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.
Perception Channels: tactile ; chemical
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).
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
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.
Positive Impacts: body parts are source of valuable material
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.
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.
Primary Diet: omnivore
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).
Biogeographic Regions: nearctic (Native )
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).
Habitat Regions: temperate
Terrestrial Biomes: forest ; rainforest
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.
Range lifespan
Status: wild: 3.0 (high) years.
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).
Range mass: 0.3 to 6.4 kg.
Range length: 35.0 to 94.0 cm.
Average length: 74.0 cm.
Other Physical Features: endothermic ; bilateral symmetry
Average basal metabolic rate: 5.299 W.
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.
Known Predators:
The mating season for opossums lasts from January to July. Copulation is usually initiated by the male. After copulation, the female rejects any more solicitations. The egg is fertilized in the Fallopian tubes. Birth occurs about 12.5 to 13 days after copulation. The average litter size ranges from 7 to 9. Depending on latitude, opossums have one or two litters per year. The young opossums weigh about 0.16 grams at birth. They are fixed to the nipple for the first 50 to 65 days of their lives. By 95 to 105 days, the young no longer depend on their mother. There is no maternal bond between the mother and young after they are weaned. Females are able to breed in their first season (McManus, 1974).
Breeding season: January-July
Range number of offspring: 1.0 to 13.0.
Average gestation period: 12.5 days.
Range weaning age: 95.0 to 105.0 days.
Range age at sexual or reproductive maturity (female): 6.0 to 12.0 months.
Range age at sexual or reproductive maturity (male): 6.0 to 12.0 months.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); viviparous
Average birth mass: 0.147 g.
Average gestation period: 12 days.
Average number of offspring: 15.
Parental Investment: altricial ; female parental care
