The only menace to which ’possums have not as yet adapted is the automobile. They are slain by the hundreds of thousands every year by onrushing vehicles.
Some years ago, a workshop group I was with visited the Etowah Mounds State Historic Site near Cartersville, Ga. Among the artifacts on display in the museum adjacent to the mounds were a number of small clay effigies depicting various animals.
Among these was the head of an animal that had served as a pendant. We all peered into the glass case trying to determine its identity.
After awhile, someone remarked, “Look, it’s grinning!”
At that point no one needed to name the animal in question. We all realized it was an opossum. A flamingo may hold its head upside down and seem to “smile,” but the opossum is the only critter that “grins” all of the time.
What are ’possums grinning about? I think I know the answer, but I’ll give you awhile to think about it...
An article in Smithsonian magazine titled “A Few Miles of Land Arose From the Sea — and the World Changed” by John F. Ross discussed the significance of the appearance of a land bridge (the Panamanian isthmus) between North and South America about 3 million years ago. Some scientists are now viewing that event as one of the most important since the death of the dinosaurs 65 million years ago.
For one thing, the land bridge rerouted ocean currents, so profoundly altering the northern hemisphere’s climate it may have triggered the series of Ice Ages that also began 3 million years ago. The land bridge also allowed numerous animals to pass from North into South America.
Among those that trekked northward, the lowly ’possum has been among the most successful, because it has been highly adaptable.
Humans have not stemmed its progress, which has now reached into Canada. Our barns and outbuildings provide den sites. Our garbage is a never-ending source of nourishment.
They may have small brains and be a touch dim-witted, but ’possums can find food. And they remember exactly where they found it in the first place.
One researcher tested various animals for the ability to recall which of four runways was connected to a food box. ’Possums scored better than cats, chickens, dogs, goats, pigs, rabbits, rats and turtles.
’Possums can adapt themselves to just about any circumstance. They have, for instance, developed immunity to the Crotalinae subfamily of snakes, which includes the very ones encountered on a regular basis in the Deep South: rattlesnakes, copperheads and cottonmouths.
And they have carried this specific adaptive response to an environmental threat one logical step farther. They have learned to kill and eat snakes. In some areas of the country, copperheads constitute up to 6 percent of the ’possum’s diet.
But when faced with a situation it can’t handle physically or mentally, a ’possum has evolved a backup plan for that, too. It does what it’s most famous for — it “plays ’possum” by curling on its side, closing its eyes, lolling out its tongue and lowering its heartbeat in a feigned-death posture.
If need be, it can remain in this catatonic state for up to 6 hours. Once the danger has subsided, the ’possum picks itself up and goes about its two main items of business: finding food and reproducing.
The only menace to which ’possums have not as yet adapted is the automobile. They are slain by the hundreds of thousands every year by onrushing vehicles during the nocturnal hours. Caught in the headlights’ glare, they freeze and are doomed. It’s too late to “play ’possum.”
But the automobile is a new challenge. They have only been around for a little over a century. Give these adaptive critters a little more time to form a response. And that’s what I think they’re grinning about. They’re absolutely sure they’ll have the last laugh.
George Ellison is a naturalist and writer. His wife, Elizabeth Ellison, is a watercolor artist and paper-maker who has a gallery-studio in Bryson City. Contact them at email@example.com or firstname.lastname@example.org or write to P.O. Box 1262, Bryson City, NC 28713.