Toledo Magazine: Playing 'Possum'

7/23/2006

OK, so why did the chicken cross the road?

To show the opossum how it's done.

There, the fun is poked - ouch! - and the common opossum is put in its usual lowly place, at or near the bottom of the mammalian pecking order. Or dead on the side of life's road.

But to brush off this amazing wild creature with mere vaudeville slapstick is to overlook its fascinating adapations, singular physical characteristics, and its endurance as a species.

It generally is harmless, retiring, nocturnal, and solitary. Most of all, it is a survivor.

Dr. Pat Rusz, director of wildlife programs for the Michigan Wildlife Conservancy, points out that the fossil record shows that the opossum has been around North America for at least 70 million years.

Such longevity alone is testimony to the opossum's survival adaptations as a species, if not as an individual caught in the headlights. But there is much more to know and appreciate:

One count tallied 65 species of opossum in the Americas. But the Virginia or common opossum is the only species native to the United States and Canada.

Opossums are members of the marsupial family, most of which are native to Australia and include kangaroos and koalas. In marsupials, young do not develop in a uterus, as with other mammals. They are born very early on and must scramble to find the mother's cozy, fur-lined, abdominal pouch in which to complete development.

Opossums are born only about 12 days after mating and are furless, blind, deaf, and smaller than a honeybee. Up to 20 can fit on a tablespoon. They nurse in the pouch for six weeks to two months, but even after leaving the pouch they must depend on the mother for transport.

Emerged young climb on the mother's back, clutching her fur with foreclaws and wrapping their prehensile tails around hers. At about 3 months of age young opossums can manage on their own.

A mother opossum only has 13 nipples in her pouch, so any young in excess of that in a birthing do not survive. Dr. Rusz notes that a nipple swells in the baby's mouth, causing it to "lock on" for about 50 days, whereupon the baby, now the size of a mouse, falls off because of its weight.

The babies at this point open their eyes, and after about 80 days, at the size of rats, they are able to leave the pouch for short periods. Fully grown, the common opossum is about the size of a small dog or domestic cat, ranging 25 to 40 inches long, including tail, and weighing 4 to 14 pounds.

The fur is grayish white merging to an all-white head that is tipped with a pointy pink nose. Their mouths are filled with 50 teeth, more than any other mammal, and opossums will open wide and bare their teeth -called gaping - in attempts to deter enemies.

When attacked, or even approached by predators, opossums may "play possum," that is, act dead. Some researchers think it is more than a trick, but an actual fainting out of fright. Frightened opossums may seem dead for anywhere from a minute to an hour or more.

Other times an opossum may growl, hiss, or simply run away when confronted. In any case, they are not dangerous or aggressive animals. They seldom carry rabies but do not make good pets.

Opossums have five toes on each foot, with each back foot having a thumb-like big toe to help in grasping and climbing. Dr. Rusz noted that opossums are the only nonprimates with these opposable "thumbs."

As adults, opossums do not hang by their tails - that is an old wives tale. But they do use their tails for gripping and maintaining balance in trees.

The classic opossum-in-the-headlights, alluded to earlier, reflects the animal's mainly nocturnal habits. After separation from their mothers and except for breeding, opossums generally are solitary.

They may travel two miles or more each night in search of food. They are omnivores, meaning they will eat anything that does not eat them first. Their diet may include roadkill carcasses, mice, bird eggs, frogs, snakes, earthworms, salamanders, crickets, grasshoppers, butterflies, and other insects.

They also may dine on fruit and in vegetable gardens, feasting on the likes of tomatoes, and they may rummage in pet-food dishes left outside and untended or garbage cans left unsealed. These animals have a sharp sense of smell, well-suited to finding dinner in the dark.

Opossums tend to live near river and stream corridors, but may be found in open woods, farmlands, suburbs, and cities. They prefer ground dens in abandoned woodchuck burrows, drainage tiles, brush piles, or hollow tree trunks.

In winter they mostly sleep but they do move about occasionally. They home range usually is about 40 acres.

In a tribute to the late legendary comedian Rodney Dangerfield on the first anniversary of his death, a skywriter stroked the word "respect" in the sky over Los Angeles.

Respect is something Rodney always quipped that he got none of. Maybe the opossum, like the comedian, deserves some.

Contact Steve Pollick at:

spollick@theblade.com

or 419-724-6068.

An opossum baby is born after only about 12 days and is smaller than a bee.

An opossum "playing dead" actually may have fainted in fright.

An opossum's home range is just 40 acres.

An opossum has 50 teeth, more than any mammal.

The Virginia or common opossum native to North America has been here for some 70 million years.

Opossums share a trait with vultures - they have a keen sense of smell and they can eat anything.

An opossum adult cannot hang by its tail, but may use it for assists in gripping and balance.

Opossums are the only nonprimates with opposable "thumbs."

The common opossum is North America's only marsupial, developing young in a belly-pouch rather than in a uterus.