Opossum: Biology, Life Cycle and Habitat
America’s only marsupial tends to have a bad reputation. Perhaps, it’s the opossum’s appearance
and nocturnal lifestyle that makes this creature so unappealing. After all, spotting a large rat-like
creature with beady eyes and a scavenger’s appetite in a beam of light is just plain creepy.
Surprisingly, the answer is yes. Compared to other types of wildlife, they are very helpful.
Opossums not only play an essential role in the ecosystem, but they can also be a valuable
asset to your garden, in spite of the fact that most people are quick to control their numbers.
Opossums, sometimes called possum, benefit your garden by ridding it of small insects and
pests. As omnivores, opossums consume a variety of foods. This includes the beetles, slugs,
and snails which damage garden plants.
These nocturnal creatures also consume plant matter. In general, the opossum prefers fallen
or rotting vegetation to fresh. Cleaning up dropped fruits and vegetables, which can harbor
disease, is another benefit to having these creatures around.
Test your knowledge: Take the Opossum Quiz.
|Length (without tail)
||Males: 32 inches
Females: 28 inches
||Gray in color, though
their coats may vary
from red to brown.
(about ½ survive)
||Owls, hawks, red foxes,
There are actually 60 species of opossums, with the species Virginia opossum being native
to Wisconsin. This is actually the only marsupial, meaning pouched animal that is found in
Canada and the United States.
Opossums have sharp claws that help them dig into the bark of trees while climbing. They
also have a long gripping tail which they use as an additional limb during climbing. The rear
limbs have clawless, opposable thumbs. These prehensile tails are hairless. Possums have
hairless ears and a pink nose at the end of their flat, long snout.
Opossums can vary greatly in size. The average one will be around the same size of an average
house cat, but they tend to be smaller in the tropical areas and larger farther north. Their fur
is usually gray but it can be anywhere from black to brown to white due to variations in their
guard hairs. These guard hairs can also vary in thickness.
Their mouth holds the most teeth of any mammal in North America — 50.
Although a litter of opossums may have up to 20 joeys, less than half of these animals will
survive on average. When opossums are born, they are as small as honeybees and completely
helpless. Joeys will crawl into their mother’s pouch immediately, which is where they develop
and stay safe. Not all of the newborn opossums will make it this far. Eventually, the possums
get larger and occasionally leave their pouch. They will also ride on their mother’s back while
she goes out in search of food.
You can find the Virginia opossum throughout North America and Central America to the east
of the Rockies. They span from southern Ontario to Costa Rica and are expanding their range
Possums tend to live by or in wooded areas, particularly those that are close to water. They
are also frequently found in urban areas. Since they are excellent climbers, it is not uncommon
for possums to nest inside of tree holes. They can also frequently be found in dens that were
previously made by different animals.
Opossums don’t build shelters themselves so you can find them in old buildings or sheds as
well or in fallen logs, hollow trees, and cavities in brush piles or rocks. They will bring nesting
material to their chosen shelter.
Opossum Eating Fruit
Possums are scavengers, which means they will eat whatever food they can find. Because
of this, they will frequently be found by human homes, raiding dumpsters and garbage cans.
Opossums will also carrion, which is why you will frequently find them by roadkill. Additionally,
these animals eat fruit, nuts, and grass. As omnivores, they also hunt birds, mice, worms, insects,
and snakes as well as chickens.
Possums have a relatively small brain, but are able to find food as well as remember where they
found it. In fact, opossums scored better than cats, rats, rabbits, and dogs in some tests for their
memory. They can also remember how toxic or noxious substances taste.
Opossum Playing Dead
Perhaps the most common possum behavior is 'playing possum.' This is their defensive mechanism
that naturally occurs when they are threatened by a predator, such as a bobcat, fox, or dog. They
will flop on their sides then lie on the ground. Their eyes will either be closed or they will stare into
space with a fixed view. At the same time, these marsupials extend their tongues to complete the
impression that they are dead. This has proven to be an effective way to put predators of guard
and give the animals the chance to escape.
Possums are not typically aggressive, but they do have a defensive posture when threatened. If
cornered, they will either sit back or crouch down and open their mouth. This displays as many of
their teeth as possible. This action is accompanied by screeches or growls that tend to get more intense.
Opossums are also great climbers, spending a great deal of their time in trees. Their biology helps
with their climbing capabilities. If caught and then handled, possums will frequently defecate and the
glands by the base of their tail will release a secretion that is pea-green. Possums are mostly nocturnal,
typically foraging after dark. When it gets colder out, such as during winter, they are more likely to be
active during the day since they need to eat more.
The breeding season for the Virginia opossum can begin as early as December and continue through
October with most infants born between the months of February and June. A female opossum may
have 1-3 litters per year. During the mating season, the male attracts the female by making clicking
sounds with his mouth.
Eleven to thirteen days after mating over 20 infants may be born, although an average litter consists
of 8-9 infants. The infants are so small at birth that 20 could fit into a teaspoon. Each of the hairless,
embryonic-looking “pinkies”. At birth, the infants must make a long and difficult journey from the birth
canal into the pouch, latch onto a teat, and continue their development. The mother helps by licking
the hair leading into the pouch, providing a moist path for the infants to follow.
The young remain in the pouch for about 2 1/2 months and at around 55-70 days the eyes open. As
they become too large to fit in the pouch, they climb onto the mother’s back and are carried as she
searches for food.
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