggs, crustaceans, berries, fruits, and small mammals.
In Connecticut, opossums usually begin breeding in early March, and the gestation period lasts about 13 days. Opossums produce one to two litters each year. The average litter size is 9, and the young are very tiny (about the size of a navy bean) and blind when first born. They crawl a few inches to the female’s pouch, attach themselves to a teat, and remain “locked” on to it for approximately 60 days. After 80 days, young opossums are weaned, leave the pouch, and typically can be seen riding around on the female’s back. By 100 days of age, they are usually independent. The next litter is born about two weeks after the first litter is weaned. Opossums may breed during their first year.
Opossums will use abandoned den sites of other wildlife, cavities in den trees, trash heaps, rock piles, brush piles, or buildings for shelter. They do not hibernate in winter, but will usually “hole up” during cold, adverse weather. In Connecticut, opossums can suffer from frostbite and may be missing the tips of their ears and tails.
Mortality factors of opossums include humans, predation, parasites, disease, exposure, and starvation. The biggest threat comes from humans and automobiles. Main predators include dogs, coyotes, foxes, bobcats, large hawks, and great horned owls. The chance of rabies in opossums is extremely rare.
When frightened, opossums bare their 50 sharp teeth and hiss or growl. However, they would rather avoid confrontation and be left alone. Being non-aggressive, opossums readily retreat to trees, brush piles, or other available cover when pursued by humans or predators. A common defense mechanism is feigning death, or “playing possum,” when cornered or threatened. Some predators may think the opossum is dead and go away.
The opossum can legally be trapped and hunted in Connecticut. In recent years, the opossum harvest in the United States has exceeded one million pelts, valued at more than $2.5 million annually.
Management of Nuisances
Having an opossum in your yard shouldn’t be a problem. This non-aggressive and non-destructive animal will not dig up yards, attack or threaten pets, or dig burrows. Opossums may get into garbage or pet food that is left outside and will sometimes raid poultry yards or gardens to feed on vegetables, apples, and strawberries. However, they are more beneficial to humans than harmful because they feed on many types of insects, like crickets and beetles, as well as on mice and voles.
The best advice is to let opossums have their space and learn to live with them. However, if you really want to discourage this neighbor, there are a few measures you can take.
Eliminate or secure food attractants. Bring pet food in at night. Keep garbage covered and in a secure area (garage, shed). Pick up fallen fruit from under fruit trees. Properly maintain poultry yards and houses. Protect gardens with fencing. (All of these measures also may reduce problems with raccoons, skunks, and bears.)
Keep your yard well lit at night. Opossums prefer darkness and usually avoid well lit areas.
Eliminate hiding places. Put fencing around hiding places under decks, sheds, and other structures. Hardware cloth can be attached to the bottom of decks. The fencing should be bent outward, extending approximately two feet, then buried a few inches below the ground.
Horse owners should pay attention to the risk of opossums transmitting a serious disease to horses through fecal contamination of feed and water. The disease, known as Equine Protozoal Myeloencephalitis (EPM), is caused by a protozoal parasite whose eggs are shed in an opossum’ feces. Infected wildlife show various signs of illness, including symptoms of central nervous system disease. This disease also has been transmitted to other wildlife (raccoons and skunks) and domestic pets (cats). Most opossums probably are not shedding the parasite and very few of the horses exposed to the parasite will develop EPM. The disease risk can be minimized by preventing opossum’s from getting into domestic animal food and water through secure storage, good animal care practices, and wildlife-proofing of barns and other buildings.