Didelphis virginiana
Virginia opossum

Opossums are found in North America, from Central America and Mexico in the south, through the United States east of the Rocky Mountains and north into southwestern Ontario. Opossums are also found along the west coast of the United States. Their range appears to be expanding northward (McManus, 1974).

Opossums are found in a variety of environments, ranging from relatively arid to mesic environments. They prefer wet areas, however, especially streams and swamps. It is hard to determine the exact home range of an opossum because of their unusual movement patterns (McManus, 1974).

Opossums have a heavy set body that resembles a large house cat. They have a long head with a pointed snout. Their faces have long whiskers. All opossums have long, tapered tails with a scaly appearance. Females have a fur-lined pouch to carry their young (Baker, 1983). The color of the opossum varies by the region. Northern populations have thick underfur that is white in color and has black tips. The pale guard hairs give the opossum a gray appearance. In southern populations, the underfur is much sparser. Both northern and southern populations have white cheek hairs (McManus, 1974). Total length varies between 350 and 940 mm, tail length varies between 216 and 470mm. Males are larger than females with male weight ranging from 0.8 to 6.4 kg and female weight ranging from 0.3 to 3.7 kg (Wilson and Ruff, 1999).

Virginia opossums rarely live for longer than 18 months. The oldest known opossum in the wild was 3 years old when last captured. Although they are preyed upon by several predators, most are killed by cars.

Opossums are nocturnal animals and have very poor social development. Females tend to live in groups, but the males fight when confined together. Groups of opossums are composed primarily of young because of their short life span.

Opossums, both male and female, can be aggressive when threatened. They use various forms of intimidation to defend themselves but usually play dead when they encounter a more powerful opponent. Opossums usually travel across the land but will swim in some cases to escape danger. For grooming, opossums use their hind feet to clean their fur and wash their faces with their fore feet. To transport her young, a mother places them on her tail and back. (McManus, 1974).

Opossums are omnivorous, including a wide variety of food in their diet (Baker, 1983). A majority of their diet is composed of insects and carrion. Opossums are also known to eat plants, including fruits and grains in season.

Virginia opossums are well-known for pretending to be dead to avoid being eaten by predators. This is called "playing dead" or "playing possum." When a Virginia opossum thinks that it is being threatened it will go into a catatonic state where it appears to be dead, they go limp and their breathing becomes almost undetectable. They re-awaken when the perceived danger passes.

Virginia opossums are preyed on by predators such as coyotes, foxes, large owls, and hawks. As young they may also be preyed on by snakes and smaller birds of prey, such as falcons. Humans hunt Virginia opossums for food.

As scavengers, Virginia opossums play an important role in the ecosystem by eating foods and garbage that other animals may not. They are important prey items for predators in the areas where they occur.

Occasionally opossums have been known to get into human garbage, however their foraging activities are typically not disruptive (Baker, 1983). They are scavengers and rarely prey on live animals. Opossums can carry and transmit human diseases such as rabies, as can most mammals.

In the southeastern United States, opossums are sometimes hunted for food. Opossums are used as research animals in a variety of laboratories, their fur is used occasionally, and they help to control garden pests. ()

Adapted well to the presence of humans. Opossums appear to be extending their geographic range. The population density in the wild is not very high (one animal per ten acres).

Opossums have a defensive tactic called (appropriately enough) "playing possum." In this, the animal fakes death to thwart an attack, and reaches a state of catatonia.

When America was first colonized by Europeans, these possums did not occur north of Pennsylvania. As time passed, they moved north and westward on the Great Plains. In 1890, they were introduced to California. They spread on the west coast. Today in Michigan, they are currently spreading into the Upper Peninsula.