On a recent trip to southeast Minnesota’s beautiful Bluff Country, I encountered an opossum crossing the road. The curious fellow took its sweet time as I slowed down and stopped to observe.
Not even so much as looking up or breaking stride, the opossum continued to the other side of the road and then disappeared into the ditch.
While it’s rare to observe opossums here in the Northland, the strange-looking animals are observed with increasing regularity throughout the north-central part of the state. Most Minnesota opossums, however, inhabit woodlands throughout the southern region.
About the size of a house cat and around three feet long from the tip of its pink nose to the tip of its naked tail, the Virginia opossum, which resembles an overgrown rat in some ways, is far removed from a rodent. In fact, unlike any North American mammal, the Virginia opossum is the only marsupial in the entire North American continent.
Marsupials are typically associated with Australia, such as kangaroos, wombats and koala bears. In fact, 140 species of marsupials are found in Australia. Moreover, while most of Australia’s marsupials are found nowhere else in the world, it is ironic to note that marsupials evolved first in North America.
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Like all mammals, marsupials have fur and suckle their young from mammary glands that produce nutritious milk. However, what they do have that no other mammal has (although even amongst marsupials there are exceptions to even this unique trait), is a “marsupium,” or pouch as it is commonly called. Most marsupials have permanent pouches, but there are a few that have temporary pouches and some that have none at all.
While all marsupials give birth to live young, what is unique is that the gestation period of marsupials is very short, resulting in the birth of undeveloped young.
However, the newborns have surprisingly well-developed forelimbs with strong claws that enable them to cling to their mother’s belly fur and crawl to the safety of her protective pouch. Once inside the warm and snug pouch, the offspring locate a teat and attach themselves, begin suckling, and continue their development. The whole ordeal, from birth to pouch, is completed with no help from the mother opossum whatsoever.
The security of their mother’s pouch is such that for another month’s time the baby opossums are in and out and rarely go very far. When they are about the size of mice, opossum babies begin spending most of their time hitching rides on their mother’s back until becoming more independent and eventually leaving altogether.
Virginia opossums are covered in grayish fur everywhere except for its feet, tail and ears. The nakedness of these body parts might lend credence to why the animals are not often seen farther north. Nonetheless, the assumed shortcomings haven’t stopped the non-hibernating opossums to taking up residence in Minnesota.
Other anatomically unique features of the opossum are its tail and “thumbs.” The tail is essentially another limb, “prehensile” as it is called, and able to wrap around and grasp limbs as an adaptation for climbing. The thumbs, or “halluxes,” are indeed opposable just like our own thumbs. Though located only on the rear feet, an opossum’s halluxes enable the animals to securely grasp branches as they maneuver up and down trees.
Perhaps one of the most interesting opossum behaviors is what it will do when threatened or frightened. Purely a survival mechanism, opossums are masters at fooling would-be predators into thinking that they’re dead. It’s of course where the expression, “playing ‘possum” originally came from.
Virginia opossums will frequently roll over, stiffen itself out, salivate and breathe ever so slowly and shallow in a coma-like state that can last as long as four hours. Such behavior often confuses predators that are accustomed to prey that run away or try and escape. Thus, some potential predators give up and leave.
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I do believe that it’s only a matter of time before opossums begin showing up here in northwest Minnesota. Please let me know if you ever observe one this far north, as we get out and enjoy the great outdoors.
Blane Klemek is a Minnesota DNR wildlife manager. He can be reached at bklemek@yahoo.com.
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