North American Opossums

Scientific Name: Didelphis virginianus

Description: Opossums are marsupials (mammals with a pouch in which they carry their young), a primitive group of mammals found most commonly in Australia. Kangaroos, koalas, and wombats are other well known marsupials. Opossums are the only marsupials in North America. All other mammals are placentals, which means their young develop within a saclike membrane called the placenta inside the mother’s uterus, rather than in an exterior pouch.

In Australia and elsewhere, many species of marsupial have been out-competed and even driven to extinction by more modern mammals. Yet, the opossum has adapted to the changing environment in the Western Hemisphere, and continues to thrive.

Opossums are inhibited animals, especially in daylight or under artificial light, but are by no means stupid. Results from some learning and discrimination tests rank opossums above dogs and more or less on a par with pigs in intelligence.

Opossums readily use trails made by other wildlife or humans near creeks, ravines, and wetlands. Like raccoons and foxes, opossums use culverts as a safe way to cross under highways and roadways.

Distribution: With few natural predators, the absence of hunting, and an abundance of food and shelter, opossums have adapted well to living close to people in urban and suburban environments. Except for higher elevations, opossums now occupy most human-occupied habitats in British Columbia, Washington, Oregon and Idaho. Due to humans introduction of the Opossum to Salts Spring Island, Texada Island and other Gulf Islands the species have become a nuisance in an area that they were not native to.

Wildlife Management: Trapping and relocating an opossum several miles away seems an appealing method of resolving a conflict because it is perceived as giving the animal a second chance in a new home. Unfortunately, in addition to being illegal under the “British Columbia Wildlife Act” moving opossums often will not solve the original problem because other opossums will replace them and cause similar conflicts.

It is legal to trap an opossum, and then release the animal at the site of capture. With this option, the opossum is trapped and released on site after its reentry into a structure is prevented by physical exclusion.

In such a case, the opossum is evicted within its home range and because it is familiar with its surroundings, it can soon find suitable food and shelter. In the event young are present but were not noticed prior to trapping, allow the female back inside to tend to her dependent offspring.

A downside to this approach is the possibility that the animal may simply enter someone else’s attic, chimney, or similar place. Then, if someone else has to trap the animal, they will be dealing with a trap-smart opossum, making its capture difficult.