Last month I participated in the annual Big Bog Adventure Day where northern Minnesota school children arrived by the busload to learn about everything floral and faunal in the patterned peatlands of Big Bog State Recreation Area near Waskish.
Students from elementary age to senior high experienced outdoor classroom activities that included fishing in Ludlow Pond, hiking on the Big Bog Walk, orienteering at the beach, birding in the forest, and much, much more in a day of fun-filled environmental education.
My program, which is a favorite topic of mine, taught elementary kids about some of the mammals of Minnesota. Set up on the beach and picnic area of beautiful Upper Red Lake, it was my privilege to spend the entire day talking to grade school children about the many different mammal pelts I had arranged across two large picnic tables.
I told stories about hibernating black bears, fun-loving otters, pouncing red foxes and tree-climbing fishers. We laughed about the skunk and weasel, marveled at the wolf and bear and wondered about the bobcat and marten. We had a lot of fun.
However, there was one furry critter that not many children knew much about, albeit most students guessed the correct answer with just a little bit of prodding along with a clue or two, which surprised me nevertheless. After all, as far as I know, the Big Bog has never been home to this unusual Minnesota mammal, at least not yet.
Southern Minnesota, however (and moving northward), is home to one of North America's most unique and unusual mammals, the Virginia opossum. And while it's very rare to observe one of these creatures in the northland, the strange looking animals are observed from time to time in the north-central part of the state.
About the size of a house cat at around 4-12 pounds and about 3 feet long from the tip of its pink nose to the tip of its naked tail, the rat-like opossum is far removed from a rodent in many, many ways. In fact, unlike any other mammal in North America, the opossum, or "possum", is this continent's only marsupial.
Like all mammals, marsupials possess a hairy covering and suckle their young from mammary glands that produce nutritious milk. However, what they do have that no other mammal has is a "marsupium", or pouch, as it's commonly called.
So, what's the pouch for? First off, all marsupials give birth to live young, but the gestation period of marsupials is very short, resulting in the births of underdeveloped, helpless, hairless and completely blind young.
The tiny 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 the protective pouch. Once inside the pouch, the young 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.
Female opossums give birth to usually seven to eight babies, and sometimes many more. After they're born, each of the young completes its solo journey to their mother's pouch. Like other marsupials, they attach themselves to a teat and begin feeding. And it's there that they remain for a little more than two months before venturing out for the first time.
Even so, 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 dispersing.
Opossums are covered in grayish fur except for their feet, tails, 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 unique features of the opossum is its tail and "thumbs". The tail is "prehensile" and able to wrap around limbs as an adaptation for climbing. The thumbs, or "halluxes", are indeed opposable just like our own thumbs and are located only on the rear feet. These appendages enable opossums to securely grasp branches as they maneuver up and down trees.
But perhaps one of the most interesting opossum behaviors is what it will do when threatened or frightened (indeed, all my students knew this!). Purely a survival mechanism, opossums can trick predators into thinking that they're dead. It's, of course, where the expression, "playing possum" comes from.
In playing dead, an opossum will roll over, stiffen itself, salivate and breathe slowly in a coma-like state that can last as long as four hours. Such behavior often confuses predators that are accustomed to prey that runs. Thus, some potential predators give up and leave.
The Virginia opossum, a strange but interesting mammal, has found a niche in Minnesota. If winters continue to remain mild, perhaps opossums will be showing up in the Red River valley and the Big Bog. For that, I guess, we'll have to wait and see as we get out and enjoy the great outdoors.
Blane Klemek is the Bemidji area assistant wildlife manager, DNR Division of Fish & Wildlife. He can be reached at firstname.lastname@example.org.