Photo by: Patrick Connolly
Species: Virginia Opossum
Scientific name:Didelphis virginiana
Status: common (introduced)
Description: Opossums (most people call them possums) are quite distinctive looking. This mammal is cat sized, with grey fur, small black eyes, white face, pointy snout (nose) and a long tail (minimal fur). These mammals have small black ears that, like their tail, have limited amounts of fur. Possums tails are pretty unique, they are quite scaly looking and are prehensile (can be used to grasp and hold things). This species is nocturnal, preferring to hunt and move at night. They are also active year round and do not hibernate, but in extreme weather will stay in their dens for long periods of time. As they do not hibernate in the winter, possums commonly suffer from frost bite on their tails and ears (areas with little fur).
Habitat: Possums live in damp woodlands or forests that are near water. However, they have adapted well to living in cities. Originally this species was a warm climate mammal, and therefore, cold climates can limit their ranges (where they are found on the land).
Breeding: Possums are North America’s only marsupial (females have a pouch). Possums will live and raise young in dens. Dens are most often dug by another mammal in the ground, or can be in a hollow tree/log, under a building or in a rock pile. Females will give birth to a litter with up to 25 young. The breeding season lasts from mid-winter to late-fall. Typical gestation (embryo development) is 12-13 days, after which the young will crawl into the female’s pouch and continue to develop in there. In the females pouch, she will have nipples (13 on average), where the babies can get milk and continue to grown. Each baby will attach itself to a nipple, so if there are more babies than nipples, some of them will die. Baby possums will spend about 3 months in their mothers pouch before emerging and will stay on their mothers back when she is moving out of the den.
Diet: Possums are omnivours, which has lead to their success in establishing outside of their natural range (Virginia). They will eat invertebrates, insects, small mammals, birds, grains, berries, fruits, grasses, carrion (dead animals), snakes, bird eggs, corn and really anything they can get their hands on.
Threats to species: Possums are a prey species for a number of different animals including hawks, owls, large and large mammals. In addition, this species is commonly hit by cars on roadways as they move and forage (look for food) during the night. They are also susceptible to a number of pathogens (e.g., ticks, fleas).
Threat to humans: Possums are considered a nuisance when their numbers are high, they may create conflict with humans when they are in garbage, at bird feeders, or inside buildings.
At birth, possums are the size of a honeybee-making them the smallest baby mammals in North America.
Although they have prehensile tails, possums do not hang from their tails like children’s stories describe.
“Playing possum” is what possums will do when threatened and cannot scare away the threat-they scream/screech, roll on their back, dangle their legs, close their eyes, roll out their tongue, drool and let out a horrible smell from their anal glands.
Possums have the most teeth of any North American mammal, with 50 teeth in their tiny mouths-they will show you their teeth when threatened.
Ontario Ministry of Natural Resources-http://www.mnr.gov.on.ca/en/Business/FW/2ColumnSubPage/251071.html
Eder, Tamara, and Kennedy, Gregory. 2011. Mammals of Canada. Lorne Pine Publishing. Edmonton, Alberta.