Opossums
The Virginia opossum (Didelphis virginiana) is more closely related to kangaroos than to any other mammal in North America. It’s our only member of the ancient group of animals called the marsupials, or animals with pouches.
Opossum is the official name. However, both opossum and “possum” were written down by early colonists as approximate translations of the Virginia Algonquian word “apousoum,” which meant “white animal.”
While once non-existent in New England, opossums are abundant in Connecticut, Rhode Island, and Massachusetts. They can even be found as far north as Vermont and Maine.
Identification
Virginia opossums are about the size of housecats, and are mostly grey, with a white face. They have a pointed nose, short legs, and a long rat-like tail.
These animals walk in a curiously slow, hobbling manner. However, they’re able climbers. They often use their flexible tails for balance, or to hold nesting material when climbing, and young use their tails to cling to their mothers’ backs.
Behavior
Virginia opossums are mostly active at night. Their eyes are well-adapted to darkness. During the day, they den up in cavities, such as hollow trees, brush piles, or spaces under structures built by people.
In the warmer months, opossums wander widely in search of food. They rarely spend two consecutive days in the same spot. In the fall and winter, they occupy a more permanent nest lined with leaves. They’re not true hibernators; except for brief periods during severe weather, they’re active throughout the winter.
When confronted by a predator the possum’s first line of defense is to hiss, growl, and show its teeth. If the predator is not deterred and the opossum is attacked, it plays dead. While in this catatonic state, the opossum falls on its side and becomes completely limp, with its tongue hanging out of its mouth. It often defecates and may also emit a greenish, foul-smelling substance from its anal glands. During this state—which can last up to six hours—the opossum’s breathing and heart rate decrease.
Life Cycle
Virginia opossums mate from mid-winter to mid-summer, and often have multiple litters in a year. Females give birth only about two weeks after mating. The newborns are grossly underdeveloped—naked, blind, and almost transparent, they’re only about half an inch long and weigh 1/200th of an ounce, slightly smaller than a honeybee.
They immediately climb into the female’s pouch and attach themselves to one of 13 teats arranged in a horseshoe configuration. If there are more than 13 babies, only those babies able to grasp a teat will survive. Once the nipple is in the baby’s mouth, it swells, making it virtually irremovable. This vital connection remains unbroken for about two months.
At about two months, their eyes open and they begin to spend time out of the pouch. The young are fully independent at about three months.
Food
Virginia opossums are omnivores. This means that they will eat a variety of foods, including meat and plants. Insects and carrion (dead or decaying animals) are important parts of their diet. They will also eat amphibians, reptiles, earthworms, birds, and small mammals, as well as seeds and fruit.
Situations & Solutions
Virginia opossums and people rarely come into conflict. If an opossum dens in an undesirable location, usually the best solution is patience; the animal will probably move on after a few days.
Opossums in Your Home
The best way to keep opossums and other wild creatures out of homes and other structures is to exercise prevention. Make sure all entrances to likely den sites in your house are closed off.
If a Virginia opossum has already established residence, wait until it leaves on a feeding foray. Once you’re absolutely certain that the tenant is out, close the access. Opossums adjust easily to eviction.
Orphaned Opossums
Virginia opossums are often struck by vehicles, probably because of their slow gait, low intelligence, and fondness for carrion. Because they rely on their mother’s pouch, young opossums are particularly vulnerable if a mother is killed.
If you encounter a litter of orphaned opossums, call MassWildlife 508-389-6300 for advice on the best course of action.
Opossums and the Law
Relocating wildlife is illegal in Massachusetts. It is detrimental to the well being of wildlife as well as the public. If sick animals are transported and released in other locations, diseases can be spread. Learn More