Biology Reference
In-Depth Information
7
It Isn't Acting: The Opossum
MYTHS
Opossums pretend to be dead when danger threatens.
Opossums hang by their tails while they sleep.
Young opossums travel by hanging by their tails from their mother's tail.
WE TEND TO THINK OF MARSUPIALS IN TERMS OF THE CLASSIC KANGAROO,
BOUNCING ALONG WITH ITS JOEY'S HEAD VIEWING THE WORLD OVER THE TOP OF
ITS MOTHER'S POUCH. Marsupials are a diverse lot, however, as demonstrated by the opossum
(Didelphis virginiana).
As our continent's sole representative of the marsupial order—creatures that
carry their young in a pouch—the opossum is an object of considerable interest. Simply called “pos-
sum” most of the time, except in highly formal usage, this house-cat-sized creature has expanded its
range greatly during the past few decades, bringing a new and interesting creature to many areas where
it was previously unknown.
Despite their status as our only native marsupial, possums are best known for “playing possum,” a
phrase that has become common in our language as a term for feigning such things as illness or sleep in
an attempt to deceive. Actually, the common notion of playing possum is somewhat off the mark: the
possum isn't playing at all, if playing is meant as an intentional act of deception.
Possums aren't, to use a current expression, the brightest bears in the woods, and they don't think in
terms of playing dead to deceive an enemy. When a possum is threatened, it's likely to first show its
teeth and hiss almost like an angry cat. If that fails to frighten a would-be predator, the possum may run
away or climb a tree. As a last resort, however, the creature falls into a sort of catatonic state, body limp
and eyes wide open. This is not a conscious act of pretending, but is really a genetically programmed
reflex action. Sometimes this defensive adaptation works, and a predator loses interest in a victim that
appears to be dead. Even after the threat is gone, though, the possum may remain in its comatose state
for hours!
